223 barrel muzzle thread option 5/8 vs 1/2

[jackal2001]

I'm going to go with something from compass lake, looking for advise on AR15 223 Wylde threaded in standard 1/2x28 or the 5/8x24. This may host my AAC M4-2000 which from my research all their brakes in either 223/308 will work with my can.

Is there any real word noticeable difference in accuracy, for the better, if I go with the 5/8x24 threading?

 

[502Chevelle]

I think that if there was a problem with 1/2 x28, the companies would have gone away from it. I think that you would be good with either. That being said, if you go with the 5/8, you can swap all your stuff back and forth with your other rifles as long as you don’t screw a 223 brake on your 308 ( and the op says, well duh!).

 

[jackal2001]

All my stuff is 1/2x28 so this would be a one off. Just looking to a really high end build and squeeze all the accuracy I can out of it.
I've read that with the added steel around the muzzle when doing 5/8 it should increase accuracy due to less expansion as the bullet passes through that area. It may be all BS for all I know.

 

[Constructor]

Not when the bullet passes through, removing all that metal to get down to the 1/2" thread allows the muzzle to expand. You can check with .218 and .219 inspection pins. If a .219 goes in but stops 5/8" in where the threads do then you know the muzzle is swelled.

 

[FishinGuns]

Does the muzzle still expand with a properly torqued and rocksett muzzle device on a 1/2-28 muzzle?

I’ve been wondering that lately.

 

[jackal2001]

Does the muzzle still expand with a properly torqued and rocksett muzzle device on a 1/2-28 muzzle?

I’ve been wondering that lately.

Thought the same thing.

 

[Constructor]

Rifling in button barrels is formed by the button pushing outward, it compresses the material that forms the grooves. That creates stress in the barrel. When material at the muzzle threads is removed there is less material to hold the shape and size formed in the rest of the barrel. The muzzle swells as soon as the threads are cut, screwing a muzzle device on is not going to squeeze the bore back down.

In 2009 I purchased 10 or 11 barrels from different companies to test and figure out what I wanted to use in builds. All but one did not shoot very well so I tried to figure out why one shot well and the others did not. In the end it was the muzzle, I cut the threads off and recrowned the barrels and all of them shot better. In all the tests I ran in 2009 bullets like the 69gr SMK that were a full.224" diameter the accuracy was not effected as much. Bullets like the Noslers and fmjs that were .2235" in diameter groups size increased over 1 MOA in the barrels that had 1/2" threads.

 

[MPDS13]

I have never had a problem with the 1/2x28 threads. I would want to keep all my 223/556 stuff separate so it can’t be accidentally swapped over. But if your 556 can fits on the 5/8 version. Then there is less likely of that happening.

I had a precision bolt gun built once and the builder suggested 5/8x24 for the barrel. Said it wouldn’t make a difference as I was going for accuracy and not worried about suppressor comparability Since all I had at the time were 30 cal cans.

 

[jackal2001]

Rifling in button barrels is formed by the button pushing outward, it compresses the material that forms the grooves. That creates stress in the barrel. When material at the muzzle threads is removed there is less material to hold the shape and size formed in the rest of the barrel. The muzzle swells as soon as the threads are cut, screwing a muzzle device on is not going to squeeze the bore back down.

What about cut rifled barrels like Kriegers?

 

[Josh1978]

My ARs are all 1/2-28. Never had any trouble with them.

 

[Steel head]

What about cut rifled barrels like Kriegers?

They don’t have the same internal stresses.
Really good button barrel are stress relived and exhibit less problems.

1/2-28 is fine for AR’s.

 

[Constructor]

What about cut rifled barrels like Kriegers?

Not as much stress in cut rifled barrels.

 

[Constructor]

They don’t have the same internal stresses.
Really good button barrel are stress relived and exhibit less problems.

1/2-28 is fine for AR’s.

Most button rifled barrels are stress relieved. Like I said earlier all you have to do to figure it out is run a .219" inspection pin down in the muzzle and see if it stops about 3/4" in.

Some people are fine with 1.5-2.5" groups at 100 yds, some aren't satisfied unless they are closer to 1/2".

 

[B y r o n]

Something you may want to think about is the muzzle device. If you are looking for the most effective device than you may want to stay with the standard. 1/2-28 are sized for .223/.224 projectiles where 5/8-24 are sized for 6mm/.243 or .308 projectiles. Another thing to remember is that suppressor usually need a certain amount of shoulder for the best support. Also, heavy muzzle devices hung off thin barrels isn't a good idea. Only you seem to know the specifications for your barrel so you'll have to make the best choice for your parts.

 

[FishinGuns]

I’ve contemplated that as well. Do .308 muzzle devices, mainly 1 to 2 baffle brakes, effect accuracy on .223, 6mm, or 6.5mm projectiles? If shot only suppressed?

This thread is a can of worms I’ve been thinking about for a bit here!

 

[AccuSol-ERN]

If you are squeezing out absolute ultimate accuracy.....take a look at what that group is doing. Either no brake or custom threads to leave the most amount of material possible.......yes even on those no stress cut rifled barrels.

Just sayin'

Having said that......if you are wanting unbelieveable accuracy from an AR......try again.

But I don't know shit about fuck.

Ern

 

[FishinGuns]

For me, it’s about choices available to me for builds I’m in the process of gathering parts for. If I can make a better decision at little to no extra cost, I’ll just do that and get’er as close as I can. Makes sense in my head, at least.