hmm. .357 loads

[John3921]

Many years ago - before Algore invented the internet, I bought a S&W 686 6" .357 mag. I loaded for it on a single stage press with a Lyman balance beam scale. I weighed out every load to +/- .1 To the best of my recollection. I do have an old RCBS uniflow powder measure, but I believe I checked every throw.

At the time I was sold Blue Dot for powder. I use the Lyman 358156 155 gr gas check mold with hornady gas checks, bullets are sized to .357 (a bit too small I realize). Per the Lyman manual #46 the Blue Dot load should have given me 975 fps at 8.5 grains, and 1277 fps at 10.5 grains. This is using a small pistol magnum primer. The bullets are seated to the top groove (The 358156 has 2 crimp rings and a lube ring) and have an OAL of 1.585"

Trying to get the Lock-n-load setup I loaded a few rounds to the 8.5 grain load and used winchester small pistol primers as I couldn't find any small pistol magnum primers.

Off to the range with the chronograph.

5 shot group of the original loads with magnum primers avg velocity of 1210 fps with a max of 1298 and a min of 1162.

The 5 loaded on the LNL with SPP and 8.5 grains BD were an avg of 1072 fps with a max of 1147 min of 1023.

Found it interesting, and somewhat disconcerting, that even with the SPP primers I'm running 100 fps faster than the book, and with SMP primers closer to 235 fps faster.

The lyman manual says that the 10.5 gr 1277 fps load is a 40,000 psi load and is max. My old notes indicated cratered primers at 10.0 grains.

 

[Walkalong]

Many years ago - before Algore invented the internet, I bought a S&W 686 6" .357 mag

Same here. I should have kept it.

100 to 200 FPS difference from a reloading manual using a different bullet, primer, and most especially gun, is not unheard of. Blue Dot does better as pressure goes up. It doesn't like low pressure much.

I shot Blue Dot and lead in .44 Mag back in the day, but these days I have gotten away from Blue Dot. Other powders just work better for most everything.

I would suggest some 2400 for those lead bullets in .357 Mag. I believe you will be pleased with it.

 

[murf]

that lyman data was shot out of a four inch universal receiver. same info is in the lyman #49 manual.

that .357" bullet diameter may have something to do with your higher velocities. lyman probably used .358".

murf

 

[John3921]

I expect some variation - but the published Lyman velocities are for the exact bullet. Possibly different in only alloy composition. I believe the Lyman manual is for Linotype bullets, my casting mix for the original loadings was a lyman no. 2 alloy - as close as I could get in any case. I guess that's why you always start at minimums and work up.

I have a .358 H&I die coming. We'll see how much difference that makes. I went to the gas check bullet because I had terrible leading problems. It could be it was just the bullet being somewhat undersized. I have no leading issues with the gas check, but it would be nice to not have to fool with them.

I'm reading up on powder choices - there seems to be no limit on choices. I sent an email off to Alliant today asking about 20/28 uses in handgun. It is so similar to universal clays in shotguns - I'm wondering if it would work ok for 9mm.

 

[Steve C]

100 fps off the book velocity isn't unusual in my experience. Difference in guns, temperature, elevation all affect velocity. Different guns of the same manufacture and barrel length can have 100 fps + difference in velocity, see the article in the Speer Manual. Living in Arizona where the temperatures are higher I commonly get the books velocity taken from a 6" barrel using my 4" guns. On the other hand I have a 8-3/8" M27 that shoots relatively slow with chrono'd velocities no greater than what I get with a 6" barrel revolver. There are no rules regarding the ballistics, just a moderately informed guess as to what your results may be. Actual measurement with a chronograph is the only way to know for sure.

 

[John3921]

Next round of data. Ordered up a .358 H&I die for the lube sizer. Ran 5 rounds of the .357 sized rounds through the chron - Avg 1105 fps +65 / -73. Ran 6 of the .358 sized rounds over the chron - 1193 fps avg +37 / -28 fps.

 

[Blue68f100]

Yes, Tighter bullet seal to barrel = less gas leakage = more velocity. This as why sizing a lead to the bore is very important. It also reduces leading.

 

[murf]

john3921,

slug your barrel. some guy named elmer keith recommended to size lead bullets .001" over groove diameter. no. 2 alloy should not lead at 1200 fps. so, sizing with that new die of yours should let you get rid of those gas checks. need to slug the barrel, though.

i have been running bludot through my s&w revolvers for many years. i have had good success with cci 500 primers. they have a thicker cup than winchester and better resist flow back into the firing pin hole. early 686s had a problem with enlarged firing pin holes and the thicker cup should give you a bit of added insurance with this problem.

luck,

murf

 

[zxcvbob]

I never had good luck with Blue Dot in .357 Mag, and I think it was because I mostly shoot cast bullets. It might be OK with heavy jacketed bullets, I dunno.

Try Herco, AA#7, and/or 2400. AA#7 especially is just like Blue Dot without the drama. And Herco is kind of like a magnumized Unique.

 

[ljnowell]

Lead 357 mag loads and 2400 go together like peanut butter and jelly.

 

[John3921]

The bbl does slug right at .357. .358 should be the right sizer. I do like how it cut the velocity spread in half. My 9 mm slugs at .356, so I think the .357 sizer still has a job.

Still bothers me that the avg velocity is some 240 fps faster than book. And I'm using small pistol primers - not small magnum.

I'll probably fool with powder a bit - but right now the lgs is selling 1 lb's at about $23, Hate to buy a lb of fertilizer for $23 to test a 100 bullets, LOL.

I'm working on .45 acp loads and 9mm loads. I also load a lot of .410 (W296), 28, 20, (alliant 20/28), and 12 gauge (clays) skeet loads. Somewhere in there is the 'right' powder.

 

[murf]

158gn lswc, 10.1gn bludot, cci500 primer, 1280fps avg

shot out of my 4.625" blackhawk. this gun shoots the 180gn bullets better.

murf

 

[SDGlock23]

My favorite load for the .357 was 14.8gr 2400 under a 158gr Missouri SWC @ 1.605". Average of 1499 fps from 6" Ruger GP100. Accurate, powerful, and very consistent.

 

[mebe007]

2400 and h110/ win 296 are my go to mag powders for 44 and .357mag. However I do keep 1lb of blue dot on the shelf just in case

 

[John3921]

David - no - I haven't ventured above 8.5 gr BD yet this time around. In my ancient Lyman reloading manual I have a note in the margins that indicates I had cratered primers at 10.0 grains BD with these bullets sized at .357 The Lyman manual indicates 10.5 gr as a max load. That was probably from about 1990 or so.

I am not really looking for whambos. Just range loads. I should probably be using .38 spcl brass - I just didn't want to mess with yet another variable.

 

[zxcvbob]

I am not really looking for whambos. Just range loads. I should probably be using .38 spcl brass - I just didn't want to mess with yet another variable.

You'll probably be happier with the results using a faster powder, like Unique, Green Dot, or even Red Dot or Bullseye, and they'll be cheaper to load. Blue Dot does not burn very well until you get closer to a max load, and then it starts getting squirrely if you go a little too high.