My 338 Sherman Shortmag

[elkaholic]

View attachment 103616 Accuracy testing time. Best 3 shot/100 yard group was 60.7 gr RL17 at 2782, 2787, and 2792. I'll load some more around there but looking good

Nice Aaron! If you ever have anyone passing through here, let me know and we'll set you up

 

[drgalan]

......and the load development continues! Went out this morning before the storm and lit up a few with the following data.
ADG brass 225gr Badlands Bulldozer 215primer seated .20 off the lands
RL16
61 2740'
62 2781'
63 2830'
64 2868'(excessive pressure)

Varget
57 2731'
58 2800'
59 2851'
60 2878'
61 2932' (excessive pressure)

W760
64 2804'
65 2855'
66 2886'(appears to be max pressure)

IMR 4064
58 2851'
59 2909'
60 2949'(exceeded pressure slightly)

RL17
61 2776'
62 2829'
63 2857'(at max pressure)

I will continue to explore the powders in this faster burn column as they appear to be mating well with the lighter weight projectile. I loaded up a few with W748 but the downpour forced this "to be continued"
As a side note, I am really impressed with the Bulldozers from Badlands. Oh and lastly, I realized that I never did get to max pressure while using Varget with the 250 Bergers, so that will be coming soon too. Perhaps that will yield the "temp stable combo" we're looking for

 

[elkaholic]

Thanks Doc, that's some good info!

 

[ruby76]

Thanks Doc, that's some good info!

X2. I foresee building some spreadsheets in the near future, just to keep track of all this great info. Very interesting how different powders and burn rates are performing.

 

[elkaholic]

I would love it if you guys could compile some load data listing all the usual data. I need to get something similar together for ALL the Sherman cartridges.

 

[ruby76]

Great to have it in one place for sure, for each cartridge. I spent many hours searching through threads and other Sherman owners' testing info to try and narrow down choices.

 

[drgalan]

Well had just enough time to light up a few more before the torrential showers showed up again.
ADG brass 225 Bulldozer 215 primer and seated .20 off the lands

W748
57 2748'
58 2811'
59 2853
60 2868'
61 2919' with more room to go

IMR3031
55 2834'
56 2858'
57 2896'
58 2936' with more room to go

I would've tried IMR 8208XBR but didn't have any on hand. (In case some of you are thinking that)
I continue to love this lil' cartridge. Not only efficient but very versatile in terms of powders that can be used. I'm gonna keep testing but if I had to hunt tomorrow, I have a number of loads I could use. To date my rig will launch a 250 Berger @2800 + , 285 ELDM @2600+ and 2900+ with the 225 Bulldozer(hoping to hit 3000)

 

[elkaholic]

That is some good work Doc. This is really intriguing to me that slower powders that are known to give good velocities are not keeping up with faster ones! It's not that you can't load enough as you have Over Pressured with some! You didn't just go a little faster burn either, but substantial. It has me scratching my head a little to be honest!
VERY GOOD INFO

 

[elkaholic]

Just got off the phone with Doc and his data really has my wheels turning! My long action 338 Sherman will run about the same max velocities but with more convential, slower burning powders which fill the case. When Doc reached 2902 with W760, I was frankly amazed! Ya, it was a STIFF load! I went out a couple days later and tried some H414 in my long action just to prove what I already knew. Sure enough, I dang near blew the primer at 2800'! H414 and W760 are the same powder. Don't ever be fooled that a short powder column does not affect burning rate and internal ballistics. I certainly don't have a perfect explanation for it, but it's there.

 

[ruby76]

Well the wheels are sure turning. I'll have to have another look through the 300SS thread to check for faster powders tried with heavier bullets. I'm sticking to my thinking regarding temp stable powders, I'll have to do some more research on that. Any insight on potential choices? I'm interested in some info on varget based on docs results to date.

 

[drgalan]

It was that very experience that made me consider trying the faster burning powders. I don't have a perfect explanation either, but I thought that pushing the bullet out faster would reduce pressure while increasing velocity and it did. It seems to me that the traditional slower burning powders build too much pressure before launching the projectile thus limiting terminal velocity. Another independent factor is the bearing surface of the bullet and perhaps even twist of the barrel ( I'm running a 1:9.3)
In my earlier posts, I completely forgot to mention that I've been using the same 10pcs of ADG brass for the majority of all the data I've collected. So to all my fellow reloader readers, be advised that at $2.50 a piece for brass, your getting the cheapest brass you'll ever buy, lol. When you divide the number of usable times you can reload those puppies, they are pennies on the dollar. The quality is superb as I have "redlined" them over and over and still loading them again this week.
When I first spoke to Rich regarding this 338 SS I knew it would be in the winner circle! It gives me much pleasure to help him and others build usable data and look forward to hopefully capturing some kills on video this season!.... I have officially retired my 338 ultramag

 

[elkaholic]

Well the wheels are sure turning. I'll have to have another look through the 300SS thread to check for faster powders tried with heavier bullets. I'm sticking to my thinking regarding temp stable powders, I'll have to do some more research on that. Any insight on potential choices? I'm interested in some info on varget based on docs results to date.

Varget may well be a good choice and I think Docs suggestion of 8208 has some merit too.

 

[drgalan]

As I read my post from last night, I realized that I said something incorrectly. I meant to say....it seems to me that the slower burning traditional powders build too much pressure before launching the projectile thus not allowing one to achieve optimal terminal performance. ( not terminal velocity as I said previously.)
Just wanted to make sure I clarified this detail. Have a great week everyone!
Oh and you may want to call Rich and get in line to build your 338SS. I suspect there will be a long waiting list before to long.

 

[KMG]

I have my barrel on the way already. Thanks for the tip Rich on the Rock Creek being a goodun. I picked up a 28" fluted 5r. Now looking for a donor action.