Personal record for cylinder throats


Well-Known Member
OK, rainy afternoon. Decided to drag out a few rarely fired revolvers and see what the barrels and cylinder
throats measure.

Old S&W Regulation Police, is first up. I picked this up at a bargain price at a gun show, some idiot decided that the
exterior of the barrel needed "his help". Filed it all over, no caliber markings left, lots of ugly file flats, really ugly, why
I got it for a song. This is a J-frame, short window, chambered in .38 S&W, not .38 Special. OK, so I knew the barrel
would be a bit larger, since the standard bullet diameter for .38 S&W is .360, not .357 or .358 for the Specials. Barrel
took a .349 pin, fell all the way through, zero frame thread restriction. Now the cylinder throats. Start with a .360 pin,
passes right through. OK, .361....hmmmm, seems loose, way loose, actually. I look at the front and there is a LOT of
clearance around a .361 pin.:headscratch: What the heck. Finally I find a pin that fits the cylinder throats nicely.....
.378 diameter!!:embarrassed: On what planet is that considered a "proper dimension" for the cyl throat for a .38 S&W which
fires a .360 or .362 ish bullet???

Wow. Still trying to digest that one. So, almost .020" over the correct throat size. Gee, maybe this one needs
a new cylinder or just sending it down the road.



Staff member
.378" huh? Wow. From the sound of the file marks maybe the same person decided it also required a throat reamer. You know, to make it shoot. :eek:


Well-Known Member
OK, did some more thinking and figured out Bubba decided that he needed to IMPROVE
this old girl, and idiot-reamed the cylinder full length to take a .38 Spl case. It
will probably fire a .38 Spl WC flush loaded cartidge. Of course, huge oversized throat,
but it is only about 1/8-1/4 inch from the case mouth to the forcing cone, so the
bullet will be into the forcing cone before it fully exits the case. :headscratch:

It will easily chamber a .38 Spl cartridge, but the bullet sticks out on a normal
round, but flush WC will "work". I suppose I will have to try a few low pressure
WC test rounds on this one. I guess the filing was to remove the "no longer correct"
caliber marking. I wonder if the cases will even eject? Thinking about the 'direct from
case to forcing cone' situation, it may actually be halfway accurate.

There are sure a lot of fools out there running around. I guess just a 3/8" drill bit
and you get .378 throats. THERE! I fixed it! I'm sure the idiot thought. The rear
of the cylinder gauges correctly for a .38 S&W chamber.

Last edited:


Well-Known Member
Hmmm. A replacement .38 Spl J-frame cylinder is too long, can shorten it in the lathe.
Then ream out to .38 S&W, OR...... shoot proper .38 WC ammo in it with proper throats.

Will check with my S&W guru to make sure that a later, longer J- cyl will fit with reasonable
rework. I suppose the first order of business is to see what it does with low pressure .38 Spl
WC loads.

Last edited:


Well-Known Member
Thanks, Brad.

No chance of getting a .378 bullet into a .38 S&W case and then chambering it.

Bubba's 3/8" drill "fixup" job.



Well-Known Member
Used cyl on eBay is under $50, has enough meat to rechamber no problems, or
just use .38 Spl WCs in the old girl, but with a proper, unstepped chamber and
a proper throat size.


Well-Known Member
I know a guy that could hook you up with a heeled "38-38" mold for around 100$... I know, I know, stop helping.

I wonder how the throat on the barrel looks.


Well-Known Member
Bill, try .357 Maggot wadcutters, seated flush. The brass should be near cylinder length, should be a good experiment. Load to very low pressure, of course. 2.7 grains of Bullseye, Titegroup, or Clays should be plenty. If the Maggot brass doesn't fit flush w ou th the end of thy cylinder, you can always ge Max brass and trim it down just for kicks to see how she shoots. The only concern is if you can chamber a groove-sized bullet loaded in longer brass.


High Steppes of Eastern Washington
That modification was actually encouraged in the 1960's! The only problem was that the rear of the case swelled up and you couldn't get most of them back into the cylinder.
Is it possible to drill it out a little more, fit sleeves, and rechamber properly?
Are you thinking of something like sleeve the cylinder and rechamber for one of the 32's and then use a barrel liner to match the rebuilt cylinder? If you can do the work yourself, it might be cost effective, but not if you have to pay a gun smith.


Well-Known Member
I have a long frame window J frame .38 Special cylinder in hand, will be shortening
it for that gun. Then it will be a .38 WC only gun until I can find a .32 cylinder to rechamber.
I checked the serial number just today, and it is just over 1500.....a VERY early gun. Seems
worth putting it back right. A bit of a challenge is always fun.



Well-Known Member
My wife has a pristine old nightstand S&W model 32-1 Terrier ( 2" barrel ) in 38 S&W caliber. The barrel slugs out at .361" and the cylinder throats are .362" very easy to load for with a .361-.362" bullets
I have honed out my lee .358" SWC and along with some beagle tape & it cast about .363" approx 160 gr SWC's ( CC load)

I also have some .360" hard Cast Commercial bullets which are 125 gr TC that is a good practice bullet from CB Bullets and a dandy original 148 gr Round nose 38 S&W original from Mattt's bullets which he cast for me in soft "Cowboy" lead and at a dia. of .363"
Ben also turned me on to the Lee 9 MM Makarov bullet which is about .365 as he cast them at about a 100 grains they are now the favorite practice load!