S&W chamber sizes

[velocette]

Verrry interesting, I was test chambering my latest batch of 100 .38 Spl. reloads. I use a speedloader & test chamber all the ammo I plan on using in my club's pseudo PPC competition. I usually get one or two that don't chamber properly. This time I got 15 that would not chamber.
Inspection revealed that all but two were PMC brass. These reloads are 148 grain Double Ended Wadcutters. Both ends are identical. All of the PMC rounds that would not chamber had a concentric bulge right at where the DEWC end was in the case. Rather apparently the PMC brass is thicker than others at that part of the case.
Also interesting was that the PMC rounds that would not chamber in my 5 screw 1954 Target Masterpiece (forefather of the model 14) they ALL chambered in my model 15-2 Combat Masterpiece made many years later. To be honest, some of them did chamber in the 15 snugly but without using force. None of them were +P or +P+ brass.
Something else to watch for when reloading for my revolvers.

 

[CoalCrackerAl]

Always something to learn with our hobby.

 

[ontarget]

Sounds like a good thing you do test your ammo. In the middle of a match is a bad time to find out they don't fit.

 

[NIGHTLORD40K]

My M17 doesn't like to chamber Winchester White Box, but my Dan Wesson .22 and Colt OMM digest them fine, so it must have slightly tighter chambers.

 

[sparkyv]

There's always something...isn't there?

Something else to watch for when reloading for my revolvers.

 

[Jim Watson]

I have some WW double cannelure brass from factory wadcutters.
Said to have no internal taper in the seating depth.

 

[velocette]

Nightlord & Jim W, Interesting that my two non PMC rounds were both WCC (standard, no cannellure) and they had the same concentric ring where the base of the DEWC was. Another brand of brass off the DEWC load list.

 

[AzShooter1]

Do factory loads work with no trouble? If so it looks like it's a reloading problem. Especially with wadcutters you have to make sure they go in straight or they will bulge the case ever so slightly that they will no seat properly.

Give your brass just a little more belling before you insert the bullets.

 

[DR505]

I bought a finishing reamer for my Model 17-4 and 18-3. After just a few rounds cases started sticking. The finishing reamer, even though it shaves very little metal, does the trick.

 

[AzShooter1]

I had to do that to both of my 617s. It's an easy job. Looks like S&W uses their tools a bit long before replacing them.

 

[Riomouse911]

I used flexible chamber hones and my drill press to help my rimfires and .38’s with chambering.

It was super easy and they all chamber and extract much easier now.



Stay safe.

 

[Pat Riot]

Could it be that PMC brass is just a little thicker beyond the point where standard bullets are pressed to in manufacturing? Wadcutters do go further into the case.
My first experience with wadcutters was a 500 round ammo box full of Federal 147 grain repackaged factory ammo just a couple of years ago. Perhaps this is why an older gent in line at the ammo shop told me “If you’re interested in reloading wadcutters after you shoot those up keep your brass segregated and you shouldn’t have any problems. Use the same brass over and over for wadcutter rounds.”
Also, I recall a guy I worked with years ago that said he only used Federal brass for his wadcutter loads.
The conversation with the older gent at the ammo shop a couple of years ago got cut short because we got called up to the registers to pay for our CoVid ammo bounty and we didn’t get to speak afterwards.
My first 1000 reloads were with DEWC ammo and were shot out of 5 different guns.
Also, I do bell out my ammo when reloading, especially with HBWC loads.

 

[mcb]

I have had similar problems with PMC brass in both 38 Special and 38 S&W. It was even worst in 38 S&W. I sorted all the PMC out and set it aside.

 

[J-Bar]

You got me curious, so I measured some components.

I use home cast wadcutters in Starline brass for plinking with my .38 Specials. The bullet drops at 0.360". I do not run these through a sizer, but load them as is.



After lubing with liquid Alox, it's up to 0.363":



My fired brass mikes 0.382" and I bell it to 0.390"; not much, you can barely see it, but it works:



The finished cartridge mikes 0.376" at the crimp, and still drops easily into a Dillon gauge (as it should, since the cartridge specs list a case diameter of 0.379").



I plunked this round into several different S&W .38 Special revolvers without any problems.

So your problem may be the brass (I admit I am a fan of Starline brass), but you might also want to check bullet diameters as well. It would be interesting to know just how big the bulge in your cartridge is.

 

[halfmoonclip]

For the OP, you describe a 'concentric bulge'. I have that happen when a bullet really doesn't want to seat, and causes the brass bulge, exactly as you describe.
Too, had a 3" M60 that wouldn't chamber a great many rounds; sent it back to Smith, and they made it right.
Moon

 

[velocette]

What I actually have is a series of brass cases that have noticeably thicker case walls at the same point as the bottom of the DEWC. The expanded ring is the same all around indicating that the bullet is properly centered.
I measured the thickness of the case wall at the level where the DEWC sits in the case. The PMC brass all measured 0.0230" +/- .002" I then measured Federal, Winchester, Starline & RP brass, the thickest of them was 0.019" and down to 0.016"
The PMC brass has thicker walls. Those that load DEWC bullets, be aware of this. HBWC will probably not have this problem due to the thin walls of the Hollow base bullet at its bottom.
Finally, the small chambers of the K.38 are due to it's being designed as a target revolver with tight chambers, The same with my many target rifles and match pistols.

 

[film495]

what is your process? I don't really load wadcutters, but do .38 Special, and have seen various types of bulged cases for various reasons. you may want to play with some of that PMC brass and just make dummy rounds. I'd bet you a dollar, something small like putting some mica or lube on the mouth of the case would make that bulge less. I'm not sure, but I think that bulge is like a wave, and I think from the case deforming or kind of crushing and not just expanding. someone who's done what you're doing probably can give better perspective. I'm just kind of speculating based on some nuanced things I've seen. If you're going to crimp them anyways, getting the bullets to go in a bit smoother with some kind of lubrcant might fix that. or just use that brass for LRN or something else that doesn't seat as deeply.