WIN 21 with 2.5" Chambers

[ejsxs]

After receiving Galanzan´s tools this week I measured my Win21 16GA 28" barrels. Bores are 0.670 as described by Ned Schwing´s book ("Winchester´s Finest: The Model 21", p. 94) and chokes constriction are 0.028 L; 0.010 R, that is Full and Mod. Nevertheless, board tests show that actual patterns are closer to IM and Cyl. Chamber length is 2.5", surprising, since Schwing says in page 96: "Throughout the entire production era the Winchester Model 21 was chambered for 2 3/4 inch shells". Galazan instruments are reliable. Anyone with similar experience?

[budrichard]

I have the Galazan chamber measuring kit that has different collets for the various gauges. I have found the 3" Model 21 chambers invariably measure 2&7/8" with the gauge. I wonder if the Model 21 chambers are very close to tolerance and outside of current SAAMI tolerances? In any event I never had a problem using 2&3/4" shells in the pre-war 16 I had(SKEET).
Since your constrictions are quite close to the lower tolreance for FULL and MOD, I would have no concern over the actual patterns which are somewhat ammunition dependant anyway.
What are the specs on your 16, year etc and do you have pics?-Dick

[ejsxs]

Richard,

My 16Ga Win21 was built in 1949 (Cody Museum letter) though the serial number is rather low (7xxx). Pistol grip, BT kidney pattern, SST, black walnut. Possibly brought to Chile by member of the USA Embassy, as other two cases I know of. As far as I am aware there are four more guns of this model here, all of them in 20Ga. Mine needs reblacking of barrels and frame, some day I wish to send it to CSMC for facelifting. Yes, I fired 2.75 shells for the last three years after purchase with no problems, now chambers are 2.75" after cone straigtening. Bores are mirror like, no need for burnishing, extended cones were recently burnished. Weight is 3130 grams (6 lb 14 oz.), that is suitable for a carrying gun, but PG and BT makes it a good standing gun for clays and pigeon-dove.

[M&M]

I also have a 16 ga. Win 21. The barrel is marked 2 3/4" but, in fact had 2 5/8" chambers. I am confident of the measurements as they were done with two different types of gauges. I have the blade type from Galazan's and the smith, Larry Feland of Cypress, TX has the cylinder type.

Mine has been opened to 2 3/4" and the forcing cones lengthened. I was not concerned with the changes, as mine is definitely a shooter. The factory wood was gone when I got it, I think it has had a re-blue, and the chokes may have been opened. (marked I/C/mod and measure .004 and .008) The .004 does fall within the Winchester guidelines, but the .008 is a little more open than the listed .010 - .015.

In any case, after 30 years of not shooting it due to poor fit, I decided to make it my own. After having it fit to me, I purchased a beautiful piece of California English feather crotch and it is at the stock maker now. I may post some before and after when I get it back.

[ejsxs]

M&M,

congrats., for making it your shooter. As regards to stock, I have kept mine 16Ga with the original one adding a 1.125" wood suplement that fits well with winter clothing. Gun-fitting showed that mine was cast-on, I bended it to my measures and now is performing on a par with other two 12Ga AYA SxSs on feral pigeons. My view is that Mr. Olin´s people were not using the right tooling sometimes as regard to chambers. Please send us pictures of your gun, I am now learning (slow process anyhow) to post pictures of my guns.

Regards,
EJSXS

[budrichard]

My experience with Win 21 chambers using the Galazan Pro Gauge set has been that 3" chamber guns measure invariably slightly short. The guns I have measured were all 1950 or later Model 21's,two 'Ducks' and one a Custom Shop 20 gauge. I don't believe these guns were manufacturing errors but may be related to the measurement tool or Winchester standards.
We all know that a 3" shell is not 3" in length and maybe Winchester wanted to assure that the opening of the shell caused an effective seal. The point is, the individuals are gone and we don't know the reason for this.
Now for early guns, I will concede that thier may have been manufacturing differences but usually Winchester employees knew thier craft.
Maybe Grant can give us some insight.
But I would caution, that before one assumes that a chamber is incorrect and that machining is needed, to fully investigate what you have. -Dick

[Slidehammer]

In the era of paper hulls and cardboard/fiber wads, manufacturers looked at chamber dimensions and forcing cones differently than we have somewhat regressed to today.

It was common to chamber somewhat short for the ammunition intended. Theory was less gas blowby letting the hull open slightly into the taper of the forcing cone.

Winchester was a believer in this method. Prior to plastic hulls, Winchester chambered a gun for 2 3/4" loads to an actual chamber length of 2 5/8". I have measured many Winchester chambers including Model 21's and find this the case. Logic tells us that a 3" gun would have chambers cut to 2 7/8" length. I haven't measured a 3" chambered Winchester...

Winchester followed this procedure for many years.... Early Winchester Model 97's from the turn of the century (1900) had 2 5/8" chambers in 12ga. (Some 12ga loads were 2 5/8" early on in roll crimp).

I have measured three WW1 era Winchesters in 16 gauge. The standard hull length back then for 16 gauge was 2 9/16" length. The chambers were cut to a length of 2 7/16" in these guns..... Seems Winchester believed the chamber should be 1/8" shorter than the hull and did for many decades.

I have lengthened three 16 gauge chambers (to 2 3/4") and cut a 1 1/2" length forcing cone in two early Winchesters and one Remington. I WOULD NEVER DO ANOTHER! I wish I had left them alone! The 1/8" short hurts nothing with plastic hulls as they are actually thinner at the mouth than papers were.

Slidehammer

[ejsxs]

Slidehammer,

interesting viewpoint, I believe you say this from experience and practicality, maybe I would think twice next time. Anyhow, my Win21 concentration improved producing less 5" patches in a 30" circle on the iron board with similar quantity of pellets.

Regards

[budrichard]

I think Slidehammer is correct.
In terms of then and now, the ammunition of the early 20th century was different than the ammunition of today, so if one does lengthen chambers and obtains improved patterns, then, fine. But I would caution, that unless one uses brute force counting as in old or the newer digital assessment tolls, that differences in patterns may be perception.
In any event if its done and works, great. If not done and you are concerned with a short chamber, consider testing before machining. The old machinest adage is, "you can take it off but you can't put it back".
As I said, I had/have 3" chambers that measure short but work just fine.
-Dick