Vectan GM3 Testing in 38sp

[jonp]

I tested Vectan GM3 today in my 38sp. Here is a picture of the powder that I posted earlier:
141526

The firearm is a SW 14-4 Target Masterpiece
I used: 3.0gr GM3
Random Brass
Lee 358140 SWC
Alloy 20:1
Fiocchi SPP
Bens Liquid Lube
Sized .358

It was 76 and sunny with 54% Humidity. I used a F1 Shooting Chrony.

I shot 5 strings of 5 shots each.

1: 699.7 / 705.0 / 679.4 / 746.6 / 728.1 MEAN 711.76 SD 26.1
2: 717.3 / 737.8 / 752.4 / 723.3 / 713.4 MEAN 728.84 SD 16.11
3: 701.1 / 720.2 / 742.7 / 716.7 / 728.9 MEAN 721.9 SD 15.36
4: 724.0 / 757.3 / 751.8 / 723.7 / 751.9 MEAN 741.7 SD 16.48
5: 731.6 / 735.4 / ERROR / 703.0 / 750.6 MEAN 730.15 SD 19.87

Mean and SD for all shots: 726.75/ 20.22

No leading observed and little unburned powder. Recoil was light.

Note: I used a Lyman 55 for measuring. I tested 5 throws in 5 separate tests and averaged 3.1-2.9gr for each of 5 tests with most being either 3.0 or 2.9gr. This powder is fairly consistent.

An average of less than 5% in velocity over a 29 shot string seems pretty good to me.

[dougader]

Good info. Nice to know. Thanks for posting your results.

[texassako]

Thanks for the update. I find it funny that GM3 looks like dirt and could be an alternative for 'flaming dirt', aka Unique.

[jonp]

Further testing. All components the same except for powder weights. In this test I ran 10 shot strings of each weight increasing .2gr for each test.
Weather 83 and sunny with a slight breeze. Humidity 48%

3.2gr: 802.6/787.5/764.7/778.4/763.6/754.1/784.0/789.4/789.6/747.6

3.4gr: 803.1/802.4/826.8/826.7/802.6/789.5/813.5/835.8/791.3/820.5

3.6gr: 812.8/886.4/811.1/ERR /885.6/897.3/886.4/880.4/904.5/895.5

Mean:
3.2gr- 776.15
3.4gr- 811.22
3.6gr- 873.33

SD:
3.2gr- 17.77
3.4gr- 15.05
3.6gr- 35.53

Note: On the third string of 3.6gr if the abnormally low velocities of 2 shots and the ERROR are thrown out the Mean rises to 890.87 and the SD drops to 8.43. This bears repeating to see if this holds.

The SD seems to be dropping with an increase in powder charge. There is no evidence of pressure and the recoil is still very manageable. I am going to further increase the powder charge to get to a level consistent with Unique in velocity which with a Saeco #052 WC 148gr is 926 FPS or erratic readings result. I believe that an increase of .2gr GM3 to 3.8gr will get me there with the previous data.

Lyman's 4th Cast Bullet Handbook suggests a maximum velocity with this weight bullet at approximately 950fps using #2 alloy. I have had small amounts of leading using 20:1 AC with 3.6gr easily removed with Hoppes #9 and a brass brush but expect much more with 3.8gr.

This shotgun powder is next to Unique in the burn charts that I have found and I am testing it as an alternative to Unique. So far the velocity seems close but higher than Unique with the same charge weight.

[azoldbiker]

I shoot & reload: 9mm (124 gr) and 45 ACP (230 gr). I have been using Win 231 for many years. Since Win 231 is no where to be found, I bought some GM3 at Dillon. Nobel Sports burn rate chart shows it to be close to both 231 and Unique. Following your load rates for 38 SP, would it be a good starting point to use the recepies for 9 and 45 acp?

[Outpost75]

How do you find the particle size of this in regard to measuring in a machine such as the Dillon? How does it compare to 231 or WST as to fouling? How dirty is the brass afterward?