Reloading For AG-42b-Safe Powders?

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Lahti

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Hello,

I followed lee load data for 6.5x55 mm with 129 and 140 grain projectiles and H4895 powder, staying on the lighter end of the listed loads. When I fired, the primers popped out on 2 of the rounds, and 3 of the cases were tight in the chamber and hard to extract. This was with ppu brass that had been fired once before, so it wasn’t loose primer pockets. I risked putting a few of these rounds through a Swedish Mauser and had no signs of pressure or other issues.

Based on this, I’m assuming that it was a poor choice of powder for that action, causing the bolt to open before the pressure had dropped. Does anyone know what powder is recommended or safe for this rifle? PPU 6.5x55 seems to work fine, does anyone know what powder they use for this cartridge?

Thank you for your time.
 
Thank you for the feedback. Is that for 6.5x55 generally or for AG-42’s specifically? I was using 33.5 grains of H4895. I know IMR4895 is not identical but do they not have similar burn rates? I could of course be wrong about what the issue is, but my assumption was that the pressure curve of the powder I was using was wrong for where the gas port is on this rifle so it opened when there was too much pressure, so I would need a different type of powder.

Thanks
 
You need be more concerned about mil-spec primers to prevent slam firing with the bolt still semi-open.It will make a mess.
 
^^^^^CCI #34 primers

Also get a copy of a Sierra 5th Edition reloading manual and read the Gas Gun Reloading section (page 165), then ask questions here.
 
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Hello,

Thank you for suggesting the sierra manual, I will pick up a copy. I have been using CCI #34 primers for all semi auto loads, and haven’t had any issues in any other rifle to date (garand, svt, Johnson, g43) following minimum published load data and checking what powders were suitable. This is the only time that hasn’t worked out for me, so my assumption was that I needed a different powder to get the correct port pressure for this rifle to fire safely. I will read the Sierra manual and hopefully get some more insights on which ones are suitable here, but will happily take any suggestions. If 4895 powders are commonly used with this gun, there may be some mechanical issue I have yet to discover with it.

Thanks,
 
4895 is a good choice of powder.

A popped out primer might mean the load was too mild, or that the case was sized to a short headspace.

Are you sure about the powder charge weight? 33 is a bit mild.
 
Hello,

The Lee loaf data that came with my reloading dies had a range of 33-36.3 grains of H4895 for a 129 grain bullet (Hornady), and 32.5-35.8 grains for a 140 grain bullet. My thoughts were that I would load light and then if it wouldn’t cycle, add to the charge until it would. Even at this low level the rifle cycled fine, save for the 2 rounds that blew primers and the others that were tight in the chamber. The load data for IMR 4895 is 35 to 39 grains, higher than the Hogdon powder. I can see the primers popping out due to the load being too light, but would the difficulty extracting be expected as well? I had thought that was from the extractor pulling the case out before the pressure had dropped. The headspace is a possibility, I do not have any specific gauge to check this and simply use calipers.

It seems that IMR 4895 is the recommended powder for this, and that I might have better luck working up from it’s starting load for this rifle, and not using H4895? Are their burn rates substantially different, or am I completely off base to be looking at the burn rate as the potential cause of the problem?

I appreciate all of the input!

Thanks,
 
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Doug Bowser's book recommends these powders for the AG42B: IMR 3031, IMR 4064, H335, WW748, IMR 4895, BLC-2, AA2460 and AA2520. He had the best accuracy with 140 gr bullet Max OAL 3.15", min OAL 3.025". IMR 4895 35.9 Gr. Also does not recommend powders slower than IMR 4064 in Ljungman rifles. He does recommend CCI primers since they are harder than other makes.
 
Lahti, the Ag 42B can be very finicky to load for and has a very narrow operating range.

It likes to be loaded close to the higher end of it's pressure recommendations in most manuals.

Ganderite likely hit the problem right when suggesting "mild loads" may be your issue.

They were designed to work in the same pressure range as the standard issue 6.5x55 issued ammo. I believe they were intended to shoot the 140 grn SBT bullets but they also chambered and shot the 160 grain round nose as well.

These rifles had issues with firing pin protrusion and losing extractor assemblies. when they were first sold off as surplus, they came with a small tin of extractor assembly parts, firing pins with springs and a gauge to check protrusion. If the firing pin protrudes to far, it doesn't matter which primers you're using, an out of battery KaBoom could happen. Heed mbogo's advice closely. It could save your rifle or a body part.

These were very early semi auto military firearms. Extremely well made and functional but not all of the Gremlins were sorted out before being issued.

The original powder used by the Swedes was closer to N133 or 3031 in burn rate than 4895. This would give it a faster but slightly shorter pressure curve.

3031 or 4895 would be acceptable alternatives IMHO.

Try this site for almost any questions you have on your rifle and the loads it likes

Swedish Military Firearms Forum
 
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I got my first AG 42 around 1973 from Robinson's in Victoria.

Bearhunter is correct about the issues. I and two fiends got these rifles at the same time, and all would intermittently pop primers in the then available surplus ammo. They were a reloading nightmare, very hard on brass. Through the following years much was written detailing the AG 42's history. Some said that the Swedish military had trouble getting them to work properly given the expectation of using ammo common to bolt guns and (possibly) full autos as well. The last possibility comes as internet speculation. I know nothing first hand of what Sweden used. There were threads suggesting that the Swedish military advised lubing the brass, which led to further discussions of bolt thrust and on to the reasoning behind fluted chambers. I have never read any comments by a Swedish soldier.

There were some interesting experiments done by a guy in Oregon using an adjustable gas block. Unfortunately, this was internet talk and his posts seemed to disappear from the net about 15 yeas ago.

Over the years a half dozen AG 42s have passed through my hands; they are somewhat left friendly. I sold the last one about 3 years ago. Unfortunately a basement flood in 2014 turned my notes into chaos. Many of my old log books were ruined. I have no recipes left; I do remember settling on IMR 3031 with 140 grain bullets. I do not recall any of mine needing small base sizer dies, but be careful about overzealous resizing. Do not push the shoulders back and create excessive headspace issues.

Unfortunately the whole 6.5 x 55 scene is a mess due to the North American fixation on .473 brass case heads. I have found brass everywhere from .471 to .479 over the years. These bolt faces and extractors are designed to use the proper .476-.478 rim. With the extraction violence in an AG 42 you want to be very careful with chamber cleanliness and surface condition. As direct impingements go, they do not get much more direct than these guns; your whole face is right there.

i will also go back and correct my earlier post. Not all Sierra manuals have the gas gun section. My old 2nd edition does not have it. The Sierra 5th edition, and presumably later editions, contain the good info. Stay safe and be thinking with these rifles.
 
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My pet load for my AG42B is : 140 grain interlock, Win large rifle primer, 36.0 grains of IMR4895, cases are Federal or Igman and the OAL is 3.031. Perfect for me, without any issues.
 
They will if you try to single load them without putting the safety on.
Loading with chargers/stripper clips and a magazine in the gun can be done without turning the safety on.
There is an excellent video about this on UT.
 
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Hello,

Thank you all for the feedback, I will load up some IMR 4895, 140 grain projectiles with CCI #34 primers and give it a try when my local range reopens! I was surprised to learn that some of the issues I ran into that I thought were overpressure issues could have been due to light loads, that is good to know for the future. I’m assuming that the bullet weight is also important for this design, and that straying below 140 grains is not wise? As for the brass case head, any brands to steer clear of? PPU is my go to as it is available in every caliber I’ve needed.

As for the action, it is definitely the most unique rifle to reload that I’ve had the fortune of owning, it’s a shame they aren’t more common.

Thanks
 
mbogo3 said:
Curious.........did the 8mm Hakim have the same issues with ammo?
Click to expand...

Yes, maybe worse. Very ammo fussy. The fitting wasn't nearly as tight as the Swede built rifles. Still very functional though and intended for completely different conditions of use, for troops with minimal training.

The Hakim I had was disposed of purposely because of it's function issues with different ammo.

That being said, they did seem to have fixed the firing pin breakage issues. Failure to extract some types of ammo was its biggest issue for me. Maybe my rifle was a one off???
 
I load with 36.5gr IMR 4064 behind a 140gr HPBT for my ag42 with no issues in Nosler brass. This is 1gr less than the max load listed in my Lyman book for 6.5x55 Swede. In the same book it lists 32.5-36.5 IMR 4895 so you are on the low end and I’d like to agree with Ganderite twice in saying you may have a slight excessive headspace condition if you are poping primers (do you have a neck sizer die to try and see if the issue decreases?) Friend had an Enfield on the large size of headspace that liked to protrude primers a bit. I have heard of low pressure rounds causing primer protrusion because not enough pressure to drive the primer against the bolt face. That said I wouldn’t expect low pressure round to be hard to extract. In regards, PPU I would assume their brass is good, the plus side being the gun is European and so it the brass so they likely used both followed CIP whereas sometimes CIP rifles and Saami brass can cause issues.
 
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