doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Cut Barrel on double?

That is incorrect. For the barrels to "run parallel" at the last few inches they would have to be bent substantially at some point back. By looking down the bores from the breech ends you can see concentric rings that are clearly aligned equally on all sides. Were the barrels bent, in order for them to become parallel, the rings would not be concentric at that point (in the bend).

What you are seeing from the outside, that makes it look that way, is the way the barrels are struck. Usually, with better guns especially, the barrels are thinner just behind the choke, the the walls thicken slightly through the choke area and at the muzzles. This is a result of sriking (filing) done to create the right handling characteristics, and also to protect the muzzles by having a little more metal there.

SRH

Stan is right. I have never seen a set of double bbls which became parallel at the muzzles. As well as looking down the bores as Stan suggested I have also measured a few sets of bbls. I did this by measuring the bbl od at regular intervals & then measuring total width across the bbls at the same intervals. In every case I measured the bbls continued to converge all the way to the muzzle.
This bbl convergence is put there for the very purpose of causing both bbls to hit at the same point, if they were parallel they would impact apart due to the guns movement prior to the shot exiting the bbls.

So theoretically, cutting the barrels should not change the convergence, and POI should be the same as before, at least with light loads?

I say theoretically, because I realize there are other factors involved that will have an effect on POI as well. Cutting the barrels will reduce the weight and I think that could affect the POI as well.

Am I correct?

Well, for whatever its worth guys, the whole idea behind this project was to create lotsa smoke and noise - if I manage to actually HIT anything with it, well - thats just bonus for me...lol

Its just a "fun gun" to take out back and let the newbies experience the fun of touching it off - its neither a serious hunting or target shooting gun - just a play toy is all...

Your assistance with this project has been GREATLY appreciated!! Thank you to all who spoke up!!

Before the chambers are cut there would be about 1/4" more separation center to center on the breech than the muzzles. Simple math tells you the patterns would converge and cross at some point.

With both barrels regulated, isn't it the torque that makes the barrels shoot to the same point?

It will of course vary a bit from maker to maker & type to type, but on a typical 12ga double the bbls will converge at an approximate rate of .011" per inch. On a 30" bbl'd gun the difference in width of the C/L would be about .330" or a bit over 5/16". This will result in an extension of the bores axis crossing around 2 yds (6 feet) in front of the muzzles & they will then have a separation of about 15" at 40 yds. The torque / twist of the gun upon firing does indeed cause the right bbl to impact further right than its static point of aim & the left bbl to impact further left, thus they tend to impact the same point at practical shooting distances. "IF" the bbls came to a parallel condition the right bbl would impact to the right of point of aim & the left bbl to the left.