Confederate
Member
If you thought this was going to be an answer to the question, no such luck. I just wanted to toss it our for discussion. In the 70s, more was written about the effects of barrel/cylinder gaps, not only for velocity, but accuracy.
The specs for revolvers in those days were simple: acceptable B/C gaps were anywhere from .004 to .009 inches. Some gun writers back then attempted to find various models of the same gun with different gaps and compare them, but individual differences in the guns themselves interfered. The barrel specs on two guns of the same make and model could easily account for differences in velocity and accuracy. Some of the more enterprising gun writers used Dan Wesson revolvers with gaps set to different sizes. (DW revolvers came with a gauge to set their guns for .006, which was the industry standard goal.)
Back then, .357 mags were the hot setup, so most writers used them, though some tried .22LR since DW made revolvers in that caliber as well. Many buyers back then wanted to milk as much velocity out of their .357s as possible and the big myth in those days were that a .357 really didn't produce magnum velocities in guns with barrel lengths under 6-inches. So they wanted to find guns with .004 gaps. Some writers, however, said that while velocity increased slightly with tighter gaps, accuracy tended to be best from guns with .006 gaps.
Now some people think they got burned if their B/C gaps are .006 or .007 (and some will go so far as to want to return guns with .007 and over), but I haven't seen anyone actually do any studies on B/C gaps recently. I also don't know if revolver manufacturers have changed their specifications since the 70s. I just picked up a .22LR with a .010 gap because it seems to shoot very well, doesn't spit and is as accurate as my others. It was a good price and I couldn't pass it up.
But most of what's on the Internet is opinions. No one really has actually compared guns to see what effect the gaps have. One source even stated that 30 percent of the blast could be wasted through the B/C gap. That doesn't seem right based on what I've read. Back in the 70s and early 80s, gun writers tended to be more oriented towards things like this. Now most writers just want to fill up space describing guns that are already photographed in great detail and spout unfounded opinions.
What do you think? Has anyone read any articles backed up with empirical data? Or has anyone done any studies on this themselves?
This is a revolver held up to a strong light. The gap is not actually as
pronounced as how it appears here.
The specs for revolvers in those days were simple: acceptable B/C gaps were anywhere from .004 to .009 inches. Some gun writers back then attempted to find various models of the same gun with different gaps and compare them, but individual differences in the guns themselves interfered. The barrel specs on two guns of the same make and model could easily account for differences in velocity and accuracy. Some of the more enterprising gun writers used Dan Wesson revolvers with gaps set to different sizes. (DW revolvers came with a gauge to set their guns for .006, which was the industry standard goal.)
Back then, .357 mags were the hot setup, so most writers used them, though some tried .22LR since DW made revolvers in that caliber as well. Many buyers back then wanted to milk as much velocity out of their .357s as possible and the big myth in those days were that a .357 really didn't produce magnum velocities in guns with barrel lengths under 6-inches. So they wanted to find guns with .004 gaps. Some writers, however, said that while velocity increased slightly with tighter gaps, accuracy tended to be best from guns with .006 gaps.
Now some people think they got burned if their B/C gaps are .006 or .007 (and some will go so far as to want to return guns with .007 and over), but I haven't seen anyone actually do any studies on B/C gaps recently. I also don't know if revolver manufacturers have changed their specifications since the 70s. I just picked up a .22LR with a .010 gap because it seems to shoot very well, doesn't spit and is as accurate as my others. It was a good price and I couldn't pass it up.
But most of what's on the Internet is opinions. No one really has actually compared guns to see what effect the gaps have. One source even stated that 30 percent of the blast could be wasted through the B/C gap. That doesn't seem right based on what I've read. Back in the 70s and early 80s, gun writers tended to be more oriented towards things like this. Now most writers just want to fill up space describing guns that are already photographed in great detail and spout unfounded opinions.
What do you think? Has anyone read any articles backed up with empirical data? Or has anyone done any studies on this themselves?
This is a revolver held up to a strong light. The gap is not actually as
pronounced as how it appears here.