Morphing the 7x57mm into a 270/308

D

Dogger

New member
A 270 Winchester throws a 130 grain spitzer (Sectional Density .242) at about 3060 fps. A .308 throws a 150 grain spitzer (SD .226) at about 2820 fps. What I am interested in is handloading a 7x57Mauser cartridge with Speer 130 grain Spitzer soft points (sectional density .230). Idea is to approach the velocities of the 270 Winchester with the sectional density of the 308 to make my 7x57 flatter shooting with adequate punch for eastern white tails. Does this make sense? Has anyone done it? What powders do you suggest? Thanks. :)

If this is indeed a good combination, why is it not a factory load in the various 7mm??
 
Dogger. I agree that there is a lack of different factory loads for the 7X57MM, and those are underloaded due to the weaker rifles made at the turn of the century. (19th century that is :) )
Your idea may have some merit, but I wonder if the 130 gr. Speer bullet is constructed heavily enough for deer. I fear it may come unglued as closer range shots. I believe that if I were going that route, I'd use something like the Sierra spitzer flat base, or maybe the Nosler Partion, also 140gr. in weight. While I am no fan of the overpriced premium bullets, the Nosler might be the best bet if a close range shot should present itself.
IMHO, the 7X57 MM is one very underrated cartridge, that can be loaded to it's full potential by a careful reloader.
Try the 130 gr. Speer and do some serious testing with wet newpapers and gallon milk jugs. If the bullet hold together, fine. If not? Go to the heavier bullet.
Paul B.
 
I have been using the 139gr boat tail hornady in my old remington 7x57. I have been using 3031 for powder but load it down a bit as the gun is around 100 years old. It reaches right out and whacks the coyotes at longer range than I expected. This bullet with a top load has more knock down and less drop than a .300 mag 150 factory load at 600yds. I think you are going in the right direction here, that 7x57 is a winner or a round.:):)
 
Dogger. Try the Hornady 139 gr. Interlock. It has proven to be quite accurate in my 7X57's. The Sierra 140 gr. SPFB and SPBT work well, and Nosler's Ballistic tip's (140 gr.) were only fair in my rifles.(I have 3 7X57MM rifles)
Paul B.
 
If you are using the 7mm in a good Mauser 98 action or in a modern Remington action, you can go pretty hot. I don't give handloads on the internet, but with the right powder, you can shove a 130 grain well over 3000 and a 145 grain at 2900+. The 7mm is an excellent all around cartridge; its only drawback in the eyes of many has been the scarcity of good cheap surplus ammo, with the emphasis on cheap.

If you treat it as a sporting caliber, buy new factory loads or new brass, and use good handloads, it is about as good as anything around until you get into the magnum class.

Jim
 
My 7x57 is a new Ruger M77 Mark II. If the rifle is anything like their revolvers I imagine it can handle pretty hot loads?
 
Hi, Dogger,

That rifle is more than strong enough for a souped up 7x57. So is a Winchester Model 70, which I also failed to mention.

If you own any old 7x57 rifles, like an old rolling block or a pre-98 Mauser, make sure you keep the hot cartridges separate from those suitable for the older rifles.

Jim
 
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