Loading heavy (69gr+) .223 for 1/7" AR's

[Ardent]

I started loading 75gr AMAX's to mag length, shoot OK, but I don't like how the case neck is floating over the taper of the bullet nose, I want a 75gr class bullet that loads to mag length in AR's but still ends up with the bearing surface of the bullet in contact with the edge of the case neck. I see that federal loads the 77gr Sierra in its service rifle loads, so it must seat "properly". How about the Hornady 75gr HPBT?

Thanks!

 

[HeadDamage]

The 75gr HPBT is fine seated to mag lenght in an AR15... I've done it and they shoot great but I'm going to try the 77gr SMK for the hell of it any way :wink:

 

[Ardent]

I think I might just have to try both too If you shorten the plastic tips of the AMAX's they'd be alright, but it's too much trouble for my liking... :?

 

[HeadDamage]

Just tried the 77gr SMK today... fantastic!

 

[2katz]

By cutting a slot in front of your mag will get you a little extra lenght. Seen one on an americain gunboard a while back, he said it worked great.

There is a mag made by Long Range Products that takes a Sierra 80 grain MatchKing. The guy's name is John Snick.

DPMS sells his pruduct. http://www.dpmsinc.com/10Expand.asp?ProductCode=MA-LRP

 

[maynard]

From what I have heard the 77gr SMK are made to shoot loaded to mag length.
I shoot 80gr SMK from a bolt rifle single loaded, but would like to try some 77gr just to see how they shoot at 1000 yards.
Maybe in the spring.

 

[Silverback]

The US Military uses 77 gr SMK's loaded to mag length called the Mk262 Mod 0 and the Mk262 Mod 1. Here is a quote from the AR15 Ammo Oracle.

The cannelured 77 gr load was designated Mk262 Mod 1, and the orginal Mk262 was re-designated Mk262 Mod 0. Recently, Sierra agreed to add a minimal crimp to their bullet, and this has since replaced the Nosler bullet in the current versions of Mk262 Mod1. As of April 2004, Mk 262 Mod1 has seen extensive use in Afghanistan and Iraq, in carbines with barrels as short as 10.5", and has proven to be very effective at ranges that M855 is woefully inadequate from the same weapons. It is also commonly used in the Army's "Special Purpose Rifles" (SPRs), which are accurized 18"-barreled rifles used by soldiers with additional combat marksmanship training in a squad sharp-shooter role.

 

[ssgp2]

I shot my AR at 600yds last weekend with some 75 bthp in front of some varget/ccibr,win brass.
The elevation of my group did not exceed 1/2moa!
The wind messed up a great group
The load is compressed enought to make a dent in the bullet, but no pressure sign on the brass
I get about 2850fps.