AR Sponsor
Posted: 11/6/2008 7:38:13 AM EDT
What is the twist for a standard AR, 1:9? I this is correct what is the max on bullet weight for a 16" carbine barrel?
|
|
I guess 1/9 is the most common in the civilian world.
anyway standard military twist is 1/7. take a look HERE |
|
Here is an article that might help...
Getting into a Twist about your Twist?! Anyone that spends any amount of time at the rifle range or hunting lease will inevitably find himself within earshot of two people discussing barrel twist. Twist as discussed here, refers to the rifling in the barrel of modern rifles making a full 360 degree turn in a given length of inches. As an example, a 1x7 Twist means the rifling makes one 360 degree turn for every seven inches of barrel. As it pertains to .223 projectiles, several different twists are currently produced. Not all ammo shoots well in all twist ratios. A barrel with a 1x7 Twist tends to be too tight for most lighter, more commonly fired ammunition. Originally designed for the military's use of SS109 (the official NATO name of 5.56mm, or .223), further military testing concluded other twist ratios are actually superior for this steel core bullet. 1x8 Twist is best suited for 69-80 grain bullets. Our Federal .223 69 Grain BTHP Match Gold Medal is some of the best on the market for this twist ratio. 1x9 and 1x10 twist ratios are sort of the "middle of the road" for .223 projectiles, and these are the most common. We suggest our Hornady TAP 55 Grain. On the lighter side of things, a 1x12 boasts excellent accuracy on standard and lighter projectiles in the 40-52 grain range. Older M16 rifles were manufactured with the 1x12 Twist ratio. Our item number ARR-115 offers a conversion upper for your AR that takes less than a minute to install, and the barrel has a desirable 1x12 twist ratio. If you are buying a varmint rifle chambered in .223, chances are it will sport a 1x12 Twist Ratio. Our Federal Premium .223 Remington 40-Gr NBT is perfect for varminting. Last, we have the 1x14 twist ratio. Probably the least accurate ratio unless you are into bullet tumble as opposed to spin unless you are shooting custom loads. |
|
Quoted:
1:7 is going to be your best choice for shooting the heavy stuff. A 1:9 is going to be a good choice for shooting the standard 55 grain ammo - it's also going to be the cheapest most common ammo out there. So would 1:8 twist be right in between? Would it be ok to shoot 55gr in them out of a gas piston AR? |
|
1/7 is ok for everything from 40 grains and up. you wont notice the difference in accuracy unless its in a BR rfifle thats costs 8k
1/9 will shoot up tp 75s fine 99 times out of 100 all those twists are for very specific needs for people trying to wring every bit of accuracy out of a gun, but 1/7 will be the most useful |
|
There are no absolutes. Each rifle is going to be different. The rate of twist and the suggestions here are simply a starting point. You'll have to test real ammo in your rifle to know anything for sure.
Distance makes a big difference too. My 1/9 24" Bushy will put heavy 77gr rounds almost on top of each other at 100m but open up HORRIBLY at 220m. The more "ideal" weight 62gr fodder is almost as accurate at 100m as it is at 220m if I do my part. So if I were deer hunting, I'd load up with 77's and restrict my range. It all depends..... |
AR Sponsor