I've tried searching google and got ambiguous answers as to what exactly counts in the measurements.

I saw on this forum in a search that it is measured from the cylinder to the end of the barrel.

Measuring the 610, is measures 3.75". Is that a standard for "4 inch" models? Are Smiths like a 2x4?

Measure from the front of the cylinder to the end of the barrel. If it’s a 4 inch barreled revolver, it should measure fairly close to that stated length and well less than a 1/4 inch variance. No, it shouldn’t measure significantly less than the stated size in the way a 2x4 does.

Yes make sure you're measuring from beginning to end of the barrel. The "inner" end of the barrel is called the Forcing Cone and stops just a fraction of an inch from the Cylinder. It's easiest to just measure from tip of barrel to cylinder face.

Here's a model 10 with a 2" barrel.

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Revolver barrel length is measured from the face of the cylinder.

S&W barrel lengths are nominal and can vary somewhat from the length specified. I have seen barrels as much as 3/8" shorter than specified length, although only 1/8" is quite commonly seen. A barrel that measures 3 3/4" is probably specified as a 4" barrel. If you have the original box simply check the end label. Typical S&W 2" J-frame revolvers of all calibers are 1 7/8" consistently.

Interestingly the barrels of Colt revolvers usually measure nearly exactly the specified length, to within a few thousandths of an inch.

I originally thought you would be asking what barrel length should a beginner buy.

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Gunsmithing since 1961

I also expected a request for recommendations on barrel length.

What’s really confusing is that a 4” .45 ACP revolver has a longer breach to muzzle measurement than a 5” 1911. However, you do lose energy at the cylinder gap.

Is that an unfluted cylinder model?

There were 2 runs of the 3 7/8 inch barreled 610s, one a 610-2 pre-lock and another 610-3 with the IL.

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Yes it is. It's closer to 3/16 shorter than 1/4 shorter.

Apples and oranges. Revolver barrel length is measured from the face of the cylinder to the muzzle. Semi-automatic barrels are measured from the face of the standing breech to the muzzle, just as rifle and shotgun barrels are. This is just a different standard that is generally well understood. not confusing at all.

Yes, there is some loss in pressure, that affects velocity, because of the barrel-cylinder gap, but not generally the same as the difference between a 4" and 5" barrel of a firearm of the same type would be. The difference of two different individual firearms of the same make, model, caliber and type can be even greater.

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This is an excellent explanation.

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So it would be my guess you have a Model 610 that has a stated barrel length of 3&7/8 inches and so the actual length is measuring at 1/16th shorter, which would not be unusual.

In the case of J-frames with a 1&7/8 inch barrel, Smith & Wesson does in fact state the length as precisely that. However, many in the gun community refer to them as 2 inch.

Does S&W actually state this in their literature? I have never seen this.


For decades, S&W referred to the barrel length as 2”. The 1 7/8” is a fairly recent innovation due to folks not understanding +/- tolerances.

Kevin

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