Author Topic: Ultra Slug bore and groove diameters? (Read 600 times)

BillinOregon · « **on:** October 23, 2004, 05:57:12 AM »

Guys, this has probably been asked before, but can you tell me the bore and groove diameters of the 12 and 20 gauge Ultra Slug barrels? I believe the twist rates are 1:28 for the 20 and 1:35 for the 12, right?

BillinOregon · « **Reply #1 on:** October 26, 2004, 08:32:46 PM »

Rats. Guess nobody knows.

Gowge · « **Reply #2 on:** October 27, 2004, 05:25:38 AM »

The 12ga is probably same as others @ around 0.727" groove & 1:34" twist.... Not too many manufacturers are making fully rifled shotgun barrels these days.

Some of the aftermarket rifled choke manufactuers use different sizes for their choke tubes. These are .730" groove according to the info on the link: http://www.carlsonschokes.com/remington.html

Maybe this is something SAAMI needs to address and establish some sort of standard for 12 & 20ga shotguns?

GOOD LUCK!

BillinOregon · « **Reply #3 on:** November 01, 2004, 07:22:22 AM »

Thanks Gowge. Actually, James Gates of Dixie Slugs told me ithe 12-gauge groove diameter should be between .727 and .730. I note that a fellow over at accuratereloading.com said his 20 gauge Ultra Slug was .624 in the grooves, and that H&R/NEF said the barrels are made of 1137 cold drawn steel.

Gowge · « **Reply #4 on:** November 01, 2004, 09:12:12 AM »

Yea, James is up on all the various fully rifled barrels for 12ga. He's sorting out the 20ga rifled barrels now so he can offer a 20ga hard cast slug sometime in the near future...

Have you seen that discussion on the new X-Terminator slug - 730gr @ 1400fps? That thing is awesome! IF anyone ever needed a big powerful 12ga slug for backup or protection against Bears, that's the one I would choose!

The crew at Dixie Slugs are the experts when it comes to hard cast slugs & rifled barrels.... and their Predator slug is no slouch for smoothbores, either! :wink:

GOOD LUCK!