Question about Threading on a lower

[Baconator]

I have a TM 80% that I completed at roccobro's place. This was originally for a pistol but I decided to use it for a rifle. It had previously had a pistol tube on it when I was building the pistol.

I purchased a stock from stag and I cant get the tube on. I tried the tube on another lower I have and it goes on fine. This one won't go past half way. I don't understand because it previously had a tube on it. Is there anything I can do? I don't want to break the tube by forcing it on there.

[tanakasan]

Measure the new tube OD and look for burrs/nicks on the threads.

The receiver already has had a tube on it, I suspect the new tube.

Robert

[Baconator]

Measure the new tube OD and look for burrs/nicks on the threads.

The receiver already has had a tube on it, I suspect the new tube.

Robert

That's what I thought too but it threads easy onto 2 other lowers from Palmetto State Armory that I have. I would just throw it on one of those but I don't have any spare LPK's laying around.

[kurby09]

check the actual threading on the reciever, did you or could it have been stripped in anyway? if anything try runnng a tap through it to clean up the threading and see if that works. I had to rethread my tm 80% lower because metal shaving debris was in the threaded area when i went to go install the tube and it tweaked and messed up the threading on my receiver so i went and rethreaded it to clean it up and now its back to normal and the tube went on just fine afterwards.

[wash]

If you can get a carbine tube castle nut on the buffer tube, it's threads are fine, look at the lower.

To feel for screwed up threads, use a dental pick or a similar tool to probe the bottom of each thread.

[G-forceJunkie]

If "In the jungle, the mighty jungle" is close to me, I think I have the right tap to chase the reciever threads. But only if you change that stupid line and fill out your profile properly

[ar15barrels]

If the tube threads 1/2 way in, the threads are just tight.
Take some 120grit lapping compound and lap the threads in with the buffer tube you want to use.
Just make sure you clean all the lapping compound off afterwards.

[Baconator]

A calgunner let me borrow the tap and I got her done. Thanks everyone.

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