I own an M&P .38 4" barrel #S976xxx. I was told that if the lands and grooves are the same size that it was made to only shoot lead bullets. If the lands are smaller than the grooves it was made to shoot FMJ. New one on me. I'm also new to old M&P Smiths and this forum.
Jim

I believe that someone was blowing smoke up your kilt. Someone who can give a better answer will be along shortly.

I had typed out a slightly longer answer and then decided that the question had to be different than what I understood it to be and that I should shut up.

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NHI, 10-8.

When your gun was made I bet 99% of all revolver ammo used lead bullets. As far as I know S&W never rifled revolver barrels with the intent of tailoring them to one bullet material or the other. Except maybe the revolvers in 45 ACP. I have heard that they don't shoot lead bullets real well because they were designed for FMJ military ammo. I'll have to test mine and see. But I suspect your gun will shoot either lead or jacketed bullets with very little if any difference in accuracy.

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No life story has happy end.

Welcome! If you meant to type the "width" of the lands and grooves being different for lead vs. jacketed bullets that is a new one for me too. Someone here probably has the answer.

By the way, your .38 M & P likely shipped in 1947, and we like photos .

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Alan
SWCA LM 2023, SWHF 220

Yes, it sounded weird to me. The whole subject came about due to the fact that I was going to load some Rainier bullets to work a load for the pistol. Copper fouling was the issue at hand. I am really not too worried about it.

Murphydog-I was talking about width. In this pistol they are equal looking to the naked eye.

And yall get your picture!

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Probably early 1948 with that SN. Remember, essentially the same revolver used military jacketed bullets throughout WWII. In general, there is seldom any reason to use jacketed bullets in these if lead bullets are available.

I agree that lead is probably the first choice, but it doesn't have anything to do with the rifling. That said, I have had great results with plated bullets, also, in 38s. Switched to lead because they are cheaper, more available, and ... just better. I have also had the best results with 158 grain bullets, especially in fixed sight revolvers, as they are most likely to shoot to point of aim. The 125 grain bullets will often shoot low.

+1 on the .358 diameter

I just got the pistol a few weeks ago and havent even been able to shoot it yet. This is my first revolver. Automatics have always been my thing. Shot an old S&W M&P at the range last month and fell in love with it!. Then I got this one. I loaded up 40 rounds with assorted brass, 4.2 grains HP38, 158gr lead SWC. If the weather gets better and then I get a break during my Christmas vacation you can be sure that I will be at the range trying it out.

The bore is in really good shape. The exterior of the pistol shows wear from being holstered.

Cant wait to send projectiles down range!

Jim

That load should work very well in your M&P. Medium crimp should be used.

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H Richard
SWCA1967 SWHF244

First, welcome. Second, get your pocketbook, credit card etc ready, I can bet this will not be your last.

It sounds like an old wives tale to me. I shoot FMJ ammo with my 67-1 all the time and when I'm really "On" I can stack one round on top of another at 30 feet rather predictably. When 5 shots produce a hole at 30 feet that can completely be covered by a dime you know you are getting good accuracy worthy of a bit of bragging, even if you were cheating by shooting off a sandbag.

However, I did have some absolutely MISERABLE leading the one time I shot a box of Blazer LRN with my model 620, which features an ECM machined barrel. Just 50 rounds of that **** was enough to require over 12 hours of scrubbing with a 50/50 mix of peroxide and vinegar that I never care to repeat. Partly due to this experience and partly due to concerns about lead exposure I now only shoot either jacketed or plated bullets.

There are much easier methods to remove bore leading.

BTW, I like your old pre-10 .38 M&P. It has real character. It is from my favorite period of S&W manufacturing.

Free advice from "experts" -- including many on this and other forums -- is worth exactly what you pay for it. What you were told was bunk, whether given seriously or as a joke.

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Pisgah

SP mentioned what I had been thinking of - the specific issue reported about different type of ammo and rifling for the ball ammo in .45ACP.

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NHI, 10-8.

Even when a firearm is specifically designed to shoot a certain bullet type, there may be others that it just happens to shoot better. Gun making is not an exact science. They only way to determine what it will shoot best is to try a wide variety of bullets and keep careful notes. My guess is that it will shoot all types about equally well.

This is about rifle barrels but may be germane to this topic:
If I recall correctly, the old British Lee-Enfield had 5 groove barrels. Somewhere along the line, at least some of the manufacturers went over to four or even six groove barrels. Then during WWII, due to the urgent need for rifles, they went to a two groove barrel, among other manufacturing shortcuts, to speed up production. To the astonishment of many "experts", it was discovered that there was no discernible difference in accuracy, regardless of the number of grooves.

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You're shy a few manners.

but it won't shoot +P+!! You should just send that inferior treasure to me. :<)

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Dave

+P or not, I think I will keep this one Dave!

And thanks to everyone for debunking the myth about the 'lands and grooves'. Sounded weird from the get go.

Jim

No, then it would be a smoothbore...



I only comment because it made me laugh!

In general, the answer would be "Hogwash". There is a bit of truth to the statement regarding .45 ACP chambered revolvers such as the M25. The barrels frequently have a little shallower grooves than some other calibers since they were designed to shoot ball ammo. If using lead, stay away from swages bullets. Not hard enough to grip the shallow rifling very well. Hard cast bullets do fine. Don't have to be extremely hard either. Your .38 should thrive on lead bullets. I wouldn't worry about plating either. Just plain lead, properly sized and lubed, and not excessively hard will do fine.