Barrel Thread Pitch

[Engineerpower]

Doing some R&D on a threaded barrel concept, and had a quick question about the preferred pitch.

I'm most familiar with 1/2-28 for muzzle devices, but see a number of 9mm pistol barrels in 13.5mmx1LH as well.

If a R51 threaded barrel were to hit the market, would y'all be interested in the metric thread, or would the 1/2 thread be preferred?

For suppressors, all mine have been Form-1'ed and I haven't paid much attention to other commercial pattern as they don't constrain my design.

[1911SHOOTER]

Engineer,
     Have you noticed that there is no room on the end of the barrel for a suppressor?
The end of the barrel is flush with the front of the slide.    Or do you intend to fabricate
a totally new longer  barrel?
Blackie

[Engineerpower]

Never doubt a man with a machine shop and a little time on his hands...

Yes, I've done the CAD for a barrel extension to thread onto the end of the stock barrel and allow the threads to start 0.125" from the end of the slide and allow suppressor and other devices.

I'll have the prototype machined up next week for T&E, and will report back with some teaser pics. 

[1911SHOOTER]

Engineer,
If you come up with a standard threaded barrel, I will be interested.
No Metric stuff.
Blackie

[Engineerpower]

It being late, I'm just gonna leave this here...



More info tomorrow...

[Engineerpower]

Finally had all the parts and tooling come in, and we fab'ed up the prototype extended and threaded R51 barrel. Using the factory Gen2 barrel, a 416 Stainless extension is semi-permanently attached with internal threads and high-temp threadlocker, and the new muzzle is threaded the standard 1/2-28. OAL extends 0.85" from the front of the slide.

The thread protector is SS as well, and actually helps pull the barrel forward quite nicely for disassembly. With a suppressor attached, The balance shifts forward a bit, which feels quite nice to me. The factory rifling and muzzle aren't touched at all during the process.

Looks like we're going to do a first run of 25 pieces, anyone interested? Working through pricing and marketing right now.

[SCurmudgeon]

WOW, that is cool.  I don't understand everything you said, but I like it.  Where did you get a barrel; that didn't have the grip ridges?

[funflyer]

WOW, that is cool.  I don't understand everything you said, but I like it.  Where did you get a barrel; that didn't have the grip ridges?

He used a factory barrel and machined just the outer diameter at the front to remove the grip serrations and thread it for the extension, a very good idea. The only question I have is, are these barrels the latest run from Remington or the ones floating around for sale on Ebay and other places.

[SCurmudgeon]

Thanks.  I can barely see where the barrel extension fits over the top of the original barrel.  That is a good idea!

I'll let EP confirm, but it looks like he used a standard Gen 2 barrel.  The link below elsewhere in our forum has pics of the differences between the Remington stock barrels and those offered on ebay.

http://r51pistol.com/r51-general-discussion/r51-barrels-on-ebay-cheap/

[SCurmudgeon]

Looks like we're going to do a first run of 25 pieces, anyone interested? Working through pricing and marketing right now.

Yes, I'm certainly curious.

[1911SHOOTER]

Thanks.  I can barely see where the barrel extension fits over the top of the original barrel.  That is a good idea!

I'll let EP confirm, but it looks like he used a standard Gen 2 barrel.  The link below elsewhere in our forum has pics of the differences between the Remington stock barrels and those offered on ebay.

http://r51pistol.com/r51-general-discussion/r51-barrels-on-ebay-cheap/

SCurmudgeon,
Check with Iklawson,  He and I bought an ebay barrel, there are no differences in them!   Trust me, If Kirk says they are the same,
they are the same!  Take it to the bank!
Blackie

[Engineerpower]

The only question I have is, are these barrels the latest run from Remington or the ones floating around for sale on Ebay and other places.

I'll be totally upfront: my prototype is a Gen2 barrel I bought off eBay for T&E (here's the link: https://www.ebay.com/itm/Gen2-REMINGTON-R-51-FACTORY-BARREL-9mm-LUGER-P-R51-GENUINE-remington-gen2-gen-2/201858320078).

I compared this to the stock barrel that came with my Gen2 R51, and the only difference I can identify is the machining technique on the sides at the barrel pin hole. On my old one, it was machined as a pocket and on the eBay one, it was machined as two slots; functionally and by all other appearances they're exactly the same and it ate 2 mags without a hitch this afternoon. It arrived to me totally clean, in 'new, unfired' condition, and fit perfectly into my slide.

I'll let EP confirm, but it looks like he used a standard Gen 2 barrel.

Correct.

I can barely see where the barrel extension fits over the top of the original barrel.  That is a good idea!

Thanks! MUCH easier and cheaper than machining a whole new barrel from a rifled blank. There's another shop that does this technique, but they charge $160 to do it to YOUR barrel, rather than provide you with a second one. We'll be shipping you a new barrel, and beat this price by quite a bit.

[funflyer]

I compared this to the stock barrel that came with my Gen2 R51, and the only difference I can identify is the machining technique on the sides at the barrel pin hole. On my old one, it was machined as a pocket and on the eBay one, it was machined as two slots; functionally and by all other appearances they're exactly the same and it ate 2 mags without a hitch this afternoon. It arrived to me totally clean, in 'new, unfired' condition, and fit perfectly into my slide.

That one seems to be the genuine article then, great. Looks very promising. Are you also going to do some accuracy testing to compare with the original?

[lklawson]

Thanks.  I can barely see where the barrel extension fits over the top of the original barrel.  That is a good idea!

I'll let EP confirm, but it looks like he used a standard Gen 2 barrel.  The link below elsewhere in our forum has pics of the differences between the Remington stock barrels and those offered on ebay.

http://r51pistol.com/r51-general-discussion/r51-barrels-on-ebay-cheap/

SCurmudgeon,
Check with Iklawson,  He and I bought an ebay barrel, there are no differences in them!   Trust me, If Kirk says they are the same,
they are the same!  Take it to the bank!
Blackie

FWIW, I agree with Blackie.  I've not found any difference between the bbl which came with the gun and the fleabay, right down to the fact that both of them seem have SAAMI minimum spec leade/freebore.  I should probably buy chamber gauge or something but I'm pretty cheap. 

Peace favor your sword,
Kirk

[Engineerpower]

. Are you also going to do some accuracy testing to compare with the original?

I will probably do this when I build my 9mm suppressor. I've been sitting on an NFA stamp for a while, just have had to many 'must-do' and need-do' projects before I get around to 'wanna-do'...

...SAAMI minimum spec leade/freebore.  I should probably buy chamber gauge or something but I'm pretty cheap. 

I was thinking about that last night; have you considered using a throat reamer to open up the free bore a little bit? I have the measurement equipment other than the reamer, if several people need their barrels reamed, we could offer this as a service. Maybe an option on the threaded barrels!