doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Barrel Regulaton - Update

What the hell are you talking about?

That's about the silliest experiment I've ever heard of.

All firearms are compensated for drop, just look at one. Over and under guns also use various tricks of the trade, including bending the lower barrel, to regulate to point of aim.

SxS barrels converge at the muzzle. This compensates for torque. The chosen load does indeed affect POI, no argument. That's the FIRST thing I mentioned to the man.

BUT, what he's describing now is a physical impossibility unless the gun is three feet wide across the breech.

Barrels are assembled to a design spec and that's it. I dont know of one maker who "regulates" shotgun barrels on a production gun . Why not work it out mathematically? that will tell you exactly wear the barrels converge, cross over and wear the theatrical pattern centers will be at any set distance.

When it comes down to it, its the shooter who hits the target .Nothing to do with some mythical barrel maker making magical barrels the do the work for you.

For the load to raise the POI, wouldn't shooting a slower fps loads shoot higher?, like the barrel will be a bit higher in recoil before the shot leaves the barrels?
Just a thought.
Franc

I shot nice gobbler this spring with my SBE 'gangster style' at 35 yards....

Doug I think the point is that if the left barrel shoots 6" to the left at 16 yards it will shoot 12" to the left at 32 yards and 18" to the left at 48 yards, everything else being equal.

Vice - versa on the right barrel.

I assume Greg has since concluded he didn't check the POI/POA correctly when he wrote his first post on the previous thread.

If the gun was currently shooting as Greg posted in the first thread it would still be my conclusion that he has a barrel regulation problem.

Best,


Mike

Normally yes, Franc. This is called 'barrel time'. But... a SxS is subject to a phenomenon called 'barrel flip' which is related to the flexibility of the barrel set. It's a different animal than, say, a Ruger Redhawk.

Barrel time WILL effect latteral POI, somewhat. There are variables here, consider the effect of cast for instance. That would change the lever problem wouldn't it?

Guess why the Ruger Gold Label failed to sell? They couldn't find an economical high volume production method for the barrel set so they gave up. As it turns out, when a man buys a SxS shotgun he sort of expects it to shoot where pointed from both barrels.

And JOe, I normaly just ignore you but if you fired your SBE 90 degrees out of plane you wouldn't hit crap at 35 yards unless you pointed right and high because guns shoot left and low when fired 'movie' style. I call BS on your turkey.

Greg, are you claiminmg that your gun will still have POI as first described and second described based only on patterning distance??? I'm having trouble with that. What phenomonen would cause the pattern center to follow a horizontally curved path (not to be confused with the ballistic arc)?

Hi all, very good points made by all. As I said, I think this was a classic case of the Indian and not the arrow.

I took her out again today. I shot 23 out of 25. Same as yesterday. I didn't re-check the POI. To be honest, I'm not going to worry about this gun anymore. She's shooting fine now.

I will add that I had shot Federal Game Loads and RST, both to either check the POI (I used RST's) and at clays (FGL). When I used the FGL I shot 12 out of 50. Today and yesterday I used Winchester Game Loads. It seems that this gun likes Mr. Winchester.

As someone said previous, it was perhaps MY technique and MY screw ups. I'll settle for that.

All I know are the results of today and yesterday. I'm happy and I'm not going to dwell on it.

Again, thanks for all the great responses, I did learn from you all as I always do. Thanks!

All the best!

Greg

After some years working on aerospace dynamics analyses and more years as a professor of mechanical engineering teaching dynamics, I can see no way that patterns with the described horizontal spread of 14 inches at 16 yards could be even close to converged at 30 yards.

Either something has dramatically changed and patterns are now close to convergence at 16 yards, or they are still badly out of convergence at 30 yards.

Since convergence seems not be have been actually measured at 30 yards, perhaps the patterns opened up enough to break targets there even with poor convergence. If the "Winchester Game Loads" are promo loads with soft shot, deformed pellets can cause breaks fairly far from the pattern center.

I suggest a follow-up series of actual convergece tests at both 16 and 30 yards under a fixed set of conditions. There may still be a convergence problem with the gun that should be fixed by the importer. Now is the time to have it done.

Try shooting the gun at 10 yards, from a bench, with the front hand supporting the forend on sandbags or a bench rest. Aim carefully down the center of the rib, put the front bead in the center of your aiming point, hold the gun very steady and squeeze the triggers like you would a rifle. Both shots should make one pattern, from the size of a coffee cup to a dinner plate, depending on the chokes. You should not have two separate patterns.