doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Barrel Imtegrity Question.

I have a L.C. Smith That has what can best be described as a "crease" about 10 inches from the breech. Its is barely visible from the inside and the outside. It could be a barrel defect, or a repaired dent from long ago. How do I find out if it is safe to continue shooting?

I believe your going to have use your gut feeling....

The only thing I'd worry about with a crease would be that it might create a stress point, sort of like when you machine a drive shaft on a car and accidentaly machine in a small groove, or forget to machine a radius where the shaft widens, abrupt changes can create stress points.
I remember this from a metal removal (machining theory) class I took in college, perhaps one of the engineers on the board can elaborate.
Steve

Improved:
Is this "crease" longitudinal or radial? In either case, it is a flaw. If it is 10 inches of the chamber it can also be a disaster waiting to happen. I'd not shoot this gun very much it at all. Especially since it is an L. C. Smith. Best to have a top barrel man evaluate the barrels before touching off another round.

I would use a very long string and a big shell for the first shot and still worry shooting light loads. A very lite load of fast powder should reduce the pressure at the 10 inch mark. Something like 7625 might be still building pressure at the 10 inch mark. A good barrel man could turn out to be very cheap.
bill

The crease is radial on the #1 (right barrel). Very difficult to make out, unless you know what to look for. Any Suggestions on a good barrel man?

BTW. I have had about 200 round through this gun, but still am concerned.

Could we see a pic? I work on (and shoot) junk LC Smiths and would like to see what you are talking about. The pic of the split barrel and that guys shortened middle finger scares the crap out of me. How would I let people know what I think of them if that happened to me? I killed my first ever double on quail with a 1927 Elsie today.
CHAZ

"perhaps one of the engineers on the board can elaborate."

You are correct in your remembering.
One can visualize stress as flowing lines through a material, any abrupt transition causes these stress line to concentrate and increases the stress. If that increased stress is above the Ultimate Yield Stress than failure occurs. Most of these types of classes have a simple demonstration of how this occurs with the use of a lexan machined model and polarized glasses. Wearing the glasses one can see the 'stress' lines in the model and as this stress is increased and/or varied, the stress lines change and/or concentrate. Of course today with computer simulations, these are probably not used anymore.
Any abrupt change in the lattice structure of a metal has to viewed with caution and single use of the material may not provide a rupture but may rupture on multiple uses and there is simply no way to know once the material homogeneity has been compromised.-Dick