doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com INTENTIONAL PITTING OF SHOTGUN BORES

I recall reading years ago about the practice of intentional pitting of shotgun bores. the purpose was to make patterns as wide as possible for close bird shooting. the idea was to create a rough surface, so lead shot would be scored and thus fly in an irregular pattern...is this info in greener's book or else where? or did I imagine it?

Couldn't you have old Ed Lander just build you a blunderbuss?

Ed if that's so I must have a lot of guns previously used by folks who shot close birds...Geo

I believe I've read that some have experienced tighter patterns if the parallel at the muzzle is slightly roughed. Speaking of using shot cups, of course. Makes sense if choke helps pull the wad away from the charge.

Ed..I have read WW Greener The Gun & its Development at least twice,& can't remember anything to do with that.
Unless folks who didn't clean their bbls noticed a wider swath as the pitting developed..????
why wouldn't you just use some banged up, out of round type pellets (rejects) ?..instead of messing with the bores...it would do probably do something similar.
Kinda like that "Square/cube " shot thing a few years ago.
Though I like the last bit of the muzzle roughness idea, of retarding the shotcup, & letting the pellets fly out on ahead...
Joe...is that idea used/&/or accepted to work???..seems like it could/should
franc

Jack O'Connor

Many older trap shooters would roughen their chokes to retard the wad.
Some say Baker choke tubes have this effect.
Mike

John Singer wrote
I thought I would share the following with all of you.
I recently purchased an old book The Shotgun Book by Jack O'Connor. The book was published in 1965.

There is an entire chapter devoted to "The Choke in the Shotgun Barrel".

The following exerpts are from that chapter:

"This whole business of constriction is complicated by the fact that the surface of the choke itself has an important bearing on the density of patterns. It would seem reason reasonable to assume that the choke with a very smooth surface would pattern better than a rough one. Actually, just the opposite is true.

I first learned of this phenomenon from the late E. Field White, the inventor of the Poly Choke. His theory was that when the choke is glass-smooth, the wads are not retarded, smash into the rear of the shot column, and scatter the shot. On the other hand, if the surface of the choke is roughed up, the lighter wads are retarded, lag behind the shot charge, do no smash into the shot column, and do not disperse the patterns.

He also told me that it is possible to get full-choke patterns from a cylinder barrel if the barrel is long enough and a bit rough...

It is common for the pattern efficiency to fall off in trap guns that have been shot thousands of times until the choke portion of the barrel has been polished glass-smooth by the passage of the shot. Patterns are then brought back to full choke by roughening up the choke portion with emery cloth or by some other means. An engineer who was formerly head of the deprtment of research and development of one of the major manufacturers tells me that he found the condition of the surface of the choke to be almost as important in getting tight patterns as the amount of constriction. Experiments by Oberfell and Hompson verify the necessity for a slight Roughness of the choke for best patterns."
http://www.duckhuntingchat.com/forum/viewtopic.php?f=14&t=125212

as I recall, this intentional pitting of bores, in order to score shot was done prior to ww1 and before we had shot cups...

maybe I am just imagining this...

You didn't dream it ed. Somebody else may have but it is definitely in writing.

I have a book from a little known contemporary English shooting instructor that moved to the USA. He talks about some guys in England used to piss down their new barrels in order to pit them. He said the purpose was to make the shot spread. He said it was effective.

If I find the book and the quote I will post it.

I was half right.

"Successful Shotgunning" by Peter F. Blakeley, page 142

No mention of pissing down the barrel but he does talk about a badly pitted barrel with numerous poorly removed dents owned by a gentlemen named Will, known as a crack shot. Blakely's theory was that the effect of bore scrub opened the pattern and lengthened the shot string. Since he talks about bore scrub I think he was talking about cartridges without shot cups but he doesn't so state.

Franc, as memory serves me, I believe that is part of the choke system the Soviets used in their trap guns along with a type of jug choke behind the normal one.

(Sorry Ed to steal your thread.....didn't mean to.)