7.62x39 and repurposed CETME surplus powder

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bearhunter

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I had a complete right shoulder replacement at the end of April. It was or seems to be a complete success. Still I have been warned to forgo shooting for a while yet, other than very low recoil firearms.

That's OK, I can live with that for a while anyway.

I picked up a very nice little Howa 1500 chambered in 7.62x39 on a mini action. In reality it's just a short action with everything else being the same as its big brother.

OK, time to work up a decent load in a very strong action.

All of the loads listed in the manuals are safe for the SKS and AK style rifles. The Ruger Mini is much stronger as are most of the bolt action rifles out there, soooooo why not use a fast powder to get the pressures up as well as the velocities???

I have several pounds of powder that came with several thousand 112 gr bullets pulled from Spanish CETME cartridges. The primers were failing and the people at SFRC, a banner sponsor, offered me the powder when I purchased all of the pulled bullets they had in stock. It was very cheap and looked like it might be interesting for such cases as the 7.62x39 and maybe in smokeless loads for black powder cartridges.

It's a bulky powder and looks like IMR4227 but it's faster burning.

SFRC was good enough to send a few boxes of loaded ammo so that I could weigh the charges and bullets to get a perspective of what to expect. Each case averaged 28.5 grains of this powder and was filled to the base of the bullets with a bit of compression.

With this as a guideline and the bullet diameters being similar albeit a lighter bullet, a similar load density should work well with the Hornady 123grn x .310 diameter IL bullet. I filled several of the cases to the top of the shoulder with the surplus powder and weighed the charges and took an average. 18.5 grains.

So I loaded up one cartridge with 18.5 grains over CCI 250 primer, under a 123 IL bullet. Off to the farm to give it a whirl from a rest from which I could fire the rifle without holding it and from about ten feet away. Well, it went bang. The case extracted easily with the primer slightly flattened but no other signs of pressure. This looked pretty promising to me.

Five more cartridges were assembled and taken to our range, which just opened yesterday after a day of welcome rain. I wanted to check out recoil. Thankfully it was very light. Not only that the rifle seemed to like the load. I suspect and hope the bullet is travelling over 2550fps. The next batch will be checked over a magnetospeed and the rifle sighted in for accuracy. Hopefully it will group well enough for shots out to 250 yards.

If not, then it's either a 243Win or a 257 Roberts for the rest of the hunting season.
 
Interesting, thanks for posting this. Also, I hope your shoulder replacement heals up nicely. Let us know what the magnetospeed ends up reading, seems like a nice plan over the 243 to me. I'm sure you're shoulder will let you know soon enough. Good luck!
 
This is where a Chronograph is a must.

If you get anywhere near 2500 fps with a 123 gr bullet over 18.5 grs of powder in the 7.62X39, you're looking at pressures well above 50K psi - too much for an SKS, but ok in the Howa?

That said, I'm willing to bet in comes in at 2000 fps +/-.
 
Andy said:
This is where a Chronograph is a must.

If you get anywhere near 2500 fps with a 123 gr bullet over 18.5 grs of powder in the 7.62X39, you're looking at pressures well above 50K psi - too much for an SKS, but ok in the Howa?

That said, I'm willing to bet in comes in at 2000 fps +/-.
Click to expand...

Andy, I would agree with your valued assessment if I were shooting this ammo in an SKS. I'm not. The rifle it will be fed to is a HOWA 1500. This rifle is rated right up there with the strongest actions available.

My pressures very likely are over 50K and that's OK as extraction is effortless.

Yes I'm being optimistic about velocity. I can always hope.

Other powders listed in the Lyman manual give 2400fps at SKS safe pressures. This powder will hopefully give me better results. If not, back to experimenting.

The powder I'm using is fast but should be appropriate for the task. The magnetospeed will help deduce where I'm at velocity wise and will give some indication of pressures. I haven't had any success on the internet to find anything pertinent to this powder.
 
Bearhunter, I went down this road with a couple of 7.62x39 A CZ and Zastava. Yes you are right about the actions being able to take more pressure. I did not have the powder that you are using but tried a few other fast powders. I also used Privi brass with the LR pocket and Rem brass with the small rifle primer. Both brass had very close to the same powder capacity. I doubt if you can get more than 50k with the large rocket. It is a small diameter case and there is not much metal around the large primer so I was getting case head expansion a lot earlier than with the Rem brass. I was able to exceed 2600 with the 123 although I preferred the Sierra .311 125 gr bullets. All the 123 I found were very explosive at 2600. I personally would stay away from 4227. Years ago a gun nut from London who did a lot of varmint shooting with wildcats told me that 4227 is very pressure sensitive and produces pressure spikes a lot earlier than other powders. This was well over 50 years ago and we were discussing the 222R at the time. I had the best results in my testing with IMR4198 and AA 1680. With the small rifle primers I could fill the case up with 4198 and have no indication of pressures. 2 grains less in the Privi cases resulted in a stiff bolt lift. That is why I went to 1680.
At 2600 I had excellent brass life and good accuracy. This is just what I found.
Neil
 
Neilm said:
Bearhunter, I went down this road with a couple of 7.62x39 A CZ and Zastava. Yes you are right about the actions being able to take more pressure. I did not have the powder that you are using but tried a few other fast powders. I also used Privi brass with the LR pocket and Rem brass with the small rifle primer. Both brass had very close to the same powder capacity. I doubt if you can get more than 50k with the large rocket. It is a small diameter case and there is not much metal around the large primer so I was getting case head expansion a lot earlier than with the Rem brass. I was able to exceed 2600 with the 123 although I preferred the Sierra .311 125 gr bullets. All the 123 I found were very explosive at 2600. I personally would stay away from 4227. Years ago a gun nut from London who did a lot of varmint shooting with wildcats told me that 4227 is very pressure sensitive and produces pressure spikes a lot earlier than other powders. This was well over 50 years ago and we were discussing the 222R at the time. I had the best results in my testing with IMR4198 and AA 1680. With the small rifle primers I could fill the case up with 4198 and have no indication of pressures. 2 grains less in the Privi cases resulted in a stiff bolt lift. That is why I went to 1680.
At 2600 I had excellent brass life and good accuracy. This is just what I found.
Neil
Click to expand...

This is very interesting and thanks for the information. I just might have to look for some small primer hole brass again. I tried once before and there was none to be had in Canada.

I don't have any 1680 on hand and will have get some to go the route you advise.

The surplus powder I do have on hand only resembles imr4227 in appearance. It is much denser. I weighed a Lee scoop of the surplus powder to compare it to imr4227 and it is about 25% denser by volume.

Just to update my experiment the original load of 18.5 grns generated velocities from 2180-2205fps. I was hoping for more but there weren't any pressure signs at all. I have added more powder in half grain increments until I have reached 21.5 grns of the surplus powder in the case and velocities are also increasing. Hopefully I can get to the range on Thursday to test his load for velocity and accuracy.

My wife is married to a cheap beastard. I would really like to use this powder. I suspect it would also be OK for cartridges like the 45-70, 577-450 and 43 Spanish to duplicate black powder loads with a smokeless powder. My shoulder won't be good enough for this until after the New Year. Also, this powder doesn't seem to be as temp sensitive as imr4227.

If I can't get what I need out of this powder I will work along your trail. I agree, pushing the available bullets to fast may not yield the best result on game but it may increase my useable range to 200+ yards.
 
Try Rayner'shine for the Aa1680. He used to carry Rem brass but I'm not sure about that. I went the route of buying the UMC (rem) ammo a case for a supply of brass. At that time it was easier than finding brass alone and not much more costly. Good luck. It works well on both species of deer but does not seem to kill as quickly as a higher velocity round. I found that I had no DRT but usually a 10 yd or so followup yo a dead deer.
 
Thanks for the input guys. I honestly appreciate it.

I can't get to the range right now because my old 93 Dodge is at the doctor getting a transfer case bearing replaced. Didn't use it enough, sooooo.

John, I hope the 2500 fps can be achieved without signs of pressure. It would solve the problem of what to do with the powder per se. I am not a plinker so unlikely to use even the 30-30 for such purposes. I am not a lever fan either so the only 30-30 I have is an old Savage Model 340 which is very accurate with light bullets from 125-150 grains. It's strong and can be loaded to what the brass will take with a much better bullet selection. It shoots Spitzers and SPBD bullets much better than it does round nose bullets.
 
Both and also to see how this stuff works with small cases. I have high hopes for this stuff on large, blackpowder cases with light bullets as well as intermediate cartridges. It's faster than I thought at first and reaches high pressures quickly once its saturation point has been reached.
 
Sorry for taking so long to get back with results of this experiment with surplus CETME powder under 125grn bullets

After carefully working up the load until I started to get case head expansion the top velocity I could get was 2350 fps. Not enough for my purposes. Still, the little Howa shot this under 1 moa over 25 shots on target.

It's definitely to hot for an SKS IMHO. As Ganderite mentions, it might be great in a 30-30 with cast bullets.

I tried heavier bullets, 130 and 150 grains. Pressures went up dramatically. This powder is just to fast for heavier bullets. I will however find an alternate use for it eventually.

Now to work with some different powders. Will experiment with some of those mentioned but I don't have any on hand soooooooooooooo.
 
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