Why 1/2x28 ?

[grottulf]

7 hours ago, ltdmstr said:

 

Not at the moment, but I'm probably going to do one next week.  I'll try to remember to take some photos.

Thanks, that would be really great!

[TRUBL]

On 3/18/2021 at 12:16 AM, ltdmstr said:

5/8-18 is standard fine thread and would seem to be a good choice for 9mm.  Regarding 1/2" threads on a 9mm barrel, at the base of the threads the barrel od is .450.  So that gives you .095 barrel thickness at the thinnest point (assuming SAAMI spec .355 groove diameter).

wrong math batman.....divide that by 2 and that is your wall thickness and yes......scary!!!.....oops, someone else caught that 

 

Edited March 19, 2021 by TRUBL

[71Commander]

On 3/17/2021 at 1:08 PM, rishii said:

I seem to recall Taccom saying not to use a crush washer to time their comps because you could damage the barrel due to it being thin

Also 9mm barrels used to be commonly  threaded 1/2x36, same as the 7.62x39 which made it harder to do stupid things

My AK bbl 7.63X39 is 14mmX1 LH.

[robertg5322]

3 hours ago, TRUBL said:

wrong math batman.....divide that by 2 and that is your wall thickness and yes......scary!!!.....oops, someone else caught that 

 

Imagine if these comps were actually doing anything significant, there'd be hours of video of comps breaking off and flying downrange...

[ltdmstr]

3 hours ago, TRUBL said:

wrong math batman.....divide that by 2 and that is your wall thickness and yes......scary!!!.....oops, someone else caught that 

 

 

I know.  But someone beat you to it.

[TRUBL]

5 hours ago, robertg5322 said:

Imagine if these comps were actually doing anything significant, there'd be hours of video of comps breaking off and flying downrange...

trudat!!.....I will say that we've had a couple 5.25" barrels snap off the end when customers used crush washers.......one reason we went away with QPQ (too brittle) and went back to black oxide

[robertg5322]

23 hours ago, ltdmstr said:

 

Geez, not sure how I screwed that, but obviously you're right.  Thanks for the catching it.

No problem, catching trivial mistakes is kind of my thing... ;-).

 

 

In that vein, I actually spent two weeks in facebook jail for posting this one.

 

 

[grottulf]

We ended up threading it M14x1 instead, and redrilled and tapped the comp to match.

1/2" just felt crazy...

[ltdmstr]

Here's how I do the pin and weld for 1/2" 9mm barrel.

 

 

[ltdmstr]

Welded.

[grottulf]

Great!

Thanks for sharing!

[ltdmstr]

Next time I'll probably skip the pin all together and just weld up the groove.  Either way, it's permanent until you cut it apart.