.338 Sherman Short Mag build

Rich,

How much of the bearing surface is still in the neck of that pictured catridge?
 
They are 1.8" and change long. I suspect they probably arent too finicky with jump. They don't have a super agressive nose.
Steve....do you have any input on jump preference?
 
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**** I forget those are 338 lol. I just look at all the exposed bands and think what could be left. Lol

How much do you think is enough bearing contact % for a given caliber? Half caliber? Less more?
 
**** I forget those are 338 lol. I just look at all the exposed bands and think what could be left. Lol

How much do you think is enough bearing contact % for a given caliber? Half caliber? Less more?
I usually like more than half but this is kind of a unique situation and I think this bullet will do fine.
 
Cool

Just wanted to get your take on it. The old " rules " we see constently parroted may have once had validity and maybe with some rounds still does but with modern long bullets and cases they seem to have little to any real value.


Things like one. Full caliber bearing to neck contact. Necks 1.5 calibers yet almost no cases are manf that way 6 remmy being one exception. Many are not even 1 caliber. Ideal bullet seating is base even with case neck jumction. These things are all but impossible either from todays case short necks or bullets with long BTs even if necks were well over 1caliber.

Anyways, look'n forward to seeing some performance numbers from one of these builds once your customers gets them in hand. Keep us all posted.
 
It's been interesting trying to get by the Gremlins to get one up and running, for various reasons, but we will have at least 4 before long.
Don't get me wrong on necks, I still think that having a fairly long one is a good idea overall. One advantage is, it gives you more room (if you do decide to run the bullet out a ways).
With these first 4 builds, there will be 3 different throats! Even the shortest one cut with the std reamer will have the body/boat tail junction, slighjy up the neck for the 250 Berger.
Sometimes you can gain performance with just a little more useable capacity because it moves you into a slower burning powder. At times, this can be a substantial gain in velocity, or maybe a more stable powder, etc.
 
Thanks.
Good points on moving to a slower powder. I undestood what you meant on necks, my point is hardly any factory design gives you a great neck to work with or a coal for that matter. Think of all the PHDs working for Rem and Win and yet they chose case dimensions in the short mags that were very limiting 8n the SA that was their goal to fit. Look what you have done gained accuracy effeicency with almost no real world lose in vel certainly in a sa configration.
 
Ya, I know what you mean. it's kind of ironic that the guy I work with at ADG for my ss brass is the same guy that designed the Saum case when he worked for Remington!:D when he told me I almost said" so your the dummy that did that" Actually, he is a very knowledgeable guy and knows more than I ever will. He does like my design until it comes to producing the brass:D
 
Yep he probably not very happy trying to form a 40 degree shoulder is he lol. Not to mention to hold the 65k the brass has to go to double neck thickness right at the shoulder. It can't traverse and get thick only once it hits the body. To his credit the deisgn of the case head of the rsuam is superior in everyway to the wsm. If the rsuam had the same vol as a wsm it would have been the dominate short mag case. Now if remington could just make better quality cases.
 
I went to the range today to make some progress on my California hunting load. I loaded 10 ADG cases with 63.5 grains of H100-V, BR2 primers, and 236gr Hammer Hunter bullets. With the first five shots I dialed the scope in. The final 2 of these 5 hit within 1/3 moa, right at the bull. With my remaining 5 rounds, i shot at 300 yards. My 300 yard target wasn't ideal, not having a nice small bullseye to hold on, so i did my best. The group was about 11.5" low, which was right at what Strelok said it should be! The velocities were 2770 to 2776 fps, which slower than I thought they would be, but good enough for my hunting trip in a few weeks. I had the wind in my face, about 5-10 mph. The 300yd group had only 1" or so of vertical spread, which I thought was pretty good. Horizontally, about 4.75". Not what i was hoping for, but again, good enough for my upcoming trip.

I had hoped that I could get better velocities out of these 236gr Hammers. 64 grains produced max pressure when I tested last Sunday, but I don't want to run it that hard. I had trouble with the LabRadar last week, on top of other complications, so I don't have all the velocities from the pressure testing I did.
 
Forgot to mention that the ADG brass is phenomenal! I had a norma case that would not eject (had to use a 2x4 to knock the bolt open) after running 64 grains of H100-v. Same charge in ADG showed round ejector imprints.

I also get faster velocities with the 250gr Berger Hunter Elite (2850) than with the 236gr Hammer Hunter (2770). Bearing surface and all that jazz, I'm sure.
 
Forgot to mention that the ADG brass is phenomenal! I had a norma case that would not eject (had to use a 2x4 to knock the bolt open) after running 64 grains of H100-v. Same charge in ADG showed round ejector imprints.

I also get faster velocities with the 250gr Berger Hunter Elite (2850) than with the 236gr Hammer Hunter (2770). Bearing surface and all that jazz, I'm sure.
Good info Donald. That's pretty good velocity with the Berger which we have found to be consistent.
Donalds chamber is the std throat, by the way. He and Aaron "Ruby76" both have the same throating which runs the 250 at about 2.970" to the lands.
 
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