June
S M T W T F S
1 2 3 4 5
6 7 8 9 10 11 12
13 14 15 16 17 18 19
20 21 22 23 24 25 26
27 28 29 30
Who's Online Now
1 members (Mr W martin), 164 guests, and 4 robots.
Key: Admin, Global Mod, Mod
Forum Statistics
Forums10
Topics35,753
Posts503,062
Members14,044
Most Online462
Aug 5th, 2016
Previous Thread
Next Thread
Print Thread
Page 1 of 4 1 2 3 4
Joined: Jul 2010
Posts: 707
Sidelock
**
OP Offline
Sidelock
**

Joined: Jul 2010
Posts: 707
I heard an interesting one today from Dan at William Larkin Moore.

His claim was minimum walls of anything at or above .020" was fine (not marginal) for 2.5", vintage pressure shells.

His claim was minimum walls of anything at or above .025 "was fine (not marginal) for 2.75", modern pressure shells.


Both those statements assume the gun is within proof and shooting the prescribed shell for that gun.

I'll now wait to read your responses since I'd not heard this distinction before.

Last edited by Rookhawk; 12/14/11 07:03 PM.
Joined: Jan 2002
Posts: 866
Sidelock
**
Offline
Sidelock
**

Joined: Jan 2002
Posts: 866
Yikes!!!!!!!!!


Better to keep your mouth shut and be thought stupid,than open it and confirm.
Joined: Jul 2005
Posts: 7,065
Sidelock
***
Offline
Sidelock
***

Joined: Jul 2005
Posts: 7,065
In either case it makes a big difference where that minimum wall thickness is. If it is 3" from the muzzle I wouldn't mind shooting the 2-3/4" shell with 20/1000th wall thickness. If is it 3" from the forcing cone I don't care to shoot either gun.

Best,

Mike



I am glad to be here.
Joined: Jan 2006
Posts: 14,863
Likes: 5
Sidelock
*
Offline
Sidelock
*

Joined: Jan 2006
Posts: 14,863
Likes: 5
Sounds fine if you're the seller.

Joined: Jul 2010
Posts: 707
Sidelock
**
OP Offline
Sidelock
**

Joined: Jul 2010
Posts: 707
AmarilloMike,

Valid point. Would you argue minimum wall thickness after the first say 20" of barrel is almost irrelevant? Wouldn't the actual wall at 8" from breech being greater than say .040" be far more important?

Has anyone gone through the effort to figure out safe minimums at each point from the breech so that there is something more reliable than an overall minimum thickness number?

Joined: Jan 2002
Posts: 120
Sidelock
Offline
Sidelock

Joined: Jan 2002
Posts: 120
Everyone has to decide what minimum they want to wrap their hand around and get their face close to.

Assurances are easier to come by than guarantees.

Joined: Dec 2008
Posts: 2,292
Sidelock
**
Offline
Sidelock
**

Joined: Dec 2008
Posts: 2,292
Originally Posted By: Rookhawk
Has anyone gone through the effort to figure out safe minimums at each point from the breech so that there is something more reliable than an overall minimum thickness number?





From DuPont Powders 1933.....


For the first 8-10 inches, most factory barrel wall thickness is 35-45 thou min............butchered with anything less, I'm not interested in shooting it..........

There are quite a few pressure charts out there, PeteM will probably be along shortly and post one for you.......these show how rapidly the pressure falls off in a shotgun after the first 8 inches or so........


Doug



Joined: May 2011
Posts: 741
Sidelock
**
Offline
Sidelock
**

Joined: May 2011
Posts: 741
WHAT OF MINIMUM CHAMBER WALL AND FORCING CONE THICKNESS?

Joined: Jul 2005
Posts: 7,065
Sidelock
***
Offline
Sidelock
***

Joined: Jul 2005
Posts: 7,065
Originally Posted By: steve white
WHAT OF MINIMUM CHAMBER WALL AND FORCING CONE THICKNESS?


http://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=224972&page=1

Originally Posted By: AmarilloMike
Originally Posted By: L. Brown
But most gunsmiths that specialize in doubleguns, I think, would like to see a minimum barrel wall thickness of .100 at the mouth of the chamber.


I sure have a lot of doubles with original chambers and forcing cones with wall thicknesses way below .100" at the end of the chamber.

Fox A grade 16ga, 26" barrels, 2-7/16" chamber, 0.085" and 0.086" minimum wall thickness at the end of the chambers, .734" and .734" diameter at the end of the chambers, 5/8" long forcing cones, #4 barrels, gun weighs 5lbs 9oz, serial 302XXX.

Parker VH O Frame 16ga, 28" steel barrels, serial 134XXX, 2-9/16" chamber, .082" and 0.085" minimum wall thickness at the end of the chambers, 0.730" and 0.732" end chamber diameters, 3lbs 2oz unstruck barrel weight, gun weighs 5lbs 14oz.

Fox XE 16ga, 30" barrels, serial 301xxx, .072" and .080" minimum wall at chamber ends, 2-7/16" chambers, .733" and .733" end chamber diameters, gun weighs 6lbs 3oz

Parker DHE 16ga, 32" steel barrels, serial 212XXX, 0.090" and 0.092" minimum wall thickness at chamber ends, 2-9/16" chambers, .735" and .736" diameter at chamber ends, barrel unstruck barrel weight 3lbs 11oz, gun weighs 7lbs 4oz.

Lefever H grade 16 gauge, 28" twist barrels, .090" and .092" minimum wall thickness at chamber ends, 2-5/8" chambers, .729" and .728" diameter at chamber ends. Gun weighs 6lbs 4oz

Ithaca Flues Grade 4E 16 gauge, 28" Krupp fluid steel barrels, 0.091" and 0.092" minimum wall thickness at the end of 2-5/8" chambers, daimeters of .728" and .730" at the end of the chambers, gun weighs 6lbs 6ounces.

Parker DH 12 bore, 28" Damascus barrels, 1 frame, .086" and .090" minimum wall thickness at end of the 2-5/8" chambers, gun weighs 6lbs 14oz. Serial #84XXX, My Skeets gauges are in capable of measuring the diameters at the end of the chamber.

Bissel Birmingham boxlock, 20 gauge, 25" steel barrels, made in the 1920s, .084" and .092" minimum wall thickness at the chamber ends, 2-1/2" chambers. My Skeets gauges are in capable of measuring the diameters at the end of the chamber. Weighs 5lbs 7oz.

Best,

Mike


Last edited by AmarilloMike; 12/15/11 02:00 AM.


I am glad to be here.
Joined: Jul 2005
Posts: 7,065
Sidelock
***
Offline
Sidelock
***

Joined: Jul 2005
Posts: 7,065
Originally Posted By: Rookhawk
AmarilloMike,

Valid point. Would you argue minimum wall thickness after the first say 20" of barrel is almost irrelevant? Wouldn't the actual wall at 8" from breech being greater than say .040" be far more important?

Has anyone gone through the effort to figure out safe minimums at each point from the breech so that there is something more reliable than an overall minimum thickness number?


I beleive the .020" minimum wall thickness in the last 1/3rd of the barrel is about repair of dents. Maybe Joe Wood will pipe in here about Greener taking out his pocket knife and slitting the last half of barrel after shooting several loads thought it.

Best,

Mike



I am glad to be here.
Page 1 of 4 1 2 3 4

Link Copied to Clipboard

doublegunshop.com home | Welcome | Sponsors & Advertisers | DoubleGun Rack | Doublegun Book Rack

Order or request info | Other Useful Information

Updated every minute of everyday!


Copyright (c) 1993 - 2021 doublegunshop.com. All rights reserved. doublegunshop.com - Bloomfield, NY 14469. USA These materials are provided by doublegunshop.com as a service to its customers and may be used for informational purposes only. doublegunshop.com assumes no responsibility for errors or omissions in these materials. THESE MATERIALS ARE PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANT-ABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. doublegunshop.com further does not warrant the accuracy or completeness of the information, text, graphics, links or other items contained within these materials. doublegunshop.com shall not be liable for any special, indirect, incidental, or consequential damages, including without limitation, lost revenues or lost profits, which may result from the use of these materials. doublegunshop.com may make changes to these materials, or to the products described therein, at any time without notice. doublegunshop.com makes no commitment to update the information contained herein. This is a public un-moderated forum participate at your own risk.

Note: The posting of Copyrighted material on this forum is prohibited without prior written consent of the Copyright holder. For specifics on Copyright Law and restrictions refer to: http://www.copyright.gov/laws/ - doublegunshop.com will not monitor nor will they be held liable for copyright violations presented on the BBS which is an open and un-moderated public forum.

Powered by UBB.threads™ PHP Forum Software 7.7.5
(Release build 20201027)
Responsive Width:

PHP: 7.0.33-0+deb9u9 Page Time: 0.039s Queries: 35 (0.012s) Memory: 0.8522 MB (Peak: 1.8991 MB) Data Comp: Off Server Time: 2021-06-24 08:05:51 UTC
Valid HTML 5 and Valid CSS