Powder Suggestions for .38 Special +P?

[fecmech]

Waywatcher--If you are getting leading with Unique I doubt it's the powder. What size are your bullets? Are they bigger than the throats on your gun, they need to be. See if a bullet simply falls through the throat( bad) or must be pushed through the throat (good). If the throats check out, are they bigger than the groove size in the barrel(good) if smaller (way bad), this will require slugging the barrel. Attaining 800-900 fps with lead in the 38 spl is not difficult with a 158 gr bullet, the Lyman cast bullet manual lists a number of powders that do it. Just a few, 5.0/231gives 934 fps,5.4 Unique gives 954 fps and 4.4 of Bullseye gives 915 fps. all at 18000 CUP.
My standard load for a 38 spl is 4.2 of bullseye behind a 158 RN which gives 896 fps out of my 6" K-38. This is a std pressure load per Lyman at 16200 cup and is extremely accurate. I use it for all my shooting including Hunters pistol silhouette. I have no idea how many I have put through the K 38 but it is well over 10-15K. I have also shot a lot of 5.0/unique and 4.9/231, all are right at 875-900 and all are accurate but not quite as good as the Bullseye in my gun and none of them lead.

 

[rcmodel]

Unique was not the cause of your leading, guaranteed

I agree completely.

Unique has been used successfully for nearly 100 years with lead bullet loads in every imaginable handgun & rifle caliber.

As has Bullseye.
It was the standard factory load powder for .38 Spl lead bullet loads for about the first 75 years of it's existence.

If you are having leading issues, then either your bullets don't fit your chamber throats, or you have a rough barrel causing the leading at higher pressures.

A case full of Trail Boss, or a reduced load of 2400 will not give you as much chamber pressure as a +P load of Unique.
Thats why it will out-perform either of the other two powders in +P .38 Spl.

rc

 

[Walkalong]

I don't mean to sound rude, but one liners like this are not helpful without any data or proof.

No problem. I made my statement for much the reason rcmodel outlined, Unique (as well as Bullseye) has been used very successfully with lead for decades.

The difference was the pressures generated, not the powder. If you tweaked your Unique load or the hardness of the bullet, you would stop the leading as well. Pretty much guaranteed.

Match the bullet to the gun, match the pressure to the bullet.

 

[Waywatcher]

My GP100 has ~.3575 throats. (all 6 are the same) .358 bullets will not go through without a hammer. .357 will fit through, but they do not just drop through, they need slight pressure. Ideally they should be bored out that .0005 but I'm not too keen on doing that with my blued gun, and besides, it shoots accurate how it is.

In case it wasn't clear: I am shooting .357 magnum with 158 LSWC sized .357 over 13-14 grains of 2400 and get very little leading.

The Trail Boss loads also get little leading. 4.2 grains under a 158 either .357 or .358 bullet.

With respect to Unique, I have tried .357 and .358 bullets, BHN 12, BHN 18, and swaged, and all leaded badly. Like sewer pipe badly. Like 6 rounds looks worse than 100 loaded with Trail Boss. I also noticed substantial "lead vaporization" with Unique. I don't know if that's the correct term, but my cylinder face and forcing cone face get silver when I'm shooting Unique, along with the nasty looking bore. Also, the Unique smokes like you'd think I was shooting black powder. I'm not ruling out anything, I'm just detailing my firsthand experiences.

I was hoping this wouldn't turn into a debate about Unique, though.

 

[fecmech]

Not trying to champion Unique or anything else but just trying to help with leading. You did not mention the groove size of your barrel,have you slugged it? IMO there is no reason for the use of .357 Lead bullets in your gun .358 is fine and BHN 12 is plenty hard. If it was mine I'd slug the barrel and see what you have. You may have a choke point where the barrel screws into the frame and then gets larger past that point, that will cause bad leading. Have you pulled a bullet after loading it, is it still .358 or did it get sized down in the loading process?? As others have posted those powders have been around with lead bullets for a long time, good luck.

 

[Waywatcher]

Thanks fecmech,

You may be on to something. I have noticed a little bit more resistance at the end when pushing a jag with a tight patch on it through the barrel from the muzzle. I haven't slugged it yet though. Would this also explain the silver on the faces?

I haven't pulled a bullet, but I'm just using basic RCBS Carbide Dies, nothing out of the ordinary and no FCD.

 

[Waywatcher]

The Bore is a bit rough too. I'm probably going to Fire-lap it, now that I hear the chorus of response.

That might even help bore out my throats a wee bit.

I am looking into the NECO Fire-Lapping kit. Any other suggestions?

 

[fecmech]

The silver is molten vaporized lead that is gas cut off the base of the bullet when gas escapes through the cylinder gap as the base clears the cylinder and enters the forcing cone. A large cylinder gap and under size bullets will increase it but it's always there with lead. My K38 and GP100 both do it and because I don't clean the exterior of my gun very often (I shoot it 4-5 times a week) it will even "lead plate" the flutes on the cylinder after about 1000 rds. When it gets real bad I clean it with the copper "Chore BOY" pads.

Before you do anything I would suggest pulling a bullet and slugging your barrel.

 

[Waywatcher]

After more research and consideration, I will not be fire-lapping. I should go get some lead sinkers and slug my barrel.

The cleanest shooting ammo ever in my GP100 is Remington 158 LRN factory ammo. No leading at all. Maybe the soft swaged lead helps seal it up and squish around imperfections.

I will also run a couple more tests this coming Monday if the weather is decent:

BHN 12 .358 bullets with 13.5 grains of 2400 and
BHN 12 .358 bullets with 4.2 grains of Trail Boss.

As an interesting aside, neither the Remington factory ammo, the Trail Boss, or the 2400 show any signs of lead vaporization. I like that.

Bullseye and Unique both give me lead vaporization; maybe this is related to the nitroglycerine?

 

[FROGO207]

I also like Blue Dot with 158 GR LSWC for my higher pressure loads. Crimp it well or it will burn dirty and velocity will suffer a little. I have 5# of 700X and am going to see if I can do anything with this in the future.