Gunsmithing Need a thread chaser/tap in 1/2x28 for my Sparrow

[bm11]

Chad at LongRifles just threaded my Lilja barrel to exact Silencerco specs, including the section for the O-ring. I received it back last night and found that I could not thread it all the way to the shoulder, probably had it close to within .050"-.100". I checked the measurements on the threads, they are all in spec with the diagram. I checked the thread pitch against a Surefire brake, and again, no issues. This narrows it down to the suppressor.

I believe the issue is that I had l put roughly 3-5k rounds through the can with my Tactical Solutions Buckmark barrel. The threads are short on that barrel, roughly .395". I think that lead has built up inside the threads in front of the Buckmark barrel and it is prohibiting the Sparrow from fully threading onto the Lilja barrel.

I think the right solution would be to clean the threads with a tap or a thread chaser. I need to know what tool to order and where, with a bit of help from you guys. I know that the pitch is 1/2x28, but I have no idea the difference between class 1, class 2, etc.

As an alternative, if Silencerco would call me for my upgrade to the Gen 2 Sparrow, I could just send this one in for the update (I have been on the list since September.)

Thanks,

-Bob

 

[Starbuck]

Re: Need a thread chaser/tap in 1/2x28 for my Sparrow

Hey Bobby, I have a 1/2x28 tap you can borrow. I used it to chase out the threads of an STW 9mm can and it worked fine. I dunno about Class 1 vs 2.....

Just LMK an address via PM.

Sam

 

[bm11]

Re: Need a thread chaser/tap in 1/2x28 for my Sparrow

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Starbuck</div><div class="ubbcode-body">Hey Bobby, I have a 1/2x28 tap you can borrow. I used it to chase out the threads of an STW 9mm can and it worked fine. I dunno about Class 1 vs 2.....

Just LMK an address via PM.

Sam </div></div>Done deal!

 

[jbell]

Re: Need a thread chaser/tap in 1/2x28 for my Sparrow

Thread classes are a way of describing how tight a set of threads fit. A class 1 is not as tight as a class 2 and that is not as tight of a fit as a class 3. Threads for a muzzle device should be a class 3 fit. So be careful about what you use to clean the threads with. I should of mentioned that to you earlier today on the phone. I think a good way to judge will be to lube the tap and thread it in with your fingers using very little pressure. If no resistance is felt until you hit the lead in the threads you will be good to go. But if it threads in pretty snug you may want to rethink it.

I by no means am the smartest tool in the shead so if I am not correct here someone please set me straight. But I think I am pretty close on this one.

 

[jbell]

Re: Need a thread chaser/tap in 1/2x28 for my Sparrow

BTW, starbuck very cool!