Guage mate

[NikatKimber]

Something like this would be a lot more accurate, and give better velocity I would think:

http://www.gaugemate.com/adapters/arsenal

Still expensive, $650 for 8 of them.

If you started with an 18-20" barreled 12ga single shot, shouldn't be too much chance of the projectile ever encountering the bore of the 12ga barrel.

 

[338Shooter]

At 1000 feet per second, the barrel time on a 24" barrel would be .002s. 12ga bore of .729 and a 9mm bullet diameter of .355. Assuming it is directly centered in the 12ga bore you'd have 0.187" of space between the shotgun barrel wall and the 9mm bullet. Dividing .187 by .002 gives you 93.5 in/s (7.79 f/s) velocity of the shotgun barrel in a direction perpendicular to the bullet's travel for the entire .002 second flight time. If you consider it from a standing start, you'll already be behind due to the barrel requiring an acceleration. I don't think it is possible with any of the caliber for the barrel to accelerate fast enough for the bullet to touch the inside of the bore.

 

[Old Fart]

I've seen something similar to that but can't remember who or where.

I remember where I saw it. I have an adapter that lets me shoot 32acp thru a mosin.

 

[dlbleak]

I've been eyeing this site for a while. looks like some cheap fun
http://www.mcace.com/adapters.htm

 

[Old Fart]

I've been eyeing this site for a while. looks like some cheap fun
http://www.mcace.com/adapters.htm

That's the one I saw too.

 

[Super Dave]

At 1000 feet per second, the barrel time on a 24" barrel would be .002s. 12ga bore of .729 and a 9mm bullet diameter of .355. Assuming it is directly centered in the 12ga bore you'd have 0.187" of space between the shotgun barrel wall and the 9mm bullet. Dividing .187 by .002 gives you 93.5 in/s (7.79 f/s) velocity of the shotgun barrel in a direction perpendicular to the bullet's travel for the entire .002 second flight time. If you consider it from a standing start, you'll already be behind due to the barrel requiring an acceleration. I don't think it is possible with any of the caliber for the barrel to accelerate fast enough for the bullet to touch the inside of the bore.

Dustin, I feel that you are not living to your full potential. Have you ever considered going back to school, and joining Lambda Lambda Lambda?

Might be neat to have an insert that was much longer, say 12" to 14" that was mostly small outer diameter, with a spacer every so often to contact the inner shotgun barrel. Hmmmm. I might like to have another cheapo single shot 12 gauge again. Maybe use a take-off AR barrel to make a 12/223 combo? That would be neat. Wonder if a Handi Rifle shotgun receiver would hold up with something like a 308 insert barrel.