Transitioning a load from new brass to fired brass

[NYDAN]

I am in a situation I have never been in before. I found a good load with new brass. See the targets below.







The first target was shot with 61.0 gr. of RL-26 and produced an average velocity of 3105 fps. The second target shot the same day with 62.0 gr. of RL-26 produced an average velocity of 3171 fps. The third target was shot about three weeks later with 61.5 gr. of RL-26 averaging 3151 fps. All three groups were less than an inch when using new brass.

I have never had such good groups with new brass. Usually, I get better groups and more velocity with fired and partially full length resized brass. (Bumping the shoulder back .001" to .002".) I have seen from 30 fps to 70 fps differences in velocity from new brass to fired brass.

I think my approach would be to load up rounds with 59.0, 59.5, 60.0, 60.5, and 61.0 gr. of powder to see what charge I need to get about 3150 fps with fired brass. Then load up about 4 rounds at the charge that produces about 3150 fps and test fire those for a group.

Is that the approach others would take?

Dan

 

[JD338]

Dan,
I would just reshoot the 61.0, 61.5 and 62.0 grain loads in the fire formed cases. Pick the best load and then work with your seating depth.

JD338

 

[DrMike]

Dan,
I would just reshoot the 61.0, 61.5 and 62.0 grain loads in the fire formed cases. Pick the best load and then work with your seating depth.

JD338

Excellent advice. It is essentially what I would do.

 

[NYDAN]

Maybe I am overthinking it. My concern was that Speer reloading information shows their top load of RL-26 with 130 gr. bullets at 60.3 gr. with a velocity of 3171 fps. My load at 62.0 gr. was achieving that velocity with new brass and I was concerned that I might go over pressure with fired brass. That was why I was thinking of dropping back on the charge a bit.

Dan

 

[Elkman]

Maybe I am overthinking it.

Yes you are, and you already have great advice. Will be waiting to see how your next groups go.

 

[JD338]

Maybe I am overthinking it.

Yes you are, and you already have great advice. Will be waiting to see how your next groups go.

+1
Keep in mind that the reloading guides are based on their test parameters. Every rifle is different, as is each lot of powder. Working up carefully is good. I believe you have a safe load already established for your rifle so you should be set. You could also load just 3 rounds at 62.0 grs in fire formed cases and confirm the load. Watch for sticky bolt lift, ejector marks on the case and flattened primers.

JD338

 

[mjcmichigan]

Agreeing with Jim and others. Given variability in new brass vs fired... it’s going to be better behaved shot to shot.
It appears you found a good nose, given the consistency your group produced. You’ll know on the first shot if the second or third will give you any pressure signs.

I think you’re good.


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[NYDAN]

Thanks, guys. I really appreciate all of your thoughts and reassurances. It will be a while before I can shoot again.

Dan

 

[truck driver]

Dan you have received great advise from the experts here and there isn't much if anything to add except Though the groups look good I don't look to repeat the same findings with once fired brass since the parameters has changed and virtually can't be repeated out side of a laboratory with new brass. I look for improved groups with once fired since every piece should have the same dimensions.
As for excessive pressure remember you are going by a Lawyer based liability publication and is only a guide to get you started.
If you think there is a problem with pressure change the primer and go with a standard primer instead of the magnum primer. You will be surprised at the results.