357 magnum load going to try Saturday...First time! What do you think?

[Hondo 60]

derek45 - oooo-ah-ah-ah down right purty ammo!

 

[AJC1]

FYI, Your load with 8.3 gr of Unique is probably over the SAAMI 35,000 psi limit. It is just under the old 1987 Hercules load data I have. The older data used the cup measurement methods. Many loads using the cup method were found to be under reporting peak pressures. Charges were typically reduced quite a bit after they figured out what was going on.

The 2004 Alliant data (using the newer methods that report in psi) goes to 7.8 gr for a 158 JSP. I looked at Alliant on-line data and 7.7 gr was the highest charge I noted for any 158 bullet.

I ran a 158 gr cast with gas check through Quickload and found predicted pressure for 7.7 gr goes right to the SAAMI limit with the bullet seated 0.360" deep. Going down to 7.6 grs lets you seat as deep as 0.377" with predicted pressure right at the limit.

The GP-100 is pretty tough. I am guessing it can take more abuse than your loads. Running a few hot loads through a GP-100 for load testing is one thing. Loading above SAAMI does run some risk given that some of your ammo could potentially end up in a much less stout gun. I would recommend backing off consistent with the Alliant on-line max if you are going to use Unique for a regular load. You will still be getting close to 1300 fps in your 5" revolver.

I'm always curious about the caution about custom handloads ending up in a different gun.... how exactly does that happen? .357 is running a dollar a shot. Is someone feeling comfortable enough to let themselves pilfer your ammunition?????

 

[forrest r]

Nice follow-up.

Results are always interesting.

Powder charges really don't mean much without your reloads col's. Any idea what the col of your loads were???

Amazing accuracy??? Any pictures or the load shot xxx @ 50ft/25yds/50yds/etc

I've never seen holes in paper +/- twice the size of the bullet diameter??? I've seen bullets tumble and leave holes of sideways bullets before.

 

[lordpaxman]

Thanks for the range report. I was following in interest - would have been good to get chrono results to see where you ended up. Good luck.

 

[derek45]

With quality jacketed or hardcast bullets, you will get very good accuracy from hot H110/win296 and 2400 magnum powders

I've never had great accuracy from plated

 

[EricBu]

I'll chime in, I don't have any specific input on the plated issue, but I did have the rare opportunity this weekend to shoot 4 completely different types of .357 magnum, with the exact same load....16.5 grains of H110 under a Zero 158 grain JSP. I though some of you would like to see the incredible spread of velocity by type and barrel length. Cliff notes: Barrel length wins by a massive margin.....but a semi-auto in .357 (Coonan Arms 1911) beats a longer barrel length revolver. Each gun fired 10 rounds through the chrony at the same distance from muzzle, below is the average velocity of those 10 rounds (actually, I shot 5x 10 rnd strings from each gun, the data below is from the last 10rnd string for each gun, which is what I put in my record since each gun fired each string virtually identically). SD varied from 12 for the Marlin, to 14 for the Coonan, and the highest of 25 for the SP101. This was with mixed headstamp brass, untrimmed, and were loaded on a RL750 in a run of 1000 rounds. I will be loading another batch soon with brand new Starline, and expect that will cut the SD in half, at least for the Rifle and the Coonan. So this is to show what you might be planning on for your velocity based on the book, may not in fact be accurate...based on factors like whether the manual used a proof barrel or not, temp, elevation, barrel length etc. So the only way you'll know for sure with your plated bullets, load down, and test out of your gun and see where you're at. In my mind, 16.5 grains of H110 is a pretty warm load, but YMMV.

Coonan 1911 - 5 inch - 1310
Ruger Blackhawk - 7 inch - 1270
Marlin 1894 - 16 inch - 1734
Ruger SP101 - 3 inch - 1008

 

[Hooda Thunkit]

.16.5 grains of H110 under a Zero 158 grain

Ruger Blackhawk - 7 inch - 1270

A few years back I tested 357 Mag with H110 and a cast and checked 358156, in a 6.5" Blackhawk.

I settled at 15.4 gn, because the velocity peaked very close to what you got.
I added powder to whatever the book(s) max was, but neither velocity nor accuracy changed. The only difference was the muzzle flash (fireball) and report.

 

[EricBu]

A few years back I tested 357 Mag with H110 and a cast and checked 358156, in a 6.5" Blackhawk.

I settled at 15.4 gn, because the velocity peaked very close to what you got.
I added powder to whatever the book(s) max was, but neither velocity nor accuracy changed. The only difference was the muzzle flash (fireball) and report.

Oh yeah, this load could be tweaked for each of those guns to a pretty big degree. But, the Coonan only get's better up to about 17 grains, which is where pressure signs start appearing for that particular gun......but those bullets are zinging out of there at ~ 1650. 17 grains in a revolver......if you miss your target, you can roast it with the muzzle blast. My normal revolver load is down around 15.5. I definitely think H110 is not the best short barrel revolver powder out there, but it sure runs good in the Coonan and the Marlin.

 

[Hooda Thunkit]

Oh yeah, this load could be tweaked for each of those guns to a pretty big degree. But, the Coonan only get's better up to about 17 grains, which is where pressure signs start appearing for that particular gun......but those bullets are zinging out of there at ~ 1650. 17 grains in a revolver......if you miss your target, you can roast it with the muzzle blast. My normal revolver load is down around 15.5. I definitely think H110 is not the best short barrel revolver powder out there, but it sure runs good in the Coonan and the Marlin.

I wanna come over and shoot your Coonan.

 

[Bfh_auto]

Oh yeah, this load could be tweaked for each of those guns to a pretty big degree. But, the Coonan only get's better up to about 17 grains, which is where pressure signs start appearing for that particular gun......but those bullets are zinging out of there at ~ 1650. 17 grains in a revolver......if you miss your target, you can roast it with the muzzle blast. My normal revolver load is down around 15.5. I definitely think H110 is not the best short barrel revolver powder out there, but it sure runs good in the Coonan and the Marlin.

16.5 is my load with 158s. It does very well for me just like you saw.
I've since moved to 180s because they get better velocity compared to the charge weight with h110 than 158s in my experience.

 

[joneb]

FYI, Your load with 8.3 gr of Unique is probably over the SAAMI 35,000 psi limit.

Good catch, I would think 7.3gr of Unique would be a good place to start with a 158gr plated bullet for 357 mag.
Just because I can't detect over pressure signs doesn't mean the load isn't beating up my gun.

 

[mjsdwash]

I'm always curious about the caution about custom handloads ending up in a different gun.... how exactly does that happen? .357 is running a dollar a shot. Is someone feeling comfortable enough to let themselves pilfer your ammunition?????

I have a few friends that buy handloaded ammo from garage sales and pawn shops. Lots of issues. One gave me a bag of rifle rounds... loaded with pistol primers, case length exceeded max trim length, two dangerous conditions, especially together, so it can happen. We all have heard the gunshow KB's.

 

[AJC1]

I have a few friends that buy handloaded ammo from garage sales and pawn shops. Lots of issues. One gave me a bag of rifle rounds... loaded with pistol primers, case length exceeded max trim length, two dangerous conditions, especially together, so it can happen. We all have heard the gunshow KB's.

I guess that if you have any intention of someone else using it in a sale transaction, it better be spec in every way. I would never do that for liability reasons.

 

[mjsdwash]

I guess that if you have any intention of someone else using it in a sale transaction, it better be spec in every way. I would never do that for liability reasons.

yea, exactly. I hit spec in every way, and test fire each lot, and I still refuse to sell/trade/give away (except in group shoots, with MY firearm). Its very scary that many people buy this regularly. Maybe I'm paranoid because the one time I got a good amount of used ammo, it had a %100 defect rate, but we have a pawnshop that sells used ammo, and I have friends who buy it, and the few times I have seen it, it had bad loads too.

 

[EricBu]

As far as selling reloads for profit...I guess if you like the inside of a prison. Just ask Doug Halg about that...he sold reloads at gun shows and out of his home for years under the radar....and then he sold tracers to the Vegas shooter. His finger prints were on some of the rounds, and they matched the tool marks on the brass to his equipment. This should clear up any confusion on whether or not it's legal to sell reloads for profit:

https://www.atf.gov/firearms/qa/person-who-reloads-ammunition-required-be-licensed-manufacturer

I think the key word is profit. It's probably fine if you load a batch for your buddy and he pays for the components. I wouldn't sweat that, though I try and make them pull the handle (teach a man to fish so to speak). But <shrug> people do what they do, and there are a LOT of really bad reloads floating around the market, swap meets, and gun broker right now. Which will cause a crackdown on this sort of thing, and get the ATF even further up our asses.

 

[Stopsign32v]

FYI, Your load with 8.3 gr of Unique is probably over the SAAMI 35,000 psi limit.

Got it straight from the latest Lyman manual

 

[forrest r]

Getting it " straight from the latest Lyman manual" doesn't mean much if you look at the big picture.

"straight from the latest Lyman manual" 16.3gr of h110 is the starting load.

16gr h110 vs 8.3gr unique
The 16gr/h110 load is 8fps slower & has 6,600psi less pressure then the 8.3gr of unique load.

Yet the h110 load blew the bullet out but the unique load had "amazing accuracy" (what ever that is).

Most people would find it odd that a starting load would blow a bullet out & a max load that had more velocity/more pressure is amazing.

 

[P Flados]

Your Lyman manual is reporting pressure in CUP.

That is a warning sign that this is "old data" even if it is in a recent edition. FYI, I have a 1978 Lyman Pistol & Revolver Handbook that has this same exact data in it.

When I see data reported in CUP, I always go looking for newer data. The CUP methods were pretty crude compared to the newer methods.

Again, Hercules/Alliant used to go this high, but then backed off when they switched to the newer instrumentation that is reported in psi.

I know that Quickload has its limitations, but it is predicting pressures pretty close to the newer Alliant data. For the Lyman load, it is showing about 120% of the SAAMI 35000 psi limit for 8.3 gr Unique under a158 JHP at 1.590 OAL.

With both Quickload and Alliant saying what they do, are you sure you want to use data that was generated before 1978?

Again, the GP-100 is one of the best choices I can think of for trying hot stuff. Just remember that there are other much less stout guns out there.

And for those that wonder, ammo does get dropped, misplaced, lost, separated from labelling etc. I have found some of my old ammo that I had no idea of the contents. The right answer when "finding" suspect ammo is to pull it down. Not all people with handguns choose the "right answer" on every occasion.

 

[Walkalong]

Got it straight from the latest Lyman manual

That's a max charge, did you work up to it?