How far to thread the muzzle

[BOLTED]

Hello all,

I am having some barrels threaded for suppressors, and the gunsmith would like to know how far I want them threaded. I THINK he said the standard is about .4 or .5 for the 223 and .6 to .7 for the .308. A Thunderbeast Arms will go on the .308's, and a Griffin Armament for the AR-15. The suppressors and brakes I am using now, may be different in the future, so I'm really looking for "fit all" length.

Should I ask him to crown or do something else to the end of the barrels after threading? If so, how many degrees should it be cut at if at all? All of them will be wearing a muzzle brake with and without the suppressors.

Remington 700 .308, 5/8x24x?
Armalite AR10 .308, 5/8x24x?
Lilja AR-15 223, 1/2x28x?

Thanks in advance for your input!

Dave Johnson

 

[hpshooter]

" A Thunderbeast Arms will go on the .308's, and a Griffin Armament for the AR-15."

I would check with the suppressor manufacture for the recommended thread length.

 

[BOLTED]

I may use different suppressors or brakes in the future, so I edited the post to reflect that. Just looking for what length most people are threading to on average that should accommodate most muzzle devices.

Thank you.

 

[Alex Wheeler]

5/8x24 is typically .6" long.

 

[GenePoole]

I usually go with AAC's blueprints:

http://www.advanced-armament.com/assets/images/pdf/manuals/ThreadGuideREV_01-040513.PDF

 

[clowdis]

"Generally" speaking, .437 for 1/2-28 and .562 for 5/8-24. BUT you will occasionally run into a suppressor that needs a different length. Checking with the manufacturer isn't a bad idea.

 

[BOLTED]

Thank you all for your input. I ended up sending him the specs from the Thunder Beast Arms website. It seems to be in line with what you guys have suggested. Thunder Beast specs were what I was planning on going with, but I have found that there is a wealth of knowledge to be found here.

No one has chimed in on how to leave or cut the end of the barrel though. Does it not matter much? There wont be much meat left on the very end of it, and I don't want it to bell. The AAC spec says to recrown if the barrel has been shortened, but it doesnt give the crowning spec.

 

[savagedasher]

"Generally" speaking, .437 for 1/2-28 and .562 for 5/8-24. BUT you will occasionally run into a suppressor that needs a different length. Checking with the manufacturer isn't a bad idea.

That should work but the thread need to have a relief cut at the back . Larry

 

[X Ring Accuracy]

Once barrel is set up to thread, never a bad idea to make sure the crown is cut correctly, especially if using a factory barrel.

 

[shortgrass]

Just take a look at the threaded muzzle of a AR15 and a AR10. The threads for muzzle attachments that are installed from the factory are 5/8" long. Most suppressors are sized and developed around the ARs, so..............