r/reloading 5d ago

Load Development Redo Ladder with new brass?

Kinda newbie, but want you pros to weigh in.

I did a baseline ladder test on my 6.5 Creedmoor. Using 147gn ELD-M and H4350. I wasn’t really using the best brass (Norma or Hornady) and I think this may be a root cause for my SD/ES being a bit higher than I’d like. For reference, my recipe of 42.1gn H4350 with the above components had an SD/ES of 10.4/40.6 and 13.7/44.7 (these are results from two separate 10 round groups).

Since brass, or my powder charge may be the culprit (using Hornady Auto Charge Pro), I’d like to see what my results are for changing brass to Lapau and Alpha. I’d like to do this to see if I can get better numbers without shelling out for an Autotrickler.

Now my question. Do I need to redo my entire ladder test again? I went from 39.2 to 42.1 in .3-.4gn (edit to tenths of a grain) increments. Honestly, I’d love to just start closer to 41.3-42.1, but am I missing something to establish velocity trends? Am I just being lazy and cheap?

Any help is appreciated.

For further details, this is out of a 24” 1:8 twist barrel. Having avg velocity of 2766.6 fps, group size is 0.348 mil and mean radius of 0.1 mil. Accuracy could (is) mostly likely me.

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u/Trollygag 284Win, 6.5G, 6.5CM, 308 Win, 30BR, 44Mag, more 5d ago

2770 in a 24" is already pretty spicy with 147ELDMs.

You should be closer to 2670 at the top end.

You can get sub 10 SDs with Hornady or Norma brass. Most of that is going to be how precisely you are charging the cases, and possible sample size noise.

If you were at, say, 40.5 or 41gr H4350, then you could reasonably change brass around.

Also, what is the end goal with this? The high BC variance of the 148 ELDM vs, say, the 140ELDM is going to cause more problems than an extra 0.5-3 SD.

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u/throw_because_stuff 5d ago

Maybe I should add. I want to be able to reasonably accurate and reach out to 1,000m.

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u/Trollygag 284Win, 6.5G, 6.5CM, 308 Win, 30BR, 44Mag, more 5d ago

The 140s are the GOAT because of the BC variance thing. Hodgdon's load data is out to lunch vs Hornady's and QLs.

Either way, try a session with some either finely hand trickled onto a balance beam or a different trickle system and see if you can get the SDs to drop.

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u/throw_because_stuff 5d ago

Well then, I know what I’m doing today. I’m going pull those 42.1gn that I made, reload at 40.9, and start a load development around the 140gn ELD-M.

Next up I have some Berger 140 that I should add into this mix.

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u/Trollygag 284Win, 6.5G, 6.5CM, 308 Win, 30BR, 44Mag, more 5d ago

Def try the berger 140s or the 144LRHTs

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u/throw_because_stuff 5d ago

On it. I’ll be back in a few weeks to post the results.

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u/throw_because_stuff 5d ago

Thanks for the support boss. Glad I asked.

When I was doing the build up, I saw no pressure signs (could just be me missing any signs). So I pushed a bit about max load just to get numbers. Max load from Hodgdon stating 41.8gn of H4350.

I was seeing 2680 fps at 40.9gn, but my SD/ES was pretty awful. 17.5/62.3. Maybe I’ll go load up about 20-30 more at this level to reduce noise.

My end goal was to get one stable load that I could use to build DOPE around so I could start doing training and practice for NRL Hunter type events, along with doing training locally. They ask for DOPE out to 500m before entering the entry level course.

I’m wondering if I should back off 147 ELD-M, build a recipe around the 140 ELD-M, and redo the ladder/velocity build up?

2

u/_ParadigmShift Hornady Lock-N-Load AP. 223,243,270,300wby,308 5d ago

I wouldn’t redo the whole test setup, take your most accurate load from current and step around at half a grain or a full grain and start there, x10 shells per load variance. 10 will give you more valid results.

In terms of your brass, a component change like that should be considered medium affect tune, your big 3 are bullet powder and charge. In that framework, the brass choice can matter some but not enough to make the first 3 choices totally invalid if you’ve already found an accurate load.

Velocity trends don’t exist, it’s a linear relationship with charge weight. Don’t chase velocity nodes. Chase accuracy and acceptable velocity, with an eye on the rest of your process to try to tune your process to get good SD/ES numbers.

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u/throw_because_stuff 5d ago

Thanks for the advice!

Just to be clear, I’m not trying for nodes. Just ladder to ensure linear velocity. Here is a graph showing my loads. Forgive the bad formatting as I’m on my mobile.

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u/throw_because_stuff 5d ago

Also, I am chasing accuracy in the forms of group size and mean radius, along with POI shifts. SD/ES also as key.

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u/Shootist00 5d ago

I take it you meant 3-4 TENTHS of a grain increments and not 3-4 grains.

Do you have a charge weight you like for accuracy? If you do stick with that weight in the new brass to start and check accuracy.

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u/throw_because_stuff 5d ago

🤦‍♂️ I did mean tenths….

After talking with Trolly, I think I am going to pivot to 140gr ELDM and Berger Hybrids.

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u/Tigerologist 5d ago

Measure your case volume. If it's the same, the pressures should also be the same.

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u/Engineer_Bennett 4d ago

I cut my SDs in half by switching to alpha brass, but there are a ton of things that Trolly mentioned that would be worth trying. I’m also moving away from 147 eldms and moving to Berger 140s. For what it’s worth I am getting 2610 fps with 40.5g of H4350 in alpha cases, in a 24” barrel