Patrick L
02-25-2011, 09:32 AM
I recently corrected a problem that has been bothering me for 20 years in one gun, just recently in another.
Both my 5 screw pre 25 .45 ACP and my 4 screw pre 29 would bind in DA firing. One shot a cylinder would hang up, and no it wasn't always the same chamber. The .45 would do it 99% of the time, sometimes I could get thru six shots but then always the next 6 would have one stick. The .44 did it once or twice evey cylinder full.
I have had the .45 for just over 20 years now, and I had been told by a "gunsmith " (quotes mine) that the gun was just very tight and that the buildup from my lead bullet handloads was causing the binding. For years I would clean it scrupulously during shooting sessions, even carrying a stainless toothbrush to scrub the cylinder face and breech face between each cylinder full. I had bought this gun to compete in bowling pin shoots, so this was not a good situation. The bowling pin shoots eventually dried up, and I do lots of other shooting activities (I am the definition of jack of all trades, master of none) so the problem was sort of forgotten/lived with for years, as the gun was shot only for fun and usually single action bullseye style. I figured it was just a flukey situation, and I was dumb enough to accept the "expert"'s diagnosis. I really liked the gun, especially since it was a pre model 5 screw, so there was no way I was going to get rid of it. I just lived with it.
Fast forward to last summer and I acquired the pre 29. It displayed the same tendency to bind during DA shooting, but even worse, so I figured there had to be another explanation. The guns were clean, so that was not the problem. I was beginning to fear maybe the indexing parts (hand, star, etc.) might be worn, as both guns are 50+ years old, and repairing them might be pricey.
Then someone on the S&W forum suggested that the guns might have some excessive cylinder endshake (this was after about 50 kind souls who didn't read my post saying that the guns were "scrupulously clean" responded telling me I needed to clean the guns.) I purchase a set of those Power shims and went to work. I did the .44 first, since it was newer to me and I was "hotter" for it. The gun would only take one shim, it wouldn't even close on two. A trip to the range put 50 rounds through it DA, smooth as butter. Success! I didn't get around to tackling the .45 until this week. This one took two shims, but the end result was the same! I realize I am opening up the barrel/cylinder gap a bit here, but given the choice between a tight gap and a gun that works, I'll take the working gun. My theory was that during recoil, the loose cylinders were moving forward as the guns recoiled back, and indeed the buildup of firing residue between the barrel and cylinder face was the problem. The guns could be dry fired until the springs broke and nothing would happen, but add in the recoil of live rounds and things would shift.
Here's the pre 29
http://i204.photobucket.com/albums/bb157/patrickl_01/Pre%2029/Pre29052.jpg
And here's the pre 25, although it now has a set of Eagle repro Cokes
http://i204.photobucket.com/albums/bb157/patrickl_01/Bullets/GunStuff053.jpg
Both my 5 screw pre 25 .45 ACP and my 4 screw pre 29 would bind in DA firing. One shot a cylinder would hang up, and no it wasn't always the same chamber. The .45 would do it 99% of the time, sometimes I could get thru six shots but then always the next 6 would have one stick. The .44 did it once or twice evey cylinder full.
I have had the .45 for just over 20 years now, and I had been told by a "gunsmith " (quotes mine) that the gun was just very tight and that the buildup from my lead bullet handloads was causing the binding. For years I would clean it scrupulously during shooting sessions, even carrying a stainless toothbrush to scrub the cylinder face and breech face between each cylinder full. I had bought this gun to compete in bowling pin shoots, so this was not a good situation. The bowling pin shoots eventually dried up, and I do lots of other shooting activities (I am the definition of jack of all trades, master of none) so the problem was sort of forgotten/lived with for years, as the gun was shot only for fun and usually single action bullseye style. I figured it was just a flukey situation, and I was dumb enough to accept the "expert"'s diagnosis. I really liked the gun, especially since it was a pre model 5 screw, so there was no way I was going to get rid of it. I just lived with it.
Fast forward to last summer and I acquired the pre 29. It displayed the same tendency to bind during DA shooting, but even worse, so I figured there had to be another explanation. The guns were clean, so that was not the problem. I was beginning to fear maybe the indexing parts (hand, star, etc.) might be worn, as both guns are 50+ years old, and repairing them might be pricey.
Then someone on the S&W forum suggested that the guns might have some excessive cylinder endshake (this was after about 50 kind souls who didn't read my post saying that the guns were "scrupulously clean" responded telling me I needed to clean the guns.) I purchase a set of those Power shims and went to work. I did the .44 first, since it was newer to me and I was "hotter" for it. The gun would only take one shim, it wouldn't even close on two. A trip to the range put 50 rounds through it DA, smooth as butter. Success! I didn't get around to tackling the .45 until this week. This one took two shims, but the end result was the same! I realize I am opening up the barrel/cylinder gap a bit here, but given the choice between a tight gap and a gun that works, I'll take the working gun. My theory was that during recoil, the loose cylinders were moving forward as the guns recoiled back, and indeed the buildup of firing residue between the barrel and cylinder face was the problem. The guns could be dry fired until the springs broke and nothing would happen, but add in the recoil of live rounds and things would shift.
Here's the pre 29
http://i204.photobucket.com/albums/bb157/patrickl_01/Pre%2029/Pre29052.jpg
And here's the pre 25, although it now has a set of Eagle repro Cokes
http://i204.photobucket.com/albums/bb157/patrickl_01/Bullets/GunStuff053.jpg