1x9 or 1x7?

[Guns and more]

I'm shopping for an AR. I think Colt because, well just because.
The 6920 carbine has a 1x7 twist.
The 6721 has a 1x9 twist.
The 6721 also has a heavy barrel, and as far as I can tell, that's about the only difference.
So, I'll use it lightly, target shoot, and probably use the .223 ammo readily available. That might be 55 gr. if it's the best value.
Would I be better off with the 1x9 twist?
I've heard two different stories on the 1x7 Mil spec. Some say it's for the heavier 65 gr or 70 gr. bullets, and some say it's for the longer tracer rounds.
Or, would a shooter like me even notice the difference?

 

[athensguy]

Either will be fine with 55 gr. 1x7 stabilizes 75+ gr. loads a little better. 1x9 will let you go a tad lighter.

 

[Dr. Tad Hussein Winslow]

1 IN 9!!

Pet Peeve / Point of Order, thankyouverymuch:

1. 1 IN 9 means what it says and refers to twist rate

2. 1 TO 9, or "1-9" is pronounced "One To Nine" and refers to a variable power rifle scope's magnification range.

3. The "X" stands for "BY" and indicates multiplication or precedes the Objective lens size, as in "1-9X40", or "1 TO 9 BY 40". There is no such thing as a One BY Nine twist.

Carry on.

 

[DarkCharisma]

1:7 stabilizes 70+ gr. ammunition better. Some of the bigger Match and Nosler rounds are in the 75 to 77gr. neighborhood, and will give better results then the same round in a 1:9 barrel.

 

[Walkalong]

1X9 would be a BIG bullet.

Twist rate is beaten to death. Check at Arfcom (fac #4, #5).

 

[Guns and more]

1 IN 9!!

Pet Peeve / Point of Order, thankyouverymuch:

1. 1 IN 9 means what it says and refers to twist rate

2. 1 TO 9, or "1-9" is pronounced "One To Nine" and refers to a variable power rifle scope's magnification range.

3. The "X" stands for "BY" and indicates multiplication or precedes the Objective lens size, as in "1-9X40", or "1 TO 9 BY 40". There is no such thing as a One BY Nine twist.

Carry on.

That's what I love about THR. There are so many people willing to tell you what you didn't ask.

You must hate it when the Ammo Forum (recommended above, thanks) says this:

What bullet weight can I shoot in my (1/9, 1/8, 1/7, etc.) rifle?

Carry on.

 

[jaholder1971]

Get a 1:7 twist.

The trend in .223 Remington is heavier bullets and they need the faster twist. Why anyone puts a 1:9 or slower twist on a .223 today is probably still listening to old K-Tel records, too.

 

[proven]

i don't own any, but i believe the slower (1 in 12) twist is better for light varmint loads.

 

[rcmodel]

1&9 will do all that needs to be done for most folks.

A 1@7 would maybe be best for long range match shooting with very heavy bullets.

For a varmint hunter like myself, a 1^ 9 will handle all the lighter varmint bullets probably better then the 1#7.

Guess I'll go dig out the K-Tel records now, for some good family entertainment tonight!

rc

 

[Guns and more]

Twist rate is beaten to death. Check at Arfcom (fac #4, #5).

Nice chart, but they never tested the lighter bullets in the 1 in 7 twist.
They do say: "test in your own rifle."................. I don't have the rifle yet!

Maybe I should get one of each!

Thanks to all for your help. I think if it was critical, someone here would know.........so I'll just get what is a good value.

 

[Onmilo]

Get a 1 in 9 twist barrel.
At todays prices, you will find much better deals on 50 to 62 grain bulleted ammunition than 68-77 grain ammo.

 

[Coronach]

1:9 is a good vanilla twist rate. It will shoot most anything just fine.

1:7 is a better bet for heavy bullets. If you know you won't be shooting lightweight bullets (think sub 55 grains), it is a better bet, because the current emphasis for general use is towards heavy bullets.

Me, I have a 1:9, a 1:12, and two 1:7s. I think I have most every angle covered. If I could have only one, it would be a 1:7, but if I had a 1:9 I would not feel overly disadvantaged.

 

[briansmithwins]

My 1/7 rifles are better with 75gr bullets but 50gr and 55gr stay under 2MOA, which is good enough for me. BSW

 

[Pilot]

1:8 :d

 

[RockyMtnTactical]

It shouldn't matter all that much unless you are shooting a lot of 77gr bullets or 45gr bullets.