12ga full-bore HP slug: Inputs needed!

[z375]

This design was inspired by a brass conical spacer found in the grip of an old
Crosman 357 Co2 pellet gun which measures .747" at the base, used to fill the gap when switching over from 12gram cylinders to the 8gram ones. Incidentally I use it to condition 12ga hulls and it works well! :mrgreen: As shown the total length is .835" but personally feel like a .900" or even a full 1.000" should fly better. I wanted a larger hollowpoint for it to open up rapidly on close-up hogs, also the lack of driving bands are due to the already minuscule bearing surface (.205") What do guys think?

Please feel free to chime in on this, your thoughts, opinions, suggestions are all welcome!

http://i21.photobucket.com/albums/b284/z375/12gaslug_zps9e94624e.jpg

The full-bore .735" Lyman next to the spacer that inspired the slug
http://i21.photobucket.com/albums/b284/z375/DSC06689_zpsc44fef68.jpg

[turbo1889]

I wouldn't trust that short of a bearing length combined with that long of a nose not to tip to one side on the way through the forcing cone. I'd extend the bearing length to at minimum 10mm on your drawing and adjust the nose profile curve to match. The effect on the nose angular curve would be minimal and it would be more then worth it to get some decent bearing length. Make that one change, and it should work in a rifled slug barrel 12ga. gun.

[catboat]

+1 about concern of little bearing length. It looks similar to a hollow-pointed version of a muzzle loading "picket bullet". I remember reading about "picket" bullets in Ned Roberts book about muzzleloading. The short contact surface design with the bore did not promote alignment or accuracy.

The trouble with the 12 gauge is that is just sooo big a diameter for elongated bullets. Personally, I think the future for deer hunting with shotgun slugs is with the 20 gauge (rifled bore). You CAN get elongated bullets, won't need a shirtedbase (that can collapse), and the mass (weight) of the projectile will be "reasonable". A 20 gauge elongated slug, shot through a rifled bore, will also have a higher ballistic coefficient (less drag than a 12 gauge slug at 500-700 grain range. Especially with all the powders available today...a good 20 gauge full bore, lubed (not shot with a cup or wad) slug is just ripe for product development.

No reason why you can't try your design. That's the fun part for the experimenter.

Just my 2c.

[jmort]

"Personally, I think the future for deer hunting with shotgun slugs is with the 20 gauge (rifled bore)."

I think Ajay is right there with you on that one, except with sabots.

[longbow]

Not sure of your intentions as to gun/barrel but unless rifled it won't work at all.

I agree with previous comments about too short bearing length as well. I would extend bearing length to at least the bottom of the HP which would make it about 11mm long.

Also, in my opinion the HP is way to big and the slug will either open up like a big washer and not penetrate if malleable/soft lead or will simply fragment if ACWW or harder.

Greg Sappington designed a large HP slug with the intent that the nose would fragment making multiple projectiles, and so it did but that HP was not even as large as yours.

Most people seem to go for a large meplat and heavy slug for penetration and tissue destruction rather than rapid expansion. No personal experience with slugs and hogs here but since factory Fosters, Lee and Lyman Fosters are often criticized for not enough penetration I have to think a large HP like that is best suited to milk jugs full of water.

Just my $0.02 as well.

Longbow

[Chicken Thief]

If you start out at 3/4" then who needs expansion ;)

[z375]

Change made to the length as per suggestion, and visually more proportionate too, with an addition of a lube groove the bearing area length is now .4027" (10.23mm) and its starting to resemble the Fosbery slug, i'm not complaining!http://i21.photobucket.com/albums/b284/z375/12gaslugdriveband_zpsbb17d0ac.jpg

[z375]

No opinions on this one? Please feel free to make suggestions, criticize etc!

[oldandslow]

z,
I experimented with both sabot and full bore slugs in 12 gauge smooth and rifled barrels and finally found the AccurateMold #730-770 grain slug to be both accurate and effective. It'll give two inch groups at 50 yards with my Rem 870 rifled barrel and zips through both sides of a pig leaving good blood trails. Mine run about 1000 feet/second and the recoil is moderate and tolerable. I've run it faster but the recoil becomes brutal. I'm in agreement with the others above that a HP is probably not needed. Good luck.
best wishes- oldandslow