The skinny on the 375 EPSTEIN

J

JasonYuke

CGN Ultra frequent flyer
Rating - 100%
152   0   0
Location
North Kawartha's
Thank you all for responding to my first post on the 375 Epstein, the truth of the matter not alot is known about this rifle cartridge but I was given the Artical and book by BIG MIKE'S EPSTEIN, founder of the 375 Epstein



I have suggested a load that some had said too much however the skinny on the epstein is a fat widened neck mad from a 375 H&H case, or a 338 case does infact out perform the H&H by a landslide and almost ( buy 30 fps) performs to velocities close to the 378 Wby with 25-30% less powder. It realy is an increadible case design. Both showing 5500 FT LBS of energy.
The other remarkable fact of this cartridge case comb accuracey is best with high preasure, Mikes pet load showing 3/4 inch groups with 77g of 4350 at 5537 ftbs and the slower round opened up.

Chrony resulty show a 270 gr slug loaded with 78 g IMR 4350 pushing 3043 fps vs the 378 with 108 gr of 4350 pushing a 270 grain slug at 3078 fps, awesome power.
Mikes original design was to match the H&H velosities, but this case design exceeded all expectations, and beca,me one of the best efficient cartridges in the Magnum family.

So the skinny is its its very close to the 378 with less powder, and less preasure, Their are rummors floating around due to the lack of info on this Epstein Mike never pushed it harder, but there is still room in the case!! LOL!

Should be a heck of a CAT to play with.
Regards
 
JasonYuke said:
Thank you all for responding to my first post on the 375 Epstein, the truth of the matter not alot is known about this rifle cartridge but I was given the Artical and book by BIG MIKE'S EPSTEIN, founder of the 375 Epstein



I have suggested a load that some had said too much however the skinny on the epstein is a fat widened neck mad from a 375 H&H case, or a 338 case does infact out perform the H&H by a landslide and almost ( buy 30 fps) performs to velocities close to the 378 Wby with 25-30% less powder. It realy is an increadible case design. Both showing 5500 FT LBS of energy.
The other remarkable fact of this cartridge case comb accuracey is best with high preasure, Mikes pet load showing 3/4 inch groups with 77g of 4350 at 5537 ftbs and the slower round opened up.

Chrony resulty show a 270 gr slug loaded with 78 g IMR 4350 pushing 3043 fps vs the 378 with 108 gr of 4350 pushing a 270 grain slug at 3078 fps, awesome power.
Mikes original design was to match the H&H velosities, but this case design exceeded all expectations, and beca,me one of the best efficient cartridges in the Magnum family.

So the skinny is its its very close to the 378 with less powder, and less preasure, Their are rummors floating around due to the lack of info on this Epstein Mike never pushed it harder, but there is still room in the case!! LOL!

Should be a heck of a CAT to play with.
Regards
Click to expand...

That's freaking amazing considering that the IMR site lists 78.5 gr of IMR4350 gives 2710 fps and my own crony reading confirm them.

The Epstein appears to be nothing more that a .300 Win Mag necked up to .375. This makes it a .375-338 with a long neck.

The velocities claimed are ridicules.
 
Last edited:
It seems high yes! but The guy I bought the rifle from claims these velocities as well! I will confirm these velocities

Anyway you look at it its a neat cartidge!
its not just a 338 necked up, It is blow out a bit lengthened neck and very small shoulder on it, There is a 3 die step. and the case will hold 80 grains of powder IMR 4350 ( just loaded one with 79.0g) and 270 Nosler.
Will tell the tail at the range,
I just wrote what I read buy the guy who built one.

Do you own one? I would like to learn more about it.
 
Last edited:
there is no free lunch

to think a wildcat based on a H&H case can be loaded to the same speeds as a 378 WBy at sane pressures, is pure BS :)
​
 
LOL! I guess time will tell, I suspect the same don't always believe what you read, but hell its a great artical.
BTW there is a 27" barrel on this particular firearm!!

And I will be more than happy to match the 375H&H performance.
 
Last edited:
I have a 375 Wby with a 27" barrel, and it won't give me those velocities with what I consider safe pressures. The case capacity for the 375 Epstien and the 375 Wby are almost identical (and the Wby has more freebore, to boot), and there is no free lunch. I too have an old article espousing the greatness of this cartridge, and most of the testing was done long before pressure testers were available to the general public. Do as you like, but be careful. - dan
 
I've had a bunch of H&Hs a 375 Ackly and the 378. Get a chrono and test some loads. I think you will be quite surprized. Don't forget you need to be able to reload these cases. The 378 will do 3000+ fps with 300 grs. and is on a different planet than the rest.
 
No worries guys I am excited but not stupid!
I loaded one case tonight to see how much powder it would take and 80g is it max compressed. max HOWEVER !! They are loaded between 72.0 and 75g to start with
HEY if I can = the 375 H&H I am happy.
Got a chrony and I will report the real number to you guys.
cheers
AAfter looking at it in real to real times not 1972 times, Its like the 30-378 reports of huge velocities in now day can only dream of tose velocities, and are 200-220 fps short of the mark.
It is what it is I will post the results.
 
no I hear ya!
Intresting thing is a 338 case will not work! nor the 300 tried it tonight.
You need a 4 step die not a 3 like I said I figured out the die step proccess and need a 375 H&H case to form it, the 338 does not have the lenght and will not work, not making it a 375-338 necked up way different it seems to
push the H&H case down fattens it and lengthens the neck, very little few thous trim, It uses the whole brass! and very sharp short shoulder.
Intresting
 
Wildcatters always make exaggerated and grandiose claims about their creations, when really, they were just loading to extreme pressures (most of them having no way of measuring them). Look at all the wildcats that have been legitimized, then go find some pre-existing load data. In all cases, the velocities achieved by the wildcatters is a lot more than what the factory versions of the same rounds produce. Reason: factories actually measure the pressure! The 22 'varminter' reportedly was able to produce nearly 5000fps, but take a look at any published data for the 22-250 - MUCH lower. Rocky Gibbs' wildcats were the same way. There are anecdotal stories of how shooters would abandon the lanes next to him at the range when he showed up to test his loads

Same idea here. I fully expect you'll be able to beat 375H&H velocities, and maybe even approach 375WBY velocities. But to hit 378wby velocities? Danger, Will Robinson!!! The 378 is loaded quite hot as is, and to match that with a smaller case I wouln't be surprised if you were exceeding 80kpsi, and maybe even pushing 100kpsi (which would not necessarily kB a very strong action on the first, tenth, or even hundredth shot)
 
Well back from the range todaywith the results from the chrony!!

270 gr sp hornady over the chrony measured 2710fps with a helthy dose of powder Imr 4350

I also pushes a 300 grain bullet 2660 with the max dose of IMR 4350
 
Not what Big Mike claimed, but really appreciate your telling it like it is Jason.

Still, it easily duplicates factory 375 H&H, and that certainly isn't bad.

What were the loads?

Ted
 
Well Why not I loaded IMR 4350 76.5g for the 270 and max for the 300, same loads, I left a bit on the table with the 270 but that was max for the 300.
I am guessing that 2750- to 2790s will be it for the 270 with 80.0 grains compressed.

It will not run with a weatherby a friend brought his 378 out and with 109 of RL-19 chronied 2900 fps max load, thats cooking!
 
You must log in or register to reply here.
Back
Top Bottom