Ladder test 26 nosler

[6.5notcreedmore]

I have a browning x built in 26 nosler that I’ve been developing a load for. I ran a ladder test the other day and I’m trying to make sense of my data. I would love to hear some outside input. 2 shots per powder charge. 140 gr nosler ballistic tip. 2.575 trim. 2.7925 cbto. 3.3175 coal. Federal gold medal large rifle magnum primer. US 869 powder.

84 gr 3332 - 3319
84.1 gr 3324 - 3340
84.2 gr 3330 - 3350
84.3 gr 3345 - 3343
84.4 gr 3350 - 3339
84.5 gr 3369 - 3338
84.6 gr 3317 - 3297

Obviously my next step is to load 10 rds with 84.3 gr and shoot for groups but I’m curious why the step drop in velo from 84.5 to 84.6.

Side note barrel was clean before shooting with 1 fouling round before collecting data.


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[ckleeves]

In a cartridge with that much capacity doing .1 grain changes is pointless. IMO there isn’t really any meaningful data really there so I wouldn’t overthink it. If you load that 84.3 it’s not going to have a ES of 2 fps again, when on both sides with only a .1 grain difference there is 11 and 20 which aren’t bad at all. Load 10, chrono them and see what the group looks like.

How did the group from those 14 look?

 

[6.5notcreedmore]

I was making some adjustment’s to my scope while I was shooting over the chrono. I wasn’t trying to shoot groups this time.


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[A382DWDZQ]

Depends on your goal. If 84-84.5 is the charge you are looking for, then I would just pick one of those and see how it shoots. Otherwise, keep going up in 0.5 increments until you hit pressure. You’ve only got about 10% of the posted charge weights reflected and as is already mentioned, sample sizes are too small do to rely on.

 

[6.5notcreedmore]

My goal is long range accuracy. I’m thinking that if I up my powder charge way up there I’m going to start to get excessive fouling. I’m already pretty dirty after 20 rounds.


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[wind gypsy]

Unless you're using a high end scale, it probably doesn't even resolve accurately to 0.1 grain so to think 2 shots at a given charge weight is really tellin you something is misleading. The only thing your data tells you is what velocities to expect with that charge weight. Pick one and shoot it.

Especially with something as obscenely overbore as the 26 nosler, i'd subscribe to the general idea of @Formidilosus "painless load development" method. Pick good components, load using solid practices, shoot it. If it's not accurate, change a component. If it shoots relatively accurately, dont waste more time with load dev.

 

[6.5notcreedmore]

To add a little clarity. I chose to load 10 rounds at 84.3 gr because I had the most consistent velo from 84.2 to 84.4 not because I managed almost the same velo between two shots of 84.3.


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[JF_Idaho]

What kind of scale and brass prep are you doing?

Those velocities are all over the place. I don't think there's any statistical value from the session.

And for sure step up to atleast half grain steps, maybe more. At over 80 grains a tenth is ridiculous.

I usually even run 3 tenths steps for a .223 when the overall is low to mid 20 grains.

 

[6.5notcreedmore]

Okay… I measure my powder charge with a rcbs charge master light and I verify with a hornady pocket scale, if the don’t measure the same I dump the load back into the charge master and throw another load. I feel like maybe I’m not getting exactly the load I think I am but that all of my loads are very consistently charged. For my case prep I full length size with whidden gunworks bushing die and I shoulder bump .003 and then I trim to 2.575 and I am using federal gm 215m primers. I am on my 4th firing on this brass. Currently I am not in possession of an annealer. When I get one I will start over with new brass and will anneal after each firing.


Perhaps I could perform another ladder test and up my charges by .5 gr increments but I am already way above the velocity predicted in the loading manuals.


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[JF_Idaho]

You don't have to up them if you're comfortable at the velocity you've achieved as long as you're good on pressure signs (flattened primers, stiff bolt/ejection) you could go up a bit more.

I'm not familiar enough with the 26 nosler to say what peak velocities should be.

Neither of those scales would I trust to be too accurate. Maybe 1/10th of a grain on their very best day. Your brass prep sounds pretty good.

 

[Mike D Texas]

Is this using new brass?


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[6.5notcreedmore]

I am currently on my 4th firing. Prime pockets are still tight


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[6.5notcreedmore]

While I appreciate what you are saying, I would like to point out that the advertised accuracy for the chargemaster lite is +/- .1gr. I should be able to reliably load 84.3 gr if all I am really hoping for is something that is more than 84.2 and less than 84.4.


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[ckleeves]

US869 is temp sensitive enough I won’t mess with it but it does give good velocity. It can get a little squirrelly if you’re loading near the top and shooting in warm temps.

If it groups good with that 84.3 I don’t know how keen I would be on pushing much higher with the velocity it’s giving. Shoot a few progressively warmed up rounds and make sure when the weather gets hot you won’t be getting into the danger zone if your going to be hunting/shooting in hot weather.

If the groups aren’t to your liking I think I would try N570, it’s hell on throats but with a 26 Nos everything is so I wouldn’t worry about it. StaBall HD might be worth trying also, it’s been available and seems pretty stabile in the little bit I have played with it.

 

[DakotaBPNW]

Just call it 84 grains and shoot it. Don’t bother with too much screwing around with your 26, it likes to eat brass and barrels

 

[6.5notcreedmore]

It’s a browning x bolt I am more than likely only getting one barrel on this action so I would like to develop something that works well before I pull my scope and scrap the rest of it. My next rifle will be something a little less wild on a more modular platform.


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[JF_Idaho]

I know. Don't get me wrong, I own a chargemaster light. It's usable for sure and with an 80 grain load 1/10-2/10 should not make much difference.

That's more my point though. You take those 7 loads that you posted and with that error that you just alluded to .18 grains (one being .09 high or .09 low) you've really only covered 2 loads because the spread in your weights are in the margin of error both ways.

More was just about stepping up to .5 or more increments.

 

[wind gypsy]

If the 10 you loaded at 84.3 shoot into a group that's less than 1.5 MOA, i'd just call it good and proceed on.

Also, if you get an annealer, no reason to start with new brass. I'd keep rollin with what you got.

 

[6.5notcreedmore]

1.5 moa isn’t going to very good at distance. I’ve got other guns that are just for plinking. I want a gun that will reach out and touch something. I should have done more research before buying this gun, I think I would have gone with something like a .260 Remington or maybe even 6.5x47. I do agree with everyone who says the 26 nosler is just way too much over bore.


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[ResearchinStuff]

You're on a path to torching the barrel during load development. Here's a way to actually get something more than range time from that tube:

1. Painless load development: https://rokslide.com/forums/threads/painless-load-development-mine.238400/

2. Understand statistical validity and group size repeatability:

3. Understand weapon engagement zone and how baseline accuracy impacts it:
Post in thread 'Why Match/Target Bullets For Hunting' https://rokslide.com/forums/threads/why-match-target-bullets-for-hunting.203770/post-1976374