I am considering a few different SW L frame revolvers, all with at least 6" barrels, all of them factory new. I reload for .357 (I shoot a 586-8) and while I'm a safe reloader and always stick to book loads, I do like to load toward the hotter end, often with heavy bullets. Will the extra chamber in the L frame 7 shot cylinders have any effect on my reloads? Are the cylinder walls thinner and weaker than the 6 shooters? Will I have to tone down my reloads?

The 7 shot cylinder is actually stronger due to the offset notches.

I recently tried out some pretty warm 125 grain loads using 21.0 & 21.3 grains of H110 in my 620, which is a 7 shooter. By feel I would estimate a muzzle energy in the mid 500's so muzzle velocity was approaching 1400 fps. The ONLY issues were excessive muzzle flash and they were about as loud as a 4 inch 500 Magnum. Other than that, no harm at all and all ejected with a very light tap on the ejector rod. My advice would be load them up. I'll also state I envy you being able to find heavier bullets suitable for a 357 Magnum, because around here the 158 grain XTP's are unobtainium.

I used to be of the same opinion as Mack, but I have reconsidered. While it is true that the offset bolt notches take away that one weak point in the cylinder (thinnest wall thickness in the 6-shot cylinder would be under the bolt notch), the fact that the chambers are moved closer together in the 7-shot guns makes for a consistently thin wall thickness between chambers.

The fact that the cylinders are the same diameter and the concentricity of the chambers, whether 6 or 7 shot, has to be the same, indicates that the chambers are closer together thus reducing wall thickness. Whether or not the consistent wall thickness between cylinders, of the 7-shot, is more or less than the wall thickness under the bolt notch of the 6-shot is unknown and would take somebody with the proper type of calipers to determine. If they are the same thickness it might still be better to have a consistent wall thickness than to have a chamber where one point in the chamber is thinner than the rest. Pure speculation.

Simple solution: Don't exceed SAAMI specs for .357 Mag.

Adios,

Pizza Bob

__________________
NRA Benefactor Member

A few year ago when I visited the S&W factory, I was told the same thing by one of the S&W factory repair guys.

The 686, 7 shot cylinder was stronger than the 6 shot becasue of the offset notches.

As others have pointed out, the 7-shot in theory is stronger. The L-frame will handle any sane load, but if you really want to push the limits of the gun it won't matter if it is a 6 or 7 shot. Neither one will be able to produce 44mag performance without giving in.

I only shoot hard cast lead! Jacketed .357 are unavailable here in any weight except 110 and 180. I scored some Speer 125's the other day but only 200 of them. That's not even enough to work up a load.
I'm considering buying one of the new TALO 7" 3-5-7 revolvers with the unfluted cylinders.

The thinner chamber walls are still thicker than the 6-shot cylinder with the notches on, instead of between, chambers. At the notch, those are paper-thin by comparison. That has always been the weak spot.

__________________
Pisgah

If the Speer 125's you scored on are the jacketed hollow points marked for "plinking" I would suggest that you plan on using them in a 38 special load. I recently picked up some Blazer Brass 357 Magnums that feature this bullet at a velocity of only 1150 fps and at a 50 foot indoor range that features trapazoidal bullet traps I was getting pelted with fragments on nearly every shot fired. That same day I was also shooting those 1400 fps. Hornady XTP's and didn't get hit by anything. IMO these Speer 125 grain bullets just aren't strong enough to withstand true magnum loads and are best treated as 38 spl. only bullets.

BTW, I have one more box of that Blazer Brass and that box will get shot up at a 50 yard indoor range that's nearby. Because I just don't feel like getting pelted again.

The 7 shot is stronger due to offset locking notches, according to Herb Belin, S&W's Chief Engineer at the time the 7 shot L frame was introduced. We had this exact discussion at the SHOT Show the year the 686+ was introduced.