300 Sherman Shortmag (SS)

[elkaholic]

That helps a lot! Thanks Shawn. I think it may be the one that will produce the best results......Rich
Do you happen to know what your throat length is? That is if you don't mind sharing that? You can PM if you like. I just checked the burn rates and was a little surprised to see N570 being a fair amount faster than RL22.

I meant N560 not N570. I am starting to wonder if N570 might work since it is so dense? You could probably get close to 68-69 grs. in the case.....Rich

 

[shawnb]

Yes these are validated drops out to about 800. The chrono is a prochrono and its actually pretty close. Usually within 25fps for me.

Kinda sucks that 560 didnt make the cut. Its shooting very well for me but thinking if i had a longer throat a little slower would be better. Thats just a hunch based off testing 4350, 4831sc, 560, h1000.

I couldnt get enough h1000 in to get good speed. And 560 is on the verge for my shorter throat, especially with the 208eld.

 

[Idaho Trecker]

Shawnb, its looking like this case is really not liking the same diet you are feeding your saum.

After yet again another trip to Lewiston I picked up some Magpro to try with high hopes since it was looking like this case would hold right at 70 grains to base of the neck and was supposed to be a little slower burn rate. Again the hopes were dashed away when my first shot with 66.5 grains over the magneto only showed 2789 fps. My last shot with a compressed charge and way way to much pressure only netted 2907.

 

[gilmillan1]

Yes these are validated drops out to about 800. The chrono is a prochrono and its actually pretty close. Usually within 25fps for me.

Kinda sucks that 560 didnt make the cut. Its shooting very well for me but thinking if i had a longer throat a little slower would be better. Thats just a hunch based off testing 4350, 4831sc, 560, h1000.

I couldnt get enough h1000 in to get good speed. And 560 is on the verge for my shorter throat, especially with the 208eld.

I would not trust a prochrono, they are not accurate enough. U need a better chrono. At a minimum, a magnetospeed.

 

[Idaho Trecker]

Made a try with IMR 4955 to see where that would put me since it is supposed to be temp insensitive and all the other good stuff. Made it to 61.5 grains with very hard bolt lift, cratered primers, and very pronounced extractor mark. This max load only hit 2860 fps.

The first trip out this morning I had 4 loaded up with 63.3 grains of rl22 to see how the ES and SD were but unfortunately my magneto had some issues and some stitching broke on the strap so I couldnt use it with this first trip. Even with throwing one shot I still ended up with a .75" group at 100. Still super impressed how this rifle shoots everything incredibly accurately!

At this point I may just stick with RL22. There are only a couple other powders I may try including Superformance, IMR 4831, and possibly get some win 780.

 

[tbrice23]

Did you try 7828 yet ?
I can't remember if you had .

 

[elkaholic]

780 might work? It has about the same burn rate as H4831 but is a ball powder and the case will hold more. I have had good es and accuracy with it, but have never had top velocities.....Rich

 

[Idaho Trecker]

Did you try 7828 yet ?
I can't remember if you had .

I havent tried 7828 but it looks like it will be to slow for the amount I can fit in the case even with ssc.

 

[tbrice23]

Or Magpro.??

 

[Idaho Trecker]

Tried magpro (page or 2 ago) didn't work either. It can hold alot but it actually burns quicker than what the charts show at least in this case.

 

[Idaho Trecker]

Last second trip made out before dark to try a short pressure test with Superformance. Ran 62-65 in 1 grain increments and finally found a powder that will rival RL22.

62 2898
63 2925
64 2980
65 3020

The 64 grain load was very sticky and had a flat primer with some cratering and extractor mark. I decided to fire the 65 grain load just to see how high it would go since I knew 1 more grain wouldn't be the end of the world. With Superformance I was able to pressure out whereas I didnt hit as much pressure with a compressed load of RL22 at 66 grains. It appears that both powders will be good pressure-wise around 2900-2940 fps. The 4 shot group this morning with 63.3 grains of RL22 was very accurate. I'll try and get out this week and see if Superformance will group at all.

 

[shawnb]

This is interesting. I used 560 because i figured it was close to reloader 22 and thats what lots of data said the saum could get the most speed from. Doesnt seem to be the case for you.

I d be interested to see if 570 would work good because of the density of it as rich said. But thats a lot of money for new powders that may or may not work for you.

Good luck and hope you get where you want.

 

[elkaholic]

This is interesting. I used 560 because i figured it was close to reloader 22 and thats what lots of data said the saum could get the most speed from. Doesnt seem to be the case for you.

I d be interested to see if 570 would work good because of the density of it as rich said. But thats a lot of money for new powders that may or may not work for you.

Good luck and hope you get where you want.

Speaking of powder; Ryan is learning what it is like to be the guinea pig for a brand new wildcat. Something very interesting though is the fact that the SS and saum act very differently.....Rich

 

[Idaho Trecker]

Shawn... it seems to be going better now that I have 2 powder choices that are where I want to be. I wish they were better powders in regards to temperature sensitivity. It appears that 560 is closer to h4831 from the charts (other than the newest hodgdon chart) in burn rate. After talking to Rich and some others it doesnt look like 570 would work either. I'm going to see where H4831 gets me since it would be nice to have a more temperature stable powder to work with.