Stocking up 5.56 - 55, 62, or Heavier?

**MMH** · February 12th, 2009, 09:43 AM

I'm stocking up on ammo. I have a heavy barrel, 1-9 twist, non-chromed 20" AR-15. Best prices on reloadable stuff seems to be on PRVI Partizan. So, should I get the:
M193 - 55 grain
M855 - 62 grain steel core
69 grain match (I think this is loaded to 223 pressures, not 5.56)

I'm leaning towards the M855.

**QuakertownRich** · February 12th, 2009, 09:48 AM

Depends on how fast your barrel twist is. I believe the equation is: faster the twist (1 in 7 or 1 in 9) go heavier like 62gr or 65. slower the twist (1 in 12) go lighter like 55gr. I'm sure I'll be corrected if I'm wrong. I have a 1 in 9" twist and have used 55gr w/o problems hitting paper.

**dirksterg30** · February 12th, 2009, 10:05 AM

My personal stash is mostly 55gr. (5.56mm M193). I have some M855 as well, but from what I have read, M193 has better terminal ballistics for unarmored opponents. If/when I am able, I'd like to replace both with 68/69gr. rounds. My AR has a 1/9 barrel, and does fine with any of these rounds.

**Farbmeister** · February 12th, 2009, 01:08 PM

Heavy bullets are to go through things (windshields, doors/sheet metal).

If you are getting close to 100+gr you should set up to 6.68 or even AR-10/.308 type rifles.

**Kaos** · February 12th, 2009, 01:13 PM

I get whatever I can get.

**Guns4Fun** · February 12th, 2009, 01:22 PM

My suggestion

Buy plain ol wolf 55g for plinking and get real federal xm193 for shtf. Sight in your gun with the federal xm193 and you won't be too much off target when using the wolf for plinking---just a little low.