Yip, about 1800 ft/sec seems to be the upper velocity limit of lead / PC bullets.
This is the velocity I get from my 357 Magnum rounds when firing out of my Rossi Puma lever action rifle.

Nice write-up. The couple of Russian AKMs that I have fondles over the years really impressed in terms of their fit and finish.

Quote from: Krazong on May 08, 2024, 01:39 PMMy "shake and bake" method did not go as planned.  I can coat them and load the bullets, fire them in my 9mmP and 762x39, but about 2/3 of them will keyhole over 10m range and will loose all accuracy.

I'm back to using plain old lubed cast lead in my 9mmP and 38Spl.  Velocities in my 357 Mag dictates a copper jacketed or plated bullet.

Interesting. I shake and bake and have had unchecked bullets up to 1800fps with no leading and no keyholing. If they are sized appropriately I can't think why PC bullets would be more inclined to tumbling than traditionally lubed.

I did find that a change from MS200 to S121 caused me some tumbling on 9mmP pellets but I resolved that by bumping the charge a bit.

Setting up the sizing die according to the above procedure eliminated the cracked cases I got from my 7x57mm and increased accuracy.

My "shake and bake" method did not go as planned.  I can coat them and load the bullets, fire them in my 9mmP and 762x39, but about 2/3 of them will keyhole over 10m range and will loose all accuracy.

I'm back to using plain old lubed cast lead in my 9mmP and 38Spl.  Velocities in my 357 Mag dictates a copper jacketed or plated bullet.

Looking at the 7x57mm Mauser, it never really went out of production, but it did stop becoming a military cartridge back in the early 1900's when it was replaced by the 8mm Mauser.

It is still a very popular cartridge even today.

Good day all.

This will be a side by side comparison of most of the obvious differences between the Norinco  Type 56 (Chinese copy of the AKM) and Russian manufactured AKM.  I know everybody refers to these rifles as the AK47, but this is not entirely accurate.  The original AK47 had a milled receiver which was replaced by a stamped receiver in 1959.
Multiple versions of these were manufactured.  The two examples I used for this comparison are both fixed stock variants.  The Chinese Type 56 was manufactured in factory 313 in China and has a fixed under barrel folding bayonet. The Russian variant was manufactured in the Izhevsk factory as identified by an arrow inside a triangle engraved on the receiver.

I am also not going to go into detail about the trigger group of the two, as the Type 56 in my possession is not a military variant which a select fire capability, but is the export, semi auto only variant. The Russian AKM is a full military variant, with almost all the goodies fitted to the trigger group for select fire capability. It does have a semi-auto only disconnector fitted, making it legal for me to own here in sunny  South Africa.  It would not be fair to compare the trigger group between these two.  If anyone want details on the Russian trigger group, please let me know.  Mine is still fitted with the fire rate retarder as well as the secondary sear on the hammer which is triggered when the bolt goes into battery.

Basic operation of the two are the same, but a lot more machining marks can be found on the Type 56 as opposed to the Russian AKM.  The fit, finishing and polishing is a lot better on the Russian AKM as can be seen in the photos.

Below is s picture of the two rifles, side by side.  Russian one is on the top.


An easy way to identify the Chinese variant is by looking at the front sight post.  The Chinese one is fully enclosed while the Russian one protected by two "half moons"


The gas tube also differs in that the Chinese tube will vent excess gas to the sides (notice the holes) while the Russian one vents it's gas from the front where the tube makes contact with the gas block.


The rear sight on the Russian AKM is graded up to 1000m while the Type 56 is only graded to 800m.  The rear sight on the Russian AKM seems to be a bit thicker where the slit for the rear sight is cut.


The receiver cover on the Russian AKM has some textured spots punched into it making it less likely to flex than that of the Type 56.


A Close-up of the markings on the Type 56.  This one was manufactured in Factory 313 and is the fixed stock, 56S variant.


A close-up of the Russian AKM.  This one was manufactured in the Izhevsk factory in 1960, as indicated by the arrow inside the triangle.  Also notice that the stock, bolt and lots of other parts have the last four numbers of the serial number stamped into it.


Magazines also differ slightly from each other.  Notice the extra rib on the outside of the Russian magazine.  It's difficult to spot, but the Russian magazine also has a triangle with a little arrow inside it, similar to the stamp on the receiver.


The magazine release lever also differs slightly from each other, the the Chinese variant having a more rounded appearance than the plain Russian one.
Chinese Type 56


Russian AKM


As stated before, my Type 56 was never capable of being select fire.  This is evident when looking at the selector on the T56.  It has only two positions, as opposed to the three of the AKM.  Interesting that the F position on the T56 is actually the "Full Auto" position.  It has obviously been built without the select fire capability.  Looking at the Russian AK, the AB would be the full auto setting, and the oA would be semi-auto.




A close-up photo of the lever used to remove the gas tube.  Notice the circular machine markings on the T56.



A close-up of the front sight post as well as the gas block.
Notice the smoothness of the Russian AKM as opposed to the T56.  The gas vents can also clearly be seen on the AKM.  Unfortunately my AKM did not come with a slanted muzzle brake.  It came instead with just a thread protector.  My T56 is not threaded at all at the muzzle end.



The bolt of the AKM and the T56. 
Notice that the  AKM is painted black while the T56 is left "in the raw"
The bolt on the AKM also has a lightening cut.  Both have free floating firing pins.



I know there are a lot of factories in China manufacturing the T56 and they might not not all be identical to this T56.  Overall both are great!  Both function and cycle 7.62x39 ammo reliably but the overall build quality on the AKM is much better than the T56.

Quote from: janfred on May 08, 2024, 11:34 AMSet your die up according to the following procedure.

https://www.gscustomusa.com/faqsizerdie.html

Not only will your headspace problems disappear, your cases will last longer as well and you will still have reliable hunting ammo.

Thanks, will do.

Set your die up according to the following procedure.

https://www.gscustomusa.com/faqsizerdie.html

Not only will your headspace problems disappear, your cases will last longer as well and you will still have reliable hunting ammo.

Quote from: janfred on May 07, 2024, 11:34 AMDs J

Please describe how you set your sizing die before sizing your cases for this specific rifle and batch of cases.

Good evening Folks, work keeps me from chatting here, and it will be the same for the next few weeks.

In short: I read and follow the manual to the letter. It is for a RCBS full length sizing die in a Rockchucker.

If memory serves correct, the procedure is to screw the die down untill it touches the shell holder. Then there is something about screwing it out, or back, two turns, and then to lock the nut.