Gunsmith/Machining Gurus - Change Thread on Muzzle Device?

[LRShooter101]

Calling all gunsmith / machining experts! I am checking to see if it might be possible to redo the threads on a muzzle device? Specifically would it be possible to take the 7/8"x14 threads found in a Barrett QDL Muzzle Device and "open up" / rethread that muzzle device to 1"x14?

At this point, I am not sure if it would be better (or easier) to rethread the barrel or rethread the muzzle device? As my luck would have it, the barrel on my .50 BMG is threaded 1"x14, and the Barrett is the only suppressor that I can find in stock anywhere.

Needless to say, the threads on the muzzle device would have to be perfect or you could be "grenading" a .50
BMG suppressor with a baffle strike.

Thanks in advance!

 

[lariat]

nobody can answer the question as you have left out the current dimension details. What is the OD of the can where it threads on to the barrel? You need to know what the resulting wall thickness would be as measured against the thread major in addition to the material the can is made of. You also need to look at the thread depth that you can put in the supressor vs the thread length on the barrel, etc.

There are some of the details that you need to provide. If you can provide those it would help the thread along. But even if it looks like it’s a go you still need to find a gunsmith that is willing to do the job.

 

[Makinchips208]

Calling all gunsmith / machining experts! I am checking to see if it might be possible to redo the threads on a muzzle device? Specifically would it be possible to take the 7/8"x14 threads found in a Barrett QDL Muzzle Device and "open up" / rethread that muzzle device to 1"x14?

At this point, I am not sure if it would be better (or easier) to rethread the barrel or rethread the muzzle device? As my luck would have it, the barrel on my .50 BMG is threaded 1"x14, and the Barrett is the only suppressor that I can find in stock anywhere.

Needless to say, the threads on the muzzle device would have to be perfect or you could be "grenading" A .50
BMG suppressor.

Thanks in advance!

Yes theoretically the threads can be cut to 1”-14.
Concentricity/alignment, and a variety of other factors can come into play, as already stated by @lariat

 

[LRShooter101]

nobody can answer the question as you have left out the current dimension details. What is the OD of the can where it threads on to the barrel? You need to know what the resulting wall thickness would be as measured against the thread major in addition to the material the can is made of. You also need to look at the thread depth that you can put in the supressor vs the thread length on the barrel, etc.

There are some of the details that you need to provide. If you can provide those it would help the thread along. But even if it looks like it’s a go you still need to find a gunsmith that is willing to do the job.

Not sure if you understood the original post? This is regards to a Barrett .50 BMG Suppressor and the QDL Muzzle Device that is used to mount it.
https://barrett.net/products/accessories/suppressors/qdl-suppressor / https://barrett.net/shop/qdl-muzzle-brake-kit
As such, the Can does not thread on the barrel, the QDL Muzzle Device threads on the barrel, and the Can attaches that device. The "thread modification" would be made to the muzzle device not the Can.

To your point, there is a valid question if it would be acceptable to remove 1/16" from each side of the existing threads from the QDL Muzzle Device?

The best answer, is most likely to have the barrel rethreaded. However, that is also going to be the pain in the ass answer when it comes to shipping the .50 BMG to a gunsmith who can do the work!

 

[jetmd]

Your location shows Southern Indiana correct?

I would recommend using someone within a days drive.

Think SAC in Ohio
Even if your in the Southern tip of IN it would be an easy drive.

Call ahead, plan your work and work your plan.

If you need someone closer ask and I’m sure we can find you a good smith.

 

[jetmd]

Geoff Corn used to be in Southern IN
Don’t know if he still is?

Has done work for me in the past and I would highly recommend him!

 

[308pirate]

Specifically would it be possible to take the 7/8"x14 threads found in a Barrett QDL Muzzle Device and "open up" / rethread that muzzle device to 1"x14?

ETA: Wait if you're talking about opening up internal threads, yes it can be done.

Assuming there's enough wall thickness left and subject to an extremely good lathe setup.

 

[oldrifleman]

Grind or bore the device out 1/8 and re-thread. You just need a decent machinist and enough material on the muzzle device to lose 1/8 and still be strong enough to handle the loads.

 

[ken226]

It's a muzzle device, so he's talking about enlarging a female threaded hole.

A 1-14 tap drill is .9375", diameter, and the major diameter of your existing 7/8-14 thread is .875"

So, as long as the outside diameter of the device is sufficiently large as to not leave the wall too thin, it should be doable.

 

[lariat]

Please tell me how to make a 7/8" thread grow into a 1" thread.

I really cannot grasp how that can be done.

Open up the hole and rethread it. But you bring up a good point. I am not at the shop with all my charts but if the 7/8”thread major is less than the 1” thread minor or there is minimal engagement there could be problems. I’m thinking about thread engagement %.

It’s easy to say “rethread it”, but there are things to factor in.

 

[oldrifleman]

Yep, can it be done, yes, should be done, not sure. Not a lot of material left by the time you cut the old threads away.

 

[lash]

I know this is not what you asked, but you could use a threaded adapter. 1-14 female to 7/8-14 male. It would add just over the length of your 7/8 thread to the barrel length. Rockset it on.

 

[308pirate]

Open up the hole and rethread it. But you bring up a good point. I am not at the shop with all my charts but if the 7/8”thread major is less than the 1” thread minor or there is minimal engagement there could be problems. I’m thinking about thread engagement %.

It’s easy to say “rethread it”, but there are things to factor in.

I thought the op was talking about external threads, hence my now deleted comment

And as you say enlarging an internal thread to a size so close to the original needs a thorough review of all dimensions and tolerances. Even the tread class has an effect.

 

[LRShooter101]

Thanks to everyone for the feedback!

That idea on making an adapter is an interesting one.

I have sent messages to a couple of gunsmiths that I use, but with the Holiday I don't expect to hear from anyone for a couple of days.

I was initially wondering why Barrett did not offer a 1" option, but then I remembered it was Barrett!

End of the day, I am pretty sure that it will come down to rethreading the barrel, which sucks that there are not more options out there.

 

[lash]

Maybe PM this guy, who is making 1/2 to 5/8 muzzle thread adapters. I don’t know if he’ll do it, but it’s worth asking.

Accessories - FS: Muzzle Thread Adapters 1/2-28 to 5/8-24

I have a few more of these thread adapters for sale. They are precision machined from 303 Stainless, on a CNC Lathe. OD threads are Class 3a, and ID threads are Class 2b, OD and ID are concentric within .0003-.0005 . Any questions feel free to message me. I have these listed a couple places and...

www.snipershide.com