Cylinder Throat Reaming

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Nick_C_S

New member
I'll spare a long story. I've been shooting and loading ammo for revolvers for decades. I have a Smith 67 whose charge holes seem to need reaming (I'm guessing about .0015-ish) so I can shoot .358" lead slugs without leading up the throats something fierce.

Does anybody know who does this kind of work (in the U.S.)? I'm not comfortable attempting this myself. I'm not a machinist; and at best, have only the most rudimentary knowledge of such endeavors.
 
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Dufus

New member
It ain't a real hard task. Browells has the reamers.

I have done a SBH, a Blackhawk, and a S&W.

Results were very good on all three. I don't really know any gunsmiths that do it although it should be any easy task for an experienced person.
 
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Nick_C_S

New member
Gordy seems to be all things rifle. Didn't seen anything about revolvers.

The Brownell's route is starting to look better. I really really don't want to ruin my gun though :p.
 
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pete2

New member
The only 2 guns I've had trouble with had oversized throats. A Ruger New Model .45 Colt and a S&W Model 24 .44 Special. Both leaded and both would not shoot groups. I don't normally even check the throats unless there is a problem with accuracy. I would venture to say most have tight throats.
 
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Nick_C_S

New member
When I shoot .358 lead bullets, I get a ton of leading in the throats and up the barrel, from the breech. Even after three cylinder's worth, the leading is extensive. These are your basic 750 f/s wadcutters. Not that it matters - it it's a lead bullet, it lays down lead. I know about barrel fit, hardness, all that stuff.

So just for fun, I loaded some .356" 147 grain 9mm bullets and shot 70 of them with no leading in the throats, and just a little bit at the very beginning of the grooves, past the forcing cone. They seemed to be accurate too - amazingly.

.356 bullets will fit in the throats. .357 bullets won't. Well, they might, if I pushed really hard.
 
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tangolima

New member
You may have found the alternative solution to your problem. For cast bullets, the ideal combination is with throat diameter 0.001 to 0.002" larger than barrel's groove diameter. Then the bullet diameter is the same as the throat diameter.

Throat diameter in your revolver is 0.356". Slug the barrel to find its groove diameter. If it happens to be 0.354 to 0.355", you are in luck. No need to ream. Just load with 0.356” bullets.

If it is 0.357", as what it is supposed to be, then you will need to ream the throat to 0.358". And you will load with 0.358" bullets.

Tight throad and barrel happen more often than I have thought. I have a colt police positive that is supposed to shoot 0.361" bullets. It never worked well. I couldn't load the rounds in the cylinder unless I seated the bullets low. Then I found the throat was 0.357" and the barrel 0.355". 0.357" bullets (available for tight target barrels) worked much better. Then I tried 0.356" for 9mm, and it worked even better.

-TL

Sent from my SM-G930T using Tapatalk
 
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Nick_C_S

New member
So I got on Brownell's site and ordered the throat reamer and pilot pack. They arrived a couple days ago.

I checked the throats on my Model 67 and the .3570 pilot clears in all six throats.

So I'm a bit confused. When I shoot .358 bullets, I get tons of leading in the throats and barrel breech.

I know this: I won't be reaming anything until I know exactly what's going on - if ever.

BTW, I have fire-lapped this gun. And it did seem to help a little. Well, I'm not sure how much it reduced the leading (a little, perhaps), but I did notice that the lead seems to clean out a little easier.
 
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pete2

New member
I have several .38 Special and .357 revolvers, I shoot .358 cast in all of them without major leading. Right now I use 158 RN cast from Dardas. I have also used 158 Speer RN lead and Hornady 148 HBWC. No major leading with any of them. I've got some 158 SWC Hornady lead HP that measure .357 and they seem to work ok in a 642 revolver, I haven't tried them in other guns. The Speer and Hornady bullets are softer than the cast bullets.
Guns don't always go by the book
 
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AzShooter

New member
I made my own tool to open up the throats on my 627. It made a very profound difference in the groups. I went from .356 to .358 and used .358 bullets. I molded my own 168 grain bullets from a special mold and it was the best bullet I ever shot.

When I gave up on center fires I gave the mold away to another happy shooter. The guy that bought my 627 tells me it's the best shooting gun he ever had.

Take your time, do it right and it will work out for you.
 
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