Will a 1/7 twist shoot 55 grain bullets?

Have a 1/7 rra that shoots them very well over 25.0 h335. I routinly get < 1" at 100 yards with both xtreme and midway dogtown bullets.

Of course it will.

But, 55 grain FMJ cannot be considered truly accurate out of anything.


rc

....Define "accurately"....

If you are referring to 1 MOA, uhh, no. If you are referring to 3-4 MOA, much for feasible.

Yes, 1/7 will stabilize 55 gr bullets. Expect practical accuracy over precision.

My 1:7 barrel loves 55gr Hornady VMax and Nosler ballistic tip bullets, easily sub MOA. 55gr RMR FMJ's I'm lucky to get 2-3 MOA but I still have some work to do dialing in that load.


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I only have 1:7" twist on all of my AR's. But as was already stated, most 55 grain fmjbt factory loads aren't so accurate and 3" at 100 yards is doing good in most cases.

Doesn't keep me from shooting them for cheap plinking, as long as your expectations are reasonable.

I see you said reloads, so there's room for tuning if you want to jump into that.

It will do fine from 55 to the 77. 1 inch groups would be quite feasible from your carbine with a good 55gr bullet. 2-3 moa for the cheap fmj factory stuff. It's the best twist rate in my opinion for the ar15.
The 55gr hornady sp is cheap and accurate and if you want to find the accuracy potential of your gun hand load some 75 or 77 match bullets.

ColoradoShooter77 said:

I realize the FMJ's aren't the most accurate bullets, I was just wondering if the bullet would "overstabilize". Obviously, the answer is no

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Correct. Basically, a bullet is stable during flight, or it is not

Recently picked up a 18 inch psa wylde barrel in 1/7 and it shot sub moa 5 shot groups with cheap Aguila 55 grain. Just try it and find out.

Just today I got a 2" group @ 70 feet with 55gr m193 pulls. Using irons off a sled, perfect for plinking in my book.

Best load was 24gr of H355. This was out of a PSA melonite 1:7 upper.

The 1 in 7 is faster than you need so is technically over stabilized. This is not necessarily a bad thing. If the bullets are of good quality , well balanced and concentric, they should shoot pretty well. Maybe not as good as the perfect twist, but , close enough for most purposes. The bullet spinning faster will magnify any imperfections as compared to a slower twist. I have a Savage with a 1 in 9 twist that shoots flat base 40 grain Speers a round half an inch. It definitely is over stabilized. As has been pointed out try it and see.

My own experience has been some will and some won't. Nosler Ballistic Tip Boat Tail 55 grain bullets, Winchester brass, CCI BR-4 primer, 25.2 grains VV N-135 powder, OAL 2.260 and I can guarantee keyhole 8" groups at 50 yards. Either of two Colt 1:7 twist barrels. That was my worst case and they shot very good in my 1:12 bolt gun. The 1:7 barrel velocities were about 3180 FPS.

Overall I never had much luck with groups using the 55 grain and lighter bullets in my 1:7 twist rifles. They work fine for many but I never had much luck.

I suggest you make some loads and see what you get with your guns.

Ron

My 1/7 didn't do very well with 55 gr. It does sub min with 77 gr bullets. Some rifles will do well others will not. My 1/9 twist only does well with 69 gr Noslers. Other 69 gr are less accurate.

I've had some pretty spectacular groups using a 52 grain BT Hornady A-Max, out of my 1/7 20" bull barrel AR15, slightly under a moa, however it definitely prefers the 69 grain and up projectiles. There are quite a few options to the hand loader.

A fast twist is rarely a disadvantage -- as long as the stress and centrifugal force doesn't cause the bullets to come apart in the air.

The real problem -- if you have a problem -- would be that fast twist rifles are often designed with longer throats to accommodate longer bullets. Shorter bullets may have to be loaded well out for best accuracy.

I have a PSA 1/7 that shoots Hornady 55 gr fmj just fine. Prints somewhere in the 2-3 moa range. No trouble hitting the 4" gong at 100 yards.

My PSA has a 1:7 barrel and loves M193, so I would say yes.

Now, I will say that this is not a scoped rifle and I have only used iron sights with any of my semi-autos. I'd like to say I'm good enough, but I know I can't match the precision of someone using glass. If your question is more along the lines of "will I lose 1/2 MOA" then I have little to offer.
Though if you're asking whether or not you can confidently nail an apple at 50 yards if you do your part, then I can say for certain... yes!

I tested a Mossberg Thunder Road edition with a 1/7 0r 1/8 twist and the lighter bullets simply would not group worth a darn. I switched to 69 gr. and got sub MOA. 62 gr. shot about 1.5MOA.

My 6920 SOCOM has a 1 in 7 barrel and I recently shot just a hair over MOA using 55gr FMJ reloads. You should be fine

for general plinking fun, my 1/7 barrel does just fine with 55gr, but does much better with 62gr.

Like everyone is saying, it depends on the bullet.
Milspec 55gr FMJ isn't match grade bullets. However, you "might" find an individual lot that exceeds the "average" performance. I bought a quantity recently of some Federal FMJ bullets that over 27.0gr of BLC2 will hold the X-ring on the 200yd targets at CMP Talladega. That's 2 moa at 200yds. That's good enough that I couldn't tell them from either 69gr or 75gr match bullets. At 300yds, I could tell a small difference. 600yds, was however altogether different. I could keep them in the black 6moa, or 36". With 75gr match, you can shoot X's all day, with 80gr Match Kings, you can pick which corner of the X-ring you want to group them.
This is with a 1/8" Wilson Match barrel.

I plan to get a quantity of Midsouth 55gr HP's for short range practice, and 200yd matches. At 8cents, they're hard to beat. They typically shoot bug holes from my M700 Rem in .22/250 over 39.0gr of H380 for 3,700fps. If they'll stand that, they'll take 2,900fps from your 1/7" 16-18" bbl.

Just don't expect a Blitz, or SX type bullet to stand it (very thin soft jackets, soft lead cores).