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Posted: 2/4/2014 7:50:19 AM EDT
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I am building a 5.45 AR and have a 1:8" twist four groove barrel on the way. I'm very unfamiliar with 5.45 rounds.
I'm seeing a wide variety of rounds available - everything from 53 grain milsurp to 69 grain Wolf. What 5.45 rounds won't stabilize in my 1:8" four groove barrel? Mods- if this needs to be in the ammo section please move and I apologize for posting in the wrong section. |
| The surplus ammunition, designated as 7n6 will be your best bet. There is a current mix of Bulgarian, Ukrain, Soviet, Polish, Romanian and East German in the country, most common being Bulgarian. It uses a corrosive primer compound, thorough cleaning will be essential but is not flesh eating acid like some jack asses make it out to be. The projectiles use a steel core, but it is not armor piercing. The purpose of the core is to destabilize the projectile once it contacts tissue, this effect solely earned the 5.45x39 a "poison bullet" title. Steer clear of heavier bullets, not due to the weight itself, but the repurposed jackets originally formed for tracer rounds produce very unstable flights when solid led cored. |
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I did extensive testing with every type of milsurp and wolf. The milsurp was 2.5-3-5 moa and the wolf was actually a little better, 2 - 2.5 moa. (Don't know it it was 69 grn)
1/8 twist should be able to stabilize it. Buy some and check. Its the only way to be sure. |
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Quoted:
The surplus ammunition, designated as 7n6 will be your best bet. There is a current mix of Bulgarian, Ukrain, Soviet, Polish, Romanian and East German in the country, most common being Bulgarian. It uses a corrosive primer compound, thorough cleaning will be essential but is not flesh eating acid like some jack asses make it out to be. The projectiles use a steel core, but it is not armor piercing. The purpose of the core is to destabilize the projectile once it contacts tissue, this effect solely earned the 5.45x39 a "poison bullet" title. Steer clear of heavier bullets, not due to the weight itself, but the repurposed jackets originally formed for tracer rounds produce very unstable flights when solid led cored. Thanks. Is there a weight you would say is "no greater than"? Would the 69 gr Wolf be good to shoot? |
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Quoted:
I did extensive testing with every type of milsurp and wolf. The milsurp was 2.5-3-5 moa and the wolf was actually a little better, 2 - 2.5 moa. (Don't know it it was 69 grn) 1/8 twist should be able to stabilize it. Buy some and check. Its the only way to be sure. Thanks as well. I plan to buy milsurp by the spam can and didn't want to be stuck with slightly less than 1080 rounds of 5.45 because the 1/8 wouldn't stabilize the round. It is more efficient to buy, shoot and check if the commercial 69 gr would keyhole or not since I could buy Wolf/Tula/Brown Bear in smaller quantities. |
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The whole reason for building a 5.45 AR is to take advantage of the inexpensive surplus (7n6) ammo...that aside (because I guess someday it will run out) 1:8 should be OK for even the longer (and therefore heavier) projectiles. Standard twist rate for 5.45 is 1:7.5, except in AKSUs where it is 1:6.3 due to their shorter barrels.
At worst, you may not fully stabilize the longer 69-70gr pills. |
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10-15 years ago I bought 7 crates of the Russian 7N6 ammo plus a couple cases of the 60 and some 70gr 5.45 that really shot great. My AK74s preferred the heavier stuff, so I shot it all first. Then along came my 2 - 5.45 AR rifles. I have shot 9 cans so far and love it, but this last can has produced a few problem rounds. I never had any FTF/FTE till this last can, seems the primers are harder and a few cases are oversized. Still not bad for practice ammo and a training weapon.
A previous post said to stay away from the heavier stuff, but my experience was different (in my ak74s)- I wish I could find some more of the 70 gr stuff again to try in my 5.45 ARs. I have seen some of the newer 69gr stuff available that I intend on trying, will order a few hundred rounds in case it is what he warned against. If I remember right, the 70gr ammo was Silver Bear, has been 10-15 years since I had it. The weakest link on these used to be finding good, reliable mags, but this is no longer an issue. My luck has gone great using the Gen2 windowed p-mags with the slightly modified followers, this is my preferred magazine any more since I hated the cheap feeling C-p and ASC mags (even tho mine fed reliably). Everyone loves shooting my 5.45 ARs, they are a blast to shoot. I like the 7N6 ammo just fine even tho it is corrosive- no biggy. Just wash the salts away and relube. Buy as much ammo you can afford while it is still relatively cheap- who knows how long it will be available at todays prices (is still 50% higher than before). YMMV but I love shooting 5.45 rifles... 
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