doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Lengthening forcing cones....good or bad?

Can you give us Mr. Bell's quote on that one. Larry whatsis said the same thing a while ago. Are you quoting Larry or Sherman Bell? I guess I don't quite understand the meaning of your post.

One would hope that purchasing at the Perezzi level would get you a reamer not on it's 649th tube, but, the only guarantee is death and taxes.

While we are on "minor improvements" Dr. Sane, lets forget, for a moment, the advancements in petrochemical engineering that gave us plastic hulls and wads-do 'ya think a turn-o-the-century P gun would have identical chamber dimensions to one produced, say, yesterday?

I think not. I've seen enough Winchester SX2s to know that the bore and choke dimensions aren't going to be identicle to your model 12.

Let's assume there is a reason for this. It's OK to admit you don't know why.

Best,
Ted

I wouldn't count on lengthening a forcing cone reducing max pressure to any extent. Pressure has peaked & starting to fall by the time the shot gets into the cone. To effect pressure by much the chamber is going to have to be so short as to actually retatrd the opening of the crimp.

Every shell out of a single box of shells fired through the same gun will give a slightly different pressure reading. I Highly suspect had Bell run a lot larger sampling those pressures would have tended to be even more equal than he showed.

I'm sure there have been some dimensional fluctuations over the last 120 or so years but my take would be that they were, if intentional, market hype just like today or inconsequential. I'll omit chamber length since that really has no bearing and was for other reasons anyway. And the simple fact the "modern" dimensioned ammo will work quite well in guns from the turn of the last century is notable.
As you correctly note the REAL advancements have been in the bits and pieces shoved into the gun and not the dimensional standards to which the guns are built. That does not negate the simple fact that guns have been built to a dimensional standard that has not changed in any significant way whatsoever for that whole time. I cannot attest to the Perazzis at that time depth since they did not exist then, but I would suspect that the likelihood of elderly Berettas, Purdys, Greeners, etc., being dimensioned similarly would be quite high.

I mean, it's a (hopefully) straight round tube and the choke area is concentric to the rest of the tube. Admittedly the quality production of such a device does potentially pose some difficulties but the concept is about as complex as a rock.

have a day
Dr.WtS

PS - the only comment that comes to mind on the topic of long cones reducing pressure when people are too stupid to use the correct ammo is DUH! The pressure spike reduction would have to be marginal, but an effectively longer chamber is a longer chamber no matter how you may construe it.

As I recall, Sherman Bells comments about pressure versus chamber length mention the inconsequential differences as Wonko says. I'm still waiting for the Bell quote that says anything contrary. Very few quality makers have gone to longer cones, again contrary to what some posters state. Long cones are absolutely risky in repeating shotguns considering the prevalence of separated hulls today. They can also be risky in break open guns used by those who don't check their bores every shot before loading another shell.

I'll say it again, I'm certainly no proponent of taking a pristine high value collectable or even low value rare high condition gun, and modifying it, I will modify my mostly bottom-feeding guns to suit me and sleep well at night.

Actually, I don't bother to touch the cones or chokes of most of my guns. I just received a nice little 20g Grade 3 NID, factory SST, ejector. back from restoration by Gunter Pfrommer. (Yeah, I know some of you will want to fight about restoration too. Well this one had one leg in the junk pile already). It doesn't have, nor will it get, long cones.

I don't advocate anyone modify their vintage gun with long cones or open their chokes (my modern tight and tigher 28"/28g Repro will keep its chokes and cones as is). But, I do know that there is a performance advantage to be had. To say such things don't exist is just ignoring facts. To say they are only for someone of a particular level is as rediculous as saying you need to shoot a predermined qualifying score before you're allowed to own a certain gun.

If anyone wants to pursue testing of long cones for themselves, I have a couple reamers I would modify your test barrel with to support your curiousity.

If long chamber cones are so desirable ,why dont the manufacturers do them as standard? Has any asked Beretta, Ruger, Galazan, Mossberg ,Remington ? Has any one asked the cartridge loaders the same question?

My suspicion on why it's only done by some performance gun makers is that it bucks the manufacturer standards organization specs (SAAMI, or other foreign orgs). SAAMI specs include the cone. Most of the makers you mentioned are likely SAAMI members, except maybe Galazan.

Krieghoff choose to go the long cone route a long time ago. I think someone mentioned Kolar did as well. Possibly other target gun makers have as well.

Caesar Guerini and Beretta offers modified forcing cones on their target guns:

Caesar Guerini
Beretta 682

Baserri claims they have eliminated the forcing cone entirely with their Tri-Bore barrels.
Baserri

Question is whether they believe it works or they think their customers want it.

SAAMI is of course only a recommendation, not legally binding. Also I believe their recommendations for the cone are for a "Minimum" cone size. Any maker shoud be quite free to lenghten theirs to their hearts desire & still be able to say it was to SAAMI Specs.