doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com 2 1/2" shell loads

Can someone point me in the right direction to find data on loading 2 1/2" shells? Your own recipes are welcomed as well.

Ballistic Products "Advantage" manual has been my go to for 2 1/2" data

What kind of hulls are you using? Here's a 2 1/2" load from Hodgdon using a cheddite hull Hodgdon Load.

Ken

Most 2 3/4 loads will fit in a roll crimped 2 1/2 inch hull.

Look at the Parker loading forum, a member just posted a list of loads for 2 & 1/2 16 gauge, if that is what your are looking for.

I've been loading 12 gauge 2 1/2" shells for a couple years and quite satisfied with the results.

Basically, I used the same recipe for my 12 gauge 2 3/4" loads with 1/2 and 3/4 ounces of lead shot using Alliant Extra Light powder. I've been loading those for 6 years and had them tested by Tom Armbrust back in 2015.

I use 12 gauge 2 1/2" RST hulls (Cheddites I believe), Cheddite primers and CB6100-12 (neon green wads). Probably not necessary but I trim with a scissors about 1/16" off the ends of the petals of those CB wads.

For 1/2 ounce: I started with 14 grains of XL powder with a Circle Fly 0.135" thick card wad in the bottom of the CB wad. Those tested out at an average 3100 psi pressure and 1187 fps. I bumped the powder charge up to 15.5 grains of XL, same wad etc. and they tested out at 4600 psi and 1373 fps. It burns a little dirty but does well for me.

For 3/4 ounce: same as above: 15.5 grains XL and the 0.135" thick wad is not needed. I couldn't find my test data but IIRC, the psi is up a little and the speed just a little lower.

I pretty much just shoot 12 gauge 1/2 ounce loads in all my 12 gauge guns for my sporting clays and skeet shooting. Occasionally, 3/4 ounce for longer shots.

Ballistically, those 1/2 ounce 12 gauge loads work quite well with the speed you'll get, around 1325 fps.

As for the mechanics of loading them, I use my MEC Sizemaster and add a 1/4" thick spacer at the pre-crimp and final crimp stations as pictured below.

They load nice and shoot nice. And by the way, I shoot those 12 gauge 2 1/2" loads out of my H&H back action hammer gun with steel barrels Nitro Proofed for 1 1/8 ounce.

Please let me know if you have any questions.

Jolly

Mec makes a 2 1/2" conversion which works quite well, I have one on my 12 and 16 ga loaders and no longer bother with 2 3/4" shells even shooting 2 1/2 in my 2 3/4" shotguns. In my 12's I load 11/16 of 9's for skeet(odd bar that I found in my parts box) and 7/8 oz of lead 8's and ITX 6's for trap, SC and waterfowl hunting. I still have a case each of B&P High Pheasants 2 1/2" 1 oz 6's and 7's for hunting. I roll crimp the Non-Tox so it is easy to tell the difference.

16's get 3/4 oz of everything except 1 oz of NP BB's for coyote hunting out of my drillings

Occasionally I play with loading 2 1/2” shells but usually I just shoot longer 2 3/4” in all my short chambered guns. Tens of thousands of rounds through my early damascus barreled guns and never a problem. Seems the same mentality that says shooting smokeless in damascus guns is dangerous goes along with shooting longer hulls in short chambered guns is also dangerous. Test after test has shown it is perfectly ok to shoot longer hulls in short chambers. Oh well....

67galaxie;

Did any of this help?

Skeetx's conversion kit costs pocket change or put another way, he uses coins to shorten stages with his MEC. Hopefully he will chip in with his $.02. Gil

Purdey posted a doc many years ago about the difference in psi between 23/4 and 21/2” hulls. It is probably in Vintageguns.uk forum somewhere. I think Doc Drew posted same here as well back when...

Scroll down just past 1/3 here for a summary of “Long Shells in Short Chambers” by Sherman Bell with technical assistance from Tom Armbrust in “Finding Out for Myself” Part V, Double Gun Journal, Winter 2001. AFAIK this is the only pressure test conducted and published.
https://docs.google.com/document/d/1ZIo0y746UsSRZIgRuuxwAbZjSBHitO_EanvwLYc-kGA/edit

One load had a 1200 psi increase, which might not be "perfectly alright" in your gun, and would emphasize the importance of following Bell's advice:
“Shooting 2 3/4” shells in 2 1/2” chambers does make them produce more pressure-but in most cases it is less than a 1000 psi increase. I see no reason, related to safety, to modify an original 2 1/2” chambered gun to shoot 2 3/4” shells, if the 2 3/4” load you intend to use would develop pressure that is safe in that gun, when fired in a standard chamber!”

Of interest, but obviously different shells
“The Long 20 Bore Cartridge”, The Field in Forest & Stream, October 17, 1908
https://books.google.com/books?id=ejQevDPMUIYC&pg=PA630
2 3/4” case with “Schultze” Bulk Smokeless (42 gr = 3 Dr. Eq.)
The standard 2 1/2” case was loaded with 33 gr. “Schultze” = 2.36 Dr. Eq. (about 2 3/8) with 13/16 oz. shot.
36 gr. = 2.57 Dr. Eq. with 15/16 oz. = 4.65 tons = 14,504 psi (using Burrard’s formula) / 20 yd. velocity 1000 fps
37 gr. = 2.64 Dr. Eq. with 7/8 oz. = 4.54 tons = 14,134 psi / 1040 fps
35 gr. = 2.5 Dr. Eq. with 13/16 oz. = 3.45 tons = 10,472 psi / 1068 fps

Very Much. I appreciate all the advice