Do these primers look flatten?

[fella5]

Well I was able to chronograph the loads at 22.7gr and the velosity was pretty low. Average was 2331 so I think I will work up the load from there and see if I can get one that I like (group wise) with a velosity arnd 2550+.

Also, since I'm a newbie..... why are the loads on the Sierra Manual between an AR-15 and bolt different... I mean if you look at Varget the max on the AR-15 is 24.0gr on the bolt action it is 25.3gr? Is it because the bolt action could handle more pressue than the AR?

Thanks for the post on pressure signs!

[Unclenick]

CAUTION: The following post includes loading data beyond currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assume any liability for any damage or injury resulting from use of this information.


The Sierra book has a whole separate 15 page section in the front on reloading for gas guns. You might want to read that. Mainly, they are trying not to hit the gas port with too much pressure.

QuickLOAD agrees pretty well with your 22.7 grain load. With the short barrel it thinks you should get 2,331 fps with fired case water capacity of 30 grains, and you will have about 42,100 psi. Leaving all those conditions alone, 24 grains should run at 49,400 psi and give you 2,466 fps. 2,550 fps would mean increasing the charge to 24.8 grains, and would run right up against the SAAMI pressure limit and over Sierra's recommended AR pressure maximum.

[fella5]

Thanks... I did read that on the Sierra Reloading Manual. My rifle allows me to shut off the gas port, run normal or suppressed. When shooting these, I have the gas port shut off so I have to manually eject the round. The 22.7 was great at 100-300 yards but I'm trying to get it out to 600 without too much bullet drop. I do understand the danger about going over max loads though.

My riffle is chambered for 556 and follows NATO specs which is @60,000 CUP max.