Suggested grain weight for 5.56 reload.

[rjtfroggy]

1:9 twist barrel, 60gr flat base Sierra varmint bullet many 1 hole groups at 100 yards.

 

[Coyotefurharvester]

Sounds like the cheapest, bulk 55 gr, sp will do everything you require. Primers will be the problem, especially for mag dumps.

 

[JAlfred]

Your gun will tell you what it wants, listen to it.

 

[Oso]

So it's a PSA 1:7 16" Barrel. It's one of their MOE uppers. The 1:7 is something from what I know is better for heaver grains hense the question. I am not going over 100 yards and probably more shoot 25-50 yards as really unless I mod the crap out of it to really shoot 100 in tight groups. But do enjoy 100 yard shooting. I used to reload and shoot 30-6 and yes I know it will never be that but would still like to have fun. BTW I would also love to mag dump a bunch but can't afford too much of that lol. So just looking for a good combo that is available.

Mike,

You don't need to shoot heavies. Typical 55gr FMJ bullets work great for the distances you are talking about. The Hornady 55gr Flat Base or BTHP bullet is a great option and economic ($0.09/bullet under ordinary conditions). The 1:7 twist allows your gun to handle 55gr - 77gr bullets with no issues. The biggest issue for you with an AR15 and heavy bullets (also means bullet profile is longer) is that the cartridge's overall length is limited/restricted to the internal length (ID) of the magazine.

I wouldn't bother running 69gr SMKs or anything heavier (and more expensive) for that distance (100 yard maximum) because you will be paying 2.5x price per bullet with no noticeable difference in performance especially if you are shooting mostly 25-50 yards.

As far as powder goes there are so many options. Some of the most popular are H322, H335, TAC, 8208 XBR, CFE 223, AR Comp, H4895, Varget, Reloader 15, and the list goes on. All will provide you with an accurate cartridge that will shoot better than most store bought ammo.

With the ongoing supply shortage the trick is to stay flexible with your recipe if you can't find exactly what you need. Rule of thumb is that #1 of powder is good for 250 rounds. Assume you will use 25-50 rounds to dial in a load (powder/bullet/primer combination) so when possible you want like 300 bullets (same type and weight) so that you can develop a load and then have enough to run a small batch (250).

Good Luck!