flintsghost
Member
I am constantly amazed when I go to buy a revolver or analyze problems how little the collector or accumulator know about checking certain critical items on a revolver. I routinely ask sellers about Barrel/cylinder gap and point out that they can measure that with feeler gauges. More often than not I get some reply that says well I can see through it so it can be much or offers to check it with pieces of paper. Very few people have any idea of how to measure it nor do they have the tool to do so. You should know what it is and also have the appropriate tool to check the guns you want to purchase. Just for the record...back in the 70's and 80's the BC gap should run from .004 to .010. Then more recently, probably coinciding with the lock guns the spec was raised to max out at .012. You should know that you can make it wider but short of dismounting the barrel and do lathe turning there is no way to reduce the gap. When turning a barrel back the extractor rod must also be shortened the appropriate amount. That's why gauges are so important. Do you really want to spend your coin on a gun with a BC gap of .014 and put up with the poor accuracy that goes with it and the spitting lead that will be felt? I doubt it.
Here are 4 sets of gauges, and they include the ones from the S&W armorers kit, a set of spark plug wire gauges that are totally unacceptable, a set of flat feeler gauges that include all that one needs, and lastly a set of bent feeler gauges which would be find except they don't go small enough. If one buys flat feeler gauges buy a set that includes .004 through .010 and if you have one of the newer guns also get .011 and .012.
Factory gauges from the S&W Revolver armorers kit circa 1987. I think these need help as the give the extremes but nothing in between. Saving grace is they are narrow enough to work with J frames.
A set of automotive wire gauges that are great for spark plugs and cars but simply don't go small enough for revolvers.
A set of flat feeler gauges. They work great except for being too wide to work on J frames. Since I don't do much work on J's and have the factory armorers gauges I don't worry about it. If I ever do spend a lot of time working on J's I'll have to buy a set of these with the idea of cutting them down.
A set of bent feeler gauges that are fine for cars but don't go small enough for revolvers.
By the way when measuring, be sure to measure from both sides. BC gap is cut with a barrette file by hand and the gap is usually somewhat off, one side to the other which is not a big deal unless one side exceeds spec.
Here are 4 sets of gauges, and they include the ones from the S&W armorers kit, a set of spark plug wire gauges that are totally unacceptable, a set of flat feeler gauges that include all that one needs, and lastly a set of bent feeler gauges which would be find except they don't go small enough. If one buys flat feeler gauges buy a set that includes .004 through .010 and if you have one of the newer guns also get .011 and .012.
Factory gauges from the S&W Revolver armorers kit circa 1987. I think these need help as the give the extremes but nothing in between. Saving grace is they are narrow enough to work with J frames.
A set of automotive wire gauges that are great for spark plugs and cars but simply don't go small enough for revolvers.
A set of flat feeler gauges. They work great except for being too wide to work on J frames. Since I don't do much work on J's and have the factory armorers gauges I don't worry about it. If I ever do spend a lot of time working on J's I'll have to buy a set of these with the idea of cutting them down.
A set of bent feeler gauges that are fine for cars but don't go small enough for revolvers.
By the way when measuring, be sure to measure from both sides. BC gap is cut with a barrette file by hand and the gap is usually somewhat off, one side to the other which is not a big deal unless one side exceeds spec.
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