I recently aquired 2 S&W M-29-2 revolvers both have pinned barrels and recessed cylinder chambers. Today I chronographed them along with a Ruger Redhawk
Both of the S&W revolver have 6 1/2" barrels and the Redhawk has a 5 1/2" barrel. The ammo used fro testing was the Winchester 240 grain Jackted Soft Point

The S&W with the wood grips Chrono'ed 1323 FPS
The S&W with the Hogue grips Chrono'ed 1460 FPS
The Redhawk chrono'ed ---------------- 1380 FPS

The S&W Revolvers

http://i33.photobucket.com/albums/d62/jwp475/SW44Mags003.jpg


My curiosity got the beter of me and I began to search for the reason why one of the S&W revolvers was 137 FPS faster than the other one. First I opend the cylinders and looked at the forcing cone in each revolver and VIOLA there it was plan as day the forcing cone in the S&W with the wood grips was approximately 2 1/2 times deeper than the one with the Hogue grips.

The large forcing cone (wood griped revolver) the slower one

http://i33.photobucket.com/albums/d62/jwp475/SW44Mags002-1.jpg


The smaller forcing cone ( Hogue griooed one) the faster one

http://i33.photobucket.com/albums/d62/jwp475/SW44Mags001-1.jpg

The only way to know the velocity of ANY firearm is to chronograph it. There is no other way.

Yup, your sure right there. I carried a 6.5 inch Smith all the years I spent in Alaska. Shot a lot of metal targets with it with hot loads. Finally shot it to pieces. That sure was a great gun. Went to the Redhawk and Super Redhawks but none came close to the trigger on those old Smiths.

You've got a nice pair. Now to open up that short forcing cone. Brownell's got the reamer you need. I'd check the cylinder throats also.

I need some Hogue grips for my 29 :-)

I need some Hogue grips for my 29 :-)

Let me check my box of parts, may have one...Sq or rnd butt?

I'm assuming they both have the same cylinder/barrel gap?

I have had the same experience with a pair of Uberti Stallions in .38 Special. The same loads, from the same box, chronographed on the same day, would have one revolver consistently 125-150 fps slower than the other. A visual inspection hinted at a larger barrel gap for the slower revolver.

I'm assuming they both have the same cylinder/barrel gap?

Ya, are the cylinder gaps the same?

Jim

I'm assuming they both have the same cylinder/barrel gap?


A visual inspection shows no noticeable difference. I will get a set of feeler guages to determine properly.

The barrel cylinder gap between the 2 S&W M-29-2s was only .001 thousandth of an inch, not enough to account for 137 FPS difference. IMHO it is the long wide forcing cone.

Interesting. Dummy that I am, I would never have guessed the forcing cone would make that much difference, nor would I have guessed the forcing cones on the two 29's would be that much difference.

Learning something this early in the morning kinda takes the pressure off for the rest of the day for me :-)

Dan

A friend and I have identical GP100s 6" half underlug, his shoots 158-180 grain bullets 150 FPS faster than mine, but we are equal with 110-140 grain bullets. Figure that one out.