Model 10 Smith Bullet Regulation

[x101airborne]

I have in the past purchased several Smith model 10 police trade ins for general ranch carry. Reading up on the model 10 and it's history I have found some conflicting information on what weight bullet the different models were supposed to be regulated for. Could someone point me in the direction or tell me what weight bullets the different barrel dash numbers were supposed to be regulated for? Currently I am using a 140 grain bullet in all of them and they all shoot fairly well despite their well worn cosmetic condition. I would like to get the absolute best accuracy out of each of them but I might need to order a lighter (120 or 125) grain mold. I love the model 10's all the way around, just need a little advice before ordering a mold that may not be the best. Thanks all in advance. 

[needsmostuff]

May be wrong but I believe they were regulated for standard velocity 158 GR. jacketed roundnose bullets.
You know, Just the kind of bullet nobody with choices would pick today.

[45MAN]

x101: YOUR QUESTION ASSUMES THAT THE FS BLADES ARE SO ENGINEERED AND REGULATED, ME I THINK GUNMAKERS MAKE FS BLADES THE WAY THEY STARTED WAY BACK WHEN.

[strawhat]

The S&W M&P revolvers were set up for the standard 158 grain bullet of the day.

Kevin

[parallaxbill]

My 10-6 4" heavy barrel shoots light 170 gr cast to point of aim out to 70 yards. I have not tried 158 gr loads yet.

[longoval]

I shoot 125 gr XTPs over:
5.5 gr W231 for 985 fps
Or
6.1 gr True Blue for 895 fps

Unfortunately both shoot wide right (3.5-4.0”) at 25 yards, in my 4” 10-6 HB. I’ve been shooting my K38s more lately.

[x101airborne]

I had read online (and ya gotta believe everything that is online, right?) that the slim "pencil" barrels were meant for 158 grain bullets and the heavy barrels are meant for 125 grain bullets. Then another place I read the exact opposite. I did try some of my practice loads of a 158 grain Lee RF and 4 grains of Red Dot and it shot ok, not great. Of the 4 or so in my collection (I cant hardly pass on a model 10 at a decent price) some of these dont have the strongest rifling. It is there and I can see it, but it's pretty dog gone slim. Of course these being police trade-ins, no telling the round count.

[bradshaw]

May 20, 2024 6:02:52 GMT -5 x101airborne said:

I had read online (and ya gotta believe everything that is online, right?) that the slim "pencil" barrels were meant for 158 grain bullets and the heavy barrels are meant for 125 grain bullets. Then another place I read the exact opposite. I did try some of my practice loads of a 158 grain Lee RF and 4 grains of Red Dot and it shot ok, not great. Of the 4 or so in my collection (I cant hardly pass on a model 10 at a decent price) some of these dont have the strongest rifling. It is there and I can see it, but it's pretty dog gone slim. Of course these being police trade-ins, no telling the round count.

*****

Trey.... S&W's twist for .38 and .357 barrels 1:18-3/4”. Barrels are configured for a revolver model, not a bullet weight.

By my reckoning, .38 Special 125 JHP’s are excellent. Weight-wise, my preference in cast would start at 148 grains, for the wadcutter.
David Bradshaw

[revolvercranker]

I have to agree with David. The barrels have one set twist. The only difference in bullets is that the 158 grain will have more recoil thus the barrel will be slightly elevated more by the time the bullet leaves the barrel in conjunction with it's slower speed, whereas the 125 grain being much lighter is faster and less recoil thus less muzzle elevation at bullet exit and will shoot lower. It will also shoot a little flatter. I think when they first came out with the Model 10's that most 158 grain bullets were lead.

[wendigo]

I've only had one Model 10 and don't recall that I've ever shot 158's in it. It has digested a few thousand 125 RNFP "cowboy" bullets over 3 to 3.5 Bullseye (a load my Model 14 hates, BTW) and it shoots close enough to the sights for practical use on the square range. I need to try some standard pressure 158's and see how it does.

[bigbore5]

If it shoots high with 158's, then try 125s. If it shoots correct elevation with the 140's you said you were using, then 125's will be too low. The 158's will shoot a touch higher.

[lah]

The Model 10s I have shoot high with the 158 bullets at 25 yards. The 125 Lee RF hits right where it is looking.

[ideal]

Personally, I'd take this opportunity to load a few boxes of ammo with bullets I'd feel could be relied upon during bad times and see what each gun prefers you use. My favorite load for std pressure 38 Spl was a cast SAECO 382, loaded to the top end of std pressure (~5 grains) with Unique. That load really shot well for me but I simply fell out a bit with 38 Spl and started focusing more on 9mm & 45 auto semis. Davids wadcutter suggestion is really good and in my present circumstances I wouldn't feel shortchanged with some of Ed Harris' std velocity 38 Spl loads. I'm also fond of the old Ideal/Lyman 357446 SWC and have several moulds on hand to cast as many as I could ever wish for. The Keith 358429 is an exceptional possibility as well.