Berdan primer to boxer

[beechbum444]

Just wish I could find a cheap source for berdan primes brass, the few places I’ve found want almost want t he same as once fired boxer primer brass.....

[uscra112]

I disagree. How on Earth is anyone going to be able to verify what is sloppy and what is not sloppy?
No one can be 100% sure of such a conversion not leaking a lot of gas back into some 100 year old action that does not handle gas well.

What is loaded several times and what is top end loads - that is what was the pressure?
If I use your process on 30-06 cases formed and used for loading a .25-06 at max pressure do you think your process would be OK?
OK for how many reloads?

If you are saying you have 6 Sigma statistics proving your process works I would say show me the statistics but we both know you do not have a process that good nor the statistics on what you do have.

Argument for the sake of argument.

The only thing that can screw this up is to drill the new flash hole grossly oversize. Visually obvious. Ignore it and load such a damaged case to full pressure and you're on your own, Harlow.

[Larry Gibson]

EDG

"I disagree. How on Earth is anyone going to be able to verify what is sloppy and what is not sloppy?"

Simple; If the drilled flash hole is not centered and/or the boxer SR primer is not a normal tight fit in the new pocket the conversion of that case was "sloppy".

"No one can be 100% sure of such a conversion not leaking a lot of gas back into some 100 year old action that does not handle gas well."

Ever notice the bolt face of most CF rifles? They all have pitting where there is always some gas leakage around the primers. Very prevalent in milsurps where lots of berdan primed ammunition has been shot. As to "lots" of gas....if care in selecting non sloppy conversions and eliminating the sloppy converted cases then there is no more "risk" than with unconverted cases. Can anyone really ever be 100% sure of the safety of firing factory or milsurp ammunition? Don't know about you but I never am because many things we do there is always accepted risk.

"What is loaded several times and what is top end loads - that is what was the pressure?"

Several times is 6 - 10 fireings. Top end loads were 46 gr IMR4895 in the 303 and 48 gr IMR4895 in the 7.62x54R. The actual measured average peak pressures (Oehler M43 PBL) for the Ross Mk X 303 was 43,200 psi. For the 7.62x54R in the Finn M39 the average peak psi was 44,100 psi.

If I use your process on 30-06 cases formed and used for loading a .25-06 at max pressure do you think your process would be OK? OK for how many reloads?

I'm sure most everyone here see's that is a stupid question intended simply to be argumentative. The discussion on this forum regarding the use of converted cases is/was intended for use with milsurp cartridges using cast bullet loads and their attendant lower and reduced pressures. I've only tested the full power jacketed loads to alleviate any "fears" of what may occur if such converted cases get mixed in for full power loads. I do not and did not ever recommend their use for full power loads. The use of such cases as you suggest is out of the realm of this discussion or even any serious consideration.

"If you are saying you have 6 Sigma statistics proving your process works I would say show me the statistics but we both know you do not have a process that good nor the statistics on what you do have."

Yeah right, sure thing.....I've shown the actual test results based on what is done by testing posted by everyone else. Additionally I have pressure tested. Perhaps you have some "6 sigma statistics" to prove such properly converted cases are dangerous?

[uscra112]

Well done, Larry.

[yeahbub]

I have used two slightly different methods to convert cases, depending on whether they were eastern bloc berdan or western berdan. The cases from the former soviet countries nearly all have a dimple in the bottom of the case, between the flash holes. This dimple is the center of the anvil and I use an “aircraft length” 5/64” drill bit (about 5” long, better/faster if they’re split tip) to reach down in there and drill into the dimple until the drill bit wants to catch and spin the case. The anvils are tapered and when the drill gets to where it starts to break out of the anvil and starts to catch and spin the case, set the case aside and do another. Once you’ve done the quantity you want to convert, decap them in the normal manner, as you would any boxer case. The hollowed and thinned anvil will break off and the old primer will be pushed out normally. The remainder of the anvil will have to be cleaned off, and for this I use a “primer pocket uniformer”, which is an end-cutting tool, not a primer pocket reamer. The end-cutting feature will also cut the pocket to the correct depth for boxer primers. To reduce the pocket diameter on cases with the 5.5mm pockets, which are .214-.216 in diameter, I use a long 5/16” punch sticking straight up and solidly supported. The case is slipped on over the punch so the bottom of the case is resting on the end of the punch and a center punch ground to a shallow angle, about 120 deg included or a 3/8” ball bearing is centered in the primer pocket and hit with a ballpeen hammer to displace metal into the hole to reduce its diameter. One good crack should do it, maybe two, to make the diameter just a bit too small. The diameter is then corrected with a primer pocket swage tool and diameter will be spot-on. The case is now ready for priming/loading. I converted a number of 8mm cases and 7.62x54R, both brass and steel, both of which were cautiously tested to full power book loads with repeated reloadings. No negative effects or leakage were noted, except for two steel 7.62x54R cases in which the material between the powder chamber and the primer pocket was thin and separated when being deprimed. I found that some steel cases tend to have little material for cutting the pocket to a uniform depth. I don’t bother with those anymore, but I still have some converted copper-washed steel cases which have lasted and show no signs of giving up. The 6.5mm primer pockets will need a bushing most easily made from ¼” soft copper tubing. The ID of the tubing is easily swaged with a primer pocket swage tool to accept a small rifle primer, but my experiences with SRP’s commonly resulted in click-bangs, so I used my large rifle sized uniformer to cut the pocket in the bushing to LRP size. It’s useful to epoxy or loc-tite the bushings in place, as once in a while one will “de-cap” with the spent primer.

For western berdan cases, there is no dimple in the bottom of the case, so they’ll have to be hydraulically or mechanically decapped. A flash hole drill bushing/anvil removal tool can be made from a 1”x ¼-20 set screw and a friction-lock nut. Make two, one for 5.5mm pockets, another for 6.5mm pockets. The set srcews need to be bored 5/64” through lengthwise. Screw the friction nut onto the set screw so the non-allen end of the screw sticks out .150-.170”. A ¼-20 set screw will fit right into a 6.5mm pocket, so it’s finished. For cases with 5.5mm pockets, the OD of the threaded end sticking out will have to be reduced to .210-.214 diameter. This can be done with a file while spinning it in a drill. It doesn’t take much. The 5/64” center bore will fit over the anvil and keep the drill centered in the pocket and on the anvil as you drill it away. The flat face of the nut pressed against the case head will keep it square. Once through to the inside of the case, the pocket diameter will have to be reduced and swaged to size as outlined above. Radway Green cases are very nice quality as are Austrian OJP. British, Greek or other .303 cases sometimes have odd size (6mm?) primers and may need a drill bushing for that size.

A note on the difference between boxer and berdan pockets. Boxer primers are held within an overall industry standardized height and the pockets to an appropriate depth to accommodate that height. Berdan case pocket depth seems not to be standardized and cases from various countries can be shallower or deeper, as the manufacturer prefers, as long as the primer is a few thousandths below the case head for safety. This seems to be related to anvil height relative to the case head. Some steel 7.62x54R cases seem to have shallow pockets and lack sufficient material to cut the pocket to .175” depth, leaving the remaining material unacceptably thin. Some Turkish 8x57 cases have very deep pockets and result in boxer conversions with primers so deep that the firing pin can’t reach them, some .020-.030 below the case head. For berdan priming, it seems the priming pellet thickness, the cup thickness and the anvil height must all agree to produce safe ammo and the precise pocket depth is of lesser importance. When seating berdan primers, they are to be seated to a safe depth a few thousandths below the case head whether or not they “bottom out”. With boxer priming, pocket depth is critical for proper function and we seat them by feel and when they bottom out, we stop. So, the thinking behind each system is a bit different in detail and practice. Which berdan cases convert well? Only experimentation can tell. Yugo 8mm is great stuff as are eastern bloc steel 8mm (Romanian?), and most brass cased 5.5mm primed 7.62x54R. Most 7.62x39 brass and steel also works well. Happy experimenting!

[uscra112]

What's the point of doing steel cases? Should not be reloaded anyway.

[country gent]

I did some 22-250, 243, and 308s sleeving them down to small rifle pockets to see if it improved accuracy and or consistency. I made a small sleeve that pressed into the pocket and just slightly under sized hole for primer. pressed these in with red locktite and let cure. Had a .002 Press into the pockets. When cured I then swagged them out to size with a dillon swagger. They sealed and worked fine. Accuracy did improve slightly in 22-250 and 243 but you had to be at 600 yds + to really see it.

what might be interesting to try would be to just remove the berdans anvil with a uniformed and sleeve pocket if needed using the existing flash holes. Would be a pain to deprime but ignition might be improved

[uscra112]

Years ago there was brass named .30 American, which was match-grade .30-30 with a small rifle primer pocket. Obviously enough somebodies thought the small rifle primer improved accuracy, and persuaded Federal to make a run of it.

[yeahbub]

What's the point of doing steel cases? Should not be reloaded anyway.

It was a proof of concept exercise, just to see if it could be done effectively. When deciding whether to convert brass or steel, I'll go for brass. If cases have been abused, dented, or weathered, the steel cases go in the scrap bucket.

I'm curious why you say steel shouldn't be reloaded. I have a number of converted cases which are steel, have been reloaded some 6-8 times and they show no signs of impending failure. The one down-side I noticed about reloading steel cases is being unable to duplicate the fine accuracy I get from brass cases in rifles that shoot accurately enough to show the difference. When Wolf boxer primed non-corrosive commercial steel-cased .223 became available, I examined the cases and found that neck thickness and runout was essentially identical to brass cases I was using. Even so, the loads favored by the rifle would not produce quite the accuracy I came to expect from brass. Even neck-sized cases previously fire-formed to that chamber and selected for concentric uniformity didn't match the accuracy of brass cases treated the same way. The accuracy was fine for plinking and less demanding hunting situations where losing them in the weeds is likely, but I'd use brass for a match I had money riding on. It's speculation, but I attribute this to differences in neck tension and/or adhesion of the bullet to the neck which takes place over time. The steel used in these cases is of a leaded alloy which can be deep-drawn and formed with an acceptably low rate of attrition. This precludes it ever having the springiness or resilience of brass.

I remember reading about that run of .30 American, though I have not seen any so far. There was a benchrest shooter I talked to on occasion who told me of having acquired some .308 brass which had small primer pockets also. In large cases of this sort, I’d expect load density would need to be high so the smaller, less energetic primer would provide reliably consistent ignition. My click-bang experiences with SRP converted 7.62x54R cases were with cast boolits not loaded to full capacity, which is probably the reason.