12" 12 gauge ballistics

[CONNEX 3300]

Last thread I could find on this was 4 years old; so I'm going to see if there's any new info out there. So;

I'm about to begin the paperwork for a SBS. Plan is to get a Remington 870. Keep one 28" barrel for hunting, buy another cheap one to cut down to 12" or about flush with the mag cap. What kind of ballistics can I expect from the 12" barrel, and what kind of patterning? If anyone here wanted to chronograph birdshot, buckshot and slugs from their 12"ish 12 gauge I would be very grateful; but even more grateful for pattern tests with the ammo. What are your experiences with SBS 12 gauges?

 

[Ryanxia]

There are some youtube videos with guys patterning their 12" barrel SBS's. Depending on what shotgun you're using as a platform you could have the barrel threaded for a poly choke or choke inserts too I believe.

This link has a chart that may be helpful.
http://thefiringline.com/forums/showthread.php?t=337598

 

[Arizona_Mike]

The following data has been bouncing around many forums for years. Aparently first from Jason Hinkle at Subguns (reworded a bit for profanity):

Cheap birdshot- 12 gauge, 2 3/4 inches, 1 oz shot
12" barrel average FPS- 1040
14" barrel average FPS- 1069
18" barrel average FPS- 1114
19.5" barrel average FPS- 1114
20" barrel average FPS- 1108
28" barrel average FPS- 1159

Remington 00 Buck-
12" barrel average FPS- 1121
14" barrel average FPS- 1127
18" barrel average FPS- 1216
19.5" barrel average FPS- 1205
20" barrel average FPS- 1182
28" barrel average FPS- 1250

Mike

PS. The takeaway is that with fast burning pistol powder, you don't loose that much.