Hello Riflemen: I tried the bird hunting forum and have not got a response to this question yet. As a handloader my curiosity is killing me for an answer to a friends recent phone call and comment. He had no idea.
These are the mystery facts as related to me. He bought a 12 ga. rifled barrel for a pump shotgun he has. He says that it will shoot a 385 grain rifled bullet at 2400fps with a 3.5" shell. A 2.75" shell will shoot the same bullet at 1900fps. I have reloaded very little shot shells in my life. However, I do a great deal of rifle handloading and his stats confuse me. First, I think to move a 385 grain bullet 2400fps in a 40+ caliber rifle you need pressures of at least 50,000 cup. If this holds true in a shotgun does the pump shotgun have that kind of strong lock up for these pressures. I also seem to remember that shot shells use a very fast burning pistol type powder. What type of powder will do this magic and how much is used? I'm lost on this topic and though I don't doubt my friends sincerity I just don't understand the ballistics here. any help from you Handloaders will be greatly appreciated and I will contribute when I can. thank You, Hardley06.

I can't vouch for the accuracy of your friend's statement, but the 3.5" shotguns are built for higher pressures than the 3"/2.75".

Also remember that FORCE accelerates the bullet. Force is pressure x area. The area of a 12 ga slug is much larger than that of a rifle bullet. So you get a lot more force for the same pressure.

Of course, as the slug moves down the barrel, you also gain volume very quickly, as compared to a rifle.

All of that combined sort of throws out of kilter all expectations we have built up by using conventional rifles.

I don't know if the sabot 3.5 shell slug your riend is talking about really reaches 2400 FPS, but also remember that this is a sabot round. In the M1A1 Abrams, the 120mm main gun fires a sabot long-rod fin stabilized penetrator at over 5000 FPS, something it could not do with a full-caliber 120mm shell at the same pressures.

I would suspect at that performance level in the relatively lightweight shotgun, his recoil level is worse than a .416 Rigby!! What fun!!

Eldeguello is correct that the 3.5 inch 12 guage runs at higher pressure, 13,000 as compared to 11,000 for a standard 2.75 or 3 inch. Realize also that the 385 grain bullet is less than 1 oz, like a 7/8 oz shot charge. I can load 7/8 oz steel shot out of a 2 3/4 shell at 1,800 fps easily. With the right powder, it could be done. But as said. that has to kick like a missouri mule! To say nothing of what max pressure repeatedly would do for the tightness of the shotgun.

Seems like I saw similar numbers for the Hornady H2K slug.

Impressive !

I am sure Hornady is within SAAMI specs.
Might be a little tough to duplicate at home safely.

Travis F.

eldeguello

As I have talked to shooter of the 3.5" the recoil is "stiff".

He quoted an article he read AFTER he bought the gun and calculated recoil was in the 460 Mag range.


FUN HECK . . . . That HURTS!!