First ladder in working up a load for one of my 7x57's (actually labeled 275 Rigby) using some old Hornady 154gr Spire Points, IMR-4350, CCI 200 primers, and PPU brass. Not sure when I'll actually get this out to the range, but hopefully soon.
These loads come from a 1970's era Hornady loading manual, which I like to refer to as "pre-lawyer". ;-) But I agree with your concern and will work my way up slowly, looking for signs of pressure along the way. The good news is this is a somewhat more modern rifle than an old surplus Mauser, so should be able to handle a hotter charge better; but at the end of the day, I'm more interested in accuracy than seeing how fast I can push it.Some of your loads seem to be a bit warm based on published data. I would be very cautious about the last couple of loads.
Thanks, and that is probably my next step after I get an idea of what general charge weights it likes from an accuracy perspective.Hi,
This bullet is one of my favorites in my 7x57. I load and use it since 1975, pre Interlock then.
In a standard 7mm Mauser barrel, the 154 Hornady Spire Point can be loaded, with any of the 4350's, at least to 2700 f/s muzzle velocity with entirely safe pressures. Of course in a modern rifle in good shape with 22" barrel lenght or more.
I would aim to reach that velocity instead to focus on specific 4350 charge weights.
Good luck!
These loads come from a 1970's era Hornady loading manual, which I like to refer to as "pre-lawyer". ;-) But I agree with your concern and will work my way up slowly, looking for signs of pressure along the way. The good news is this is a somewhat more modern rifle than an old surplus Mauser, so should be able to handle a hotter charge better; but at the end of the day, I'm more interested in accuracy than seeing how fast I can push it.
Wow, that seems like a big difference. I would have guessed only a few grains difference.
I'll have to check my old Hornady manual when i get back home in a few days, but I want to think that one has something like 50.3 grains of IMR 4350 listed as max load for this bullet.Cash, I don't consider myself an experienced enough handloader to really offer an opinion. Have we become that litigious as a society? Possibly a reformulation of the powder since your manual was published? Others have mentioned safely pushing a 154gr bullet to 2700+ fps. The max 43.4gr load shows as only running at 2400fps in my manual.
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Great insight, and I agree. All of the reloading I'm doing is using the equipment and components that my Dad left behind, so it is mostly "vintage" (but still in great condition).I have been going back to "old school" reloading lately. By that I mean using classic bullets at modest velocities. In the 275 Rigby, I have been playing with Rem CL 150gr and 175gr and Hornady 154gr and 175gr RNSP. I have the 150/154 bullets at just over 2500fps and the 175 bullets at 2400fps. The loads are sub-MOA. I have found these bullets preform a bit better (meaning hold together and penetrate better) when they are pushed at more moderate velocities.
One thing I have noticed in a lot of the 7x57 data is they often use WW cases which have more space than any others. Fed and R-P cases are around 20gr heavier.
In the 30-06, I am loading the Hornady RNSP also at around 2400fps.
As part of this "getting back to basics" venture, we plan to use the Rigby's and their bolt peep sights as much as possible. I think these loads will be great for game here in the Texoma area.
Safe shooting
From what I understand, the current data is developed using piezo pressure measurements rather than the older copper crusher measurements. This is a more accurate method and has led to reduced maximum powder charges.Current Hornady manual shows 43.4gr of IMR-4350 as max. Damn lawyers are always spoiling folks' fun.