Inaccuracy

[Hondo 60]

I'm fairly new to casting, been doing it about a year.

I have 2 Lee molds a TL358-158SWC & a TL358-158R2.

My problem is inaccuracy.
I've slugged the barrels of 2 of 'em & come out abt .3575.
Bullets drop .3575-.3585

My guns are VERY accurate with 125gr PHPs

I've also tried MBCs 357 Action & Cowboy 11 - results haven't been very good.

The accuracy isn't terrible, but I have MUCH better luck with 125 gr plated.
I know I've tried 125 gr lead, but don't remember results.

The lead is wheel weights, & I get just a bit of leading, not hard to clean up with a strand of a chor-boy.
Lube is 45-45-10 from lsstuff.com

[Larry Gibson]

So what is the load you're using?

Larry Gibson

[white eagle]

how long you lettin yer boolits age before you load em
also like Larry said what are the particular's of your charged cartridge
these things all come into play as you are finding out
if it was easy, well you know.....

[Hondo 60]

The load is 3.0-3.1 gr of titegroup. that's a little less than min 3.2-3.8 is Hodgdon's load data.
(I've tried more 3.2-3.7 - didn't help)
I'm running some of them thru a S&W airweight-aluminum framed Model 38
That's why I want as low of a charge as possible.

The SWC are loaded to an OAL of 1.450 & the R2s are 1.495
+Ps are loaded at 3.8 gr

Age is minimal, usually less than a week.
Some as soon as 24 hrs, some about a week.

95064

[454PB]

I suspect your boolits are undersized, and they look to be way over crimped.

[375RUGER]

A lot of crimp for a really light load. 357 mag right?

[leadman]

Yes, way to much crimp. What is causing the marks just above the rim on your cases?
You should pull a couple of loaded cartridges apart and measure the diameter of the boolits. They will most likely be undersized, especially by the crimp groove.

[Hondo 60]

nope, not 357 - 38 Spl

454PB - plz read first post

[454PB]

I did read and re-read. I said "undersized" because they match your measured bore diameter. Cast boolits usually do best when sized throat diameter and/or .001" to .002" over bore diameter. How did you measure bore diameter? S&W barrels are notoriously hard to measure due to the 5 groove rifling.

In addition, the picture shows a pronounced bulge where the boolit sits in the case. That's fine in .44 magnum where you need heavy case tension, but your load is very light. It's possible that the boolits are being sized when they are seated. You could test that by pulling one from a loaded round and measuring. That heavy crimp would make the problem worse.

If that is the case, you may need to use an "M" die to pre-expand the brass, or use a sizing die that doesn't squeeze the brass down so much.

[Hondo 60]

OK, thanks for the tips.
I'll pull one & check the size.

And I'll look at the crimp.

[white eagle]

your boolits may be a bit on the soft side
age will bring them to fruit

[Animal]

I agree with the above. Open the case enough to seat the boolit partially by hand. Crimp in a separate operation. Roll the crimp down about a third of what you currently have. Pull the boolit and remeasure diameter. If the diameter is okay, rework your loads with the seat/crimp procedure we've explained.

My Super Redhawk loves your current crimp :grin:

[Larry Gibson]

Add 2% tin to your COWWs. Let the bullets AC 7 - 10 days before you do anything to/with them. You'll be surprised at how much better the bullets turn out. Note the rounded front driving bands? That is from inadequate fillout. The "leading" is probably really antimonal wash from a total lack of tin in your alloy.

Powder charge should be ok.

Suggest you try the LLA straight as per Lee's directions. Size the bullets with a Lee push through sizer of .358.

Reduce the crimp to where the outside edge of the case mouth is even with the outside edge of the driving band.

Larry Gibson

[wv109323]

In my quest to find an accurate load for a Model 14-6 S&W I had to increase velocity to around 850 to 875 FPS. My load is 4.5 gn. of WW231. I wanted an accurate load for Distinguished Revolver Competition. My bullet is a 158 gn. SWC out of a NEI mold. This load shot 1 5/8" at 50 yards out of a Ransom Rest. Group was 12 shoots. The first round was slightly out of the group due to cleaning the barrel between different loads I was testing but 11 of 12 was 1 5/8". 4.0 gns. of Bullseye shot a 2 1/8 group. I do not use Titegroup so I can not comment on it. My bullets were sized to .358 and my alloy was WW with range scrap and a little bit of 50/50 bar solder mixed in to fill the mold out. Lube was White's red carnabau(sp).

[wv109323]

Let me also add, light loads of around 3.0 to 3.3 grains of Bullseye were terrible. Groups were like 6 to 8 inches. I also found that Solo 1000 made some accurate loads of less than 3". They too were 800+ FPS.

[Larry Gibson]

Let me also add, light loads of around 3.0 to 3.3 grains of Bullseye were terrible. Groups were like 6 to 8 inches. I also found that Solo 1000 made some accurate loads of less than 3". They too were 800+ FPS.

If it won't shoot better than that with 3 gr of Bullseye the problem is in the alloy, the sizing and/or the lube.

Add the tin for better fill out, more consistent bullets and better mix of the antimony in the lead (the tin also does that).

Use the LLA straight.

Size the bullets at .358.

Use a minimal crimp.

Larry Gibson