Loading for the 5.56Nato with a 1/7 twist barrel

[HRT]

Well ladies and gents I am the proud owner of a AR15 specification built rifle which for $800 is alot more rifle than most of the premades. I have a 1/7 16" 4150 MP and pressure tested barrel and am currently mid way through the initial 500 round break in period with factory ammo. Being a 7" twist all of my research tells me I ought to be using bullets from the mid 60's and up to 77 or maybe 80 grains. Some of the experts, like my gunsmith said accuracy with the 55 gr stuff will be mediocre get into the mid 6os and you will start to see the perfomance.

I have loaded for .223 a good bit but they are 12" twist rifles and pushing 50 gr bullets pretty darn hard. The damage a 50 gr TNT wreaks on a 15 pound sod pig at 220 long steps (I'm 6'4") has to be seen to be believed. However these loads I am sure are completely unsuitable for the AR. I have been looking locally for some Hornady 75 gr BTHP bullets. None to be found. I have located several sources around the Internet in the $12/c range but sure would like some first hand comments/advice before I go the route of buying a thousand or so to get the shipping cost per bullet down. Anyone using this combo with AA 2150/2230/2520? So what is your advice? Buy a thou with $10 shipping? Buy 100 with $10 shipping? BTW my local Bass Pro is out of the reloading compionent business. Is this Nation Wide?

 

[Jim Watson]

500 round break in? For what? That is 10-20% of a target barrel's service life. My Krieger barrel had a factory recommended breakin of 13 shots; Pac-Nor said 40; Gale McMillan said a good barrel (Like his, no doubt.) needed none.

I have some Hornady 75 gr A-max that do pretty well, but I would try Sierra first, they are much more common in target shooting. Their 77 gr is meant for magazine length loading, the 80 is normally seated long for single loading in slowfire at 600 yards.

MY best .223 is more accurate with Varget or Re 15 than with AA2520, but a friend's rifle does well with it.

The Bass-Pro in Memphis no longer has reloading supplies, either.

 

[hagar]

The 75/80 AMax and 80 grain Sierra is meant to be loaded to an average overall length of 2.45 inch, and is single loaded only since they are longer than magazine length.

I like the Hornady 68 grain the best. The 75/77 bullets beat the wind a slight bit at 300, but in general are not as accurate as the 68 grain bullets. Accurate 2520 will work fine for your AR IN THE WINTER. They are temperature sensitive, and pressures spike quite a bit when it gets warmer. Varget or RL15 is what 90% of the highpower shooters use, the others shoot 4895 or something else.

 

[taliv]

most of the larger bullets you find are not going to be as entertaining on small game as varmint bullets you're used to.

you won't lose any accuracy shooting 50 grain bullets from a 1/7 twist barrel. You should try them at least before you go changing your recipe.


The only things i can think of that would make those loads unsuitable for an AR would be, unreliable cycling, or a higher pressure load designed for a bolt gun.

 

[mc223]

26.5g Varget under a molied 60g V-max works good for me in a 1 in 7.
Molied 75 A-Max and 25.5 Varget. Reduce and work em up.
If you dont like moly, start 2g lower.

The A-Max bullets need to be seated long and single fed. They cannot be seated to mag length.

Some of the lighter bullets may dissapear in a puff as a result of the fast spin and sometimes the gas hole in the AR.

 

[loadedround]

I also load for a Colt AR15 with a 1 in 7" barrel and have found that the Sierra 69 gr HP Match bullet on top of 25.0 gr of Varget/ Winchester primers/Federal cases to be a sub MOA load in my 16" barrel. Haven't tried the 77's yet, but the 55's don't group at all, they just pattern like a shotgun.

 

[tmag]

Oddly enough my 1-in-7 16" barrel (LMT chrome lined) loves 52 Sierra HPBT (or Nosler even) with 25.5 gr. of Tac. I've been able to put 10 shots in 1" at 100 yards with this load.

My rifle also loves the 69 grain Sierras--they're 1 moa bullets as well. The 68 gr. Hornadys just don't do well out of this rifle for some reason.

75 gr. Hornadys are just as magical as the 69'ers above.

77 gr. Noslers or Sierras can be 1 moa but not always.

80 gr. won't load to magazine length and I'm not shooting competition, so I'm not going to bother with them.

I use Reloader 15 for anything from 69 to 77 gr. It gives higher velocity than Varget and it gives me better accuracy. Check out Nosler's online store for good deals when they have overruns. http://www.nosler.com/index.php?p=11&b=5&s=4&t=SPECIALS! I was able to get 1000 77 gr. bullets for $108 shipped a couple of months ago. It looks like the price is about 126.95 now (but are out of stock).