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Have you compared the difference between the pre fire-formed cartridge and the fire-formed? Just curious about how much benefit is realized from such a small cartridge and if you think the extra step is worth it.
ETA-30 deg shoulder? |
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About the only difference is around .010" wider at the shoulder and changes the die formed shoulder angle from 20 ish to fire-formed 30 degrees.... the best I could figure the capacity increase with a powder the density of 4227 is right around 2 grains...haven't checked it with water yet, but I will....It is a small case so every little bit helps.... the 19 grains of 4227 is the only load that I've tried so far........as the case is now it will hold a little over 22 grains of 4227..... going to load up a couple other powders to try......so far the first day out looks ok... The brass forming and loading is pretty straight forward with the right tools, without is akin to a bad trip to the dentist office (what I had to start with)....the brass needs to be necked down in two steps, goes pretty quick........ Thanks, Kurt |
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Thanks Kurt , looking forward to see how it does. |
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Any Idea as to the chamber pressure this combination is running? Given what other similar cartridges of this size do in this length barrel 2500fps with 100grn bullet sounds like pressures for this .25x40 round may be rather steep.
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bottle neck to smaller bore = bad .......well, maybe not bad but different.......I did learn that.......loads that we run comfortably in the '40' 125gr TNT and 20gr of H4227 exhibit no pressure signs (pretty straight case to bore ).......the .25 with a grain less powder and 25gr less projectile had flattening of the primers....no ejector or extractor extrusion......some equate brass and primer reading with that of tarot cards or prospecting rods but it served Ackley pretty well...... I've got a couple other powders that I want to try....the H4227 was mainly to fire-form some brass....abrupt pressure curve..... In cases this size with heavier bullets I've had pretty good luck with 1680....still have to try it.... Thanks, Kurt |
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If I had a copper crusher or piezoelectric conformal transducer in the shop I could give you a number, I don't so that's all I have ....... no casehead expansion (a biggie), no ejector or extractor extrusion marks, good primer pocket, no pierced primer.....feel relatively safe ........I do run my chambers a little tighter than any production auto-loader that I've measured to keep brass expansion / movement to a minimum on higher pressure cartridges.....an example would be: the casehead on once fired brass from a production mil-spec 5.56 chamber wont even come close to fitting in the .25x40 chamber.....thats even after full-length re-size....have found some factory 5.56 chambers that allow the casehead to grow .002" (very bad thing) with factory loads.......way worse than anything I've ever measured with several AR cats..... I run my chambers tight for a reason ....... Hope this helps, Kurt |
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So in essence you've purposefully built a chamber that would just about NEVER show traditional pressure signs <read voodoo>. Then you proceed to look for them in your load development, while ignoring what your chronograph is SCREAMING at you. You're not gonna get those speeds from that case in your length bbl without some crazy high pressures.
As an example some of your 16" 7.62x40 loads outrun what my 26" slow twist .308x39 will do with a smaller case and 10" shorter tube and in my case some loads are already well over max. Again There's NO FREE VELOCITY LUNCH if you're achieving crazy speeds in a short barrel with a small case you must be running crazy pressures as well. Don't worry about how the cases look and pay attention to what your chrony is telling you, it's the best piece of pressure testing equipment you have. |
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SAAMI Maximum Pressure for the 222 Remington case is 50,000 C.U.P. and the 7.62x39mm is 45,000 C.U.P. The 223 Remington parent case is 55,000 C.U.P., so it is hard for me to see a direct comparison of the the cartridges you picked. Can you give a better example with a cartridge closer to the .25x40mm.
Thanks Joe |
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6mmx45 or 6mm/223 can in fact get a 100grn bullet up to 2600 fps. But only in a 24" barrel and again that with a cartridge with a good deal more case capacity. Chop the bbl down 4" and reduce the case capacity and there's no way you only lose 100fps at the same pressure. Even with the slightly larger .257dia bullets
also the ratings you cite above are the PSI ratings for those cartridges not CUP, To compare you need look at psi as cup is not the same scale of measurment for all cartridges. My 28grn load of aa1680 with 125g bullets is already great deal over x39's 45K SAAMI PSI pressure rating again in a much much longer bbl 26". |
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You are correct the numbers I listed are for PSI Not CUP my mistake. I do load for the 6x45mm but not for 100 grain bullets. With 85 and 87 grain in a AR15 20" barrel was able to go to 2700 FPS without any sings of over pressure. Using the Sierra 85 gr Game King and 25.0 grains of H335. When you look at this this load in the Sierra manual they were using a 24" barrel to get a velocity of 2700 FPS. Granted I have no idea of the actual pressure in my barrel, but working up the load from starting every increase in charge weight had a like linear increase in velocity and no sign of over pressure. Thanks for your input Joe |
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Thanks Joe.....I always seem to get picked on when I'm at work and can't reply ......
Isn't that kinda the point of wild-catting, to re-design or improve a chamber or cartridge to achieve a level of improved performance.........Do you think the indicators of traditional pressure signs have been removed making it voodoo?.... or do you think the chamber and bolt are now doing what they should, fully support the case and minimize the movement of the the brass at the point of firing so the brass doesn't exercise around in the chamber looking to extrude into any opening?.....
right now the die set is the big bummer......currently it's a 4 die set....first step neck sizer / second step neck sizer and trim / full length sizer die / bullet seater die.....a prototype set of dies costs around $300.00 from Hornady.....the barrels are average cost for a AR barrel depending on the quality of blank you want to use.....gas sysem is stock, I'm using a JP adjustable.....the thing that I think is pretty neat is that it uses totally un-modified mags....with the .223 the magazine front rib rides on the neck of the cartridge, with the .25 the mag front rib rides on the bullet which is within a few thousandths of an inch of the .223 neck....so no mag stack tension problems...... Hope this helps, Kurt |
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Krochus, I am curious as to why you only downloaded the data for the 6mm-222 from the Hodgdon site to compare with the .25x40mm (AKA: CottonMouth). The next selection just below the 6mm-222 is the the 6x45mm (6-223) which is a better comparison. Particularly since the 6x45mm has the same pressure rating as the 5.56x45mmm (52000 CUP). I have included the data from the Hodgdon site below. As you can see, from a 24-inch barrel with a 6mm bore, you can push a 100 gr pill to 2600 fps. Cutting 8-inches off the barrel would probably reduce the velocity be about 250 fps to 2300-2400 fps. 6x45mm Barrel Length: 24" 100 GR. HDY SP Hodgdon---H380 ----26.0---2397--41,000 CUP--28.0--2506--47,000 CUP 100 GR. HDY SP Hodgdon---BL-C(2)--24.5---2404--43,000 CUP--26.5--2619--50,000 CUP 100 GR. HDY SP Hodgdon---H335-----21.5---2305--44,000 CUP--23.0--2443--50,000 CUP 100 GR. HDY SP Hodgdon---H4895----22.0---2414--42,000 CUP--24.0--2616--50,000 CUP A better comparison however, would be the 257 Kimber. The Hodgdon site lists data for this caliber which I have listed below. From a 22-inch barrel you can get 2760 fps. If you reduce the barrel to 16-inches, I would guess that the velocity would be around 2400-2500. 257 Kimber (a.k.a. Copperhead) Barrel Length: 22" 100 GR. SPR SP Hodgdon---H4895----26.0---2527---MAX. 28.0---2760 So I think that the pressures that 762x40mm (Kurt) is running the .25x40mm are well within the pressure range of the 5.56x45mm (223) case. 320pf |
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how eloquent.....I need to work on that.....If I could stop playing with my voodoo dolls... I just got an idea for the AR cat I'm working on now.....either that or I'm getting another headache.......I'll call it the ?x??mm AKA (voodoo)....may do well with the New Orleans Hatian demographic...... thanks dude... Kurt |
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The small short cases tend to perform well beyond what you normally expect, even Frank Barnes noted this in his book, discussing the 22 Carbine (5.7 MMJ, Johnson Spitfire). Other such cartridges have shown similar effects.
One effect is that as the case gets shorter, the available barrel gets longer. While a 257 Roberts has a big case, in a 16" barrel, 2" of that is consumed by case, leaving less than 14" for expansion. The 257 x 40 is 0.5" shorter, so it has that much more barrel to do its work. Also, it has been shown that for the same case size, a bigger bullet will go faster, if the weight is held the same (6-223 with a 60 gr bullet will go faster than a 223 with a 60 gr bullet) A cartridge that might offer some insight and comparison is the .256 Win Mag. This is the 357 Mag case necked to .257 and was known as a really nice shooter in the T/C. If you take this same round, load it with a 100 SMK to same seating depth as the 257 x 40 and use a 16" barrel, max pressure of 50,000 psi and use QuickLoad to get an estimate, it gives 2150-2200 fps. This smaller case only allows 14.3 gr 4227... I don't think 2500 fps is unreasonable from the longer case |
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Thanks for the back-up info Marty, the cottonmouth was named for mine and Pat F's mutual friend on Sabine Pass....hope everything is going well around the casa......from the other thread/post I read today I would have to say with the way work has been lately my poison of choice: Crown on the rocks.... I ran some loads today up over 22 grains of 1680....I'm not going to post those numbers cause someone may accuse me of trying to split the atom or set the atmosphere on fire or something...the case will hold over 26gr of 1680.... Load Data: (standard disclaimer as with any wild-cat, use at own risk and work up slow) .25x40mm 16" 1:10 carbine length gas system, fire-formed brass...worked up several loads between but only posted the whole unit loads.... 100 SGK 19gr 1680 = 2,310 fps 100 SGK 20gr 1680 = 2,411 fps 100 SGK 21gr 1680 = 2,520 fps 100 SGK 22gr 1680 = ?,??? fps (21.8gr 1680 looked good, 22gr started to look a little ugly, nothing too bad, spit one primer out of ten, the other nine held ok....) the 1680 produced pretty linear velocity results from 19 to 21.5 grains....after that the velocity flattened out and pressure got more noticeable.... from a 20" 1:12 this thing with 1680 should really come alive Thanks, Kurt |
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Range results:
Load Data: (standard disclaimer as with any wild-cat, use at own risk and work up slow) .25x40mm 16" 1:10 carbine length gas system, fire-formed brass...worked up several loads between but only posted the whole unit loads.... 85gr Nosler BT, 20gr 1680 = 2,525 fps 85gr Nosler BT, 21gr 1680 = 2,642 fps 85gr Nosler BT, 18gr 4227 = 2,514 fps 85gr Nosler BT, 19gr 4227 = 2,592 fps 85gr Nosler BT, 20gr 4227 = 2,686 fps 85gr Nosler BT, 20gr 5744 = 2,441 fps 85gr Nosler BT, 21gr 5744 = 2,551 fps (very consistent, +/- 3 fps.) Averages of 20 rd. strings......bumping loads and trying some different powders with the 100 SMKs tomorrow..... Thanks, GO...LSU Kurt
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Thanks.....I started pushing the 85gr loads with 1680 today....working up the string averages.....very stoked with the results....everything looks good and action operation is perfect even at the higher velocities.....didn't shoot for groups today but had no problem hitting a 6"x6" steel plate with every shot at 225yds..... Kurt |
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Range results:
Load Data: (standard disclaimer as with any wild-cat, use at own risk and work up slow) .25x40mm 16" 1:10 carbine length gas system, fire-formed brass...worked up several loads between but only posted the whole and half unit loads.... 85gr Nosler BT, 21.5gr 1680 = 2,757 fps 85gr Nosler BT, 22gr 1680 = 2,810 fps 85gr Nosler BT, 22.5gr 1680 = 2,853 fps 85gr Nosler BT, 23gr 1680 = 2,913 fps Averages of 20 rd. strings...... the 1680 produced very linear velocity results with the 85s.......very good velocity per grain of powder...... I tried about eight different powders with the 85 and 100 grainers today.....the only thing that even came close to the performance of the 1680 is 5744 but ran out of room at 21.5grains and was still 150fps slower.... Kurt
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How timely. I was just looking at .25 caliber projectiles a few days ago as a hypothetical design exercise and here it's already been done. I was contemplating a 6.5MPC barrel but this is also very intriguing.
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thanks for the interest....what weight range bullets were you looking to use with your design?..... the first evolution of the .25x40 had the shoulder set back about .040" less than the one in the thread...made it pretty easy to get projos well over 100gr in line with the shoulder and not encroach on the powder column....after crunching the numbers it looked more like the additional weight was counter productive and decided to go with the 85 to 100gr pills, and moving the shoulder forward the .040" for the lighter bullets was an added bonus in powder capacity.... I have always liked the .25 stuff since my first .25-06.......had looked at originally using the 6.5 or 6.8 but kept going back to how well those 100gr Gamekings used to do in the 06.......and Sierra offered a match and hunting bullet in the 100gr class so that was a pretty good closer..... I really like the MPC, I guess one of the big selling points for it was for military adaptation to mag and belt-feed as it kept the 5.56 case taper.....the .25x40 is pretty straight so it comes off the mags really slick, a lot like .308 Winchester taper, and the additional shoulder width really helps with increasing the capacity for slower powders.....I promised earlier in the thread I would measure the before and after fire-forming H2O capacity but I just haven't got to it yet, but I will..... Hope this helps, Kurt |
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100gr SMK load data:
(standard disclaimer as with any wild-cat, use at own risk and work up slow) .25x40mm 16" 1:10 carbine length gas system, fire-formed brass...worked up several loads between but only posted the whole and half unit loads.... 100 SGK 22.0gr 2015 = 2,276 fps (compressed) 100 SGK 22.0gr 2230 = 2,310 fps 100 SGK 22.5gr 2230 = 2,345 fps 100 SGK 21.5gr 5744 = 2,529 fps (compressed) 100 SGK 19.0gr 1680 = 2,313 fps 100 SGK 20.0gr 1680 = 2,415 fps 100 SGK 21.0gr 1680 = 2,519 fps 100 SGK 22.0gr 1680 = 2,614 fps the 1680 is looking more and more like the go to powder....the 5744 loads maxed out on capacity but it is very close in velocity and a little more consistent than the 1680... Hope this helps, Kurt
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Accurate 2230 / 100gr SMK load data:
(standard disclaimer as with any wild-cat, use at own risk and work up slow) .25x40mm 16" 1:10 carbine length gas system, fire-formed brass...worked up several loads between but only posted the whole unit loads.... 100 SMK 23.0gr 2230 = 2,429 fps 100 SMK 24.0gr 2230 = 2,502 fps the 2230 load density is a little more than 1680 and also a little slower powder, works pretty good with the heavier bullets......the 2230 is a pretty consistent powder, +/- 6 fps....have a little more room in the case and pressure looks good.... Hope this helps, Kurt
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I am tagging this for future reference. I like quarter caliber guns a lot, and this looks like it has some fun potential. Only problem is I am already at the beginning stages of a 6.8 SPC build (18" 1:12" twist, 3 groove)...
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Quoted:
Man this round sounds cool! Quoted:
I am tagging this for future reference. I like quarter caliber guns a lot, and this looks like it has some fun potential. Only problem is I am already at the beginning stages of a 6.8 SPC build (18" 1:12" twist, 3 groove)... Thanks for the interest and words of support guys..... have been working on a couple different evolutions of the .25 and think we have decided on a final reamer....the .25 cottonmouth was kind of a test bed to see if the additional capacity created by blowing the shoulder out and changing the shoulder angle to 30 degrees made a difference with the powders we hoped to use.... what we found out was with powders the burn rate and load density of 1680 and 2230 the additional space wasn't required to reach a load capable of pushing a 85 grainer to 2,900 fps out of a 16" barrel.... It looks like the .25 that we have decided on making available will be the .25 Bailey or 6.3x40mm Bailey......it maintains the 5.56 case taper and shoulder angle but is 5mm shorter to allow for the loading of 85 to 100gr bullets.....this case geometry allows for use in the most 5.56 specific of AR mags....like the H&K 416 mags... the 6.3 Bailey case geometry has another interesting attribute: The 6.3x40 Bailey compared to a 5.56x45 Bailey = truth / justice Thanks, Kurt |
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... It looks like the .25 that we have decided on making available will be the .25 Bailey or 6.3x40mm Bailey... Bailey = truth / justice Thanks, Kurt Or go with ".25x40 Bailey" as we have all been following it. If you go with the 6.3 name you might lose people on the name recognition. Just saying. |
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... It looks like the .25 that we have decided on making available will be the .25 Bailey or 6.3x40mm Bailey... Bailey = truth / justice Thanks, Kurt Or go with ".25x40 Bailey" as we have all been following it. If you go with the 6.3 name you might lose people on the name recognition. Just saying. Hi Chris, Thanks for the feedback, I really appreciate it......have had requests both ways....personally, I like .25 .....had a couple guys point out that our other cat is a metric designation (7.62)......so I threw 6.3 out there to see what stuck.... I'm not even going to go into the name changes for each .25x40 reamer evolution, talk about getting lost.....we now try to name each reamer evolution with a distinct name to prevent a mix-up....rater than using revision 1, revision 2, etc......the names usually follow a alphabetic sequence; A, B, C, D, etc....to create a evolution timeline....hint-hint, nudge-nudge ....went up to D and came back to B (Bailey)...... with the 7.62x40 we followed a similar methodology but we have reamers that were never intended for use in a AR....example: really long throated for hanging heavies way out front in bolt-guns.... Again, I appreciate the feedback....nothing is engraved yet so it's still open... .25x40mm Bailey......I like it.... Thanks, Kurt |
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Kurt,
Darn you! You got me into another Wildcat project. I am going to do a .257-223. My goal is to have a Wildcat that is easy to make brass for and yet still run in an AR15 platform. I made up some dummy rounds by simply opening up the necks of some 223 brass by running them through my 25-06 resizer die. I can get 100 gr Sierra Prohunters to fit an AR mag and still have about 1-2mm before the ogive starts into the neck. I have to get my hands on some Sierra 100gr MKs to see if they will work... The ogive on the 100g MKs may be a bit too long. If they work, it will be very close. Any insights/suggests would be welcome. 320pf |
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Kurt, Darn you! You got me into another Wildcat project. I am going to do a .257-223. My goal is to have a Wildcat that is easy to make brass for and yet still run in an AR15 platform. I made up some dummy rounds by simply opening up the necks of some 223 brass by running them through my 25-06 resizer die. I can get 100 gr Sierra Prohunters to fit an AR mag and still have about 1-2mm before the ogive starts into the neck. I have to get my hands on some Sierra 100gr MKs to see if they will work... The ogive on the 100g MKs may be a bit too long. If they work, it will be very close. Any insights/suggests would be welcome. 320pf Neck Tension.....the experimenting we did with the .223 case showed that when loading a 257 bullet base in past the neck / shoulder junction neck tension is pretty critical to prevent bullet set-back when chambering.....seems to be more pronounced in the smaller calibers.....the neck / shoulder junction seems to act as a stop / stiffener / choke point / roll crimp to the neck that helps prevent bullets from setting back.....this is evident during seating bullets, a noticable amount of resistance can be detected while the bullet is being seated, once it drops in past the junction the resistance goes away......some of the full length models we made the bullets could be pushed in the case with finger pressure after going past the junction......firing and reloading will make the neck wall thin, the thinning of the neck wall amplifies the problem because it reduces neck tension during resizing..... in the case of the .25x40 to counter the possibility of set back we took the heaviest bullet we expected to use (100gr SMK) and laid-out the neck / shoulder junction just shy of the end of the bearing surface....no set-back.... Hope this helps, Kurt |
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Kurt, Darn you! You got me into another Wildcat project. I am going to do a .257-223. My goal is to have a Wildcat that is easy to make brass for and yet still run in an AR15 platform. I made up some dummy rounds by simply opening up the necks of some 223 brass by running them through my 25-06 resizer die. I can get 100 gr Sierra Prohunters to fit an AR mag and still have about 1-2mm before the ogive starts into the neck. I have to get my hands on some Sierra 100gr MKs to see if they will work... The ogive on the 100g MKs may be a bit too long. If they work, it will be very close. Any insights/suggests would be welcome. 320pf This may give you a starting point on back-ground and load development...... http://www.handloads.com/forum/showthread.asp?topic=2&thread=272 http://www.groupsrv.com/hobby/about36992.html |
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Any measurements yet of H2O capacity? the current configuration is right at 28 grains H2O....(27.8) Quoted:
Any new developments ? Looks nice in belts! now I just need to find someone that is willing to re-barrel their SAW ......had checked into the belt-feed conversions for the AR but was advised against it for now....... have done quite a bit of powder testing with the 16".....the 1680 still looks like the go-to powder with the 75 to 85 gr loads.....2230 and H3222 do well with the 100 grainers.......waiting for a couple 10" to test.... built a couple new .25 rifles, one as a Christmas gift to my daughter.....she started deer hunting this year and took a mature doe at 175 yds. a few weeks back......for her first shot to say I was proud would be an understatement I like to think the bench time helped her in the field....a good bit of trigger time behind a suppressed 300 whisper AR banging 200 yd. steel.... received the first set of Hornady .25x40 dies a few days ago, look sweet....are going to check a few things out and will probably move forward with an order.....was told delivery on dies could be some time during the Summer courtesy of the post election buying... Thanks, Kurt |
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Damnit all to hell!!! I start a nice build in .25-06 using a HOWA 1500 barreled action and have to go out and guy .25 cal bullets and then I see this frigging thing!!! So I can fireform 7.62x39 brass and make my 6.5G brass if I need it, fireform .223 brass for my buddies 7mmTCU, and now form .223 brass into .25Bailey for yet ANOTHER AR rifle!!! You guys need to cut this crap out!!
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............. You guys need to cut this crap out!! the voices in my head won't let me How do yo like the Howa? .....I did a couple Howa builds a while back and I wasn't sure how they would work out, everything turned out great...so far so good.... Kurt |
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Kurt,
Thanks for the help with this wildcat. Here is a photo of some dummy rounds for the 6.35x43mm wildcat. I had to shorten the case neck (~2mm) from 45mm to 43mm, so when the bullets are seated deep enough to fit in an AR15 mag. the case mouth does not ride up too far on the bullet ogive. The case neck ends up at 0.199" On Monday the drawing and dummy rounds go off to PTG.... Hopefully, in about 4-6 weeks I get my reamer. The reloading data from Hodgdon for the 257 Kimber listed below should give one an idea of the velocity potential. I am going to build a 20" barrel for this cartridge so I expect to get velocities about 75 to 100 fps slower than those listed below. 257 Kimber (a.k.a. Copperhead) Barrel Length: 22" Bullet––––––––Powder–––– Grs.––––––Vel. (ft/s)Grs.Vel. (ft/s) 75GR. HDY HP––-H335––––––28.0––––––2769––––––––-31.5––––––3195 75GR. HDY HP––-H4895––––-28.0––––––2756––––––––-31.5––––––3192 75GR. HDY HP––-H322––––––28.0––––––2806––––––––-31.5––––––3198 87GR. HDY SP––-H335––––––29.0––––––2870––––––––-31.0––––––3030 87GR. HDY SP––-H4895––––-29.0––––––2824––––––––-31.0––––––3056 87GR. HDY SP––-H322––––––25.0––––––2604––––––––-28.0––––––2868 100GR. HDY SP––H4895––––-26.0––––––2527––––––––-28.0––––––2760 From Left to RIght.Black Hills 69g 223, 100g Sierra MK, 6.35x43mm w/100g Sierra MK, 100g Sierra GK, 6.35x43mm w/100g Sierra GK, 75g Hornady V-Max, 6.35x43mm w/75g Hornady V-Max, 85g Nosler Ballistic Tip, 6.35x43mm w/85g Nosler BT, 100g Sierra Pro-Hunter, 6.35x43mm w/100g Sierra Pro-Hunter, unloaded 6.35x43mm case, and Black Hills 77g 223. Thanks again for the help 320pf |
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320pf, you may want to send a dummy round to Lee for a factory crimp die. I did for my 7mm TCU - helped to prevent bullet set-back and gave a bonus of +33fps.
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Quoted:
The reloading data from Hodgdon for the 257 Kimber listed below should give one an idea of the velocity potential. I am going to build a 20" barrel for this cartridge so I expect to get velocities about 75 to 100 fps slower than those listed below. 257 Kimber (a.k.a. Copperhead) Barrel Length: 22" Bullet––––––––Powder–––– Grs.––––––Vel. (ft/s)Grs.Vel. (ft/s) 75GR. HDY HP––-H335––––––28.0––––––2769––––––––-31.5––––––3195 75GR. HDY HP––-H4895––––-28.0––––––2756––––––––-31.5––––––3192 75GR. HDY HP––-H322––––––28.0––––––2806––––––––-31.5––––––3198 87GR. HDY SP––-H335––––––29.0––––––2870––––––––-31.0––––––3030 87GR. HDY SP––-H4895––––-29.0––––––2824––––––––-31.0––––––3056 87GR. HDY SP––-H322––––––25.0––––––2604––––––––-28.0––––––2868 100GR. HDY SP––H4895––––-26.0––––––2527––––––––-28.0––––––2760 320pf uhu.....I don't know if you've tried to load 4895 or H322 in a 43mm case but I don't think even the minimum charge data above will be able to be met. a .223 case completly full overflowing out the mouth with 4895 and H322 is right at 28grains. A favorite .223 load with 4895 and a 69 SMK loaded to AR mag length is a little over 25gr and it's slightly compressed. My 25/223 cat maxes out with H322 right at 24gr with a 100 SMK and clocks 2,600 fps. out of a 18" barrel. could not get close to 2,600fps with 4895 |
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Hi Uptown,
I have to agree. When I looked at the numbers in the Hodgdon manual they looked a bit high. But the table I listed are the numbers in the manual. I also checked the 6mm TUC in Hodgdon manual. They list a max load of H335 of 30.0g and a max load H4895 of 29.5 pushing a 6mm 70g Hornaday bullet. I guess that I can buy some H332 and H4895 and check it out for myself. I would like to get some information from you about your 25/223 cat. Is is a standard 223 case just neck up to .257. What weight bullets have you shot from it and what kind of velocities are you getting. Thanks, 320pf |
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Quoted:
The reloading data from Hodgdon for the 257 Kimber listed below should give one an idea of the velocity potential. I am going to build a 20" barrel for this cartridge so I expect to get velocities about 75 to 100 fps slower than those listed below. 257 Kimber (a.k.a. Copperhead) Barrel Length: 22" Bullet––––––––Powder–––– Grs.––––––Vel. (ft/s)Grs.Vel. (ft/s) 75GR. HDY HP––-H335––––––28.0––––––2769––––––––-31.5––––––3195 75GR. HDY HP––-H4895––––-28.0––––––2756––––––––-31.5––––––3192 75GR. HDY HP––-H322––––––28.0––––––2806––––––––-31.5––––––3198 87GR. HDY SP––-H335––––––29.0––––––2870––––––––-31.0––––––3030 87GR. HDY SP––-H4895––––-29.0––––––2824––––––––-31.0––––––3056 87GR. HDY SP––-H322––––––25.0––––––2604––––––––-28.0––––––2868 100GR. HDY SP––H4895––––-26.0––––––2527––––––––-28.0––––––2760 Thanks again for the help 320pf no prob, glad to help.....looks good... the 257 Kimber is based on the .222 Rem Mag....the Copperhead is based on the .222 Rem the load data for the Kimber looks good to me, but a couple things to take into account when comparing the 25/223 and the Kimber is the Kimber brass starts out around .100" longer than the .223 and the Kimber is loaded out to almost 2.400" COAL....a good bit longer than the 2.240" we are limited by in the AR mag......with most of the bullet up in the neck of the Kimber it makes a good bit more room in the case, especially when using flat-base 75 to 87s.... I do agree that a full .223 case of 4895 is right at 28gr.....the 69 with 25gr 4895 is also one of my favorites, consistant 3,000 fps... the .25x40mm with 23gr of H322 will push a 100 SMK 2,530fps out of a 18" middy....so the 2,600fps using 24gr of H322 from a 25 TCUish sounds good, I'm guessing it's a compressed load though.... Kurt |
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Why not just use the 25 TCU?
More case capacity and standardized dies/loading data. |
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Quoted:
Why not just use the 25 TCU? compared to what?.....223, 25/223, 25x40, kimber, copperhead, 25/222....... |
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my cat is along the lines of a 25 TCU with the case mouth and shoulder moved back about .030, the full length TCU was too long for what I was wanting to do, also used a little narrower shoulder.
as for the TCUs being standardized they are like anything else, people tweak the length, neck, shoulder width, and base dimension to fit their needs. I shoot two loads in it: 87gr TNT and 100gr SMK using H322 |
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No fireforming?
case taper the same as .223? I think I'm going to come calling for a barrel soon. |
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Quoted:
No fireforming? That is correct. Quoted:case taper the same as .223?
That is also correct. Quoted:I think I'm going to come calling for a barrel soon.
I will keep you posted. The goal was to make a wildcat that all one has to do is expand the neck and resize a standard 223 Rem. by simply running through a resizing die. The challenge of course is to keep of overall length of the round compatible with a standard AR15 mag. This can be done, however this restricts you to bullets like the Speer 87gr and 100gr Hot-Cor and Sierra 87gr., 100gr. Prohunters and 100gr Gamekings. By trimming the neck 2mm you have a few more bullet selection options. Again, thanks Kurt for the inspiration. In the mean time I am waiting for the reamer. 320pf |
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Quoted:
Quoted:
No fireforming? That is correct. Quoted:case taper the same as .223?
That is also correct. Quoted:I think I'm going to come calling for a barrel soon.
I will keep you posted. The goal was to make a wildcat that all one has to do is expand the neck and resize a standard 223 Rem. by simply running through a resizing die. The challenge of course is to keep of overall length of the round compatible with a standard AR15 mag. This can be done, however this restricts you to bullets like the Speer 87gr and 100gr Hot-Cor and Sierra 87gr., 100gr. Prohunters and 100gr Gamekings. By trimming the neck 2mm you have a few more bullet selection options. Again, thanks Kurt for the inspiration. In the mean time I am waiting for the reamer. 320pf 320pf, I may have given the wrong impression. Are we talking about the .25Bailey? |
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