More G.T. 'Bulged Barrel' Magic !

sheepherder · 05-16-2015, 06:36 PM

I recently saw an ad on Gunbroker.com for a Smith & Wesson Model 52 target pistol. It was listed as an 'ex-MTU' pistol with two magazines, some chips & scratches, and a bulged barrel...

The price was good (about half a 'new' M52) and after reading the thread that jamese posted ["Metal Lathe Work", http://forum.lugerforum.com/showthread.php?t=26030 ], I was confident that it could be 'rescued'!

That thread describes how G.T. repaired jameses bulged Mauser 1914 barrel, using a set of graduated 'squeeze' blocks to crimp the bulge down to manageable size.

After winning the auction, I contacted G.T. about the barrel, and he agreed to apply his expertise!

The base diameter of the barrel is .515" and the bulge measured .525". Repairs were effected using two steel squeeze blocks measuring 1" x 2" x 5/8" and one .517" reamed hole and one .515" reamed hole. A steel reinforcing rod of 8.75mm was used to keep barrel from flattening while being 'massaged'. The squeezing was done in a 1-ton arbor press assisted by one BMFH...

The squeeze was initially done in 90º increments with a .004" spacer between the .517" blocks; then without spacer; then with spacer & .515" blocks, then without. Finally the barrel was squeezed in ~10º increments in a radial pattern.

At this time, the bulge measures .516", one thousandth over the surrounding barrel. It could have probably been shrunk down to the base .515" but the 8.75mm rod was the closest available. Interestingly, an 8.8mm rod [9mm Luger bore size] would not go in.

Here's the step-by-step process, as quickly as I could snap pictures. Let's follow G.T.'s repair process, shown in the pics below!

1- The Model 52 as received. Complete, but worn and dirty.

2- The barrel. Sharp eyes will notice the bulge about 3/4" forward of the locking lug.

3- Closeup of the bore. The shadow in front of the chamber end is the bulge. It was quite noticeable when running a patch through the barrel. The patch would suddenly 'loosen' at that spot.

4- Barrel showing the marks where the bulge is located.

5- Reaming the "G.T. Squeeze Blocks".

6 - Finished squeeze blocks, with an added indexing pin (later shortened).

7 - Press showing barrel mid-way through the operation. Bore reinforcing rod is not visible, but it is in place.

8 - Final squeeze - shadow is gone!

Final pic shows a comparison between the bulged barrel and the repair.

A big "Thank You!" to Gerry for his ingenuity and time in helping me get this old blunderbuss back in excellent condition!!!

G.T. offers many other services. He can be contacted at - Gerald Tomek gctomeks@msn.com

05-16-2015, 06:36 PM	#1
sheepherder Lifer Lifetime Forum Patron Join Date: Feb 2009 Location: ...on the 'ol Erie Canal... Posts: 8,198 Thanks: 1,416 Thanked 4,462 Times in 2,336 Posts	More G.T. 'Bulged Barrel' Magic ! I recently saw an ad on Gunbroker.com for a Smith & Wesson Model 52 target pistol. It was listed as an 'ex-MTU' pistol with two magazines, some chips & scratches, and a bulged barrel... The price was good (about half a 'new' M52) and after reading the thread that jamese posted ["Metal Lathe Work", http://forum.lugerforum.com/showthread.php?t=26030 ], I was confident that it could be 'rescued'! That thread describes how G.T. repaired jameses bulged Mauser 1914 barrel, using a set of graduated 'squeeze' blocks to crimp the bulge down to manageable size. After winning the auction, I contacted G.T. about the barrel, and he agreed to apply his expertise! The base diameter of the barrel is .515" and the bulge measured .525". Repairs were effected using two steel squeeze blocks measuring 1" x 2" x 5/8" and one .517" reamed hole and one .515" reamed hole. A steel reinforcing rod of 8.75mm was used to keep barrel from flattening while being 'massaged'. The squeezing was done in a 1-ton arbor press assisted by one BMFH... The squeeze was initially done in 90º increments with a .004" spacer between the .517" blocks; then without spacer; then with spacer & .515" blocks, then without. Finally the barrel was squeezed in ~10º increments in a radial pattern. At this time, the bulge measures .516", one thousandth over the surrounding barrel. It could have probably been shrunk down to the base .515" but the 8.75mm rod was the closest available. Interestingly, an 8.8mm rod [9mm Luger bore size] would not go in. Here's the step-by-step process, as quickly as I could snap pictures. Let's follow G.T.'s repair process, shown in the pics below! 1- The Model 52 as received. Complete, but worn and dirty. 2- The barrel. Sharp eyes will notice the bulge about 3/4" forward of the locking lug. 3- Closeup of the bore. The shadow in front of the chamber end is the bulge. It was quite noticeable when running a patch through the barrel. The patch would suddenly 'loosen' at that spot. 4- Barrel showing the marks where the bulge is located. 5- Reaming the "G.T. Squeeze Blocks". 6 - Finished squeeze blocks, with an added indexing pin (later shortened). 7 - Press showing barrel mid-way through the operation. Bore reinforcing rod is not visible, but it is in place. 8 - Final squeeze - shadow is gone! Final pic shows a comparison between the bulged barrel and the repair. A big "Thank You!" to Gerry for his ingenuity and time in helping me get this old blunderbuss back in excellent condition!!! G.T. offers many other services. He can be contacted at - Gerald Tomek gctomeks@msn.com Attached Thumbnails __________________ I like my coffee the way I like my women... ...Cold and bitter... Last edited by sheepherder; 05-17-2015 at 04:23 PM.