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Posted: 5/16/2024 2:05:41 PM EDT
The “Most Accurate Pistols” thread (Here) got me thinking. Obviously there are a lot of factors that go into making a pistol accurate and precise, such as the operating mechanism (fixed barrel, tilting locked breech, etc), lockup consistency and repeatability, quality of the rifling, overall fitment, etc. If you shoot the same 124gr 9mm round through a sub-$400 Taurus GX4 and a $9,000 Atlas Chaos (both in a Ransom Rest) it would be reasonable to expect the Atlas to be much more mechanically accurate and precise than the Taurus.
But what factors go into making an inherently accurate cartridge itself? Assume for the sake of argument we could eliminate all of the factors from the firearm - every round will be fired through the same single shot, bench rested, fixed barrel “pistol” with the same barrel length. Now you get a bunch of different cartridges and loadings to shoot through this magical gun that eliminates all other factors - which features of the cartridge or loading will predict higher accuracy and precision? Caliber? Bullet weight? Muzzle velocity? Soft lead, fully jacketed, hollow point, wadcutter? Certainly the people who devote their lives to squeezing out the last bit of precision from a hand-held firearm seem to think some cartridges are inherently more accurate than others: ISSF 25M Centerfire pistol shooters have converged on .32 caliber cartridges (.32 S&W Long and .32 ACP) because they found it gave better accuracy than, say, a .355 diameter projectile. Colt and S&W were so intent on maintaining the use of 148gr .38 Special Wadcutter loads with such a high reputation for inherent accuracy that they both engineered semi-auto pistols to shoot exclusively those loads. Why? What about those particular cartridges/loads makes them so accurate? Please discuss! |
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Posted: 5/16/2024 2:09:47 PM EDT
[Last Edit: 42ATK]
[#1]
I think it’s a ratio of weight, velocity, durability of firearm, and cross section of bullet and there’s different ideals for every accuracy sport
That’s ignoring availability |
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Posted: 5/16/2024 2:12:23 PM EDT
[#2]
Interesting concept... in for answers from those more in the know than me.
Usually we're in for "accurate enough" because it's a handgun. |
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Posted: 5/16/2024 2:14:21 PM EDT
[#3]
In theory, larger diameter projectiles/bores should produce better accuracy.
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MI, USA
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Posted: 5/16/2024 2:43:26 PM EDT
[#4]
Quote HistoryOriginally Posted By Bravo_Six: In theory, larger diameter projectiles/bores should produce better accuracy. Really? Why are there so many options for match grade, super accurate .22LR, and virtually no match grade .45ACP (or even 9mm) that I can find? |
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KS, USA
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Posted: 5/16/2024 2:56:59 PM EDT
[Last Edit: merick]
[#5]
Quote HistoryOriginally Posted By bluemax_1: Really? Why are there so many options for match grade, super accurate .22LR, and virtually no match grade .45ACP (or even 9mm) that I can find? 22 has a efficiency of scale nothing else can touch. But if your processes can only hold a tolerance of 0.5 a grain +/- , that wouldn't effect 230 grain 45 acp much but would be bad in 22 ammo. |
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Posted: 5/16/2024 3:02:09 PM EDT
[#6]
One significant issue is headspacing off of either a case mouth or rim. Compared to a bottlenecked cartridge that headspaces off of the tapered shoulder, there's a loss of self centering as well as possible introduction of axial runnout if the mouth or rim is not square to the bore.
So the most inherently accurate handgun and load is likely to be a TC contender in 6mm BR or 22 PPC or something like that 
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Posted: 5/16/2024 3:04:36 PM EDT
[#7]
Quote HistoryOriginally Posted By bluemax_1: Really? Why are there so many options for match grade, super accurate .22LR, and virtually no match grade .45ACP (or even 9mm) that I can find? Economy of scale. There's no market for match grade .45 ACP anything anymore, and the small group of people who are doing it can do it better themselves at the reloading bench anyway. |
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AZ, USA
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Posted: 5/16/2024 3:08:31 PM EDT
[#8]
Handgun ammo has not seen the inherent design improvements that rifle ammo has see. Such as the 6mmPPC, 6.5 Creedmoor, and never ending projectile improvements. Accuracy from handguns comes from a good custom barrel, a tuned gun, and quality ammo that has been tuned to the gun. More time at the reloading bench is where all the work is done.
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Posted: 5/16/2024 3:16:38 PM EDT
[Last Edit: stk016]
[#9]
Quote HistoryOriginally Posted By cschaeff: Handgun ammo has not seen the inherent design improvements that rifle ammo has see. Such as the 6mmPPC, 6.5 Creedmoor, and never ending projectile improvements. Accuracy from handguns comes from a good custom barrel, a tuned gun, and quality ammo that has been tuned to the gun. More time at the reloading bench is where all the work is done. I would say that for 99% of handgun owners there is no need for better accuracy. If a pistol/ammo combo can shoot 3” groups at 15 yards that is good enough for almost everyone. No real reason to spend $1000+ on a custom pistol or for a company to r&d an inherently more accurate cartridge. Especially when you consider how bad the majority of the handgun owners actually shoot. Most will never reach the limit of mechanical accuracy of a Taurus using wolf ammo. |
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Posted: 5/16/2024 3:19:35 PM EDT
[#10]
necked cases should be better.
probably start with something like .30luger. |
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Posted: 5/16/2024 3:27:02 PM EDT
[#11]
I've always heard things like .32s and .44s are "more inherently accurate," and maybe there's a bit of truth to the conversation, but I find it to be a mostly pointless exercise.
Damn near every mainstream, mass market firearm is capable of accuracy that well exceeds the practical application of that firearm. Here's Jerry shooting a Bodyguard .380 turd at a 18x24 target at 200 yards.  INCREDIBLE 200 yard shot with a .380 M&P Bodyguard! #380reasons |
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Posted: 5/16/2024 3:33:13 PM EDT
[#12]
Originally Posted By 42ATK: I think it’s a ratio of weight, velocity, durability of firearm, and cross section of bullet and there’s different ideals for every accuracy sport That’s ignoring availability For this discussion we’re ignoring the durability of the firearm and focusing solely on the cartridge itself. Remove all factors that are external to the round being shot. Originally Posted By Bravo_Six: In theory, larger diameter projectiles/bores should produce better accuracy. Please explain? Originally Posted By AgeOne: necked cases should be better. probably start with something like .30luger. Because of the self-centering factor that Kuraki mentioned? So ISSF 25m Centerfire shooters might expect even better accuracy out of a .32 NAA round compared to .32 S&W or .32 ACP? 
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Posted: 5/16/2024 3:59:40 PM EDT
[#13]
Quote HistoryOriginally Posted By Rudukai13: Because of the self-centering factor that Kuraki mentioned? I've read over the years that necked cases headspace more consistency, especially if they've been fire-formed already and have an advantage in the bullet seating to the lands. 30luger also operates at a pretty mild pressure compared to something like .357sig |
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Posted: 5/16/2024 5:16:04 PM EDT
[#14]
Quote HistoryOriginally Posted By AgeOne: I've read over the years that necked cases headspace more consistency, especially if they've been fire-formed already and have an advantage in the bullet seating to the lands. 30luger also operates at a pretty mild pressure compared to something like .357sig Quote HistoryOriginally Posted By AgeOne: Originally Posted By Rudukai13: Because of the self-centering factor that Kuraki mentioned? I've read over the years that necked cases headspace more consistency, especially if they've been fire-formed already and have an advantage in the bullet seating to the lands. 30luger also operates at a pretty mild pressure compared to something like .357sig That would make sense. So there’s a good start! Our conceptual “most inherently accurate cartridge” should be bottlenecked. What else? |
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Posted: 5/16/2024 5:30:41 PM EDT
[Last Edit: Kuraki]
[#15]
Quote HistoryOriginally Posted By Rudukai13: That would make sense. So there’s a good start! Our conceptual “most inherently accurate cartridge” should be bottlenecked. What else? Bottle necked and chambered so that the headspace is indexed on the shoulder, so the design of the gun needs to take that into account. Just to clarify in and of itself bottlenecking doesn't change much. That opens the door to the wide world of accuracy tweaking that has really only been available to rifle shooters. Chamber fit or the amount of clearance between chamber geometry and cartridge geometry, lead-in, bullet seating depth, neck tension, all kinds of minor tweaks that are pointless or impossible with the current neck/rim design paradigm. I'd also wager there's significantly less effort put into projectile design in regard to consistent mass, consistent center of gravity, etc when it comes to handgun rounds, and once the "pie plate at 25 yards" has been satisfied all design effort is put into expansion or reliable feeding and the like. Same with factory loaded ammunition and charge weights. Likely measured by volume vs weight with a higher tolerance than "match" rifle ammunition, so higher standard deviation in muzzle velocity. The more I think about this the more I think that if you wanted to produce a handgun that was rifle like in accuracy and still semi-auto, you'd want a P38 like design that allowed a free floated and fixed barrel, and the sights/optics to be either attached to the barrel or to the same component fixing the barrel (like the frame). ETA: I know the OP was about the cartridge specifically but I don't think it's even possible to discuss without considering the gun's design. I don't think there's any real reason one couldn't design and produce a (traditional semi-auto) handgun that was capable of matching an AR in accuracy at 100 yards, it would just be expensive to do and no ROI because no one could realize it's potential shooting with 2 points of contact vs 3 with a rifle. I think it would look like a P38 shooting a cartridge that looked like a mini 6 PPC from a single stack magazine with a frame mounted optic. |
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Posted: 5/16/2024 5:36:06 PM EDT
[#16]
.44spl and .44 mag have always been touted as a "accurate cartridges". I've seen that explained as being due to more consistent specs across manufacturers than .45 colt however. Good question on the 1911 .38 wadcutter conversions. I always assumed it was to have a lighter recoiling gun ala Askins' Woodsman/Velodog abomination.
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GA, USA
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Posted: 5/16/2024 5:52:16 PM EDT
[#17]
The US Military Precision Pistol teams like Atlanta Arms 185JHP 45ACP and 115gr FMJ 9mm.
Elite Ammo - 45 ACP 185GR JHP Match AMU This 185GR Jacketed Hollow Point ammo is currently used by the Army Marksmanship, Marine service Pistol Teams and by some of the top PPC shooters in the world. Accuracy test requirement: 5 ten-shot groups at 50 yards, with A 5" 1911 barrel, and an average group size not to exceed 1.50 inches. This is loaded using a high quality conical hollow point bullet and is designed specifically for Match ONLY. Elite Ammo - 9mm 115GR FMJ Match AMU This ammunition is designed for extreme accuracy at 50 yards. This ammo is used by the Army Marksmanship Unit and the Marine Service Pistol team for service pistol matches. Accuracy test requirement: 5 ten-shot groups at 50 yards with an average group size not to exceed 1.5 inches. Fired from a match grade barrel fixture. Barrel testers are useful to check 50 yard groups and easier than setting up a Ransom Rest. I like 30 shot groups to see worst performance. 9mm for 50 yard Precision Pistol (Bullseye) Centerfire competition is kinda challenging as you have different bullet weights and barrel twists, so finding the best combination and speed takes testing or luck. At my skill level I just shoot 200gr cast lead SWC 45ACP for the Centerfire and 45 sections of a match. 30 shots of my reloads holds the ten ring at 50 yards with a barrel tester with only a few cutting the scoring ring. My red dot and iron sight 45 barrels have shallow chambers set up for new Starline brass to headspace on. |
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Posted: 5/16/2024 5:58:02 PM EDT
[#18]
Quote HistoryOriginally Posted By Rudukai13: Because of the self-centering factor that Kuraki mentioned? So ISSF 25m Centerfire shooters might expect even better accuracy out of a .32 NAA round compared to .32 S&W or .32 ACP? https://media.mwstatic.com/product-images/src/primary/390/390034.jpg  |
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GA, USA
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Posted: 5/16/2024 6:03:00 PM EDT
[Last Edit: Clovis_Ledbetter_Jr]
[#19]
Quote HistoryOriginally Posted By BillythePoet: .44spl and .44 mag have always been touted as a "accurate cartridges". I've seen that explained as being due to more consistent specs across manufacturers than .45 colt however. Good question on the 1911 .38 wadcutter conversions. I always assumed it was to have a lighter recoiling gun ala Askins' Woodsman/Velodog abomination. Precision Pistol competition shooters have moved away from .38 Special HBWC as you need good bullets, a fast twist barrel like the PPC revolvers, and fancy magazines to feed the cartridges. Now that 38 Super barrels are available with short chambers and good bullets are being made the 38 Super is becoming more popular. (You still have to shoot a 22 and a 45 unless you are going home early) Below is a S&W M52 modified for Precision Pistol competition. 1-10 twist barrel and custom bushing. (The shooter has small hands.) 
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GA, USA
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Posted: 5/16/2024 6:17:17 PM EDT
[Last Edit: Clovis_Ledbetter_Jr]
[#20]
There are also Silhouette competition pistols if you want to go down that rabbit hole. Palma rifle loads are pretty accurate. ;)
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Posted: 5/16/2024 6:37:01 PM EDT
[#21]
Quote HistoryOriginally Posted By Clovis_Ledbetter_Jr: Precision Pistol competition shooters have moved away from .38 Special HBWC as you need good bullets, a fast twist barrel like the PPC revolvers, and fancy magazines to feed the cartridges. Now that 38 Super barrels are available with short chambers and good bullets are being made the 38 Super is becoming more popular. (You still have to shoot a 22 and a 45 unless you are going home early) Below is a S&W M52 modified for Precision Pistol competition. 1-10 twist barrel and custom bushing. (The shooter has small hands.) https://i.ibb.co/6ZP0mWw/IMG-1571-zps04a6b8c5.jpg That's cool. I've never seen one customized to that extent. I've been googling the .38 conversions and apparently it was a 3 stage competition, rimfire, police service (.38spl) and military service (.45acp). Shooters liked having the same platform or at least grip for all 3, so the 1911 conversions became popular. It was also typically easier to shoot fast and accurately with a 1911 vs a DA revolver in the .38 stage. The .38sup was considered less accurate at the time so wasn't widely used in competition. |
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Posted: 5/16/2024 6:56:10 PM EDT
[#22]
7.62x25, i'm serious, awesome round, if you made a good pistol for it I think it would shine.
.45 colt can do some amazing stuff. Revolvers being what they are it's some work to make one super accurate, but it can be done. And in a lever action rifle where the bullet doesn't have to jump the gap, I used to roll 300 gr. loads that shot some insane groups. |
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Posted: 5/16/2024 6:59:06 PM EDT
[#23]
The most accurate I've ever fired was my fathers Thompson Contender in .22k Hornet.
Second was the 218bee barrel for the same. |
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Posted: 5/16/2024 7:50:12 PM EDT
[#24]
I like where this is headed, let’s keep the conversation going!
Quote HistoryOriginally Posted By Clovis_Ledbetter_Jr: Below is a S&W M52 modified for Precision Pistol competition. 1-10 twist barrel and custom bushing. (The shooter has small hands.) https://i.ibb.co/6ZP0mWw/IMG-1571-zps04a6b8c5.jpg Oh fuck that’s a sexy gun. Where’d you find it? |
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Posted: 5/16/2024 7:51:33 PM EDT
[#25]
Quote HistoryOriginally Posted By Dragynn: 7.62x25, i'm serious, awesome round, if you made a good pistol for it I think it would shine. .45 colt can do some amazing stuff. Revolvers being what they are it's some work to make one super accurate, but it can be done. And in a lever action rifle where the bullet doesn't have to jump the gap, I used to roll 300 gr. loads that shot some insane groups. Why do you say the 7.62x25? Follows with the bottleneck cartridge advantage explained earlier |
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GA, USA
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Posted: 5/16/2024 8:09:57 PM EDT
[Last Edit: Clovis_Ledbetter_Jr]
[#26]
Quote HistoryOriginally Posted By Rudukai13: I like where this is headed, let’s keep the conversation going! Oh fuck that’s a sexy gun. Where’d you find it? There was a machinist/Bullseyesmith named Jerry Keefer that used to post pistol porn in several firearms forums. He supported a shooter that used the M52 in Precision Pistol (Bullseye) Centerfire competitions. (You still need a 22 and a 45 for a full match) Jerry unfortunately passed away a few years ago. I used to tease him about having pictures of unobtanium, metal that most of us could never acquire. A lot of what he made was like looking at what the Soviet Union Shooting University group made for their Olympic team. |
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Posted: 5/16/2024 8:15:10 PM EDT
[#27]
Quote HistoryOriginally Posted By Rudukai13: Why do you say the 7.62x25? Follows with the bottleneck cartridge advantage explained earlier Yep, I think the bottleneck cartridge has something to do with it, but practical experience with an old Tokarev I used to own back in the day is also a reason, and let me tell you, that was a cheap pistol, lol, but the dang thing was accurate as hell, thinner bullet with a better BC than the various 9mm rounds, high velocity which seems to help a lot of rounds, like 1600 fps out of a 3-4 inch barrel, just thinking you put that round in a 5-6 inch barrel with a nice tight chamber and good things will happen. |
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USA
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Posted: 5/16/2024 8:24:56 PM EDT
[#28]
I don't have alot of comparisons, but my model 29 with handloads is the most accurate handgun I own.
This is compared Glock G19 gen 3 and 4, CZ75, Colt 1911, .357 colt , .38 apl s&w. S&w 45acp full size. |
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USA
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Posted: 5/16/2024 8:26:22 PM EDT
[Last Edit: SteelonSteel]
[#29]
Quote HistoryOriginally Posted By bluemax_1: Really? Why are there so many options for match grade, super accurate .22LR, and virtually no match grade .45ACP (or even 9mm) that I can find? The shootability factor. A mild cartridge is easier and more pleasant to shoot for multiple stages of fire. The .32s are the mildest that still qualify as centerfire. Never forget the the end result of the human mechanical interface is what wins, the pure mechanical accuracy can be sacrificed if it can be less of a scorer than say a lighter load that the shooter doesn’t get fatigued with. Jumping to rifles.......it’s why shooter shoot the AR15 for service rifle, yes the guns need less maintenance when set up than the refreshing maintenance the M14s needed after a season. A fresh tuned match M14 was not less accurate but it took a different position to shoot to not be battered out of position. An AR shooter’s position can be quite different as it isn’t subject to the same recoil. |
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Posted: 5/16/2024 8:53:01 PM EDT
[Last Edit: curiomatic]
[#30]
"Interior ballistics" is what determines a cartridges accuracy potential. The rest is up to the firearm and the shooter.
I used to use the Lyman reloading manuals. Lyman used test barrels to test various loads, and published the velocities and chamber pressures. They didn't claim that their best handload would be your best handload but their data was a good guidline. |
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Posted: 5/16/2024 9:16:03 PM EDT
[#31]
Originally Posted By Clovis_Ledbetter_Jr: There was a machinist/Bullseyesmith named Jerry Keefer that used to post pistol porn in several firearms forums. He supported a shooter that used the M52 in Precision Pistol (Bullseye) Centerfire competitions. (You still need a 22 and a 45 for a full match) Jerry unfortunately passed away a few years ago. I used to tease him about having pictures of unobtanium, metal that most of us could never acquire. I’d love to eventually own a gun with a history/backstory like that some day. A lot of what he made was like looking at what the Soviet Union Shooting University group made for their Olympic team. I’m gonna need you to say more, and I’m gonna need pictures  Originally Posted By Dragynn: Yep, I think the bottleneck cartridge has something to do with it, but practical experience with an old Tokarev I used to own back in the day is also a reason, and let me tell you, that was a cheap pistol, lol, but the dang thing was accurate as hell, thinner bullet with a better BC than the various 9mm rounds, high velocity which seems to help a lot of rounds, like 1600 fps out of a 3-4 inch barrel, just thinking you put that round in a 5-6 inch barrel with a nice tight chamber and good things will happen. Reasonable theory to test. There are manufacturers making 7.62x25 conversion barrels for 9mm/.38 Super 1911s, you could probably get a gunsmith like Accuracy X to build you a 7.62x25 Bullseye pistol  Originally Posted By SteelonSteel: The shootability factor. A mild cartridge is easier and more pleasant to shoot for multiple stages of fire. The .32s are the mildest that still qualify as centerfire. I know for competitions rules say the minimum caliber has to be .30, but for the purposes of straight-up accuracy in a centerfield cartridge would something like a .25 ACP benefit from match-grade .22 LR developments? |
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Posted: 5/16/2024 9:16:58 PM EDT
[#32]
Quote HistoryOriginally Posted By curiomatic: "Interior ballistics" is what determines a cartridges accuracy potential. The rest is up to the firearm and the shooter. Can you explain further sir? |
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Posted: 5/16/2024 9:22:50 PM EDT
[#33]
Quote HistoryOriginally Posted By Dragynn: .45 colt can do some amazing stuff. Revolvers being what they are it's some work to make one super accurate, but it can be done. And in a lever action rifle where the bullet doesn't have to jump the gap, I used to roll 300 gr. loads that shot some insane groups. The main drawback is inconsistent component sizing across manufacturers and even within the same companies at times. Everyone will tell you to avoid a pinned barrel model 25 due to oversized cylinder throats and shallow rifled barrels intended for jacketed .45acp bullets. Rugers also have throat issues and egged chambers occasionally. When having a custom built, it's common to start with a .41 or .44 cylinder and have it reamed to proper.45 colt specs. All of this leads to it's scarcity of use as a target gun, compared to .44s. |
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Posted: 5/16/2024 10:38:19 PM EDT
[#34]
Quote HistoryOriginally Posted By Bravo_Six: In theory, larger diameter projectiles/bores should produce better accuracy. What theory is that? |
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Posted: 5/16/2024 10:58:23 PM EDT
[Last Edit: AeroE]
[#35]
Quote HistoryOriginally Posted By bluemax_1: Really? Why are there so many options for match grade, super accurate .22LR, and virtually no match grade .45ACP (or even 9mm) that I can find? Quote HistoryOriginally Posted By bluemax_1: Originally Posted By Bravo_Six: In theory, larger diameter projectiles/bores should produce better accuracy. Really? Why are there so many options for match grade, super accurate .22LR, and virtually no match grade .45ACP (or even 9mm) that I can find? 185 grain SWC bullets in .45 ACP can have excellent accuracy. Federal Gold Medal Match is an example. On the other hand I had terrible results from 200 grain GMM, it was no better than 230 grain Winchester White Box ammunition. I have a physics based idea about bullet shape for stability and resistance to perturbation from the environment that is too complicated to type, boils down to a large diameter stubby bullet spinning with enough speed. Double end wad cutters and hollow base wad cutters are a good place to start. I don't see much advantage of bottle neck cases over rimmed cases unless they are sized to fit the chamber with very small case headspace. Headspacing on the case mouth would be my last choice. Bottle neck cases in revolvers are the next topic. They have a reputation for setting back against the breech interfering with cylinder operation. I have never experienced that in my Model 53 .22 Jet, and I have never heard complaints about .357 Bain and Davis jamming a revolver. |
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Posted: 5/16/2024 11:07:46 PM EDT
[#36]
Quote HistoryOriginally Posted By AeroE: I have a physics based idea about bullet shape for stability and resistance to perturbation from the environment that is too complicated to type, boils down to a large diameter stubby bullet spinning with enough speed. Double end wad cutters and hollow base wad cutters are a good place to start. I’d be very interested in hearing more about this |
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Posted: 5/16/2024 11:19:42 PM EDT
[Last Edit: curiomatic]
[#37]
.....
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Posted: 5/16/2024 11:26:21 PM EDT
[Last Edit: curiomatic]
[#38]
Quote HistoryOriginally Posted By Rudukai13: Can you explain further sir? Quote HistoryOriginally Posted By Rudukai13: Originally Posted By curiomatic: "Interior ballistics" is what determines a cartridges accuracy potential. The rest is up to the firearm and the shooter. Can you explain further sir? Part of my reply would be in the part of my post that you didn't quote. Basically, you need the most consistent velocity with optimal chamber pressures in the round that is being fired. After that, the round's accuracy is determined by the firearm and the shooter; it's pretty much Handloading 101. Pick up an ammunition reloading manual and look at the loading "tables" for a specific round. You will see their loads with the most accuracy potential are developed with various propellants, charge weights, bullets, and primers. The load development and testing process should be described in the manual. I don't know of an inherently inaccurate cartridge that is in use these days. Internal Ballistics |
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Posted: 5/16/2024 11:35:44 PM EDT
[Last Edit: AeroE]
[#39]
Quote HistoryOriginally Posted By Rudukai13: I'd be very interested in hearing more about this Quote HistoryOriginally Posted By Rudukai13: Originally Posted By AeroE: I have a physics based idea about bullet shape for stability and resistance to perturbation from the environment that is too complicated to type, boils down to a large diameter stubby bullet spinning with enough speed. Double end wad cutters and hollow base wad cutters are a good place to start. I'd be very interested in hearing more about this Large diameter to maximize mass moment of inertia (I1) about the longitudinal axis. Spinning fast enough to generate high angular momentum. A shape that is resistant to environmental perturbations, gusts mostly - and I have no idea the best shape, however the length should be short so the moment of inertia about a lateral axis (I 2) is no greater than I1 than necessary to prevent inertia coupling. I would compare some possible I2 calculations against a cylinder and a SWC to start. A SWC with a short boat tail helps get mass in the bullet and keep it out of the ends to help control I2. Might not work worth a hoot. The bullet needs bearing length inside the case for ignition and initial burning, and for rifling engagement. Effective range is a factor, too. The most accurate at 25 yards is probably not the best at 100 yards. The case should be filled with gunpowder to the bullet base without being "over bore". The capacity where additional gunpowder produces poor velocity increase. A full case to eliminate position effects. |
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Posted: 5/16/2024 11:39:49 PM EDT
[#40]
.44 Russian used to have a reputation.
Interesting thread, OP. |
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AB, CAN
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Posted: 5/16/2024 11:58:08 PM EDT
[#41]
funny that you should start a thread on this topic. I have 2 decent quality 9mm pistols, one is a shadow systems DR920 and the other is a CZ shadow 2. both have red dot optics. I casted up a few hundred of the H&G275 bullet for testing, powdercoated them and sized to .357. I loaded up a hundred rounds with 5.0 gr. of Vihta Vuori 3N37 powder and federal SPP. at a distance of 25 yards the CZ prints 1.25" 5 shot groups and the DR920 prints 2.75" groups. both have 1 in 10 twist barrels of the same length so why the huge difference? I have tried other bullets/powders in the DR920 and it does as well as the shadow 2 but the shadow 2 doesn't like those loads so WTF? I would really like to find a load that performs well in both pistols.
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Posted: 5/17/2024 12:14:11 AM EDT
[#42]
The .22 rimfire cartridge is hobbled by the rebated base of the bullet.
How about a shortened .22 Magnum for jacketed .224 inch diameter bullets? |
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Posted: 5/17/2024 8:56:13 AM EDT
[#43]
OP, I think you're missing a significant part of your question - for what purpose is this cartridge intended? At what range?
Wadcutters are used by competitors in .32 and .38 b/c they cut nice neat scorable holes in paper. Semi-wadcutters are used b/c wadcutters don't generally feed very well. 9mm 124 grn can be very accurate at 25 yds - but goes transonic before 50, causing wobble. All of your historic target cartridges were selected b/c those were the best cartridge available in the best guns available that fit the rules of the game they were shot in. If you say 1500 yd accuracy, you end up with a 20 lb bolt action .50 BMG pistol. If you say 15 yd accuracy, you end up w/ a .38 SPL wadcutter from a fixed barrel. |
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Posted: 5/17/2024 10:07:23 AM EDT
[#44]
Quote HistoryOriginally Posted By backbencher: OP, I think you're missing a significant part of your question - for what purpose is this cartridge intended? At what range? Wadcutters are used by competitors in .32 and .38 b/c they cut nice neat scorable holes in paper. Semi-wadcutters are used b/c wadcutters don't generally feed very well. 9mm 124 grn can be very accurate at 25 yds - but goes transonic before 50, causing wobble. All of your historic target cartridges were selected b/c those were the best cartridge available in the best guns available that fit the rules of the game they were shot in. If you say 1500 yd accuracy, you end up with a 20 lb bolt action .50 BMG pistol. If you say 15 yd accuracy, you end up w/ a .38 SPL wadcutter from a fixed barrel. Wadcutters are also unstable beyond short ranges, which is why they weren't used much in silhouette competitions, which tried to maximize bullet weight for cartridge. LBT WFN designs are great game bullets, but always have the caveat of comparatively poor accuracy past 50yds or so because they are damn near full wadcutters. |
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NC, USA
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Posted: 5/17/2024 10:42:37 AM EDT
[#45]
as mentioned -- a good .38spl revolver and 148gr wadcutters can make you feel like a champ
a stock Glock with bulk 115gr 9mm ? not so much |
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Posted: 5/17/2024 11:06:51 AM EDT
[#46]
Is there a definitive/known reason why wadcutters become unstable at longer ranges?
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Posted: 5/17/2024 11:12:01 AM EDT
[#47]
Quote HistoryOriginally Posted By AeroE: 185 grain SWC bullets in .45 ACP can have excellent accuracy. Federal Gold Medal Match is an example. On the other hand I had terrible results from 200 grain GMM, it was no better than 230 grain Winchester White Box ammunition. I have a physics based idea about bullet shape for stability and resistance to perturbation from the environment that is too complicated to type, boils down to a large diameter stubby bullet spinning with enough speed. Double end wad cutters and hollow base wad cutters are a good place to start. I don't see much advantage of bottle neck cases over rimmed cases unless they are sized to fit the chamber with very small case headspace. Headspacing on the case mouth would be my last choice. Bottle neck cases in revolvers are the next topic. They have a reputation for setting back against the breech interfering with cylinder operation. I have never experienced that in my Model 53 .22 Jet, and I have never heard complaints about .357 Bain and Davis jamming a revolver. Oh that's a good point. Get that center of gravity forward. |
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Posted: 5/17/2024 11:15:28 AM EDT
[#48]
Quote HistoryOriginally Posted By Rudukai13: Is there a definitive/known reason why wadcutters become unstable at longer ranges? Because they have a poor aerodynamic design. Why are things that are designed to move through the air, at high speed, pointed at the front end and sometimes boat-tailed at the rear end? |
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Posted: 5/17/2024 11:16:00 AM EDT
[#49]
Quote HistoryOriginally Posted By Rudukai13: Is there a definitive/known reason why wadcutters become unstable at longer ranges? They're not very aerodynamic and so if they're fired supersonic they go transonic relatively quickly. It's why most precision long range .22 shooters prefer sub sonic rounds to avoid that loss of stability. I imagine the high drag wadcutter projectiles get even more squirrelly. |
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Posted: 5/17/2024 11:18:05 AM EDT
[Last Edit: AeroE]
[#50]
Quote HistoryOriginally Posted By Rudukai13: Is there a definitive/known reason why wadcutters become unstable at longer ranges? An easy experiment to prove this - Take a 1X board that is longer than wide. Toss it high in the air spinning around the long dimension. By the time it hits the ground the board will start to spin about an axis perpendicular to the face of the board. There probably won't be enough time to see more than the start of transfer. The bullet will start to spin end over end. Another detail that can't be ignored are bullet shapes that will feed in auto loaders. In the search for most accurate without qualifying the type of firearm we need to look at breech seated bullets in single shot firearms. |
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