Alloy / BHN for new to me Boolits

[Krh1326]

Hi All,

I got my hands on a .40 SW slide, barrel and RSA, that will run on my 9mm Sig P229 Scorpion.
So that means I will be flinging .40 and eventually, .357sig ( as soon as I find the barrel, lol ).

The .357 sig is serious pressures, and I’m already realizing that will most likely be hardcast or lyman#2 or maybe even linotype… still researching.

The .40sw I think is going to land in the wheel weight range, or can that go a little softer…. Towards .45acp alloys ?

Does anyone out there have some advice for .40sw & .357sig? I don’t run any of my loads at max press/ fps… I get to cycling/ performance / accuracy and call it a day … usually I’m between 3/4 and 7/8 of listed loads.

[Willie T]

I cast 175 SWC’s for a 10 twist S&W M&P 40. The grooves are pretty shallow. The barrel is very good and slugs .400 dead nuts. I size to .401. Ive loaded them with W-231, AA no5, and Power Pistol. W-231 was the most consistent although the lower charges are a little smokey. Mid range charges and up, Accurate no5 burned the cleanest and is slightly more accurate in my Pistol. I have loaded bottom end W-231 loads with 50-50 clip on and stick on wheel weights. The AA no5 I load with straight clip on wheel weights. Full house Power Pistol loads are going away the fastest and loudest I load. They are also the most accurate. I cast Lyman no2 for the Power
Pistol loads.
Silhouette should work well in the 40 S&W. A gas checked 155 pushed full tilt with power pistol in a 40 s&w would be nipping at the heels of 158’s in a .357 magnum and is on my bucket list.
Be cautious with heavy bullets and very fast powders in the 40s&w.
Willie

[Krh1326]

I thank you sir.
And Dusty’s PM, too.

I do keep a supply of hp-38 ( w231) on hand, as I can load every single pistol I have with it, and I’m very happy it runs good in .40sw.
I have found good load data for the Lee 175 TC & hp38/ w231

[stubshaft]

5.2 AA #5 behind a 170 - 180 grain bullet is the most accurate and cleanest burning in my Steyr and S&W 641.

[Cast10]

I load 9mm and 10mm. I use the same mix at approx 11.3 BHN.

9mm w/ WSF & Lee 120 TC at 1055-1095fps per barrel lengths in Glocks.
10mm w/ #9 & Lee 175 TC at approx. 1225-1250fps Glock 20.

This alloy mix is SOWWs and Hardball.

No leading at all.

[Krh1326]

Awesome, thank you guys

[fredj338]

With 357sig, I would go coated & clip ww water dripped out of the oven. The 40 can run clip ww with lubes if not not pushing the top end. I have gone to PC for everything, just easier they shoot very clean.

[kevin c]

I’m in fredj388’s boat: for target shooting terminal performance dependent on hardness is not an issue, and a fairly soft alloy shouldn’t lead if coated, sized and loaded appropriately.

From reading this forum, it seems finding hard alloys is difficult for some. If a BHN around 11-12 is considered good by Glen Fryxell for most traditionally lubed cast bullets, then softer can be appropriate in most if not all the same applications when using powder coating or HiTek, and can save the hassle and added expense of sourcing hardeners.

[Soundguy]

Hi All,

I got my hands on a .40 SW slide, barrel and RSA, that will run on my 9mm Sig P229 Scorpion.
So that means I will be flinging .40 and eventually, .357sig ( as soon as I find the barrel, lol ).

The .357 sig is serious pressures, and I’m already realizing that will most likely be hardcast or lyman#2 or maybe even linotype… still researching.

The .40sw I think is going to land in the wheel weight range, or can that go a little softer…. Towards .45acp alloys ?

Does anyone out there have some advice for .40sw & .357sig? I don’t run any of my loads at max press/ fps… I get to cycling/ performance / accuracy and call it a day … usually I’m between 3/4 and 7/8 of listed loads.

I'd not go linotype.. I'd gas check and then you can get by with #2 or less.

[megasupermagnum]

The SAMMI MAP for 357 sig is 40,000 psi, and for the 40 s&w is 35,000 psi. That's no practical difference for bullet alloy. Neither of those are that crazy high of pressures. A 30-30 winchester for example is 42,000 psi.

Somewhere around COWW is perfectly fine alloy for both cartridges. 20:1 works fine too, but the only real issue is if you have say a large HP mold, a soft alloy like that can have issues with the nose deforming, especially on the feeding ramp causing reliability issues. You can coat the bullets, or not. It makes no difference. Neither cartridge runs very high velocity. If you wanted to play with light bullets in the 357 sig you might benefit from gas checks. I wouldn't bother with them in normal weight bullets in either caliber.

[Krh1326]

I thank you all, so much.