I have a 4 inch revolver and i cant determine if theres a bulge in the barrel or if its just a shadow caused by my flashlight. is there any way to determine whether or not a barrel is bulged other than by a visual observation, ie.. gauge? I also wonder if I got a dedicated bore light If that would reduce any shadows or unwanted reflections that would cause the appearance of a bulge. or perhaps im nuts.....any suggestions would be greatly appreciated.

steve

Bulges are on the outside. Carefully look down the outside of the barrel and slowly rotate it. You should be able to see it.

This is some advice another member gave me a while back. I have a 1917 with a bulge.

Use a micrometer on the exterior of the barrel. It may have a bulge so small you cannot feel it.

Take a small wire, like a paper clip, and sharpen one end. Then bend it to a short 90 degree angle. Insert the bent end into the barrel and feel for the bulge. With a little practice you will be able to detect if the mark is on the surface or if it is really an indentation/bulge into the lands and grooves. If it is an indentation, it will probably be uniform around the interior. This was probably caused by some obstruction in the barrel when the gun was fired.

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Pat Henson

Use a proper fitting jag and run a patch thru the bore. If you have a bulge, you’ll know right away. The change of resistance is impossible to miss.

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"I also cook."

Some "bulges" are artifacts of polishing. I have several prewar revolvers with straight and undistorted bores but which have a kind of subtle coke-bottle waist toward the frame. The barrel has the familiar bell where it contacts the frame, then shrinks to the "waist" and expands again slightly as you proceed toward the muzzle. There is a straight taper from the max barrel width (ignoring the segment adjacent to the frame) to the muzzle.

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David Wilson

all great advise I'll try them out thanks

i tried the paper clip and didn't feel anything but i still cant really tell because it looks to me as if i can see a slight bulge on the outside of the barrel?? not sure if thats just the contour or what. I did order a set of small hole bore gages. hopefully that should settle the matter. has anyone ever used of of those gages? I planned on expanding the gage inside the bore and pulling it out and attempting to feel any change in resistance

I have a couple sets of the ball guages that you speak of. I've used them to check cylinder throats on my revolvers. They do require a sort of delicate touch when you expand them into the cylinder throats. Sort of going from just feeling contact to full contact is only maybe a small turn of the adjustment screw. Try doing the cylinder throats first as it will require a few times for you to get the "feel". Frank

I've not handled a ringed handgun barrel that couldn't be easily seen by shineing a dim flashlight against the side of the bore from the end opposite the end you're looking into.This has been the case even when I could not find exterior evidence of a ring. I did have an old long barreled 6.5mm rifle that was ringed near its middle and hard to spot. I initially felt it cleaning with snug fitting patches over a jag then it was easy to find slugging the barrel to learn its groove diameter. I think either of those methods would be easier than trying to use a ball gauge.

Since the suspected ring is hard to find it raises the question of how the revolver shoots. If it shoots as accurately as your other revolvers then just use it and don't obsess over it.

On the other extreme in my show-n-tell box I have a 1917 .45 ACP barrel that bulged so bad over the ejector rod that it split open on both sides and the top. Its bulge was caused by firing a bullet into a preceding one that didn't get a powder charge in a Dillon 450. 1917 barrels are quite thin not far ahead of the frame.

Where along the barrel length is the suspected 'bulge' ?

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Jim
S&WCA #819

Agree with above posters. The old guys at gunshows that couldn't see as well as they once could, would lightly grip the bbls and run their hands up and down and could feel most bulges... even those that are hard to see.

In my experience, a tight fitting jag with cleaning patch will skip going past the bulge, and most can be seen as a shadow looking down the bore. If you can't see it or feel it, it may not be there. As K22fan suggested, shoot it and check the accuracy.

As a side note, I knew a gunsmith that had many home made tools of his own design. A few yrs ago, he was working on one to reduce bbl bulges. It was based on a manual pipe cutter, but a roller replaced the blade. He would tighten it as he could while rotating the tool around the bbl. Made sense. The last time I saw him, I asked about his bulge reducer, and he gave me one of those looks, and went back to his work.

Charlie

Agreed, feeling a minor bulge is easier than seeing it!

One thing about bulges and accuracy; it may be counter-intuitive, but I've never been able to document any decrease in accuracy due to a SINGLE bulge in a barrel. It just doesn't affect accuracy; certainly not enough to determine whether or not a bulge exists.

So apparently his barrel bulge reducing tool was a failure......too bad, it sounded good in theory (smile). A hydraulically boosted one might work....

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Jim
S&WCA #819

For what it is worth, years ago I had a Model 35 with a slight bulge in the barrel. You didn't notice it on the outside of the barrel, but as soon as you cleaned the barrel with a cleaning patch you could feel the resistance to the cleaning patch change. In spite of the bulge, it seemed to shoot fine. I wish now that I had kept it - Model 35s are hard to find and it was a good shooter.

Steve