12ga Reproduction Choke Help

TNR · 08-26-2017, 08:21 AM

After an long search I recently purchased a 12ga repro - 26" barrels marked IC/Mod. The gun has been used and I cant be for certain that the chokes have not been modified from original.

Using a galazan bronze gauge (which has always been good for me in ballparking the choke in classic guns) the barrels measure at almost Cylinder and not quite Cylinder.

However, using my micrometer I am getting .727 (R) .724 (L) which, given my research here, assuming a .735 bore equates to .008 (R) and .011 (L)

I've found several posts in the forum that indicate this is proper for IC/Mod reproduction barrels.

As I am still in my purchase inspection period - looking for some feedback just to make sure this is square with factory reproduction chokes.

Any feedback is welcomed.

Opening Day · 08-26-2017, 08:46 AM

Take it to a smith that has proper choke gauges, the slip in brass gauges are about as good as using a dime..

Sorry but the only way you will know is to use a proper gauge or shoot a couple of rounds on a pattern board would also tell you

Wild Skies · 08-26-2017, 10:53 AM

I wouldn't, as you say "assume" that the gun's bores measure .735" diameter. They may or may not be .735", my two 12-ga. Repros measure .730 and .731. Eric has given the proper advice in having the gun's chokes and bores measured with the proper instruments.

TNR · 08-26-2017, 06:01 PM

Thanks for the quick feedback - I understand that I cant *assume* without proper measuring equipment but without that ability at the moment I am looking for a general baseline from other 26" 2.75" chambered repros. I do understand *most* bores measured at .734-735 in the non-SSS and 3" guns.

Are those micrometer measurements at least what one would expect to see?

Ill pattern if i cant get it to a smith in a reasonable amount of time.

Wild Skies · 08-26-2017, 06:08 PM

12-ga. Parker Repro IC/M factory chokes typically have .006/.011 of constriction give or take a thousandths or two.

Bob Jurewicz · 08-27-2017, 07:01 AM

This thread has the info on choke constriction in Repros.
Bob Jurewicz

http://parkerguns.org/forums/showthr...r+reproduction

TNR · 08-27-2017, 01:40 PM

Thanks Bob - I was referencing the information in your original posting in my post! Thanks again!

TNR · 09-08-2017, 04:12 PM

Using my new "unloader" internal bore gauge I got the following

Left Bore - .735 Right Bore = .735

Left Choke .723 (.12) Right Choke .727 (.8)

I got lucky and assume right and my Mic is closer than expected.... Just happy the measurements are in line with what other members have reported on in 12ga PR and weren't opened up..