Recommended Manual for 7mm RM?

[DJL2]

I just noticed that my current manual doesn't have RL23 at all and has quite a few loads listed providing stout 7mm-08 performance. I've sourced data for IMR 4955 and H4831 on-line, but Alliant only seems to list a handful of recipes...figured it might be nice to ask before heading off into the blue. I did see someone from Berger chime in on LRH with load data for 169 VLD and RL23...so, better than nothing to go on.

Yes, I know I should have H1000 around somewhere... I'm making do with what I have and hopefully finding something the rifle likes before buying even more powder.

 

[Steel head]

Sierra and Speer data is pretty easy to find with a quick internet search.

 

[DJL2]

Thanks - hadn't considered them because I wasn't running their projos...obvious oversight.

 

[Steel head]

168-170 data for any standard type of bullet is a good start regardless of manufacturers.
Just pick a safe start point and work up.

 

[Jordanwickham]

My manuals dont have RL23 and I've never used RL23 in my 7mm RM but I did find this on my Sierra App. Should be able to make your own choices from there.
Don't go crazy but these numbers are a little conservative from my 7mm RM experience. Modern Reloading by Richard Lee is a pretty non conservative load manual but it also doesn't have RL23. I would start a couple grains below what these pages show but you should be able to go a few grains past these numbers.

 

[DJL2]

Thanks, gents. I have taken to referencing the SAAMI pressure and velocity specifications as a starting point just to frame understanding of a caliber. Between SAAMI and what I see from factory loads, many manuals do seem conservative.

 

[Jordanwickham]

Thanks, gents. I have taken to referencing the SAAMI pressure and velocity specifications as a starting point just to frame understanding of a caliber. Between SAAMI and what I see from factory loads, many manuals do seem conservative.

I have a Lyman, Richard Lee, and a Hornady manual of those Hornady is laughably low ( on the cartridges I load and my brass specs). But their max load is close to a start load in my experience. Thinking about it that kind of makes sense in a liability stand point since everyone knows who Hornady is but you would most likely only know Lyman and Richard Lee if you were already reloading.

 

[TheBoctor]

I know it's probably not recommended but when I've used powder/bullet combos that aren't listed in manuals, I find a load in a manual that has both powders listed and calculate a percentage and back off a couple grains and start working up. Say i want to use RL26 with a 195gr but it's not listed, but it does list retumbo. Find a load for another bullet (we'll call it a 180gr) that lists both retumbo and RL26, book says starting load for a 180gr w/ RL26 is 95% of the charge weight for retumbo. Find the 195gr Retumbo starting weight, calculate 95% of it, back it off a grain or two for fudge factor, and now you at least have a starting point for a ladder test. Just take nice small .2-.3gr steps as you work up and keep a close eye out for pressure signs.

DISCLAIMER- This is just an example with made up numbers. Do not reference any of the above for actual load data. Although this process is logical to me and I use it frequently, it deviates from book data and, as such, should be used at your own risk.

 

[DJL2]

Well, on the bright side, 162 SST runs safely up to 67 gn of RL23 and 66 gn of H4831sc in my rifle @ 3.230" (more conservative than the 168 data, but over the 160 data by a smidge). I need to get chrono data to compare and see if I can find a node in there (or push higher)...don't have a range close at hand with meaningful distance and 300 yds just isn't enough. I've got one ladder of 162 AMax prepped w/ RL23, need to do one for 168 Matrix...

I suppose I can burn some more factory stuff up to get a larger pool of brass to work with. Might be pennywise and pound foolish to run Hornady simply because I can buy loaded factory ammo for the cost just ADG brass...

 

[Jabot]

I got to 69.9 grn of retumbo
And 68.9 h1000
On my 7mm with a 175 grn bullet was the best numbers

 

[DJL2]

Gnnn...is there an emoji for when you accidentally delete your MSv3 chrono data? I put every shot into Sheets today as it happened...slows me down, which is good, and hopefully avoids this issue in the future. Super pissed at myself.

As best I recall, since that's what I have to go on right now, there seems to be a velocity node around 2900 fps in my T3x for the 168 Matrix...loaded all the way to 67 grains (versus 66 w/ the SST) of H4831sc. That was right at the top though. Today some old AMax up to 67 grains of RL23:

RL23	162 Amax	3.3 COL
64.3	64.6	64.9	65.2	65.5	65.8	66.1	66.4	66.7	67
2862	2898	2903	2915	2921	2937	2933	2967	2984	3011

I think I'll load a bit higher and see if I can't find a node just above 67 grains. The 2900 fps was broader to my recollection with the H4831sc.

I also grabbed up some .30-06 data today...my data are generally telling me I need a new powder scale, I think.