Berdan Primer Reloading Problem

[d'Artagnan]

I'm not new to reloading Berdan-primed cases. Previously, I've successfully reloaded the following Berdan primed cases:
1. 7.92x57:
German 1935 Polte
Czech 1950's clandestine (no headstamp)
Turkish 1950
Ecuadorian 1955
Yugoslav 1954 (Igman) and 1955 (Prvi Partizan)
Romanian 1973 and 2014 steel case
2. 30-06:
Iranian dated 44 (1344=1964-1965)
Belgian FN 57 and 58 (1957 and 1958)
3. 7x57:
Spanish FNT and PS from the early 1950's
Belgian FN 36 (1936)
4. plus Swiss 7.5x55 GP11 from the late 1970's and early 1980's.

But I'm having trouble with Iranian 7.92x57 dated 35 (1335=1956-1957), and I've got 1,000 of 'em. I found that out of 100 Iranian 7.92x57 factory loaded cartridges NONE of the primers would go off. The firing-pin-indented Berdan primers, however, come out easily with an RCBS Berdan depriming hand tool. When reprimed with Tula-brand 2011-vintage Berdan primers they still wouldn't go off. The anvils in FN primer pockets are 53 thousandths below the base; the anvils in Iranian 30-06 and 7.92x57, Ecuadorian, Romanian, and German primer pockets are 60 thousandths below, and the anvils in Spanish primer pockets are 65 thousandths below. When reprimed with the Tula primers seated from 4 thousandths (Belgian FN 36, 57 and 58) to 11 thousandths (Spanish FNT 1952) below the base, all BUT those seated in Iranian 7.92x57 cases go off. Has anybody encountered or, even better, overcome a similar problem?

 

[maxxhavoc]

For my own information, what is the Tula Part for 7.92 you are using? KV-7,62N?

 

[Swampman]

Which Tula Berdan primers are you using, the KV7.62N (NATO primer with silver compound) or the KV24N (7.62x39 primer with pink compound)?

I've loaded Iranian cases in both 7.92x57 and 30-06 with no problems using the Tula KV7.62N primers, but I honestly couldn't tell you the years the cases were produced.

I will say that all the Iranian cases that I've reloaded appeared to have fired normally with their original primers. I can't recall any that didn't have carbon residue in the cases and primer pockets when I got them.

If I were having your problem, I'd try seating the primers progressively deeper until I either got good ignition or crushed priming compound pellets.

I would suggest that you use hydraulic depriming when dealing with dud primers.
Just because they didn't go off when struck by the firing pin is no guarantee that they won't do so when you're piercing and prying them out.

 

[d'Artagnan]

Primers are Tula-brand KV-7.62N Large Rifle Primers. Lot number is 1-11, which equates to first lot of 2011. Primers actually made at Russia's Murom Apparatus Factory as were Wolf- and PMC-brand Berdan primers, as evidenced by the Murom registered trademark prominently displayed at the top left of the box.
The factory-seated primers in the Iranian 7.92x57 are rather deeply seated in the primer pockets -- but they didn't go off either.

 

[d'Artagnan]

Success. I won't bore you with the details, but the solution is to seat the primers deeper -- ridiculously deep -- into the primer pocket AND replace the 100-year old mainspring with a new 22-pound mainspring from Wolff Springs. Originally I was getting no ignition with the original mainspring and primers seated 4 thousandths deep. When I changed out the mainspring I was getting 2 rounds off for every 8 -- 25%. Terrible, yes, but better than 0 for 20 previously -- 0%. I also noted that the 2 that went off had more deeply seated primers than the rest. So I seated the other 12 even deeper and 6 of 12 went off -- 50%. Seating the next batch even deeper -- ridiculously deeper -- 10 for 10 went off -- 100%. As for accuracy, I just put the original amount of Iranian flake powder (44.4-gr) back in the case, sized the original bullet back too .323 (it was deformed when the Iranians put a HEAVY crimp on the case mouth) and seated it with a gentle crimp, and was pleasantly surprised with a tight 2-inch 10-shot group centered about 8 inches above where I was aiming at 50 yards. I would also comment that it kicked like a mule.

 

[d'Artagnan]

OK, I wasn't satisfied with just a qualitative answer (did it go boom), so I reran some tests to get quantitative answers (hard numbers).
1. I re-reloaded the 12 Iranian cases that previously wouldn't go off and 8 that did, neck sizing all. I measured the primer seating depth of all, which ranged from 2-10 thousandths. I also switched out the new 22# mainspring for a new 24# mainspring, using the 22# mainspring to replace the rather weak mainspring in my DWM Model 1908 (7x57mm Brazilian contract) Mauser, which was having the same fail-to-fire issues of the 1914 Oberndorf GeW-98. Anyway, the GeW-98 only fired one of the 12 that previously wouldn't go off, but ALL 8 that previously went off again went off -- no matter what depth the primers were seated.
2. I re-reran the test using 6 re-reloaded 1976/78 Romanian steel case rounds that previously wouldn't go off and 5 of the same that did. Same result, only 1 of the 6 went off, but all 5 that previously went off did so again.
3. I'd experienced this won't-fire-no-matter-what phenomenon with 22 1935 Polte (German) cases. Despite being reloaded three times, one case refused to go off. All the others did.
4. What I do not understand is how I could have choosen 12 of these won't-fire'no-matter-what cases out of my first 20 Iranian test cases. The second 20 cases ALL fired first and second reloads with the new mainsprings, as did 20 2014 Romanian steel case reloads.
5. Bottom line here is that primer seating depth didn't matter. A new mainspring did.
6. As for the DWM Model 1908 now with 22# mainspring, it successfully fired 12 of 13 F.N.T (Spanish) 1953 case re-reloads that previoulsly wouldn't go off using the admittedly weak original mainspring.
7. It should also be noted that both rifles fired all Boxer primed ammo I tried with their original mainsprings.

 

[Swampman]

I'm reaching here, but is it possible that the persistently misfiring cases have had their shoulders pushed back and are creating an excessive headspace situation?

Maybe enough headspace that the firing pin is shoving the cases forward in the chamber and not getting enough of a hit on the primer to set it off? Every time that happens the shoulder will tend to be pushed back a little more, making the problem worse.

Try loading a few of the non-firing cases with bullets seated out far enough that they get "jammed" into the rifling hard enough to hold the case head firmly against the bolt face. I recommend using cast bullets and a medium load of fairly fast burning powder like 2400.

Be careful if you unchamber any unfired rounds, you'll probably stick a bullet in the leade and if you don't get it out before chambering the next round, you could have a very bad day.