7x57mm Mauser Advice Sought

[SammyIamToday]

Hey Folks,

I'm scheduled to fly to Kentucky to visit family November 1st. I'm planning on doing some whitetail hunting on a buddy's farm while I'm there. I've been working up a load in my Ruger No.1 International rifle, but I'm kind of at a crossroads.

I'm using Berger VLD's (mostly because I have boxes and boxes of them from loading my .284 win). Anyways, I've gone with 180gr loads because I had more of those bullets on hand. I've managed to work up a load at 3.120" that groups under an inch with 5 shots if you allow the barrel to cool. I'm more than happy with that for accuracy purposes for whitetail, but it's only chronoing at 2015ish fps using IMR 4350 powder. It's slower than I like, but seems about right from the 20" barrel the No.1 has.

Using the Berger manual, the max charge for that cartridge is 41.4gr, but it is talking about an COAL that's much shorter. So, I guess really the advice I'm looking for boils down to 3 options:

• Try to eek a bit more charge in the current load. I've seen no pressure signs yet at 41.0gr (although accuracy suffers compared to 40.7gr - about 1.5 moa) and I'm seating longer than the book is talking about.
• Be happy with what the round is doing now. Berger says their bullets will expand down to 1800fps and my shots will be inside 150 yards, so that shouldn't be an issue. Whitetail aren't that hard to kill, but I'd still rather do the best I can here.
• Scrub the 180gr load and start with 140gr VLD's. In earlier testing, I had a good load worked up with 140gr VLD's, so it would just be a couple trips of fine tuning. The minimum charge loads here were close to 2300fps, so just going by the book, I can probably build another 2.5gr of powder on that.

Any thoughts on this would be greatly appreciated.

 

[Jim Watson]

Is the Berger data based on SAAMI "do it for the Spanish Mauser" pressures or "modern guns?"
If the former, you could overload it a bit and gain some velocity. But maybe not enough to matter.

I think the 140 gr is the better choice.

 

[SammyIamToday]

Is the Berger data based on SAAMI "do it for the Spanish Mauser" pressures or "modern guns?"
If the former, you could overload it a bit and gain some velocity. But maybe not enough to matter.

I think the 140 gr is the better choice.

I think the loads are probably the weaker Spanish Mauser types, but the book doesn't specify. I found an article on realguns with the same rifle and the guy is loading quite a bit hotter than I am comparing the 140gr loads. Although he didn't do any of the 180gr loadings.

Thanks for the head's up on that, I'll have to do some more reading, but it makes me feel better about increasing the 180gr charge if I go that route.