Thread: Range Report – IMR 4227 behind 55g SPBT in my Oly AR 15.

I lied, I must be a compulsive experimenter.

I told you all that the IMR 4227 experiment was over and I just loaded 10 cases with 16.5g of IMR 4227 and 10 more with 16.9g (17 is max).

I got to see it through. I had always planned to stop just below 17.0g and because 16.0g cycled the AR half the time, I just got to see if 16.5 or 16.9 will cycle it all the time.

I'm going to my hunting property Saturday and finish this thing I started with the IMR 4227.

Please pardon my lying to you all.
Hack

Well, I’m done with this thread. I loaded and chronied 16.5g and 16.9g (17 was max) of IMR 4227 just to see it I could get the action of the AR 15 to cycle reliably.

Result – Neither load made the AR bolt’s cycle reliably.

The 16.5gr reload had an average velocity of 2534.33 fps . The velocity is the result of just 4 rounds (after it didn’t cycle twice, I stopped shooting, to save bullets and 4227 powder). The deviation above and below average was 31.67 fps.

The 16.9gr reload had an average velocity of 2589.5 fps . The velocity is the result of 7 rounds (after it didn’t cycle twice, I stopped shooting, to save bullets and 4227 powder). The deviation above and below average was 33.50 fps.

So, I’m saving my IMR 4227 powder for my 44 mag reloads. But, if I had a bolt action .223, I’d use IMR 4227 in it.

Hack

I use AA2230 for projectiles 55gr and lower.....