Best bullet weight in 5.56 1in7 16"

[jeeptim]

Hey guys looking to load for a AR. upper stamped 5.56 1 in 7 twist 16" barell.
I got a k or so of 55gr fmj. Think this is the way to go but just not 100%.
Thanx

 

[blarby]

Your 55's will shoot very well in any twist rate of AR upper.

Enjoy !

Here is one of many very well written articles on the subject : ( ignore the source, cheaper than unobtanium is not a reputable seller in my opinion- but the information is correct)



http://blog.cheaperthandirt.com/ar-15-barrel-twist-explained/

With that said, 1 in 7 is designed for the new-fangled 77gr bullet to shoot its best- it allows the longer, heavier bullet to spin faster, stabilizing it properly for longer flight.

However your 55's will shoot remarkably well in it- and if you have a thousand of them, the primers to prime them, and the powder to propel them; you are in better shape than most AR owners these days.

The standard for 55 gr bullets is 1-9, which is what I have in my AR. This was intentional on my part, as I wanted to be able to shoot the most common and economical .223 bullet found : the 55.

62's are becoming more common, but if you went to the store right now, I'm certain in loaded .223/5.56 far and away the most common bullet weight you would find is 55gr.

If you can tell me what powders you have available, I would be happy to provide some published load data for you.


The most helpful quote for you in that article :

"The M16A2 comes with a 1:7, and the military typically shoots bullet weights from 52 grains up to 77 grains, with 62 grains being the most common in combat. "

 

[rcmodel]

The standard for 55 grain bullets is 1/12, as used in the early M16A1 rifle.

The 1/7 twist barrel came next and 62 grain ammo for it.

The 1/9 twist is a commercial AR-15 compromise between the two.

rc

 

[jeeptim]

Well the powder I have on hand.
5lb win760
4lb 4064
2lb 3031
2lb 4895
2lb TAC
Would like to use all the same powder lm a large batch loader if I can get a good load with the 760.
Thsnx

 

[rcmodel]

W-760 is way to slow burning for .223 with any but the very heaviest bullet weights.

Any of the other four you listed will do a pretty good job.

rc

 

[Eb1]

I'd try the last two. Tac and 4895.

 

[sdhunter]

25.5 grains of 3031 pushing a 50 gr v-max is my favorite load for my .223. But just like everything else, mileage may vary.

 

[Otto]

55gr. is too lite for a 1/7. When you load these, dont be surprised if they tumble.

 

[rcmodel]

They will not tumble.

They may shoot very well in fact.

You can't hardly ever over-stabilize a bullet in a fast twist barrel as long as it is jacketed heavy enough to no blow apart.

And 55 grain FMJ are not going to blow up due to high RPM.

rc

 

[handloader357]

Ive shot a ton of both handloads and factory 55gr projectiles out of both my 1 in 7 HBAR barrels. Both of those rifles are tack drivers. As long as its a well constructed bullet, there's no such thing as over stabilization.

I happen to have a ridiculous amount of 4064. All of my handloaded 223s have been with this powder and has been a very consistent load.... Probably because it's a fairly well compressed load. You wont get top velocities with 4064 but its extremely accurate in my experience.

 

[blarby]

2lb 4895

That happens to be one I use a ton of, so I'll go with that one :

24.0g H4895 ... if its I 4895 I use 24.5
CCI SRP
2.215 COAL

Hornady also lists for that TAC you have :

21.5 - 24.7(max ! ) at 2.200 COALwith a WSR primer

Or the 3031 :

20.5 -22.8 Have fun !