I am looking to take a little material off of the front sight of a 640-1 to raise the barrel a little. What's the best tool to use for this? A hand file or an electric grinder?
Thanks

Before I took material off the front sight, I would try a selection of different loads. They will shoot to different points of impact. That might be a better way to regulate the point of impact.

If you do determine to remove material, I would use a hand file, and do a very little at a time. That would be my last resort though.

Best Regards, Les

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SWCA 3084, SWHF 495, PGCA 3064

Let somebody else shoot it . . .

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Wisdom comes thru fear . . .

shoot a heavier bullet first....

Randy

There isn't a lot of material on the front sight to remove and you can't put it back once removed so, be careful. How low are you shooting and with what ammo? With a little revolver like the 640, shooting .38+P or .357 mag. might encourage you to flinch thus shoot low. With a fixed sight, I often find it necessary to use a bit of "Kentucky windage" when using various types of ammo.

Fixed sight 38 Special revolvers are regulated for 158gr bullets..

Lighter ones shoot low... Heavier ones go high.. Reason for this

is known as ''Dwell Time''...Length of time bullet stays in the barrel.

Lighter ones generally are faster and stay in the barrel for less time.

Barrel does not rise as far during recoil with light bullets...

Resulting in bullet shooting lower...

If you are shooting anything lighter than 158 gr. bullets it is completely normal for the gun to shoot low. S&W .38 Special & .357 Magnum revolvers are regulated (sighted) for this bullet weight. Bet you are shooting 125 gr. ammunition, aren't you?

Instead of worrying about a couple of inches low simply learn to base your judgement on group size. Accuracy has nothing to do with where a gun shoots, but the size of groups it is capable of, totally independent of the operator. If you must simply learn to hold 2-3" high. If a defensive handgun shoots within 3-6" of point-of-aim at 12-15 yards that is completely adequate for the purpose for which it is intended.

Reason for this

is known as ''Dwell Time''...Length of time bullet stays in the barrel.

Lighter ones generally are faster and stay in the barrel for less time.

Barrel does not rise as far during recoil with light bullets...

Resulting in bullet shooting lower...

SW282,

More information than necessary and totally incomprehensible to anyone not well founded in mechanics, and also incorrect although this has been repeated many times. It is all due to relative mass between the gun and different bullet weights. Any if the rest about "dwell time" is a result of the relative velocity. Heavier bullets cause more recoil and therefore more muzzle rise before the bullet is released from the muzzle. The slight difference in barrel time has much less influence on muzzle climb that the simple difference in relative mass of the lighter or heavier bullet relative to the effective mass of the revolver. Relative mass of the revolver includes a percentage of the weight of the gun, your arm, jewelry, etc., not just the gun itself unless it is free to recoil unimpeded

You will forever be known as "Bubba"!

You got good advice here.
Do not change the gun before you change ammo and grip (hold).
Try a closer target and have a friend try.
Also realize they shoot to six oclock.

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Some assembly required..

My 640-1 shoots to POA with 158 grain .38 specials or 158 grain .357's. If I were you I would listen to the guys here trying to help!

Thanks, three of us have shot all with similar results. We all used the same loads though.

That was smart to have others shoot it. My buddy sometimes complains about the accuracy of his new guns until I shoot them. It could be a person's grip or shooting characteristics. Since that is not your problem, please try the load as suggested above first. If you have a 640-1, you have the removable front sight, right? If so, not such a harsh thing to file it a tad if you NEED to. Just my opinion.
Dave

I disagree with learning to hold "2-3" high". Once you've determined the load you intend to shoot and it's still shooting low, use a file and slowly remove little metal at a time until you're shooting point of aim. The front sight is replaceable on the 640-1, so it's not like you're doing something that can't be undone.

I was shooting 158gr rn bullets with 3.6 gr of hodgdon tite group powder.

If your sure of the ammo you want to use, and that your shooting style is "settled", then go for it with a fine file, as long as you know your capabilities for such work.
Don't worry about what some mythical character named "Bubba" would do at the kitchen table, other than eat his corn flakes! Bubba might not be able to shoot well either; that does not mean the rest of us should just give that up too. Its your gun, your sight blade and your file.
I once had to file down the front sight on a Ruger Blackhawk and was pleased with the result. It was shooting 6 inches low at 25 yards.
I have a M640 Pro that shoots low with my chosen ammo, Speer 135 gr SBGD's, but the sight is a Tritium night sight, and there is no excess metal to remove. I would rather it had a pinned "regular" front blade like yours, but I bought the Pro model for a feature that it didn't have; the internal lock, and it is my every day carry gun.


Best,
Rick

With the 640-1, if you screw it up, you can replace the sight easily.

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Centennial Every Day

+1

Mine shoots low and right at 10 yds with weak-sister wadcutters, but does right well with .357 Magnum 135-gr GDHP handloads.

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Now go make God proud...

One solution is to paint the just tip of your front sight with red paint. When shooting lighter weight bullets I just use the bottom of the red paint line as ypur POA. When you shoot 158 gr. ammo line up using the top of the sight.

Thanks all, I will be documenting the grouping with different ammo and loads. I will only modify the sight if there is a consistent pattern of shooting low.