80% buffer threads

[Just.a.guy]

Hi Guys,

I have an 80% lower that I completed a while ago. I'm looking at the buffer threads, and comparing it to my SW MP15. The buffer threads on my MP15 go all the way to the pocket, but on the 80% they only extend to the buffer retaining pin hole. Pic attached...



Is this a problem? Can I screw the buffer tube in far enough that the buffer retaining pin keeps the buffer in the tube, or am I going to have issues?

If this is a problem, how can I fix it? I assume I'd need to tap the rest of the threads, where can I get a tap this big?

Thanks!

[G-forceJunkie]

It will be fine. No reason for the threads to past the center of that hole.

[xjdesertfox]

The threads of the bufer tube should not be past the retaining pin since the nipple of the retaining pin has to stick up. It doesnt need to be threaded past the pin, otherwise your pin would be doing nothing.

[Just.a.guy]

That's what I figured, I just wanted to double check as it looked different from my store-bought lower.

Thanks folks!

[raven290]

It was explained to me once that the ones that don't go all the way to the pocket use the commercial sized buffer tubes and the ones that do use the mil spec ones. It was an LGS employee that told me that however, so someone else should probably chime in on this.

[Nathan Krynn]

It was explained to me once that the ones that don't go all the way to the pocket use the commercial sized buffer tubes and the ones that do use the mil spec ones. It was an LGS employee that told me that however, so someone else should probably chime in on this.

Total BS.

Any lower can take either. The real difference is the OD of the tube not the threads.

Someone who posted before answered correctly. What is the point in threading beyond the buffer retainer hole when you will never be able to screw in a buffer tube beyond the nipple of the buffer retainer.

Nathan

[kcstott]

Most lowers are thread milled so it should be fine.
If it was done with a tap then it needs to go past a little so there is full thread to proper depth.

this right here^^^^^

when I tap a receiver 90% of the time threads go to the pocket. Thread milled is full depth where the threads end.

[VytamenC Tactical]

DELETE

who ever machined your lower used a thread mill rather than a tap. a thread mill is a

[Sticky]

this right here^^^^^

when I tap a receiver 90% of the time threads go to the pocket. Thread milled is full depth where the threads end.

The lowers that I used for my builds were thread milled all the way through, no issues whatsoever..

[bohoki]

as long as the tube threads in all the way you are good

you can get away with loads on an 80% every one i've made looks like crap but it works i dont need a serial number you can just tell with all the mill lines and steps and wonky oval drill holes