5-screw M&P bulged barrel question

[meh92]

Hello everyone,

I found a 4" 5-screw .38spl M&P with a bulged (but not split) barrel about 1.5" forward of the forcing cone. Beyone that, the mechanicals appear in good working order. I am thinking about buying it (on the cheap) and making a shooter out of it. I just have a thing for old 5-screw K-frames.

How can I tell if the bulge has affected the threads and frame? If it had, would there be any hope in rebarreling it?

I'd appreciate any comments or suggestions.

Thanks

 

[meh92]

Hello everyone,

I found a 4" 5-screw .38spl M&P with a bulged (but not split) barrel about 1.5" forward of the forcing cone. Beyone that, the mechanicals appear in good working order. I am thinking about buying it (on the cheap) and making a shooter out of it. I just have a thing for old 5-screw K-frames.

How can I tell if the bulge has affected the threads and frame? If it had, would there be any hope in rebarreling it?

I'd appreciate any comments or suggestions.

Thanks

 

[john traveler]

1.5" forward of the forcing cone would put the bulge outside of the frame threads. I would deem it safe and practicable to rebarrel for a couple of reasons:

1. S&W threads are not set up like tapered pipe threads. There is some play between the frame and the barrel tenon. Most replacement barrels thread in loosely until the barrel shoulder butts up against the frame. There is plenty of "meat" at that point in the barrel to resist bulging into the frame.

2. I've rebarreled many revolvers, including some with barrel bulges at the frame threads, and none seemed to suffer for accuracy after replacing the bad barrel.

It might be a good idea to examine the underside of the frame at the yoke cutout with a magnifying glass and good lighting. If there is any cracking or bulging, it will be there where the frame/barrel contact is the thinnest. If the machined yoke cut looks like it is wrinkled or distorted, beware: it may be sign that the frame was stressed.

Not an absoute, but it is common knowledge that pre-model marked S&W M&P guns used a relatively mild automotive quality barrel steel that is not nearly as strong as the steel in the post model numbered M&Ps. Ask any old time police armorer how many bulged barrels and dimpled cylinders he has seen from M&P revolvers from the 1930s, 1940s and 1950s.

 

[Alk8944]

meh92,

Shoot it, and if accuracy is acceptable, and if the barrel is otherwise OK I can virtually guarantee it will be, just use it as[is and don't worry about it.

My most accurate .32-20 revolver, out of 8 I own, is a 6 1/2" 1902 built in 1905. It has a bulge right at the barrel lug, and being a black powder and transition to smkeless period gun which has been rode hard and put up wet many times, has a barrel most would say couldn't shoot well. I had a never installed 5" barrel in pristine condition and thought I would help the gun as a shooter by putting this new barrel in it. To make a long story short, accuracy went in the toilet, it was like a shotgun. Took the new barel out and re-installed the original and it shoots as good as ever, and it doesn't lead, either. It does make bullets with funny rifleing marks when it re-engraves after skipping over the bulge that is longer than the bullet bearing length. It is so large as to be obvious just looking at the outside of the barrel.

The usual bulged revolver barrel is neither a safety nor an accuracy problem, just cosmetic. If it shoots well and as close to point of aim as you would generally expect a fixed sight revlover to shoot, then enjoy it as is, there are worse problems in the world than a goose egg in a barrel. For some reason it seems a barrel with a bulge rarely changes its point of impact relative to the sights when a bulge occurs.

 

[Peter M. Eick]

There is a book out written in the turn of the century by Mann called the bullets flight. He documents all sorts of experiments where he cut down the barrel of a rifle/revolver and showed what happened. Pretty amazing the pictures.

Bottom line is that a bulge near to the cylinder "likely" will have little to no impact on final accuracy.

Shoot it and see if it is good enough then consider your options.