# Twist vers grn Ammo



## budgetprepp-n (Apr 7, 2013)

Ok I'm looking at a Deference rifle a A-R that has a 1-9 twist barrel.. What does this like to eat for ammo? 
It's listed ,,,,,,,,,,,,,,,,,223 / 5.56
Or what else do you need to know to make fair determination of what ammo I should try first?

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## AquaHull (Jun 10, 2012)

1 in 9 twist was designed for "GreenTip" ammo aka SS109/M855 62 gr Penetrator. 1 in 7 twist is the cool guy twist these days. I'm cool since 1 in 7 is all I have now, but if they had a 1 in 9 twist Cold Hammer Forged I'd be all over that.

It will also shoot the 69gr SMK's /Sierra Match King Boat Tail Hollow Point aka OTM/ Open Tip Match Bullet

55 gr BTHP work well out of 1 in 9


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## dannydefense (Oct 9, 2013)

M193 and M855 will shoot just fine out of 1/9. Heavier bullets will go down range at quite lethal speeds, but they may not stabilize and you could wind up putting an expensive 75gr match round sideways through your target. Pick up a few boxes of ammo, and fire them until you find the one that likes your set up best.


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## AquaHull (Jun 10, 2012)

Sideways could be lethal though


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## bad (Feb 22, 2014)

Hi, What is a deference rifle? With a 1:9 barrel you can shoot up into the mid 60's. Wolf 55 grain shoots fine. The interesting thing with wolf 55fmj is that the tips are have a jacket of copper and the nose of the bullet is hollow.

Our M16A1 rifles were 1:12" and shot 55 grain. I remember hitting pop up targets at 350-400 yards regularly with it.


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## dannydefense (Oct 9, 2013)

AquaHull said:


> Sideways could be lethal though


Sideways could be painfully lethal, and for home defense at 5 to maybe 50 yards tops, you're going to get the job done.

If you're like me, you shoot the guy in the leg for even thinking of stepping on my property, fire a couple warning shots across his bow to start him running... wait until he's about 200 yards down and yell that he forgot something, and then when he turns around... which is why I like my bullets to stabilize in flight.

That would be crazy though, I would never do that.


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## Smitty901 (Nov 16, 2012)

1 in 9 is for punching paper with lighter bullets become some what of a fad right now.
1 in 7 is you best all around for a 16 inch AR


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## bad (Feb 22, 2014)

I am not sure if it was a fad if the the entire army shot 12:1, everything comes back in style at some point.. 

Hey First Sargent, they told us that the lower twist rate made the 55 grain bullets at the time, tumble when hitting a meaty target. It was a way around the prohibition against using hollow/ballistic tips. My field in the military, didn't involve shooting the enemy with bullets but my basic infantry training had a lot of info in it. We had 20" barrels iIRC. My current AR's are 9:1 and 7:1 with shorter barrels. My stash of ammo is still 55 grain. I still have some 42 grain double HP bullets, but not shot them in my 7:1 maybe they would vaporise in mid air.


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## Smitty901 (Nov 16, 2012)

Any AR will shoot any of the listed ammo.
The M16 with a 1 in 12 and the 1 in 14 were designed to fire the 55gr 223 and 5.56. The settled on the 1 in 12.
The 1 in 7 was designed for the 16 inch and a 62 Gr bullet. You can fire the 55gr in it and hit your target how ever the group will not be as tight and there are other issues that may not have a big effect on paper.
The 77Gr rounds were added to increase stopping power and they do work but are not standard issue.
In the right hands with optics the M4 with 62 grain green tip can make the 600 meter shot. Many have no problem with 500 meters
Most can hit 450.
I have a few AR's that will shoot sub to 1 MOA. If you take one of them and load 223 55gr the groups will wander to 3-4 MOA pretty much the same with 5.56 in a 55gr.
Of course any boxed ammo is going to have some differences from one box or round to the next . But if you shoot enough you can record the difference.


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## Ripon (Dec 22, 2012)

For this I'm no expert. I have been told but can not verify they consider a 1/9 the "retail" and 1/7 the close encounter combat rates (meaning urban). Then I've been told 1/7 is more accurate long distance - I gave up. I have 1/7's on my old Colt uppers and they hit targets at 300 yards - I'm happy. 

PS...I don't know if they are sideways going through paper at 300 yards or not - not a clue - but since they go thru accurately I'll assume not.


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## LunaticFringeInc (Nov 20, 2012)

There is a lot to twist rates and whats best for the rifle/cartridge at hand than just bullet weight.

In my 24 inch barreled Mossberg MVP that has a 1-9 twist rate, I have gotten excellent results with bullet weights from 53grs to 69grs. Lighter than that or heavier than that, and accuracy starts going into the crapper and targets start looking like shotgun patterns instead of rifle groups.

Do note, that bullets such as the Barnes Tripple Shocks which have a considerably longer bearing surface (the area of the bullet that makes contact with the rifling) per their weights will require a slower twist rate than conventional bi-metal bullets.


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## PaulS (Mar 11, 2013)

The amount of twist determines the LENGTH of bullet that will stabilize. If you want to be able to shoot the longest bullets available then get the tightest twist. In my '06 the 1:10 twist will work with bullets up to 190 SpBT or a 200 grain round nose - they are similar in length. It will not stabilize a 220 grain round nose as the bullet is too long. (length from base to tip - bearing surface has little to do with it) So, in my 3006 I have fired bullets from 130 JHP to 190 SpBT into five shot groups under an inch at 100 yards. When I tried to use the 220 grain bullets they go into the target sideways and produce a pattern of about 4 inches in diameter. Yes, they would be lethal - if you actually hit in a vital spot.


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