Loading for the 280 Ackley...

60 grains of Reloder 26 under a 160 AccuBond fired at 85 degrees... Nice round primer edges, easy extraction....

After Ba adjustment (.368)... QuickLoad says 58,764 psi.

 
61 grains of RL26....3,017 fps
ES....34
SD....17

10 rounds

That's the warm weather max... Now if it holds true to what Alliant says, and only loses .5 fps/degree....I'll be flying.

May try magnum primers to lower ES...
 
Reloder 26 isn't anywhere near as slow burning as QuickLoad says it is... It is REALLY close to RL22 and MRP....Really close.

Something else I noticed, when using RL26... The barrel gets warmer at the muzzle end than it does at the chamber end.... much warmer.

That said... RL26 is a cooler burning powder than MRP/RL22...Takes at least 2 rounds to get the barrel warm enough to feel it.
 
Some Reloder 26 info...

Its a very dense powder...61 grains in a 280 Ackley case is only ~95% load density...I could easily get at least another 4-5 grains in there under a 160 AccuBond...so, no worries about highly compressed loads.

The grain size, shape, and color looks a lot like MRP...but 26 does have slightly larger grains...but not by much.

It has a very different odor than traditional powders...

Reloder 26 is produced for Alliant by Nitrochemie...it is made with the same basic process as RL17, RL33 and RL50...called "Extruded-Impregnated"...means it is extruded then impregnated with nitroglycerin (EI technology)....just a few years ago EI was cutting edge military technology, now that they have moved on to ECL technology, EI has been released to the public.

Being that they are made by Nitrochemie...these powders (17, 26, 33, and 50) are NOT the same as any of the other Reloder series powders, the rest are made by Bofors in Sweden using completely different techniques and technology.

All that is to say...there IS a difference between these new powders and the old stuff.

Some interesting technical reading on these new powder manufacturing processes...

http://www.dtic.mil/ndia/2002gun/ryr.pdf

How Alliant got their hands on the technology...
http://www.prnewswire.com/news-releases ... 78617.html
 
And most importantly...


Reloder 26 is not completely temp stable...never was meant to be nor was it advertised to be...it will vary with temps, but not near as bad as the older traditional powders.

Most are saying no more than 1 fps per degree...and often less than that...I can live with that.


Reloder 23...IS temp stable, made with TZ technology, it will be every bit as good as any Hodgden Extreme powder ever produced....but I'm predicting its burn speed will be closer to 4831 than RL22.
 
Thanks for the data points! :mrgreen:

I bought 2#'s of RL26 to try in my future 280ai build. Charge density is an important feature to me, I already bought the Redding Comp Seating die, and I don't want to have to worry about compressed loads.

In Oregon, a typical Fall can have 70F to 30F temp ranges (from October to November'ish). So 0.5 to 1.0 fps per degree F would be fine with me.

I'm going to try and run the 168's (Berger, since I can only conclude Nosler has stopped producing 168 7mm all together :roll: ). The 160 AB however looks very nice! Those seem to have dried up on the shelves as well however. :roll:
 
280 AI 168 ABLR.jpg

I played with RL-26 with the 150 ABLR and was never able to get anything to shoot consistently under .5" in My 280 AI. I knew the gun was capable of much better as I had groups in the .2 and .3 range with the 120 BT, 140 BT with three different powders, 140 AB, and 160 AB. So I switched to the 168 ABLR. I got satisfactory results with both 7828 and RL-26, but the RL-26 edged the 7828 in accuracy and velocity.

I'm not sure what happened with the first shot on the chrony, but this is the best group I have ever got out of this rifle. I just finished up some load work for my father in laws 270 WSM (150 ABLR 62.5 gr RL-23 @ 3005 fps shooting .5" all day long), and I have a little more work to do with my light 6.5 SAUM and the 142 ABLR then I'll pick up the 280 AI again and confirm this load again and do some temp tests.

My 280 AI isn't the prettiest thing is my safe by far, but it sure shoots good and has one heck of a list of dead critters to its name!
 
More temperature testing...with my new MagnetoSpeed, I have confirmed that 61 grains of RL26 is the safe warm weather max with the 160 AccuBond...I shot through both chrono's, just to see how the old ProChrono Digital stacked up against the MagnetoSpeed....the conditions are, its HOT...94 degrees.

The results are below...and also confirms that for ~$100, the ProChrono isn't a bad chrono at all...not perfect, but usable for the average Joe, if properly setup in the shade.

MagnetoSpeed
3,019
3,022
3,017
3,023
3,018

Average = 3,020, ES = 6, SD = 3
-----------------------------------------------------------------------

ProChrono Digital...15 feet from the muzzle
3,003
3,016
3,003
3,003
3,003

Average = 3,005, ES = 13, SD = 5
 
Dwh7271":10tidw8x said:
Interesting.
You like the new one?
POI shift with it on?
Yes I do....

POI shift is a non issue for me... I only use a chrono to find max and determine ES/SD... I've never shot through a chrono while working on groups.
 
I better say this here....I'm also testing Norma MRP powder in (2) 270's..my wife's and my hunting buddy's...

MRP only went up 1 fps/degree in both 270's with 140 grain bullets...tested at 66 and 94 degrees.

There is some proof in your pudding (and mine) that just because a powder does or does not work in one particular round...that doesn't mean it won't perform downright AWESOME in others.

Good thing too :p I have 6 lbs. of MRP...
 
I emailed Alliant asking if they had any load data for the 280 Ackley or 7mm RSUAM and RL26...if it is of any interest to you...send them an email...the more requests they get the sooner they'll do it.

Lynn,
Alliant has no tested load data for either of these cartridges using the Reloder-26 propellant.
I have forwarded your request onto the engineers, but there is no timetable on when these loads may even be worked up.
Thanks,
Shoot Straight
DuaneVB
CCI/Speer/Alliant
2299 Snake River Ave.
Lewiston, ID
 
Adjusted RL26 Ba, for 94 degrees, in light of a more accurate chrono and a larger sample size of my measured case capacity is .372


Case capacity updated to 73.9 grains (was set at 74)


Dialing in QuickLoad a little more everyday...

Also, I mentioned trying magnum primers to try to lower the ES...the MS chrono changed all that, turns out my ES was all in the old chrono's inefficiencies....rockin on with BR2's.
 
Ridgerunner665":1h4rc447 said:
I better say this here....I'm also testing Norma MRP powder in (2) 270's..my wife's and my hunting buddy's...

MRP only went up 1 fps/degree in both 270's with 140 grain bullets...tested at 66 and 94 degrees.

There is some proof in your pudding (and mine) that just because a powder does or does not work in one particular round...that doesn't mean it won't perform downright AWESOME in others.

Good thing too [emoji14] I have 6 lbs. of MRP...
I like hearing this.

I just bought 2 lbs of MRP to try in my 280...then I read that you had some temp stability issues with it in your AI. Hopefully my results will mirror yours in your 270's.

Thanks for the info.


Sent from my HTC6500LVW using Tapatalk
 
Great thread. I am learning stuff from this group all the time.

Lynn, please provide the e-mail address for DuaneVB at ATK and I'll send him a note per your suggestion.

What does "full caliber" mean in the presentations you provided links to?

For those looking for 168 ABLR. Bruno' had two boxes on the shelf when I was there last week. Call them as they may still be there even though their web site says they are on backorder. Their inventory control system isn't that great.

http://www.brunoshooters.com/category/nosler_accubond_lr_7.html
 
To contact Alliant... http://www.alliantpowder.com/questions/default.aspx

Full caliber means the projectile fills the full diameter of the bore.... An example of a sub-caliber round are the old Remington Accelerator rounds.. .22 caliber bullets in .30 caliber sabots.

In military usage.... Sub- caliber rounds are flechette and penetrator type rounds (tank shells)
 
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