My 338 Sherman Shortmag

[waspocrew]

I was able to sneak out today and play with a few pieces of ADG brass. I shot increasing loads of W760 starting where I left off last time. Shot 62gr to a max of 67gr Behind a 215 primer and launching a Berger 250gr OTM. I was able to achieve a max velocity of 2900+ and incidentally drilled 'em in the same hole. Bolt was sticky at this max load. Primers were not flattened and web measured 0.553". I'm definitely impressed with ADG brass and look forward to getting my order.
***As Rich has mentioned in his posts, I also would underscore that everyone loading for their weapon is responsible for their own safety. The information I post is for my weapon. I do, however, hope it is helpful to others who are developing a recipe that may work in their weapon.

Nice stick!

What brake is that? I've seen the MBM mentioned, but it didn't quite look like the lil' beast.

 

[elkaholic]

That is flat cookin' doc! Thats both ends of the spectrum with the Sherman brass now with the same result. (6.5SST to 338 SS) That ADG brass is TOUGH!
I really think that there are 2 or 3 powders that may give more velocity than W760, if you can believe that! I think Superformance for sure but it has lousy temp stability. I also think RL17, H100V, and maybe N560 might light it up.
I guy in Wy. just got his together on a long action and we throated it looooooong for the 260 Hammer. Can't wait to see what his does!
I think even the standard throat reamer is a ligit 2800+ rifle with a 250 Berger.
We need to figure out a way for Aaron to get some brass

 

[tim_w]

I was just looking at some numbers for the much larger Ruger/Hrdy case necked to 338. In general the Ruger case beats the H&H case by 100-120 fps in the 250gr range 26" barrel. Looking at the numbers posted using rl7 and the 250 hybrid they were just getting close to 3K at pressure from 26" barrel. Other powders were about 100 fps less at pressure. They did not have rl25 in there which may have worked with that larger case but still.

The numbers here from the 338SS 250 hybrid look to be close to equal to what a 338-375 H&H can do and almost 100 more than a 338 winmag. The 338-375H&H / 340 Weatherby (minus the huge freebore jump and or the 75-80 fps gained with it)

I am almost certain pressure is likely higher of course with the SS but, by design, it seems to handle it just fine straight wall sharp shoulder and all. Heavier bullets would likely be in favor of these large cases as they can use the slower powders that the SS does not have the volume for but still. WOW!!

 

[elkaholic]

I was just looking at some numbers for the much larger Ruger/Hrdy case necked to 338. In general the Ruger case beats the H&H case by 100-120 fps in the 250gr range 26" barrel. Looking at the numbers posted using rl7 and the 250 hybrid they were just getting close to 3K at pressure from 26" barrel. Other powders were about 100 fps less at pressure. They did not have rl25 in there which may have worked with that larger case but still.

The numbers here from the 338SS 250 hybrid look to be close to equal to what a 338-375 H&H can do and almost 100 more than a 338 winmag.

I am almost certain pressure is likely higher of course with the SS but, by design, it seems to handle it just fine straight wall sharp shoulder and all. Heavier bullets would likely be in favor of these large cases as they can use the slower powders that the SS does not have the volume for but still. WOW!!

Can't even tell you how many people told me " it will work fine for the smaller bores, but not when you move up to 338"!
It has performed pretty much like a WM in every bore size. As you stated, we no doubt are running high pressure at those top loads, but that is just to PROOF the brass. I'll bet docs rifle would get 20 firings at 2800 though, just like my 6.5 sst did at 3030 with a 147. What I really like is, you have a safety feature built into that brass! ES has been really low so far too, which is no surprise with the minimal variation in brass weight.
The big Ruger case holds about 26 grains more than the SS at 338 bore.

 

[tim_w]

Yes I know its crazy.

Also I only pointing out the pressure to just nip that in the butt and not look like its apples to apples. I know some people get bent over pressure from a safety stand point and its good to have a heathly margin even in brass. But after seeing the pressures limits of cases vs barrels bolts receives in the bolt guns used here you have a healthy safe zone between a blown case and firearm going boom etc. Maybe if someone pushed the lower limits in bolt reciever barrel tenon thickness etc. The point being this is not like LM/NM cases in a rem700 and running 70K and getting lug compression/setback. For this case size to S/A receivers the hoop strength is good and bolt thrust numbers from the smaller case head not to mention the effects of the straight case wall offsetting more bolt thrust than these highly tapered cases its really an issue limited to brass.

While reading brass is not a viable way to read pressure in absolute terms it does work fairly well for knowing where you are in terms of the limits of the case in that specific gun . In todays bolt actions that is really the main concern the competent hand loader has to worry about IMO.

So I have no issues running higher pressures as long as the cases can handle it. But I would not want only 2 loading from a $3 case either. Then again thats up to the person with the wallet. LOL

What is nice is when you can find that accuracy node just under where the cases are taking a bit too much abuse. Say 2850FPS 250 Hybrid 3.0"-3.1" COAL 25-26" barrel RL17 That sure would let this short action combo stretch things out there with some authority.

BTW what does Quickload say about powder burn percentage with. this type load and barrel length? What percentage of powder is burned after adjusting powder energy to correct vel? With this bore to powder volume ratio and the pressure it has to be really good.

BTW speaking of the larger calibers for this case. As vel increases for a given bullet weight as caliber increase think what vel a 250-260 .375 bullet would be maxed at if you are hitting 2900 in the 338 Just saying. Make a nice bush gun up north or a short barrel hog gun down south. Imagine what a fast moving flat nose .375 would do driving into that shoulder plate . I have seen the kind of hydraulic damage can happen when tissue fluid has no where to go fast enough.

 

[codyadams]

I personally think a 35 Sherman and 35 SS would be cool too, step next to the 35 Whelen ai. My dads 35 WAI is sending 225 sierras at about 2990 with Varget, would be interesting to see what a 35 Sherman could do with different powders!!

 

[drgalan]

Nice stick!

What brake is that? I've seen the MBM mentioned, but it didn't quite look like the lil' beast.

Thanks. The brake I'm using is a Terminator T3. I love it! The recoil is absolutely tame. I can see impact when I squeeze.

 

[elkaholic]

There is a 35 Sherman that was built a couple months ago but the guy who built it has been too busy to shoot it yet. Also, there will be a 375 Sherman running a 300 partition in a month or two.

Tim. I have not run any QL on the 338, but it would be interesting

 

[ruby76]

To my friend Aaron...that's a real nice rig you put together!....I'm hoping you can figure out how to get your hands on some ADG brass. You will NOT regret it!

Thanks, I will get my hands on a that brass sooner or later.

 

[ruby76]

On to superformance and the 250's. I loaded 61 to 65 in one grain increments for tomorrow. There's more room in the case than 65 but for now that's as high as I went until I see the results.

 

[elkaholic]

On to superformance and the 250's. I loaded 61 to 65 in one grain increments for tomorrow. There's more room in the case than 65 but for now that's as high as I went until I see the results.

You'll probably end up nearly filling the case eventually

 

[ruby76]

I also have some H4831sc I could try too.

 

[elkaholic]

I also have some H4831sc I could try too.

Pretty sure you won't get enough in the case to get much velocity

 

[mgood]

It has performed pretty much like a WM in every bore size.

I've seen comparisons of the SS cartridges to this cartridge or that cartridge, but I haven't seen the 6.5 SS compared to 264 Win Mag. It's probably been discussed and I've missed it because I'm not on here that often, but from what I have read here about the SS and what I can look up on the WM, they do look to be very close in velocity.

Anyway, I've become an 8mm junkie and I'm reading this thread with the mindset that if it works for .338, it'll work for .323.