I have a Smith and Wesson M&P15, 5.56 16 inch bull barrel with a 1:9 twist ratio. What would you guys recomend for a bullet weight to use for good grouping and best terminal damage?

With a 1/9" I would use anything under a 65gr. You can find some Hornady TAP 55gr that apparently perform pretty well, but I haven't tested them myself.

Here is a link from Box O' Truth that shows some results of 5.56 military rounds versus .223 rounds in a 1/9" barrel. After you look at that here is the second portion.

ETA: I realized the barrel used in this demonstration was a stainless barrel, so you can expect some slight variations when in comparison to yours, but this should point you in the right direction of what to expect.

This post has been edited by pleaforwar: November 5th 2009 6:28 AM

It takes experimentation to see what round works in your weapon. Some from 40 to 69 grains will shoot well and others wouldn't. Hornady 55gr TAP shoots accurately in most barrels. It's a defensive load. 55 and 62 grain soft points would do some damage.



TS


to the Armory!

Oh yea, I forgot... to the Armory!

My S&W eats anything I feed it. 55-62 grains seem to be most accurate if the brand is good.

This post has been edited by +Zeke+: November 5th 2009 8:42 AM

Thanks for the info guys. I had found a box of military ammo 62 grain that i was considering buying, but with how large the groups are i'll probably just go look for some Black Hills.

I have the same S&W, 1:9, 16" and I'll let you know what I find, I'm about to load up 55, 60, 65 & 68 grain ammo to see what I like best.

55 to 64 or so should work. If you want terminal damage are we taiking 2 pound PD's or 180 two legged varmints? The Nosler BT's and VMAX work well on the PD's. Soft point work well on the 180 pounders. If I going after 200 pound four legged deer I would go with one of the Brear Claw or Barnes bullets.

Greg

I found that a Savage bolt action bull barrel button with a 1-9 twist loves Black Hills 60 grain Vmax's. Could shoot a hair off a fly with them.
Granted it was a bolt action. But a bull barrel is a bull barrel.

62gr. and less in MY 1: 9. aboard!

So i'm gathering anything from a 62 grain and lower for accuracy and terminal damage on 180 pound critters. Sounds fair. So how doas FMJ compare to a softpoint?

Softpoints will expand and possibly split into two "chunks". They will penetrate two walls (two pieces of sheetrock/dry wall with insulation being one wall) with fifteen feet distance between walls without going through a human at CQB distance. This is with 55 grain softpoints.

FMJ will fragment after passing through two walls of the same construction at the same distance. Fragmentation ranges vary with different length barrels. This is with 55 grain FMJ.

I would not use 62gr M855/SS109 for a defensive round.



TS



The wall test was performed at Gunsite.

I wouldn't want to be the "human" in the Gunsite test! :-)

Cool. So a 62 grain will go through a wall, person and possibly something else. That's good to know. Has anyone used the barnes MPG bullets?

The 62gr M855/SS109 would likely pass through the person and possibly the wall. M855 does not fragment well. 62gr soft points or other non-M855 spec FMJ would probably work well. Soft point would do more damage (cavitation size) than FMJ. Soft points are less likely to overpenetrate than FMJ of any kind.


TS

Not to get too far off topic, but I believe that the type of bullets used by our troops (FMJ as opposed to soft points and hollow points, for example) is dictated by the Geneva Convention, to which the US is a party. Is that correct?

Yes. It only applies to the military, that's why they use FMJ.



TS