doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Winchester Model 21 chokes - Ned Schwing's book

I have three Model 21 barrels and I thought they had all been opened. All were made before 1943. A friend gave me Schwing's "Winchester's Finest - The Model 21" and as it turns out they hadn't. I am amazed at how open the chokes are. Anyway this is from the book in reference to 12 gauge:

Full - .031 to .036

Imp Mod. - .015 to .018

Mod. - .010 to .015

Imp. Cyl. - .004 to .006


According to Schwing these choke ranges were all developed using Winchester trap loads.

All of the chokes taper toward the muzzle until the last 1/4" or so and then expand till the end of the muzzle.

Best,

Mike

Edit - corrected grammar error

I have four Remingtons from the 1938 to 1947 era, and the two 30-inch full choke barrels measure .031" and .032" while the two improved cylinder barrels each have .011" of choke. Both full choke barrels pattern very full with modern shot cup ammo and both improved cylinders pattern modified.

Schwing's Winchester choke figures are correct. Winchesters are very lightly choked compared to other brands. Many buyers think their Model 21s have been bored out but they were made that way.

I have a 16 marked Mod and IM. The chokes actually measure out to .008 and .014. They seem to shoot tighter than what the actual dimesions are.

Lenard

Lenard you may already have the figures for 16 gauge but here they are:

full - .025 to .035

Imp Mod. - .015 to .018

Mod. - .010 to .015

Imp. Cyl. - .004 to .006

I have an email from the Cody Firearms museum with the actual pattern performance on a 1942 set of barrels (and gun). In some cases the barrels were actually patterned and I guess opened up more if required to meet the correct percentage for the marked choke.

Thanks Bill - I hoped someone would reaffirm Schwing's choke dimensions. When I bought the guns I thought the chokes had been opened and now I find they aren't. Usually it gets worse the more I find out about a gun I just bought - what a nice surprise.

Best,

Mike

I agree with the taper toward the muzzle as you said but not with the expanding forward from a point 1/4 inch or so back from the muzzle. Where are you getting those specs? I have measured chokes in 6 Model 21's and the only one that expands in the last section toward the muzzle is an original WS1 skeet choke. All the rest were conical-parallel. Original modified chokes will measure 20 points or tighter. I have never seen one that is more open than 20 points. Improved modified will run about 25 to 30 points and full choke 30 points or more. Sorry but if yours are more open than those specs I think they are suspect.

Hey Cherry Bomb. I measured the taper and expansion with a bore gauge. If they have been opened it is the best job I have ever seen. First rate polishing - just like the rest of the choke.

You could interperet the book to mean that the dimensions I listed above applied to guns made before 1942.(Edit - the choke dimensions I listed above applied to what Winchester was doing in the 40s according to Schwing)

I recently measured a Model 101 marked full and full that was .035 and .045. That is another reason why I find the light chokes listed in Schwing's book odd.

Thanks for your information.

Best,

Mike

Different accounts of choke diameters being on the loose side have been posted on some of the different websites multiple times. Many of those that miked the chokes also had the thoughts of the chokes being opened. I am of the belief that what Schwing wrote about them in the 21 book to be correct.

Jap Winchesters do not comply with the Schwing figures, but the dozens of Model 21s and Model 12s I have measured are, in fact, lightly choked as mentioned by Schwing. The listed dimensions come from Winchester internal memos and charts. I have a prewar 20 gauge Model 21 marked Modified and Full that is a bit on the loose side of the "chart" in the Modified barrel. However, the factory test patterning indicated a forty some percent test pattern for that barrel. Obviously, the factory barrel borers took a bit much out of that choke and thought no one would ever notice. I'm sure such things happen in the best of gun factories. Even today, that barrel is doing all it can do to make a good improved cylinder pattern. Oh, well.

How do you guys measure this dimension?

I imagine you measure the bore dia at a point in front of the chamber, them measure the choke dia, and subtract the difference?

If so, what instument do you all use to get down the barrel, and measure in front of the chamber?

Gooser