doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Proof failures

You have a point there, Roy. From what little I know, bulging behind the chokes would seem to support an obstruction. Or it's almost as if they were using steel shot.....
Mike

The choke section should never act as a restriction to properly functioning shot pellets. Rather, it is a constriction which the shot will flow through with decreasing pressure and increasing velocity. I think the disproportinate number of fowlers, as compared to gameguns, with bulges immediately behind the choke section is evidence of the larger shot usually used for fowling being more succeptible to bridging. The even brief existance of a bridge could slow the shot/wad sufficiently to create a gas hammer behind the wad. Sounds like the same thing could be happening here.

Is there an inspection that would catch a fragment, say base wad, from the first firing? Are the hulls tracable to the gun fired in?

Dig, were both barrels bulged?

I seem to recall reading in W W Greener that when choke boring was first introduced there was still a good many guns being made with low quality bbls consisting mostly of iron with very low steel content. Seems these soft bbls could not stand up to choking without bulging.
Personally I am not convinced that when that charge comes hurtling down the bore that there is not a "Check" applied to it as it hits the choke. Normally it is not so severe as to cause any problem, "But" if the bbl is too weak, too thin, too soft etc, then things can change.

In my case and the case of a Westley that came to my attention, both tubes bulged.

Too many guns are bulging in the same place for an obstruction of wadding etc to be the answer.

All the points about occasional bulges in the field are valid but in the recent cases, too much repetition is evident for it to be dismissed as sloppy cleaning or a weak tube. A lot of guns are failing where they would previously have passed. My own observations lead me to suspect steel loads are being used but I have no evidence to support this other than the reports of the number and types of failures.

miller,

What you mentioned about the choke acting as a sort of "check" seems to the logical mind to be so. However, we have been told that small shot acts like a liquid, and that as it enters the choke it actually speeds up, being subject to the venturi effect. We see other applications of the venturi effect around us, carburetors, cooling towers at nuclear reactors, etc.

I, however, am not convinced that a load of shot acts the same as a moisture laden gas, and will continue to believe that great stresses occur when the shot enters the choke constriction area. The greater the constriction the greater the stresses, I believe.

What I would find interesting is how the bulged barrels in question were choked.

Stan

Stan

A choke barrel should not fail proof because it is choked. We are missing the point here.

Dig, this whole thing with bulges and proof failures is very troubling to me. I'm planning on sending a set of barrels from a high grade Lefever for Teague liners. I certainly wouldn't want a set of unreplaceable barrels destroyed because of some stupidity on the part of the proof house. Would you suggest holding off on the lining until this issue is resolved?

Doug

I understand that Mr. Teague doesn't line barrels anymore.

John, Would it be more proper to say that Jon Connor lines barrels or is no one doing that service now???

Doug

I don't know who did Nigel Teague's lining for him but I know that Nigel does not offer that servise anymore as it was not to successfull. So he withdrew his name from it.