What gives Reloader 26!?

[HighDesertSage]

So I spent all summer getting my 7mm rem mag dialed in with a 160 Accubond. Settled on a load with RE 26 as I was very happy with the accuracy. I was getting a muzzle velocity of 2950 FPS, which I was also happy with. After going through a few one pounders of the stuff, I finally invested in an 8 lb jug, which I figured would last a while. I've gone out 3 times now, and I am consistently getting 2850 FPS,100 FPS slower than what I had been previously loading. What gives? I haven't changed anything else except the new powder. Is that much variations between lots to be expected? Any thoughts would be appreciated. Thanks guys.

 

[MT_Chad]

Reloader powders are really temp sensitive. I only shoot the Hodgdon extreme and imr enduron powders because they are temp stable.

 

[MThuntr]

lot to lot variability also nothing new...work up a new load with this lot of powder and continue on. 100fps won't affect much

 

[cahunter805]

Like stated load a few test loads higher and get back into your velocity node. How was it grouping?

 

[HighDesertSage]

Thanks for the feedback. The reloader 26 was supposedly going to fix the temp sensitivity issue. Hunts are coming up fast so I'm not super stoked on on trying to rework a load. But I'll give it a go. It was grouping excellent, sub moa, and it still groups excellent even at the lower speed. I have a few weekends left still. I will try laddering up. Thanks.

 

[p_ham]

If it's still grouping well I don't think I'd mess with it.

 

[cahunter805]

I’d load some 3-4shot groups working up by .5gr. I bet it comes back together within 1.5gr. Also like stated 2850 with a 160 isn’t terrible speed.
Good luck.

 

[Millsworks]

Doubtful that "temp sensitivity" is a factor in the velocity difference. The R 26 isn't considered one of the temp sensitive formulas.
Lot to lot can sure cause velocity changes, and usually does in any brand.

 

[belly-deep]

It’s just a slightly slower lot of powder. Keep adding until you get back to your original velocities.

Of course, some people deny lot to lot variation and think you don’t need to load starting loads.

 

[std7mag]

Yup, sounds like a slow lot.
The only powder i've really heard people having issues with temp stability is RL17.
And really only affects target shooters at long distance.
Did workups at 80 degrees, shot deer at 18 degrees. Hit on deer was maybe 1" below aim at 400 yards.

 

[HighDesertSage]

Alright, I have a little time to mess with it. I will see if I can get it up a bit and still maintain sub moa

 

[PsRpOiGrRiAtM]

Reloder 26 is still a temp sensitive powder--it just has more uniformity and a more consistent increase/decrease as temperature changes, so people know what to expect. That, however, is likely not the cause of the velocity change. Lot to lot variation happens with all powder, and something that people have been complaining about with Alliant powders for as long as I can remember.

You should be able to bump it a couple grains in .5gr increments and get back up to where you were. Good luck to you!

 

[Dan O]

When you load near max and get a new lot of powder it's a good idea to back off a bit to see if the new lot is hotter than what you were using.

Dan

 

[mrjashu]

I agree that it's most likely due to powder lot variation but have you ruled out chronograph variation by validated the velocity at distance as well?

 

[Rifles And More]

What chronograph are you using?

Is POA and POI the same?

Still groups good?

What is your ES for the load?

 

[HighDesertSage]

Is POA and POI the same?

Still groups good?

What is your ES for the load?

Magneto Speed, 1/2 MOA POI shift, groups still sub MOA. What does ES mean.

 

[antelopedundee]

Magneto Speed, 1/2 MOA POI shift, groups still sub MOA. What does ES mean.

ES = Extreme Spread?

 

[MThuntr]

ES is Extreme Spread...suggest less variation between shots = more accuracy
Standard Deviation (SD) is better indicator of consistency/uniformity for shooting = how far the velocities deviate from the mean. SD is the square root of the variation of each velocity from the mean. My statistics is a bit rusty so I could be off in trying to describe this. Lower number should correlate to more accuracy as it removes a variable effecting bullet flight. In hunting rounds having an SD in the 20s is ok...teens is real good...striving for single digits enters in match shooting and borders on OCD.

 

[VikingsGuy]

ES is Extreme Spread...suggest less variation between shots = more accuracy
Standard Deviation (SD) is better indicator of consistency/uniformity for shooting = how far the velocities deviate from the mean. SD is the square root of the variation of each velocity from the mean. My statistics is a bit rusty so I could be off in trying to describe this. Lower number should correlate to more accuracy as it removes a variable effecting bullet flight. In hunting rounds having an SD in the 20s is ok...teens is real good...striving for single digits enters in match shooting and borders on OCD.

I read the following in a book/article by a hand loading guru:

20+SD is a poor hand load but not uncommon with factory loads
15 fps SD is very good factory load
10 fps SD is a very good hand load
<5 fps SD is world class hand load

FWIW, my first two hand loading efforts ended up 9 & 11 respectively over 10 rounds (my goal was to be under 12). The Barnes VorTX factory I used for comparison was between 15-26.

 

[Rifles And More]

I thought if your extreme spread was pretty high anyway...

Sounds like a new batch of powder. I would probably live with the new normal.

Be sure to gather data every range session and keep good records. It will pan out in the long-run.