235gr 8mm Mauser Load

[am44mag]

I have a picky semi auto 8mm Mauser that does not like to cycle with cast. I have read the solution to this is a heavy boolit with slow powder. So, I bought one of those LEE 8mm KAR molds, and mine drops right at 235gr with a gas check. The slowest rifle powder I have is IMR 4350.

I cannot find data for anything over 220gr.

So, I did some looking and thinking. Let me know if I'm going about this wrong, I don't want to blow myself up after all.

Looking at two different weights of bullets (20gr apart. One is 150gr, the other 170gr), I noticed that the max charge for most powders tended to only decrease by 2gr or so when going up to the heavier bullet. IMR 4350 was one of these powders.

Would I be safe to assume that I could do the same thing for 220gr data for use with a 235gr bullet? The max charge for IMR 4350 with a 220gr bullet is 45.0gr. Would a max charge of 42-43gr be safe with a 235gr bullet? This is jacketed data btw. Reducing it by 10% might yield a decent starting load acceptable for cast. Around 37.5gr or so?

Sent from my SM-G965U using Tapatalk

[HangFireW8]

Is this a Hakim?

I had to resort to QuickLoad to get answers to my 8mm Karabiner load questions. I wanted to keep everything under 45K for a Small Ring Mauser.

Look for a PM.

[am44mag]

Yes sir, it is an Hakim. Even with that adjustable gas system I'm not having much luck. Hopefully this works. 45K would be just fine. I don't want to beat her up, just get her to cycle with something not jacketed.

[Peregrine]

What settings have you tried the gas system on? I got scared off trying to get a load working in my Hakims when I tested one with commercial jacketed ammo, both S&B and PPU to get a baseline before loading my own.

I started on the "off" (six o'clock) gas setting, and as expected it did not cycle the bolt, however oddly enough it did partially open the bolt about half an inch.
The rifle acted the same on the first gas setting, and when I tried it on the third with S&B it cycled but also blew out the primer.

I should have stopped there, but tried the PPU next and it again blew out the primer and disassembled the magazine all over the shooting bench.
I haven't seen it fit to experiment further, and have been meaning to pick y'alls brain about what could have happened.

Incidentally I also managed to badly damage an AG42b in a similar way, but with some handloads using 143 grain VLD-X and H4895. I had a primer blow out at load level that definitely should not have been sufficient to so so in the absence of any other factors.

Premature opening of the bolt leading to lack of case support?
That's my best theory but I was expecting to see the rim getting chewed up by the extractor, or other signs that the rifle was unhappy first before primers started to go.


The last anecdote I'll leave for you is that if you ever do get it to cycle reliably leave things be and don't go much higher at all. Things tend to get unexpected if you continue to work up, I had done a lot of reading and heard that warning but thought I knew better. I should have left well enough alone in the case of that m/42, I had a nicely working load in it but wanted a little bit more and all looked dandy.

I knew these rifles were tricky going in and heard all sorts of stories but I thought I had done enough reading (a lot!) about them and understood the system well enough to stay out of trouble. Clearly not.

[HBAR2989]

You may need a faster burning powder. 4350 is a no no in a gas gun like a Garand. Maybe the pressure at the port is too high due to the longer burn time of the powder.Just my 2 cents worth.

[Moonie]

Try H4895, it is designed to have large gas volume for gas driven semi's. My 8mm load with the Lee Karabiner was 35gr of H4895 for 1,850fps. This was in a bolt gun and I didn't have to worry about cycling however my experience with gas operated semi's with H4895 shows it cycles at lower loads than most other powders that are appropriate for the cartridges.

[8mmFan]

AM44Mag,

If you find a solution, would you mind posting it? I've got the Hakim also, but I haven't done much with it for about 8 years or so. Moved on to other things.

I never did try cast boolits with it. As I recall my thought at the time was that I was worried about Alox/leading getting into the gas tube. I did a lot of shooting with it at the time, but all with jacketed reloads or surplus ammo. I even pulled down a fair amount of Turk ammo (Turk being one of the big no-no's with the Hakim), reduced the powder charge, reloaded it, and ran it and the rifle shot very well with it and functioned fine.

I'd be interested in hearing from anyone who's successfully used a cast boolit in the Hakim.

Thanks for posting this thread. I'll be interested to see what comes of it. Sorry I can't be of much help.

8mmFan

[43PU]

My hakim likes 35 grn of imr3031 with that bullet , kicks the brass about 7-10 feet away

[Hardcast416taylor]

Awhile ago I asked a question here on the site for possible advice for cast loads for use in my German K & G 43 rifles. The feedback I got was leave them alone. After all parts for these rifles are about as easily found as chickens teeth.Robert

[am44mag]

Welp, I am DONE.

The gun didn't really like the Lee Karabiner. It's very rough on them and tended to shove them deeper into the case when feeding. When it did feed, it would cycle with 35gr of H4895 and spit the brass out pretty far. Not as far as jacketed rounds, but still far enough that I had to hunt for them. I also had a tiny little issue that resulted in the gun acting very strangely. The last round of the mag fed and I pulled the trigger. There was nothing. No tension, no click, and the trigger was loose. So I tried opening the action, and it was locked up like Fort Knox. So I kept the gun in a safe direction (pointed at the ground several feet in front of me) and started messing with the controls to see if I could get it to open. I jiggled the trigger a few times and BOOM. The gun went off, the brass went flying, I got covered in mud and dirt and grass, and I needed a change of pants...

I will say one thing about that bullet, it would be an excellent hunting round because the hole it left in the ground was huge. About the size of a football. I would also HIGHLY advise you not to use it in a semi auto like the Hakim. I think I'm done shooting for awhile. I might just designate that gun as a jacketed only gun. I MIGHT try my 175gr mold with H4895, but I don't know that it would cycle.

[HangFireW8]

I can imagine that Peregrine's Hakim incident might be from the autoloader seating the boolit deeper in the case, which can raise pressures quickly. Or just bad PPU ammo. By primers blown, was that removed entirely from the case, or a whole blown through the firing pin indent?

am44mag's loose trigger, I have no idea what failure modes exist in the Hakim that would lead to that (I don't have one, wish I had picked one up when they were cheap!)

BTW, QuickLoad says that 8mm+Karabiner, 35 grains of H4895 at 2.750" COAL is 30145 PSI.

[Peregrine]

Hangfire, they both had a hole blown through the primer and they were ratting around in the action when I found them.

I definitely do not think that the bullet could have been lodged too deeply in the case, but you may still be onto something. Reason being the Hakim had a bad tendency to chamber rounds so forcefully they end up lodged in the rifling, and upon attempting to extract a chambered round the brass comes out easily leaving the bullet firmly in place. In fact I had done that right at the start of my session that day when I attempted to check if it had fed correctly from the magazine, I had to tap it out with a rod before I could resume.

The m/42 does the same thing.

Maybe that could still be the problem though, the bullet being lodged in the rifling instead of being held by neck tension? It certainly wasn't crammed right in as it came out with a light tap, but given how easily the brass extracted it definitely wasn't being positively retained by neck tension.

How can that effect internal ballistics?

[HangFireW8]

Primer still in brass with a hole in it means 2 things,

1) the bolt was locked up. As you know from decapping it is not hard to remove primers, even crimped military primers will become a projectile if not supported by the bolt.

2) too high pressures.

If the bullet is snug on the rifling it can drive up pressures compared to a jump when it has some momentum. But usually that alone will not cause blown primers.

What can really blow primers is if the case mouth crimps in the end of the chamber step. Then the case cannot release the bullet and pressures go sky high.

To test this load some dummies and put them in the magazine to chamber after a live round is fired. Measure cartridge shoulder headspace before and after it is slammed into the chamber. If it goes back significantly that is most likely the problem.