4TheResistance
Member
I was working on some load data and was wondering how much pressure is needed to cycle a hungarian AK47 and I can't find the info for any make of AK's.:banghead:
how much pressure needed to cycle AK47
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Maverick223
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I don't think any two would be the same, but about 30-35kPSI (I'd speculate that it will probably end up on the high end of that range) would be a decent start IMO. Projectile weight will also make a difference, use a heavy projectile to help it cycle at lower pressure.
4TheResistance
Member
I'm using a 155gr. lead bullet and I was hoping to hear something like 16-18 k to keep it under 1400 fps
Maverick223
Member
I seriously doubt that it will be below 25kPSI (at least not out of an AK), but the moderately heavy bullet will help a bit. You may want to try +/-180gr. bullets instead. Keep in mind I am just speculating (a semi-educated guess), so you may be alright, just be careful when using reduced charges. They can result in detonation, rather than a clean burn. Very light charges should use a case filler to ensure that this does not occur.
Good luck with your project.
Good luck with your project.
Maverick223
Member
Found a couple of threads (here and elsewhere) that may help you in your endeavor:
Subsonic 7.62x39mm
Subsonic AK
Subsonic 7.62x39mm
Subsonic AK
4TheResistance
Member
I'm interested in doing some subsonic rounds but probably not for a while, I was trying to save some money on gaschecks and more expensive rifle powder by keeping it under 1400 fps, I'm using accurate 2400 (which is in bulk locally) as suggested by C.E. Harris (posted by vacek) here.
http://castboolits.gunloads.com/showthread.php?t=11518
http://castboolits.gunloads.com/showthread.php?t=11518
Maverick223
Member
They might still offer a bit of useful information, and if they can get a subsonic to cycle, you can get a load going 1.4k to cycle.
4TheResistance
Member
Ya I guess thats true. Do you think I stand a chance of blowing up with 2400. It fills the case just over half way? If I double charge it the case is overflowing a little. I always like to do a double charge just to see what it looks like in the case so I can tell if I do it on accident.
4TheResistance
Member
Also I read on one of those links somebody said to remove the guide rod when using fast burning powders so it dosen't get bent, that just dosen't make sense to me because I read that milspec cases are loaded to atround 50K to ensure the weapon will cycle. I'm probably missing something.
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Maverick223
Member
I can't say, I have never tried it, you may want to try RL No. 7 instead because it has a similar burn rate and seems to work well with light charges...but I think you will burn more powder in the process. I would proceed with extreme caution and seek help from some competent reloaders that have experience with such projects (whom I am not counted amongst). You may want to ask a mod. to move your thread to the reloading forum for a few additional responses from folks more knowledgeable and more experienced than I.
I have never heard of such an occurrence, but it is plausible that you could damage the rifle, by using a fast burning load or one with very heavy bullets. Garands have proven that proper loading can be very important for safe, reliable operation (can bend op. rods with heavy loads).
4TheResistance
Member
I don't really want to modify the rifle at all. I was just courious but I have 4 different loads of 5 rounds a piece with bl-c2 rangeing from 15005 psi to 18721 psi. I worked them up tonight an will hit the range tomorrow to see how well they perform.
4TheResistance
Member
Well if LEE is correct my load of 18.5 gr. of bl-c2 (-11gr. from the max load) is moving at about 1383 FPS with 16154 PSI. It seemed to shoot great, had one fail to feed all the way so I'm going to give her a good cleaning and do another 20 rounds of that load and see.
Maverick223
Member
Glad it worked well for you. If you continue to have feeding problems, try adding a half grain or so...often times a little can go a long way.
4TheResistance
Member
will do thanks
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