Hi, new here and I’d like to say hello to begin with and that I appreciate being part of the forum. I just acquired some 7.62x51 berdan primed brass and I plan to convert it to accept boxer primers. Seems to be a couple methods to accomplish this task. I have no experience with berdan brass, it’s my understanding that the primer pocket has to be sleeved, anvil removed and pocket deepened to accept boxer primers. My question is, has anyone ever left the spent berdan primer in place, to be use as the sleeve for the boxer primer, instead of removing it completely?
7.62x51 Berdan Brass
- Thread starter Skipp1962
- Start date
bobm
Silver $$ Contributor
Welcome to the forum.
You are facing a daunting labor intensive task converting all that brass. Assuming you have the needed tooling, like a lathe and proper cutter? Carefully open the cup end and measure the ID of the Berdan cup. Needs to be under .210 dia. to hold a boxer primer.
Scrap brass is fetching about $2.25 lb. Buy new brass.
You are facing a daunting labor intensive task converting all that brass. Assuming you have the needed tooling, like a lathe and proper cutter? Carefully open the cup end and measure the ID of the Berdan cup. Needs to be under .210 dia. to hold a boxer primer.
Scrap brass is fetching about $2.25 lb. Buy new brass.
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I have a lathe and most of what I need for the task. Took me most the day to remove those links from the cases though. Thank you for your reply.Welcome to the forum.
You are facing a daunting labor intensive task converting all that brass. Assuming you have the needed tooling, like a lathe and proper cutter? Carefully open the cup end and measure the ID of the Berdan cup. Needs to be under .210 dia. to hold a boxer primer.
Scrap brass is fetching about $2.25 lb. Buy new brass.
I second the advice Bob gave.
Welcome to the forum.
Besides the labor involved, the bushed primer pocket thing sounds like trouble waiting to happen. First off I'm assuming that this is brass from a machine gun, so it's not likely to be dimensionally consistent. And if you intend on using it in a gas gun and the bushings don't work perfectly you are likely going to have primers and bushings filling up your trigger and magazine cavities right up be to when the gun malfunctions. Hopefully it will just stop running, but who knows what will happen.
I would understand if you couldn't get brass, but 7.62x51 is not that hard to come by.
Welcome to the forum.
Besides the labor involved, the bushed primer pocket thing sounds like trouble waiting to happen. First off I'm assuming that this is brass from a machine gun, so it's not likely to be dimensionally consistent. And if you intend on using it in a gas gun and the bushings don't work perfectly you are likely going to have primers and bushings filling up your trigger and magazine cavities right up be to when the gun malfunctions. Hopefully it will just stop running, but who knows what will happen.
I would understand if you couldn't get brass, but 7.62x51 is not that hard to come by.
I appreciate the advice of those warning against modding these brass cases to accept boxer primers and maybe I should listen, but I’m confident that I can make these cases work. I think chucking them up is the lathe, with an end mill, removing the strike face, anvil and establish pocket depth, drill the flash hole, leaving the remnant of the berdan primer sleeve to be used as bushing, swage to form pocket for boxer primer if necessary. What could go wrong? Probably a lot, lol.
I removed a primer from a case earlier to get dimensions from the pocket, which is .2155 wide and .123 deep so close, but definitely needs to be sleeved And the pocket deepened. Primers are staked in place so maybe that’s a plus for this project, cause it wouldn’t budge using the famous hydraulic method. I did drill a flash hole though.
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bobm
Silver $$ Contributor
Small rifle primers? Shows how little I know of military Berdan priming. How about just grinding the end mill to the correct dia. to accept LR primers? Small boring bar? The pocket is just a little deep for flush seating. You can create a new surface for the correct depth. What country made the brass?
What am I doing?? I should be discouraging this modification! Carry on.
Keep us posted.
PS....you'll get more scrap money with the steel gone now.
What am I doing?? I should be discouraging this modification! Carry on.
Keep us posted.PS....you'll get more scrap money with the steel gone now.
Bob, I think it’s S. African brass, but I’m not certain. Here’s a better photo I hope so maybe someone more knowledgable can verify the country of origin. I kinda butchered the case removing the primer, but it may be serviceable. I still need to acquire a few things before I start production on a test batch, I’m waiting for the dies to arrive and I need a tumbler to clean the brass, but I’ll definitely keep this thread updated with my progress.Small rifle primers? Shows how little I know of military Berdan priming. How about just grinding the end mill to the correct dia. to accept LR primers? Small boring bar? The pocket is just a little deep for flush seating. You can create a new surface for the correct depth. What country made the brass?
What am I doing?? I should be discouraging this modification! Carry on.
PS....you'll get more scrap money with the steel gone now.
Cheers,
Skip
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Interesting question, one I haven’t though of until now and I hope that won’t be the case. I could just not drill the center hole, but that defeats my purpose to have reusable and relatively trouble free reloadable cases.
Thanks,
Skip
bobm
Silver $$ Contributor
Just a thought. You now have three holes to transfer ignition flame. In that same instant those three holes will transfer additional pressure forces on the primer cup. Could be a problem, no?
Are you sure you measured a .125 dia. pocket? Looks bigger in your three hole picture. .215??
Are you sure you measured a .125 dia. pocket? Looks bigger in your three hole picture. .215??
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I read an article about doing this many years back and can only remember some of the details. The guy doing this and writing the article had a flat ended mandrel of caliber size to put through the case mouth and was long enough to support the case on the web (inside). He also ground a flat tip punch that was the same diameter as the primer pocket and used a hammer with this punch to flatten the Berdan primer dimple/teat in the bottom of the primer pocket. The Berdan primer flash holes closed up from the metal being displaced and a flash hole was drilled. He also had to bush the flash hole to use standard boxer primers, but the details on that are a bit foggy. If I remember he said the inside diameter of the Berdan primers was the same as the outside diameter as the Boxer primers, but I'm not for sure on that. Another thing I do remember of this story was a Lachmiller hook tool was used to remove Berdan primers from the cases. The in the story was an almost unknown (at the time) European bolt action that was chambered for the 9.3X64 cartridge, almost totally unheard of when the story was written.
My pet squirrel would not approve, but yeah that’s on my bucket list, lol…
Adam in WI
Practically lives here
Move it up earlier, then it'll be on his bucket list...
D-4297
Gold $$ Contributor
Welcome to the Forum .
As someone who has been down this rabbit-hole on converting Berdan primer cases to Boxer , I can tell you very simply this is not something you want to do to your rifle . Many Mosin-Nagant owners attempted this , in order to re-use the thousands of Berdan cases we had shot . What I personally learned was : No matter the process , or procedure used to re-vamp these cases , roughly 75 - 80% of the primer pockets "Leaked" upon firing . Scoring and burning the Bolt-face . Making some total trash , in a very small number of firings . It is not worth the time , cost and effort to convert these cases , as purchasing boxer cases is not that expensive compared to the time and cost in your endeavor .
Been there , Tried this . And trust me on this one . It DOES NOT WORK !
As someone who has been down this rabbit-hole on converting Berdan primer cases to Boxer , I can tell you very simply this is not something you want to do to your rifle . Many Mosin-Nagant owners attempted this , in order to re-use the thousands of Berdan cases we had shot . What I personally learned was : No matter the process , or procedure used to re-vamp these cases , roughly 75 - 80% of the primer pockets "Leaked" upon firing . Scoring and burning the Bolt-face . Making some total trash , in a very small number of firings . It is not worth the time , cost and effort to convert these cases , as purchasing boxer cases is not that expensive compared to the time and cost in your endeavor .
Been there , Tried this . And trust me on this one . It DOES NOT WORK !
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