S&W Mod 27 3 1/2" barrel rebore


Doug DeGraves
January 18, 2012, 10:15 PM
Greetings all, I need some expert advice. I have a S&W Mod 27 3 1/2" barrel, the bad news is that it has a goose egg in it. Is there enough metal there in that short of a barrel to convert it to 41 Mag? 44?

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Mac's Precision
January 19, 2012, 05:34 PM
By saying goose egg are you suggesting it has a bulge?

January 19, 2012, 05:41 PM
That was the impression I got.

My personal feeling is, if so, the barrel has already been pushed beyond the yield strength of the steel.

So I would not push it any further with a thinner wall .41 Mag, or thinner still .44 Mag re-bore.


Mac's Precision
January 19, 2012, 06:03 PM
Yep Rc...that is where I was going with that. If it is compromised, it will just like a bulged shotgun barrel, eventually get worse and rupture. Amplifying the matter with a larger caliber would only speed up the poor outcome.

Secondarily, If memory serves the short barrel 27 is already pretty darn thin at the muzzle. If bored to a larger caliber I would think it would be like a gasket cutter at the muzzle. I don't think there is adequate meat there to complete such a thing.

As it stands, I'd say seek and find a replacement barrel and install / set back as needed to return it to .357 Magnum. I think this is the only cost effective option.

CSA 357
January 19, 2012, 06:06 PM
rebarrel would be the best way to deal with this, finding a 31/2 inch 27 barrel will be no easy chore i have been looking for one for years! finaly just broke down and got the whole gun! good luck

Doug DeGraves
January 20, 2012, 08:55 AM
Thank you for the advice! Just lately I've been trying to read up (and listening) on such matters and I'm getting mixed information. Some say the bulge is no big deal if it's not to bad, keep shooting it. Others say it will affect accuracy, while others say it's a safety issue. I probably should have initially given a better discription of the problem. The barrel shows no external signs of a bulge but slugging bullet reveals the loose spot in the middle then back to tight toward the muzzle. I guess my real question should have been, "what can I do with a bulged 3 1/2 Mod 27 barrel." I've not see too many 3 1/2 27s of late and they have been too expensive and too nice to modify. What I'm sort of after is a 3 1/2 27 with a round butt. I like the look of the snake barrel. I was hoping the barrel I have could be salvaged, assuming I could find a 28 to put it on. I guess a pencil holder is one use for it.

January 20, 2012, 11:54 AM
Is it an accuracy issue or not?
Only you can tell that by shooting it.

If it hasn't affected accuracy so's you can notice?
Shoot it!

I just would not recommend boring it out for a bigger Magnum caliber.


The Lone Haranguer
January 20, 2012, 12:56 PM
As well as the barrel, you would have to find, fit and time a cylinder.

January 21, 2012, 04:58 AM
If it shoots OK I would just ignore the issue as it will cost more than its worth to fix it.

Doug DeGraves
January 21, 2012, 03:15 PM
What is the range of years that the 3 1/2" Mod 27 manufactured? How many were made?

Here's an odd question, has any one seen an N frame Smith that the frame is case hardened? I'm curious on how it would look.

January 21, 2012, 03:18 PM
S&W made a bunch of "Heritage" Series a few years ago with Doug Turnbull color-case frames.
First time in history a S&W ever had a color-case frame though so they didn't sell very well to true S&W aficionado's.




Old Fuff
January 21, 2012, 05:34 PM
First of all, I would follow previous advise and shoot it to see if the bulge causes any serious accuracy problems. It may well not.

A new barrel would be a far better solution the a liner, but keep in mind you can have it lined to a .358"/16" to 1 twist, and leave it a .357 Magnum. I would then shoot it with .38 Special cases, with a 158 grain bullet crimped in the groove rather then over a shoulder at about 1000FPS out of the short 3 1/2" barrel.

January 21, 2012, 06:43 PM
i got a 6 inch bbl for a 28 for sale that will fit.you can shorten it

Doug DeGraves
January 21, 2012, 08:10 PM
RC, thanks for the links. I'm not sure I like the way case hardening looks on that much real estate, but it is interesting. What I have in mind is more of a personal artifact that shoots. Maybe if I had some nice stag grips that had similar coverage as pacmeyer round but grips, but the hammer and trigger would have to have a different finish on them too.

January 21, 2012, 09:13 PM
Can't go wrong with engraving on a blue gun if you got the money to do it!


Doug DeGraves
January 22, 2012, 07:03 PM
I should have done this at the start...I compared this Mod 27 barrel to that of my 624 3" and I was very surprized by what I found. The outside dimensions of the barrels were the SAME! I too figured I would have a gasket cutter if the 27 bbl was bored out. I will post a photo when I can.

So the first order of business is finding a suitable candidate to mount this on, then looking at the options.

January 26, 2012, 03:17 PM
Send it S&W to see what they have in stock let them do the replacement bbl.

Doug DeGraves
January 29, 2012, 02:24 PM
Next question: let's say if find a decent Mod 28 to put this barrel on, and I want to convert it to a differant caliber. Is one caliber more expensive to rebore than another? The choices are 38-40, 41, 44 Spl and 45 ACP. Thoughts?

Old Fuff
January 29, 2012, 04:27 PM
I would think that the cost would be identical, regardless of which bore size you picked. I know of no good reason this wouldn't be so.

A model 28 barrel will not have the checkering seen on the top of the rib, nor the high polish blue. This of course is a matter of cosmetics and it may not matter to you.

I see no reason not to rebore the original barrel, as apparently the bulge isn't deep and would be removed in the reboreing process.

I would forget about the .38-40 as ammunition is dificult to find and expensive. .45 ACP requires half or full moon clips, and might require a new cylinder. .41 Magnum and .44 Special should work with no problems.

January 30, 2012, 04:19 PM
The outside dimensions of the barrels were the SAME!
Bingo! Model 28's and 27's are somewhat popular for conversion to .38-40, .41Mag, .44Spl, .45ACP and .45Colt. Rebore will cost the same regardless of end result. Typically around $150. A rechamber about the same. One must keep in mind that .357 cylinders are shorter than their .41Mag, .44Mag and .45Colt counterparts and this can limit your bullet selection, depending on which chambering you choose. The .38-40 is certainly a viable choice. You'll need to handload for any of them to be economical to shoot, which makes the .38-40 no different. S&W never built the lovely N-frame .38-40 in any great numbers and hasn't offered it in many years so it will definitely be different. Though they did produce the model 544 Wagon Train commemorative .44-40 back in the `80's if I remember right. Which by all reports was a fantastic shooter. Neither is a difficult cartridge to handload for but they do require lubing cases.

Doug DeGraves
April 5, 2012, 09:04 AM
I've been thinking (always dangerous) about making this thing as unique as possible so I've been drifting toward 38-40 but since I don't have candidate yet everything is up in the air. The new question is can this 1964 barrel be used on an old triple lock? What about a mordern cylinder? Would the original triple lock crane (yoke?) have to be used or could the modern crane (yoke?) be modified to triple lock specs? The end result would be a pinned and recessed 3 1/2 inch snake BBL round butt triple lock in 38-40 with adjustable sights. Thoughts? Not breaking the bank is a factor too. Would this drastically increase the gunsmithing costs? After visiting a gun show I found the prices astounding. I did find a poor old triple lock in 45 AR in dire need of some TLC for less $ than any of the 28s I saw (I didn't see many).

April 5, 2012, 06:46 PM
As well as the barrel, you would have to find, fit and time a cylinder.
WHY? There is nothing wrong with the cylinder.

Doug DeGraves
April 7, 2012, 01:06 PM
Remember, all I have at this point is a loose 1964 vintage 3 1/3 inch barrel from a S&W Model 27, with slight bulge in it. I'd like to use it for some thing interesting as a like the look of the short snake barrel. The buldge does not appear on the outside.

Also I can't figure out how to post a photo.

Doug DeGraves
April 8, 2012, 06:57 PM
FYI, i have it on good authority that there is no practical or cost effective way to mate modern parts to an old triple lock. So back to the original plan, finding a suitable (one I can afford) 27 or 28 to put this barrel on. and now I'm in no hurry.

Doug DeGraves
April 10, 2012, 09:16 AM
So what can be done for this Triple Lock I ran across? It has a relatively low serial number (under 1000) assuming all the Triple Locks were numbered sequentially. It has British proof marks on the cylinder by every flute. I didn’t see any other proof marks on it. Since it’s not in its original condition, barrel cut down and awful rifle sight added, probably rechambered, and also in disrepair due to missing parts (ejector rod end and soem springs), what are your recommendations concerning this piece? I figure most of the collector value is already gone due to the changes made way back when. Is that not correct? My thought would be to get it in good working order first, if possible. Thoughts? Why shouldn't it be made into something more interesting. It's just plumb ugly now....

April 10, 2012, 11:05 AM
You might want to contact Hamilton Bowen and get his opinion.



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