Twist rate

[Black-N-Red]

I was reading about twist rate on 5.56 the other day & seen that everyone recommends a heavier bullet with the 1:7 twist barrel. I already had my 5.56 zeroes in 1" high at a 100yrds with the hornady American gunner 55gr hp. It shoots these at 3/4" groups at 100yrds. Not being a big rifle guy I looked at the barrel in my ar & it's a 1:7 freedom series from psa. So I think I could get better accuracy with a heavier bullet I picked up some 75gr hornady match ammo & it shot like junk! We're talking 2.5-3" groups at 100yrds. Does this seem right? Lighter bullet shooting this good out of a 1:7 barrel. If i shoot lighter than 55gr the groups open up to, it's like 55gr is the magic weight, but I can find any other shelf ammo other than the American gunner in 55gr.

On an other thought who else shoots the Hornady American Gunner ammo & how does it perform in the field?

[gatorgrizz27]

My $0.02. The 1:7 twist just gives you the ability to stabilize 75 gr and heavier bullets, it doesn't necessarily mean it will shoot them better than lighter stuff.

I'd be happy with any budget AR that is shooting sub-MOA with factory ammo, especially stuff that isn't match grade. Most $500-$750 AR's I've seen shoot around 1 1/2" groups at 100 yards.

Hornady has a reputation for building accurate ammo, you're going to have better groups with their stuff than something like a 1,000 round bulk pack in most cases.

[Black-N-Red]

My $0.02. The 1:7 twist just gives you the ability to stabilize 75 gr and heavier bullets, it doesn't necessarily mean it will shoot them better than lighter stuff.

I'd be happy with any budget AR that is shooting sub-MOA with factory ammo, especially stuff that isn't match grade. Most $500-$750 AR's I've seen shoot around 1 1/2" groups at 100 yards.

Hornady has a reputation for building accurate ammo, you're going to have better groups with their stuff than something like a 1,000 round bulk pack in most cases.

Thanks for the input.

I'm extremely happy with the gun, I bought it as a 300blk & on the way home stop at a pawn shop & they had the 5.56 upper for $290, figured I couldn't go wrong getting my feet wet in the ar world with that buy.

[Drycreek3189]

You just can't tell what a particular rifle will shoot until you try it. My 1:9 Mossbergs shoot the Hornady 75 grain BTHP like they were made for it. No 55 grain bullets shoot as well.

[txfireguy2003]

To a certain extent, a fast twist barrel, like your 1 in 7, is peculiar fine for lighter bullets, as you've seen, although not necessarily ideal for them. On the contrary, a slow twist, like a 1 in 12, is usually NOT okay for the heavies, but will be fine for the light stuff. Your barrel may shoot those 75gr bullets just fine, but it might need a different powder charge than Hornady uses.

Like DryCreek said above though, you just don't know until you try. My buddy's TC Encore in .223 has a 12 twist abs he was told that it would not shoot anything over 55 grains, but I loaded some 65gr game kings for it and they will shoot inside a dime all day. Try a Barnes (longer bullet to get same weight) and they'll hit the target sideways.

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[175gr7.62]

You can't make any sort of determination with the small sample size you have. You need to try several different types, weights, lots of ammunition for you to know what your rifle likes. I have a 1:7 Mk-12 clone that shoots in the 0.7's at 300yds with Berger 77gr OTM. Factory 64gr Powerpoints would be more accurate at 100yds if I threw them down range. Black Hills Mk-262 shoots just a shade less than MOA...most M855 shoots about 2-2 1/2".

[Buckwheat]

I shoot 65gr sierra gamekings out of my 1:9 DPMS. 1" @ 100.

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[LWD]

People get all aflutter about twist rates needlessly. Unless you're shooting benchrest, you need a twist rate fast enough to stabilize the bullet you're shooting. Forget about what weights are "best" for your twist. A chart purporting to show that doesn't have any basis for its assertions that some are "best" some are okay but not the best and the like (and makes the error of referencing bullet weight rather than length, which is what really controls the twist required). As long as the twist isn't so fast that it tears a bullet apart, which only happens with especially frangible varmint bullets grossly over-rotated, just shoot what your gun shoots accurately and meets your needs. What your gun shoots accurately is determined by a lot more than twist rate.

Rant over. ;-)

[Artos]

LWD is right...in reality, the 1/7 should shoot the 75gr just as well, but guns & bullets are funny. It may put 69gr or 75gr Blackhills / Federal match into 1/2".

If you are getting good groups with a certain ammo that suits your application, then just shoot it. You cannot condemn a certain brand or flavor across the board as it may shoot lights out in the next gun.

It gets really fun with rimfire ammo...I've seen the same gun shoot ragged holes with one ammo & 2" with the next. The same ammo in a different gun could be the polar.