Question For Gunsmiths

[eric nielsen]

Has anyone has tried machining a cylindrical spacer, OD = .378, ID = .357, length = 2mm ???

One of these, tapped down into the bottom of a 9x21 chamber, would allow someone with a gun chambered in 9x21 to shoot 9x19 Major ammo with correct headspacing, in a gun that's already designed for 1.150" OAL ammo.

Would be cool for guns with the primo WCPI barrels, like the very nice one that Erik Warren is selling: http://www.brianenos.com/forums/index.php?...pe=post&id=2471

Not sure if 2mm+ of freebore is going to mess with the accuracy of a gun. Might be worth a try for a machinist or gunsmith to try, esp. if they have an old P9 gun sitting around.

Edited November 3, 2005 by eric nielsen

[Anthony Lombardo]

Has anyone has tried machining a cylindrical spacer, OD = .378, ID = .357, length = 2mm ???

One of these, tapped down into the bottom of a 9x21 chamber, would allow someone with a gun chambered in 9x21 to shoot 9x19 Major ammo with correct headspacing, in a gun that's already designed for 1.150" OAL ammo.

Would be cool for guns with the primo WCPI barrels, like the very nice one that Erik Warren is selling: http://www.brianenos.com/forums/index.php?...pe=post&id=2471

Not sure if 2mm+ of freebore is going to mess with the accuracy of a gun. Might be worth a try for a machinist or gunsmith to try, esp. if they have an old P9 gun sitting around.

I have often wondered about this.. It would be a great way to salvage some of the 9x21 or TSW guns out there instead of spending $300-400 on a new barrel.

[10mmdave]

Done did it with (2) 10mm barrels, I think you do need a chambering reamer to do it right.

I made up a sleeve of 316 stainless steel for a light press fit, ID was slightly smaller but

large enough to get my chamber reamer in. Make it a little long so you can cut the

headspace and give it a shot.

Now these are straight walled cases and the 9 is tapered, might make the ID dimension a

bit tricky.

I believe the 1911 Jerry K book shows a conversion by drilling out the whole chamber and

silver soldering in a bored slug and re-chambering that way. Alot more work but a more

substantial piece of metal.

(now mind you this is coming from a guy who converted a Clark cut frame to Wilson/Nowlin

type with half a bolt shank and JB Weld )

[BEDELLCUSTOM]

eric are you serious or is that a real thought that you had, i hope you're kidding.

[eric nielsen]

I guess I wasn't serious

No, I don't wanna buy a gun like that either. I have a TZ, and it shows cracks in 7-8 places.

[Patrick Sweeney]

I imagine it would work, but for how long is a valid question. As an R&D, or magazine article, I can see it. For a plinking gun, fine. For a carry gun or a competition piece, I'm not sure I'd want to depend on it.

Dean Grennel did much the same thing. His bushing stock was a steel case in 9mm, that he cut and pressed into a Browning 190-something-or-other chambered in 9mm Browning Long. He did it so he could shoot the gun with .380 Auto ammo. By the time he could get the gun to cycle, the rounds were, shall we say, stout.

A few years later he managed to talk an ammo company into pressure-testing his loads. They told him in no uncertain terms to knock it off. (Not a problem in the application under discussion.)

Were I trying to bush a 9X21 to 9X19, I use a power drill to scrub the chamber, then degrease it. It press-fit the bushing in with dark green Loctite, the shaft and bearing locker stuff. Once it was set, I'd clean things up with a chamber reamer.

The problem is, all Loctite is heat-degraded. If you shoot the gun and heat it up enough, your bushing can come out. The 680 Loctite is the toughest, but even it will quit if heated enough.

[Radical Precision Designs]

I love brain teasers, sometimes it amuses me to ponder the ridiculous, so long as I understand is only something to kill time, rather than watch TV.

So here it goes. First thing is to visualize the final product dimensions and how close they come to the target dimensions. Bullet positioning and "leade" to rifling engagement are different between these two cartridges as per manufacturers descriptions. But if you are talking "9mm. Major where you would be loading longer, perhaps a "free-bore" approaching .38 Super might be more compatible than the standard shorter space available with a "stock" 9mm , and it would help keep pressures lower with these "extra long" rounds like yours Eric. (1.200+ ?), where otherwise you would be "jamming" the bullet's ogive into the rifling, and mimic a grenade. So at least we can find some "possible justification" to mitigate this brain tease. But remember that you can not un-do the extra jump you would have should you shoot normal "short" 9's.

Personally I dont like to shoot "two piece chambers". But these are not new. Quite a few barrels were made in the early days where the barrel and the chamber were made separately, sometimes of different alloys and then press fit together. I think I have a Browning High Power with a barrel like that. But this would be slightly different, in which you would approch it as you would when "lining a barrel". I would not just press fit a tiny spacer-bushing so miniscule that even if you silver soldered it in place soon enough would distort (disimilar metals reacting and eroding under humonguous pressure and heat for a short duration) and "blow" away soon enough. Especially considering the location/positioning of this tiny spacer, right on the spot where throat erosion loves to start.

So, enough ad-libing. To make it easier and not having to buy extra specially made reamers or tooling, I would push through it a larger reamer like maybe a .45ACP chamber reamer, which would bring it close to the overall lenght of the .38 Super. Now I would get busy in my lathe where I would turn down a "bushing" to press fit in there. This bushing I would promptly chamber into the 9mm. dimensions. Then I would heat up the barrel and freeze the bushing, and in an operation not unlike "sleeving" a motor, insert the bushing in place, no solder required. Then get busy cleaning it up, and presto. It would work and be safe.

But I wouldn't want one.

In the time I typed this I could have watched a few TV commercials, but this is/was better for my brain, as wasted time goes.

I am pretty sure somebody else can waste some of their time and come up with yet another way of doing it. As they say: "much a-do about nothing".

Edited November 5, 2005 by Radical Precision Designs

[Carlos]

Back when the surplus semi auto CZ ShE carbines were being imported, there was a need to convert them from obsolete 7.62x45mm cal to 7.62x39 (standard for the AK-47 and SKS).

Many thousands of steel 6mm spacers were made, sold, & installed not by gunsmiths, but rather the guns owners. I believe they were held in place by a form of super glue. The 7.62x39mm runs up to 49,000 CUP.

While a paper-thin 2mm space would not work IMHO, the idea of a newly-machined chamer insert might be feasible. Sadly, there is not much extra metal in a P9/Tanfoglio/CZ barrel to make such a modification feasible ( not like a 2011 bull barrel; plenty of meat there).