Hey, Byron; a 5.56 question for you
by Slow Hand 
, Indiana, Wednesday, June 20, 2018, 07:37 (2350 days ago)
I remember awhile back you had wrote about a good 77 gr 5.56 load. I just picked up 1000 Prvi Partisan 77gr HPBT bullets to try out. I believe that everything I’d shoot them out of is at least a 1/8 twist, and a couple are 1:7. I picked up an 8lb jug of WC844 and another of 2230, but I have several other powders to use based on you’re results.
Thanks for any advice!
Hey, Byron; a 5.56 question for you
by bj , Wednesday, June 20, 2018, 20:48 (2349 days ago) @ Slow Hand
Varget and Reloader15 are the powders most used by highpower shooters with 80 grain bullets.
M262 Mod1
This is one of two 5.56mm rounds that I have standardized for my AR15 shooting. The other is a M193 spec reload using a bulk 55 gr soft point and CFE223 powder.
My M262 Mod1 clone load is mixed but uniformed 5.56mm brass that is trimmed to length and full length sized. The bullet that I have settled on is the Nosler 77gr Custom Competition with cannelure seated to the cannelure and taper crimped. Powder is Varget and primer is Remington Small Rifle Bench Rest Primers #7-1/2. Powder charge as required to throw 2750fps from a high quality 16" chrome bore 5.56mm chamber barrel. Ammunition is loaded on a Dillon 550 using Lee dies.
This ammunition works great in all my standard chamber/barrel dimensions rifles however in my DCM Service rifle and my JP Precision Rifle it will blow primers maybe 10-20 of the time due to the tight match chambers and barrels.
It is extremely accurate and maintains a standard deviation in the single digits.
It kills whitetails like they were hit by lighting.
With the exception of the M855a1 lead free round it is in my opinion probably the optimum 5.56mm load for both long range as well as terminal ballistics.
Byron
M262 Mod1
by bj , Thursday, June 21, 2018, 20:20 (2348 days ago) @ Byron
I have noticed that some rifles built for service rifle competition have shorter throats, i.e. the opposite of long freebore, and this probably increases pressure a bit. I've read that some primers will blow easier than others but I don't know where Rem fits in that regards. Also if you have a rifle that blows primers, this might etch the end of the firing pin and make it more prone to blowing primers.