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Posted: 1/4/2021 11:41:27 AM EDT
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With the primer shortages this guy made a video with pressure and velocity testing of different primers. https://youtu.be/NGVRGsoOr6k  Failed To Load Title |
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Quoted: The only real difference is primer hardness. You may see light strikes with rifle primers in pistol. I’m sure this will be pistol dependent as well. I would think a Glock firing pin with its triangle tip and rectangular shape would do better over a more traditional rounded 1911 style pin. Edit: watched the video they did a great job . |
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Quoted: I’m sure this will be pistol dependent as well. I would think a Glock firing pin with its triangle tip and rectangular shape would do better over a more traditional rounded 1911 style pin. Edit: watched the video they did a great job . That could be. I was just thinking of modded guns with lightened springs. |
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The reason there is no pressure spike or increase in velocity is because of the amount of powder. The small pistol primer was already burning what powder was available efficiently. In fact, I’m not sure you can pack enough powder into a 9mm round to make much of a difference between the two primers. Where the difference would show up is the point where the spp was unable to burn all the powder in X barrel length where the smp would. Where that point is I have no clue but I do know it makes a difference in larger powder volumes. |
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Quoted: With the primer shortages this guy made a video with pressure and velocity testing of different primers. https://youtu.be/NGVRGsoOr6k  https://www.youtube.com/watch?v=NGVRGsoOr6kI didn't watch the video yet, but I think it's awesome that somebody put this together. I've always wondered about it. |
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Quoted: The reason there is no pressure spike or increase in velocity is because of the amount of powder. The small pistol primer was already burning what powder was available efficiently. In fact, I’m not sure you can pack enough powder into a 9mm round to make much of a difference between the two primers. Where the difference would show up is the point where the spp was unable to burn all the powder in X barrel length where the smp would. Where that point is I have no clue but I do know it makes a difference in larger powder volumes. I'm questioning the little bit I know about primers at this point. I've read that a magnum or rifle primer: - could cause unexpected pressure spikes - perform better in cold weather - were absolutely necessary with slow powder How much of this is true vs fudd lore? I wish I still had a Contender, because these tests could be more conclusive with something like .357 in a tough action. |
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Quoted: I'm questioning the little bit I know about primers at this point. I've read that a magnum or rifle primer: - could cause unexpected pressure spikes - perform better in cold weather - were absolutely necessary with slow powder How much of this is true vs fudd lore? I wish I still had a Contender, because these tests could be more conclusive with something like .357 in a tough action. Small rifle and small rifle mag primers have the same amount of priming compound, but the mags have thicker cups. Large rifle primers are a different ball game. Large rifle mag primers have more priming compound and a thicker cup vs large rifle standard primers. For example, a load I've experimented with in. 308 requires a 1.4 grain reduction of xbr 8208 to maintain the same velocity as a standard large rifle when using a mag primer. I know lots of people, myself included, who have used small rifle primers in place of small pistol primers with no issues. |
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Quoted: Small rifle and small rifle mag primers have the same amount of priming compound, but the mags have thicker cups. Large rifle primers are a different ball game. Large rifle mag primers have more priming compound and a thicker cup vs large rifle standard primers. For example, a load I've experimented with in. 308 requires a 1.4 grain reduction of xbr 8208 to maintain the same velocity as a standard large rifle when using a mag primer. I know lots of people, myself included, who have used small rifle primers in place of small pistol primers with no issues. Good to know. |
This guy did some testing too, but just on function. He has a few misfires. Small Rifle Primers substitution |
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Quoted: Not the same size: same diameter but LR is a little taller IIRC. My plan would be to use a RCBS Large Rifle primer pocket uniformer on a few pieces of 45ACP brass then seat LR primers. I think web thickness would be a concern here though. Don't want too thin of a web on the 45ACP. Of course the brass would be useless going forward for use of LP primers Thoughts anyone? |
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FWIW, I'm sure it can be done; we reloaders are traditionally a very resourceful bunch. Personally, I'm not willing to alter any of my brass to test (I have plenty of. 45acp brass) Honestly, I have no reason to at this point; I don't load anything in any quantity that uses LRP so I don't keep many on hand. I DO use LPP for a couple of calibers but have plenty for now so I don't have a need to find a workaround with LRP. Good luck if you decide to start experiments! |
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Quoted: True. I may experiment with this next I'm loading 45ACP. My plan would be to use a RCBS Large Rifle primer pocket uniformer on a few pieces of 45ACP brass then seat LR primers. I think web thickness would be a concern here though. Don't want too thin of a web on the 45ACP. Of course the brass would be useless going forward for use of LP primers Thoughts anyone? What I would do first is get an accurate measurement of the case web. Get a small rod that will fit in a 45 ACP case. 1 to 2 inches, length isn't important hang in while I explain. Place this rod in your caliper, zero caliper. (that's why length isn't important, as you are zeroing caliper) So lets say it measures .190 (made up number for this example) Ensure the flashole burr is removed as it will effect the measurement. Now take the bottom of the caliper, the part that sticks out when caliper is open. Measure the primer pocket depth. Lets say it's .20. So .190 minus .20 = .170 web thickness, cases as is. Don't know off the top of my head the difference of depth of LP versus LR, so lets say it's .10. Subtract that .10 from .170 to get new web thickness of 1.60. I have no idea it that leaves a safety margin I would be comfortable with. I would only do a few and of the same headstamp as a test. Now comes the real reason I don't think it will work, will pistol set off LR primers? Don't know. I kept explanation very simple hoping to not lose anyone. Most likely too simple for OP.  Good luck OP, I know you have plenty of reloading experience to try this experiment safely. |
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Quoted: First thought it's a poor idea, but these are desperate times. What I would do first is get an accurate measurement of the case web. Get a small rod that will fit in a 45 ACP case. 1 to 2 inches, length isn't important hang in while I explain. Place this rod in your caliper, zero caliper. (that's why length isn't important, as you are zeroing caliper) So lets say it measures .190 (made up number for this example) Ensure the flashole burr is removed as it will effect the measurement. Now take the bottom of the caliper, the part that sticks out when caliper is open. Measure the primer pocket depth. Lets say it's .20. So .190 minus .20 = .170 web thickness, cases as is. Don't know off the top of my head the difference of depth of LP versus LR, so lets say it's .10. Subtract that .10 from .170 to get new web thickness of 1.60. I have no idea it that leaves a safety margin I would be comfortable with. I would only do a few and of the same headstamp as a test. Now comes the real reason I don't think it will work, will pistol set off LR primers? Don't know. I kept explanation very simple hoping to not lose anyone. Most likely too simple for OP. Good luck OP, I know you have plenty of reloading experience to try this experiment safely. I think for now I'll find a few scrap 45 ACP cases, maybe AMERC, ream the pocket, seat a LR primer only, and set one off, what the heck |
 What if you can't buy primers for handloading, DIY ammo option  Primer experiment , what if we can't buy primers update |
 Switch Primers? - What You Should Know About Swapping Primers |
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I never would have thought to use pistol primers in rifle. Small rifle in pistol, sure. Small magnum pistol in 9mm, sure. Go the other way, no thanks. |
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Came here to post this. Looks like the consensus is that small rifle is good for almost anything, but small pistol generally can't stand the pressures of being used in a rifle. He used 6.5cm, I'd be curious if small pistol could handle 223 pressures. |
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Quoted: Came here to post this. Looks like the consensus is that small rifle is good for almost anything, but small pistol generally can't stand the pressures of being used in a rifle. He used 6.5cm, I'd be curious if small pistol could handle 223 pressures. Well he seemed to think people are doing this just willy nillly cause they got bored, but he doesn't seem to grasp that most of the people that are doing it because it's either do that or not shoot at all. Loading at the bottom end & paying extra close attention to the primers after firing will probably get people by if they are careful. The problem with the rifle primers in pistols is that you might get some combination of pistol & primer that won't ignite, but again, for a lot of people it's worth a try if it means not shooting at all vs shooting & maybe having a few duds. I think there are enough other videos showing that it's safe to do if you don't try loading the pistol primered rifle rounds too hot it's not going to blow up your gun. |
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Quoted: The only real difference is primer hardness. You may see light strikes with rifle primers in pistol. There is also a factor called "brisance".............. "Brisance Brisance is the shattering capability of a high explosive, determined mainly by its detonation pressure. The term can be traced from the French verb "briser" (to break or shatter) ultimately derived from the Celtic word "brissim" (to break). Brisance is of practical importance for determining the effectiveness of an explosion in fragmenting shells, bomb casings, grenades, structures, and the like. The sand crush test and Trauzl lead block test are commonly used to determine the relative brisance in comparison to TNT (which is considered a standard reference for many purposes). Wikipedia iconWikipedia |
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Quoted: I believe CCI has said that their CCI-400 small rifle primers are the exact same primers as their magnum small pistol primers. This is FALSE. They are NOT the same. https://thefiringline.com/forums/showthread.php?p=6811870#post6811870 See posts number 7 and 14. And see the updated ar15 post here; https://www.ar15.com/forums/Armory/Interesting-Conversation-With-CCI-Tech-About-SPM-vs-SR-Primers-Today/42-282516/ Ask CCI yourself; https://www.cci-ammunition.com/contactus Never regurgitate crap you read on a forum. ALWAYS ask the product manufacturer directly yourself. |
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Quoted: I got as far as "find a few scrap 45 ACP cases, maybe AMERC, ream the pockets" then gave up on the idea since it would be reducing the web thickness a bit about 1/100th of an inch Quoted: Quoted: AssaultRifler, did you move forward on this? Thanks I got as far as "find a few scrap 45 ACP cases, maybe AMERC, ream the pockets" then gave up on the idea since it would be reducing the web thickness a bit about 1/100th of an inch Is this dangerous or just troublesome? I’ll try seating some(I have plenty of junk 45 brass)after uniforming then check for fitment then post up my findings but first I need to get the wifee a new to us ride! |
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Quoted: Is this dangerous or just troublesome? I'll try seating some(I have plenty of junk 45 brass)after uniforming then check for fitment then post up my findings but first I need to get the wifee a new to us ride! I wouldn't go all out on this if it works, keeping two sets of 45acp brass separated forever more would be way troublesome |
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For the primer hardness issue, recall that different manufacturers have different cup thickness and hardness. When I was doing Cowboy Action shooting pretty regularly, I started getting some light strikes on my .45 Colt in a Winchester 73 replica after it was broken in some. I was using CCI LPP at the time. CCI tend to be harder to ignite than other brands. A switch to Winchester LPP solved that issue 100% with no other change. So hardness is not only a Rifle/Pistol/Magnum difference. My M1 Carbines also won't reliably set off the CCI Military SRPs that are designed for 5.56. Rob |
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Quoted: What with the differences in large pistol and rifle primer cup height, I'm thinking that using those CCI 400 primers in small primer .45 ACP might be a useful test. I have a few small primer .45 cases, and two different 1911-style pistols to test with. .008", I googled it |
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