What is the ideal bullet weight for the fixed sights that come on a 640-1 in 357 Magnum?

I think it's pretty well accepted that the sights are geared for 158 gr bullets. Right now I have 135 gr Speer Short Barrels in my .38s. I haven't really determined which shoots best in my mod 36 and mod 38 but I'm sure that I'm not going any lighter.

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"He was kinda funny lookin'"

I have Gold Dot 135 Gr plus p but also want to use a 158 gr which I think is a better weight round. I have Hornady XTP 158 GR standard pressure but don't use them because they have shown in tests that they will not expand at the lower velocity. In a .357 I think Federal Premium 158 Grain Hydrashok has demonstrated excellent performance in ballistic gel tests. I was impressed and when I can find them, I'll use them in my .357 pistols and if I can find a 158 GR plus p in a .38 that will expand I will use them also.

Hopefully, next week I'll be able to go to the range and try out some Speer Short Barrel .357's. They are 135 grain like the SB .38's. If all goes well, I hope to make them my carry round.

I recently shot my Model 60, steel frame like your 640, with 110gr .357 loads and the Perfecta .357 158gr jacketed solid point ammo. Both handled well, double taps (with practice) are possible. I shoot pie plates at 3-7 yards: all rounds are on target.

Kaaskop49
Shield #5103

Shot my M 640-1 for the first time a few days ago.
38 Sp +P were OK. On target at 7 yds. My reloads of
158 gr PB KSWC with 8 gr of Herco were OK but did
cause the bullets on unfired rounds to stick out and
lock the revolver up. Don't know if I can crimp them tighter.
Factory 357 Magnum rounds are to say the least a hand full!
All hit the target at 7 yds but second shots with the 357 rounds
were hard to bring back on target in any short time.
Think I'll stick to +P rounds in this revolver....

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The best is yet to come!

I tried 125gr in mine for first 2 range trips because it was what I had, shot low as expected but didn't group well either. Got some 158 gr and first shot at 25' was bullseye and very good groups. I was pleasantly surprised with the accuracy.

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Mike, AmVets Member, Navy Vet

Fixed sights on S&W revolver are usually regulated to a 158gr bullet...

Just a note, in my M640 Winchester 145gr Silvertip .357 Magnum ammo is scary accurate. When carries for SD that is the ammo I load.

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Freedom is never free!!

+1 with the above post with the Winchester silver tip but.........
they are very hard to find and today I just use the Hornady 140 gr bullets
for my medium weight , lower recoil bullets that shoot to POA in my revolvers.

I was checking o0n the 140gr XTP and did not see any.......
so the reduced recoil Federal 130gr might also work for you.

Good luck.

My 640 and 60 like the 110 grain 357. Corbon or Winchester. They move the plates 38s won't.

I have always used Federal 158 gr. HYDRA-SHOK ammo in my .357's. That's what is in my Taurus 66 currently. I buy them from SportsmanGuide.com