I'm surprized that the Dan Wesson revolvers haven't been discussed yet. They all featured a tensioned barrel and were renowned for their accuracy and dominated silhouette shooting for at least 30 years and some still use them. BTW, Dan Wesson was the grandson of one of S&W's founders and went out on his own when the company showed no interest in his concept of a barrel mounted under tension within a surrounding shroud. Since Dan Wesson firearms were a pretty small operation, at many times the Quality of the guns produced was determined by the cash on hand in the company coffers. So, many times during DW's history there were guns produced thatt required the attention of a good gunsmith before the first shot could be fired. Mis-timed guns, guns with out of square cylinder faces, and badly machined chambers were common complaints. In spite of all these issues, silhouette shooters kept on buying them because there wasn't another revolver made that could even approach the accuracy of a DW that was set up properly.

Fact is, a simple Engineering Statics and Dynamics analysis will reveal that a barrel under tension and supported at each end will be less prone to movement when a round is fired through it and less sensitive to harmonics. This means that the barrel will be more accurate than a one piece barrel and less sensitive to bullet weight and velocity.

S&W's 2 piece barrels are basically a copy of the concept that Dan Wesson first tried to interest the company in back in the late 60's. However, it's been modified from the original Dan Wesson design in that the barrel is formed with a flanged cap at the end of the barrel that engages the barrel shroud. Dan Wesson revolvers were threaded into the frame and retained at the end of the shroud by a nut that threaded onto the end of the barrel. This allowed the Barrel/Cylinder gap to be set and adjusted by the user in the field in order to optimize accuracy. Unfortunately, this also allowed the shooter to mal-adjust that B/C gap and I suspect that this is the reason why S&W changed to a capped barrel and also why CZ USA has chosen to halt production of the Dan Wesson revolvers. Basically, liability concerns have taken the option of an adjustable B/C gap out of the hands of a shooter.

Now, I happen to own a S&W model 620, which uses a 2 piece barrel and I believe that it's the most accurate S&W that I own. On 2 seperate occasions I've manage 3 shot cloverleafs at 30 feet with it that could be completely covered with a dime. However, that was with the iron sights and I've recently discovered the benefits of optics. Ive also started using a nearby indoor 50 yard rifle range for long range practice with my 610 and 617. Sometime in the next month I'll be purchasing a J Point reflex in a direct mount for the 610 and plan on trying it out on the 620. At which point I'll get a better idea if the 620 can shoot with my 6 inch 617 at 100 feet, the longest distance at which my old eyes can still see the contrasting bullseye on an 8 inch shoot-n-c in the poor lighting at this range. I suspect I'll find the 620 is capable of shooting well under 2 inches, my limit with the 617, at this range and may even get down to an inch or less.

Fact is, these barrels produce a revolver with accuracy that borders on stunning. Frankly, I suspect in the coming years the 620 will become a bit of a collectable once enough people catch on to the accuracy that this model is capable of. I also suspect that the reason that the 2 piece barrels are being dropped from some guns is that they cost more to produce. Unlike some who state that these are a cost cutting scheme, I happen to have been directly involved in Manufacturing since 1982 as a Manufacturing and Design Engineer. So, I am well acquainted with the costs that are incurred as parts counts are increased. There are overhead costs for each part that many ourside the field don't account for, such as the requirement for Quality control measures and inventory tracking. S&W may have implemented this design by analyzing just the Machining costs and have now found that when the costs for ISO 9000 implementation are added in, the higher parts count for the 2 piece barrels don't actually result in a cost savings. It's also a fact that the 2 piece barrels on the models that used these barrels were not well recieved by some shooters.

IMO, it's a loss for us shooters. We've not only lost the potential for accuracy these barrels can exhibit, we've also lost some of the drive for improvement that S&W exhibited when they tried makings guns with this feature. BTW, one thing I have found in using my 610, which has a 1 piece barrel, is that the one piece barrels are EXTREMELY sensitive to being "sandbagged". If you want to make a fairly accurate gun shoot miserably, try resting the muzzle of a 610 on a sandbag, groupings will quickly open up from 2.5 to 3 inches to well over 5 inches at 100 feet. I suspect that the sandbag interferes with the barrel harmonics at the muzzle end. Personally, I wish that the 2 piece barrels had been widely accepted and acclaimed, because I would love to have one on my 610.