Which twist rate for cheap AR15?

[Tony617]

I have a 1/9" twist and I have shot 50gr up to 69gr rounds.

 

[Delaware Devil]

I have a Ruger American in .223 with a 1 in 8 twist. I've shot 40 to 75 grain bullets, all with good luck. I mostly stick with the 50 grain Vmax, and Z max Hornady. I only loaded the 40 grain Vmax because that's what I shoot in a Savage in .222 with a 1 in 14 twist. The 222 with the 40 grainers is a tack driver, literally one ragged hole groups at 100 yards. The .223 shoots so so with the 40's, but shoots best with the 69 grainers, but the 50 Zmax do more damage on groundhogs. With the 50's I get near half inch at 100. Love these little 22s. Took a deer at about 140 yards with a 69 grain and it was like he was struck by lightening. Delaware is shotgun only, but uncle lives close by in a rifle friendly state. I did notice the small entrance hole, but it was all torn up inside the chest cavity.
I may be long winded, but what I'm trying to say is it's whatever shoots best in one certain gun. There are no laws governing what bullets shoot best, the tables are only a guide. Bullets have come a long way since I started reloading back in the early 70's.
Remember, safety first, always wear your shooting glasses and hearing protection.

 

[djaziatic]

Cheap ar build? 1/9 twist is going to be the most commonly found barrel twist rate. Common usually means cheapest.

 

[ZA_Survivalist]

Yeager is a blithering idiot. He is not a good representative for the gun community/culture. What he is saying may (or may not) be true, I don't know. But don't give him the business, or I should say attention. Instead, get the info needed from other sources.

Better than Gabe Suarez.
Now, that guy I cannot stand anymore.

 

[Delaware Devil]

I did find a barrel twist calculator. If anyone can use it, I'll try to post the link
Barrel Twist Calculator
I'm not real computer savy, but I think I got it right.

 

[rds801]

1/9 or 1/7....my opinion is you will be happy with either. Sounds like you are just looking for something to have fun with. My AR's (Spikes and PSA) are 1/7 and they both shoot 55gr no problem.

 

[erudne]

I would shoot 40grn in an AR as a home defense load, if I was worried about over penetration, which I am not, and as I have 5.56 barrels I'm not concerned with tack driver accuracy. Go cheap and stack deep

 

[oli700]

OP, here are some actual facts and personal experience

The 556 NATO M193 was designed for 1:12.
Slower spin allows the cannelured projectile to yaw and break apart at the cannelure allowing the 556 FMJ to achieve maximum damage. This video shows a m193 shot through a 20" barrel with a 1:12 twist

When the military needed to stabilize longer projo's in the m855 and the m856 the needed a faster twist. They settled on 1:7".

1:7 ruined the effect of all 556 FMJ in 55gr, the m193 is less apt to yaw and fracture when spooled up as fast as the 1:7 sends it leaving the in and out wound that gave the FMJ a bad rap , however the Army achieved their goal of stabilizing the m855, penetrating a steel pot helmet at 600 meters….


A 1:9 twist barrel will allow a cannelured 55gr FMJ to act more like it is supposed to.
A 1:9 usually won't stabilize anything heavier/longer than a 69gr projo, not always but mostly depending on distance shot and projectile deign and rifling method.

I have a 1:9 that stabilizes 69 SMK but keyholes 77 SMK at 300 meters. It does stabilize Hornady 75gr HPBT Match because that particular bullet has a forward scant ogive giving it more bearing surface to engage rifling……it was designed by Hornady to stabilize in a 1:9.


Here comes the 1:8" ……I believe to be the best all around twist available.
My 1:8 will stabilize 80gr VLD's to 600 meters, it also doesn't want to disintegrate 52gr SMK (many serious mach shooters use less than 55 on calm days) and really I have never seen a keyhole from it and never blew up a Dogtown 55gr at NATO velocities…..common in a 1:7 at 3200+ fps.
The 1:8 is no gimmick, it is the real deal jack of all trades, in my experience as a reloader and rifleman….take a 1:9 to 500 with 77gr SMK and you will see why the 1:8 is a great twist. If you only shoot 100 or 200 then you may never notice the difference other than less than great grouping.

 

[aznbala]

Depends on what ammo you plan on shooting. Also depends on your budget. 1/8 or 1/9 is good enough. Personally I have 1/7 but that's because I wanted to be able to shoot higher grain ammo

 

[cpy911]

I run a cheap AR-stoner from Midway USA and it is 1:9. Works great with 55gr cast bullets at reduced velocities. Point of impact and point of aim are the same for a full house 5.56 load at 100 yards.
I hit golf balls at 100yd with a Bushnell TRS-25 3MOA red dot (the dot covers the golf ball!) using cast loads from a RCBS 2-Cavity Bullet Mold 22-055-SP going about 2300-2400 fps. It does take a few rounds, but i get it eventually.
Its cheap plinking and I have had zero problems with leading the barrel or gas port after hundreds of rounds. I picked up the AR-stoner barrel for <$100 shipped from Midway when on sale. Great barrel for the price and works great for my franken-ar.