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Sidelock
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https://www.natchezss.com/b-p-competition-one-shotshells-12-ga-2-3-4-in-7-8-oz-8-1160-fps-25-ct.html

Limit one case so shipping is the killer; $22.50 to Phoenix so $11.25/box frown

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https://saintbarbsbullets.com/produ...5-1200-fps-7-8-oz-8-lead-shot-25-rounds/

This outfit has Nobel Sport Low Recoil/1200 fps, 7/8 oz. 8's. $10.35 a box, they have 200 in stock. Shipping for two flats to Phoenix is about 15 bucks and free if you order more.

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Still limited to 2.5 inch shells for me, but great to see any ammo on sale at this point...

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Dan: at the risk of repetition, and being flamed wink

1. The published pressure for the B&P 12g 2 3/4” Competition One 7/8 oz. @ 1160 fps is 7252 psi. The average increase in Bell's study was about 700 psi. Under the 1954 Rules of Proof “Highest Mean Service Pressure” equivalent transducer values as converted from LUP by Burrard’s formula for 2 3/4 tons is 8,120 psi, 3 tons is 8,960 psi.
Unfortunately, the B&P hulls after firing do measure a full 2 3/4"
2. Buried in Bell's study is a suggestion that lengthening forcing cones can somewhat mitigate the rise in pressure when using long for chamber length shells; ie. slightly more volume in which the gas expands.
3. AN EXPERT can lengthen the cones, and the resultant wall thickness, because the angle of the cone is more acute than the external taper of the barrel, will be no less than the pre-lengthening end-of-chamber wall thickness. A transected breech after Briley lengthening a short cone

[Linked Image from photos.smugmug.com]

4. The difficulty sourcing 2 1/2" shells for the non-reloader is unlikely to resolve any time soon.

Important declaimer: there is NO DATA regarding the pressure rise when using long for chamber length modern plastic hull shells in 16g or 20g.

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Drew, I am open to trying 2.75 low pressure loads like the ones above in my nitro-proofed 2.5 guns, with the more recent of the two being under the later 25-54 rules, I just haven't gotten around to it yet. Also, the barrels on my guns have factory or near factory dimensions with no wear to the bores so no issues with condition from a mechanical perspective.

However, I have no intention of altering the bores to accommodate the extended use of 2.75 shells. I already have a case of RST's and no time to shoot as it is, unfortunately.

I have some Fiocchi trainer loads in 2.75 that I am going to try a couple of in the above referenced guns at some point when time permits.

Thanks for the info.

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Preacher, back in the Spring of 2019, you argued for days that lengthening the chambers of vintage doubles would actually increase the barrel wall thickness at the end of the lengthened chambers. It took several days for Miller and I to try to convince you otherwise. You obviously still didn't believe us because you paid good money to have Briley lengthen a chamber to see for yourself that you were wrong. That original Thread was deleted, but the follow-up with the results of the needless experiment remain:

https://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=542020&page=1

And still, you were surprised at the result. Now I wonder why you maintain IN ALL CAPS, that it takes AN EXPERT to lengthen forcing cones, yet the picture of the sectioned chamber shows reamer chatter marks. I also question the second point you made:

Originally Posted by Drew Hause
2. Buried in Bell's study is a suggestion that lengthening forcing cones can somewhat mitigate the rise in pressure when using long for chamber length shells; ie. slightly more volume in which the gas expands.

Every other source I have ever seen gives the more rational explanation that a lengthened forcing cone simply gives less of a partial bore obstruction created by the end of the shell opening into the bore, so naturally there would be a slight reduction in pressure at that point. You could increase the volume into which the powder gasses expand, but with enough of a restriction, the resulting pressure could still become excessive.

Harry Truman had advice for those who are afraid of being flamed. He said, "If you can't stand the heat, stay out of the kitchen." Good advice indeed!


A true sign of mental illness is any gun owner who would vote for an Anti-Gunner like Joe Biden.

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Yes William, since "because I say so" isn't adequate, I spent the time and money to prove that I was wrong, and admitted such.

Could you please provide a link to your assertion that "every other source" explains that "a lengthened forcing cone simply gives less of a partial bore obstruction created by the end of the shell opening into the bore, so naturally there would be a slight reduction in pressure at that point."
Should be easy to find, and possibly accompanied by the credentials of the source. Or a formula would be nice; like P ∝1/V
Start with Miller's comment here
https://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=37158&page=2
"Changing the forcing cone angle (lengthening) would give a very "Slight" increase of volume in the area, which would tend to slightly decrease pressure. A "Slight" change in friction could also accomplish the same purpose."

BTW: my name is Drew and, unlike yourself, am willing to document my identity. Feel free to use it.

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For the 1 or 2 interested, I re-formatted and revised the thread William linked, and restored the images
https://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=541873

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Nope Preacher, I am not going to tediously search for every other source I and others here have encountered that states the obvious, i.e., that shooting a 2 3/4" shell in a 2 1/2" or 2 5/8" chamber generates slightly higher pressure due to the patently obvious fact that the end of the longer shell opening into the bore acts as a partial bore obstruction. And lengthening the forcing cone slightly reduces that constriction.

Your little formula, Boyle's Law, also does not either impress me, or explain why shooting long shells in short chambers results in an increase of chamber pressure. Boyles Law certainly wouldn't apply here anyway. But I guess you think posting it might impress those who think you actually know something besides "Copy-and-Pasting" things you don't really understand. It is good to see (after my prompting) that you have finally stopped posting Barlow's formula since it has virtually no application to bursting pressure for an open ended shotgun barrel. The resulting increase in volume from lengthening a forcing cone is too small to be very significant compared to the effect of forcing the ejecta through the constriction created by the end of the shell opening into the bore. A highly polished forcing cone might provide a small area of reduced friction. But the EXPERT job in your photo is certainly not likely to do much to reduce friction. I think that a machinist like Miller would see the reamer chatter marks and agree with me on that point. Interesting to see you quoting Miller here now. Too bad you didn't do the same all of those times you attempted to falsely put words in his mouth concerning what he said about no prohibition on slavery in the Bible.

Originally Posted by Drew Hause
Yes William, since "because I say so" isn't adequate, I spent the time and money to prove that I was wrong, and admitted such.


BTW: my name is Drew and, unlike yourself, am willing to document my identity. Feel free to use it.

I'd agree that "because I say so" alone isn't adequate to believe anyone here, especially considering the amount of false and incorrect information posted. Your repeated hysteria concerning cracked small bore Flues and Fox Sterlingworth frames is but one small example of false or incorrect info posted by you. But Miller and I gave a pretty clear and simple explanation of how and why lengthening the chambers of vintage shotguns would not and could not result in increased wall thickness at the end of the recut chambers. Miller even posted pictures to illustrate it for you. The fact that you subsequently paid good money to have Briley lengthen a chamber just so you could take actual measurements which proved we were correct should show everyone just how shallow your barrel knowledge, and inability to interpret numbers and facts is. But I already knew that.

And that is the biggest reason why I am not going to waste time providing you links to other sources that state what should be obvious…that fact being a partial constriction or obstruction in the bore directly in front of the chamber is absolutely going to result in increased pressure compared to the same load fired in a longer chamber that is the proper length for the shell being fired. It ain't Rocket Science!


A true sign of mental illness is any gun owner who would vote for an Anti-Gunner like Joe Biden.

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why not just lengthen chambers to 2 3/4?


keep it simple and keep it safe...
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