doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com LITTLE SKEETERS

I found some 12 to 28 ga. Little Skeeter chamber inserts I forgot I had. I ground and angle on the leading edge and they fit perfectly in a 2 1/2" chamber. A 28 ga. shell dropped in nicely and the gun closed properly. The gun is nito proved for 3 ton which I understand translates to 6,720 PSI. According to my Hodgdon book the 28 ga. shell generates 10,800 PSI. I was afraid to try it. Will the chamber insert absorb the extra pressure? Once the shot charge leaves the insert will the 12 ga. bore diameter reduce the pressure down the barrel to a safe PSI? What do you think?

I have been doing it for a while, without giving it much thought, so far nothing has let go......

i always thought 3 tons per square box (sq. inch) under imperial measurement was analogous to 900kg/sq.cm proof under the si for guns with 65mm chambers and 3&1/4t/"sq or 900kg/sq.cm for those having 70mm chambers.
prior to '89 76mm chambered guns were proofed to 3&1/2t/inch sq. or 1200kg/sq.cm.
theoretically one can shoot 65mm lead cartridges up to 1&3/16oz in three toner (it's probably old so i would stick to 1oz cip rated shells), but i would not put some american gizmo in english gun and shoot 28bore cartridges through it because that isn't cartridge for which this gun was intended. i'm sure there is a warning on box flap of those 28ga cartridges so their ass is covered and you're doing this at YOUR OWN RISK.

I never understood why anyone would want to carry a 12 bore that weighs 6 - 7lbs and then shoot 28ga in it. Sell the 12 and buy a 28.

The 6700 psi crusher rating gets close to 9000 psi on the pizeo pressure measurement system. Yes, the Skeeters will absorb most, if not all, of the breech pressure. And, yes, the expansion of the barrel will reduce the pressure a lot. So, if the gun is in shape for 2 1/2" CIP 12's, it ought to be fine with the 28's in Skeeters.

A clear answer with guts! Well done Rocketman!
bill

Actually Mike, I already have a 28, 2 of em. Sometimes a guy just feels like shooting 28's in a 12.....Might be a Kansas thing...

LD I was born in Atchison, never heard of such a thing.LOL

Thank you Rocketman. Sounds good to me. Mr. Harrell, I just received my RBL 28 and I already had two others. The object of the exercise is to find some way of shooting skeet and sporting clays with the old gun without the need to acquire special 12 ga. 2 1/2" loads, although I'm working on that too.
The conversion of British Long Tons to regular PSI is confusing to me. I assumed the 6,720 PSI to err on the safe side.
Thanks again.

RGH;
The conversion of British long tons to lbs is simply Tons x 2240lbs. This of course gives you the 6720lbs for 3 tons. The fly in the ointment here is the 3 tons is in reality "Crusher Pressure" which is not absolute pressure per square inch. Pressure as taken with a pizoelectric crystal is assumed to be exact. For "British" tons a formula has been given which is (crusher tons x 1½) - ½ = PE tons, thus (3 x 1½) 4½ - ½ = 4. Then 4 x 2240 = 8960 psi. This formula was derived from a pressure bbl having crushers mounted on one side & PE gages on the other at exact same distance (1.000") from breech & recording simultaneous readings from the same shot. It was said to have been adequately correct for pressures within normal shotshell ranges. The problem thus is not one of converting tons to lbs, but one of converting crusher pressure to psi.