S&W revolver chambers different sizes (same caliber)

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I have a 1966 Model 10-5 snub, which I'm going to try to shoot in an informal handgun match next week. I've been chamber-checking my reloads and have about 6 of ~500 rounds that hang up at the last 1/8" before entering fully. I put those aside. A couple are obviously bulged and won't chamber even with a good push with my thumb... I'll pull those and recycle the brass. The other 4 just have a little resistance but probably enough to hang up a speed reload under pressure.

Out of curiosity I tried them in my 1966 Model 28 and they all chambered fully. (The two that wouldn't chamber at all in my M10 wouldn't chamber in the 28 either.)

I imagine there are some differences in chamber tolerances?

BTW I'm using mixed range brass. I imagine a few have been loaded pretty hot...
 
Not unusual. I have two groups of brass for each caliber.

Group 1 are mixed headstamps that have been fired unknown number of times. I use this brass for plinking and informal shooting. I cull the ones that get split case mouths and loose primer pockets.

Group 2 are separated by headstamps and have been fired the same number times. My match brass is reloaded in using the same headstamp as well as my hunting loads. I pay more attention to o.a.l. in this group and the consistency of the bullets especially cast lead.
 
A thought strikes me... maybe it's the other end of the cartridges? If the bullet ogive or lube or something is hanging up a little at the chamber mouth in a .38 cylinder, it wouldn't necessarily have issues in a .357 cylinder, right?

I'll have to try them in another .38 cylinder.
 
.. maybe it's the other end of the cartridges?
Click to expand...
Simple way to find out what it is, is to color them with a black magic-marker, then force them in and back out.

Were the black rubs off is what is tight where.

rc
 
This may be a wives tale - but I have heard for many years that (at least Ruger anyway) revolver chambers were final-reamed one chamber at a time. Sounds a little far-fetched - but maybe the reamer lost a thousandth or so as it went from chamber to chamber. This would make even more sense if the chambers were bored (to final spec's) one chamber at a time with no finishing reamer used.
 
Black Knight said:
Have you tried factory loads in it? It may not be the gun but the ammo. If it is the gun a gunsmith may be able to ream the chambers to proper demensions.
Click to expand...
I've shot factory in it before and don't remember any issues... I'm sure it's primarily an issue with my reloads. I removed the post-sizing ring from my FCD but the "bulge" is so close to the rim I'm sure the sizing ring wouldn't have solved it.
 
Maybe not entirely appropriate, but a word on chambering reamers. Reamers wear as they are used. So new ones are made to the outside of the spec for the caliber. As the reamer wears, it is sharpened, becoming smaller each time. When it reaches the inside of the spec, it will be discarded rather than being sharpened again. So a given chamber can be larger or smaller, longer or shorter, depending on the reamer that was used for that chamber.

A case in point is that I have several S&W and Colt revolvers in .38 Special. .38 S&W cartridges will fit and fire in some, but not in others. In a few guns, the same .38 S&W round will fit in a couple of chambers but not in the others.

Jim
 
I would sooner think you haven't trimmed your cases or have a few short cases that escaped the crimp die. I do think your right that the problem is at the bullet end of the case, in that it is still flared a little because the case was just to short for the crimp die to effectively straighten the flare back out.

I've ran into this exact problem I described above and ran the offending rounds back through the crimp die and the same round just fell in the chamber and fell back out again.

I sort my .357mag cases to groups of .005" in length. With all the cases I have I only have 3 groups of cases. One very large group, one smaller group and a very small group of rejects that I don't load very often because there just aren't enough of them to care about. These are the ones that gave me the problems I had.
 
Interesting, TT. I'll take a look. I am running un-trimmed/mixed brass and some don't get crimped as much as others (I'm ironing out the bell in the seating die and then applying a moderate crimp with the FCD sans sizing ring).
 
The old Model 28 has rebated cylinders. Some carbide reloading dies will leave a ring down at the bottom of the case. So I would guess those would chamber in the Model 28 and be a little tight in the non-rebated cylinder Model 10.

So check your dies. Make certain your cases are within specifications just ahead of the case rim. Consult the diagrams in reloading manuals.
 
No, actually the counter bored cylinders on those would be no more likely to chamber them then any other revolver cylinder.

The counter-bore is only rim depth, so the case body still has to fit in the normal chamber as in any other gun.

rc
 
Have you measured the overall length of the empty case? Cases stretch after so many loadings, and this will cause them to fail to chamber as the case mouth in actually trying to enter the cylinder throat. And certainly they'd go into a .357 Magnum chamber.

Maybe need trimming?

Bob Wright
 
Especially if you are using lead projectiles make sure that some or all are not oversized and in need of resizing.
 
All that tedious measuring with expensive tools everyone doesn't seem to have, and SSAMI drawings are unnecessary to find out what the real problem is.

If you do what I said in post #7 with a .99 cent magic-marker, or smoke it with a even cheaper .10 cent birthday candle.

rc
 
I was having the same issue for a little while when I started reloading. I have a few revolvers with tighter chambers.
My 10-8 and 28-2 seem to have slightly large chambers, as they will chamber slightly bulged rounds with just a little pressure where my sp101 and most of my colts won't at all. Cases fired from the smiths size just a tad harder as well.

The differences in chamber size also threw me for a loop when I was setting up my dies. I used my 28-2 to set crimp on a run of plinking loads, using just enough crimp to chamber. While they slid right into the 28-2, the sp101 wouldn't chamber them without significant thumb pressure. I had to increase the crimp slightly to be able to use them.

While i have experienced different sized chambers in various revolvers, I have not experienced different sized chambers in the same cylinder of a revolver.
I have a .44 mag single action with chambers that leave stretch marks on brass like on a pregnant belly.
My .44 SRH won't even chamber brass fired out of that gun.

My problems with tight rounds were entirely due to crimp, and my ignorance in setting up the crimp die correctly. I was getting everything from bulged brass to lead rings cut or pushed ahead of the crimp.
If your reloads are fine, I'd go with rc's suggestion and find out where the resistance is coming from.
 
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I have two Rugers and a S&W in .357...

Neither Ruger will chamber a .38 S&W cartridge, yet the Smith & Wesson will...

Not recommending trying this (and I certainly would not fire them), but I did try chambering factory Remington and Winchester .38 S&W just for giggles...

ADDING:

Point being, some chambers are just more 'generous' than others...
 
Point being, some chambers are just more 'generous' than others...
Click to expand...

Yes they are, but any properly sized and crimped round loaded from a set of correct loading dies will fall in and back out of any cylinder of any revolver made unless the dies weren't set up properly OR the cases were to short to straighten out the flare.

Even if the dies are set up properly if you have a short case, and we all have them, if you set the dies up on the shortest case you can find, you will be over-crimping the longest case you can find. If that happens you will have the same problem.

Over crimping and under crimping produces the same problem, cases that won't chamber, but for two different reasons.

Over ROLL crimping will partially crush the mouth of the case and you can have a slight bulge in the mouth of the case if the case is to long for the way your crimp die is set.

Under crimping will leave a partial flare on the mouth of the case and cause the case to not chamber.

Either way the mouth of the case is over diameter for the chamber and with your cases at random length your problem will also be at random depending on which problem case you happen to get ahold of.

Is there a cure? If your loading low pressure loads, buy a taper crimp die. Then you don't need to care.

You never read about us trimming our 9mms. If you are loading higher midrange to heavy loads, you will have to start measuring your cases and grouping them so you can set you crimp die to work with 100% efficiency.

You can actually get away with .010" length groupings but your roll crimps will be all over the place. They will still chamber but won't be as accurate since this will affect pressure somewhat. Most people will never know the difference though in accuracy.
 
Stacking of tolerances...

I have noticed the same thing among my 3 357's. My 66 (no dash) has the tightest cylinder next is my 28-2 and then my gp100 purchased new 2 years ago. Loads that do not have a chance of chambering in the s&w 66 will go into the ruger with a slight push. Your loads are probably slightly out of spec and the model 10 is probably slightly tighter than the 28. It happens...
In my 4 38 S&W's from the late 1800's to the early 1900's. The differences are even more noticeable.
Shoot then if you want or toss the loads if it makes you feel uncomfortable.
 
Without actual chamber measurements, it's difficult to say what the problem is.

But if I had to guess, I'd suspect one of two problems;

1. Some cases are bulged by too tight a crimp.

2. The OAL is marginal, with some rounds simply hanging up in the throat before they can be chambered all the way.
 
If the bulge is at the base of the brass, is it possible they had previously been fired in a S&W Victory model that was rechambered from .38 S&W to .38 Spl?

I've found some like this in brass given to me by a buddy.
In my case, I know for a fact they were fired in a rechambered Brit Victory because it was my buddy's gun.
Of course, for me, resizing them fixed that.
Perhaps your sizing die needs adjustment?
 
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