Green dot for 357 158 SWC

[BigAlofPa.]

I can't find any data for green dot in my books. For 357 158 grain swc. Im thinking 5 grains would be a safe start. Anyone else try G.D for 357 ? Thanks Al.

[Tim357]

Think of Green Dot as a bit slower Red Dot

[dtknowles]

I can't find any data for green dot in my books. For 357 158 grain swc. Im thinking 5 grains would be a safe start. Anyone else try G.D for 357 ? Thanks Al.

Simple internet search "Green Dot in .357 Mag." got me this as the first link

https://forum.castbulletassoc.org/th...ated%20148HBWC.

"Green Dot is a bit slower than Bullseye or Red Dot. In the.357 Magnum you can use 5 grains as a starting load up to about 6.5 grs. Max. with a 150-160 gr. lead bulet. In.38 Special I load 4 grs. as a full-charge load with a 160-gr. Cowboy slug or 3 grs. with a flush seated 148HBWC."

Tim

[tazman]

I have an Alliant manual from 2001 that lists 6.0 of Green Dot as max with a 158 grain lead SWC in 357mag. Expected velocity was a little over 1200fps.

[Larry Gibson]

There is some older data out there some of which has proven to be way to hot to use. I recently conducted a pressure test of current Alliant Green Dot under a 158 cast Lee TL SWC. Here's what I posted;

357 and 44 Magnum with Green Dot PSI test

I conducted the pressure tests of new Alliant Green Dot yesterday (March 19, 2019) in the 357 Magnum and the 44 magnum.

Initially I started with the 357 magnum using the Lee TL358-158-SWC cast of COWWs + 2% tin, sized .358 and lubed with BAC. Cases were Winchester 357 brass and WSP primers were used. The bullets were seated to the top lube groove in the bullet and a roll crimp was applied. Testing was done with a Contender using a strain gauge located over the chamber at the SAAMI prescribed location. The Oehler M43 PBL was used to measure the velocity and pressure. The barrel length of the test barrel is 7.94". Target was at 50 yards for group size.

I started off with a "reference" test string of 14 gr 2400 under the 358156. The resulting velocity was 1537 fps at 34,900 psi. That is within the test to test variation of that load so all appeared well.

For the Green Dot test I had loaded increments of 5.5, 6.0, 6.5, 7.0 and 7.5 gr in 10 shot test strings with the 7.5 gr load being the load listed in the 1968 Hercules manual.

During the first test of the 5.5 gr load I began to have technical problems. Some loads would appear normal, some were erratic and some did not record complete data. In selecting out the shots that appeared "good" I found the 5.5 gr load was running at 31,000 psi! Further testing suggested the 6.0 gr load was running at 37,300 psi, the 6.5 gr load at 41.400 psi and the 7.0 gr load at 43,200 psi. I did not test the 7.5 gr load.

Another test string of the "reference" load revealed the same erratic readings. Thus I'm not betting these were correct though I did get a stuck cast with one of the 7.0 gr loads necessitating removal with pliers the psi was definitely there. Inspection when I got home revealed the scope base had become slightly loose and the ground was lost. I have fixed that problem and may run the 357 magnum test again in the near future.

At this point of the testing, in the 357 magnum, I would not recommend a load over 5.5 gr with the Lee 158 TL bullet seated as such.

A new gauge was attached to the test barrel and "referenced". Another test of the same loads was conducted on March 25, 2019. Results were pretty much the same with 6.0 gr Green Dot under that same Lee TL SWC bumping up close to the SAAMI MAP for the 357 magnum at 33,500 psi. The next load at 6.5 gr ran 39,400 psi so there's not much room for error.

[BigAlofPa.]

Awesome thanks. Looks like i was pretty close with 5 grains. No need to hot rod them. Nice testing report Larry thanks.

[ddixie884]

Yes, good info.........

[Alstep]

I've loaded 4.5 and 5.0 grains of Green Dot driving the RCBS 38-150 SWC in my .357.
5.0 grains shot the better group. Nice moderate load that shot fairly well.

I also found that Green Dot worked very well in my .44 Redhawk.
7.1 grains of Green Dot (RCBS rotor #16) driving the Arsenal 429421 shot to the same point of impact as 16.2 grains of 2400 (RCBS rotor #20)
In fact, Green Dot shot a better group, 30 shots in 2 inches at 27 yards, issue iron sights, supporting my hands on sandbags, with 79 year old eyes.
I usually shoot 5 cylinders, shows consistency or lack thereof.
These loads are my favorite so far, especially Green Dot. Accurate with moderate recoil that I can still handle.

[Kosh75287]

I'm guessing that Green Dot does something wondrous in shotguns that I, as a pistolero, am unable to appreciate. It was never as economical Red Dot, nor as versatile as Unique, nor the fire-breather that Blue-Dot was.
I tried about half a can in .357 and .45 Auto and it shot well enough, but it didn't burn cleaner or deliver better groups than other powders I tried. If it, and no other powder, was available, I'd certainly use it to the best of my ability, but I'd look for one of my favorite powders at the same time. I'm glad someone finds it useful.

[Alstep]

I've loaded 4.5 and 5.0 grains of Green Dot driving the RCBS 38-150 SWC in my .357. 5.0 grains shot the better group. Nice moderate load that shot fairly well.

I also found that Green Dot worked very well in my .44 Redhawk.
7.1 grains of Green Dot (RCBS rotor #16) driving the Arsenal 429421 shot to the same point of impact as 16.2 grains of 2400 (RCBS rotor #20)
In fact, Green Dot shot a better group, 30 shots in 2 inches at 27 yards, issue iron sights, supporting my hands on sandbags, with 79 year old eyes.
I usually shoot 5 cylinders, shows consistency or lack thereof.
These loads are my favorite so far, especially Green Dot. Accurate with moderate recoil that I can still handle.

Sorry about the double post.

[MUSTANG]

Thanks for the comments and Data from All, particularly the pressure test info from Larry Gibson. I wanted to load some 38's and 44's this weekend and went out to the Powder Locker to get powder for this endeavor. Discovered I had 12 one pound containers of Green Dot that I bought during the last Powder shortage because it was available and Bullseye, Unique, 2400 had become unobtanium at the time. So anyway; rather than use my stores of Bullseye, Unique, & 2400 that I find more flexible for Pistol/Rifle; I'll make up a bunch of .38's and .44's with the Green Dot Powder.

[BigAlofPa.]

Tested my loads today. Ran a cylinder through at some cans 1st. To be sure they were accurate enough i wouldn't shoot my chrono. The 1st ones i ran. Where what i loaded with 6 grains of unique. the numbers are 1044,1069,1063,1057 ,1060. and 1058.

The green dot loads at 5 grains were 908,897,933,958,898 and 913.
Very mild recoil too. So i have some room.

Gun used Ruger GP 100. 6 inch barrel.