Retumbo 280 AI

[Butte Sink]

Hello All,

I'm looking for some info for the suggested starting and max powder load using Retumbo for my
280 Ackley Improved
Bartlein 29 1/2" barrel with muzzle break
Nosler Brass
FED 215 GM Primers.

I have loaded a lot of H4831SC & RL22 and like what I'm getting. I would like to get a hold of some RL26, hearing good things but that seems impossible at this time.
I have good amount Retumbo and just wanted to see what I could get out of it..

Any info would be great.

Thanks

 

[Dusty Stevens]

I couldnt get retumbo to get right in there. The 4831sc is the way to go

 

[ebb]

They did not list 280 or 280AI in their rifle data but from the looks of similar size cases, and my success with it VV165 looks like a good one to try.

 

[ebb]

hybrid 100v looks good in the 280AI also

 

[DaveTooley]

Try long forgotten 7828.

 

[Bindi2]

I couldnt get retumbo to get right in there.

I use a drop tube to get to my load.

 

[LA50SHOOTER]

Try long forgotten 7828.

+1
58.0 gr. with the 180 gr. Berger VLD 0.003 into the lands on a 30" Benchmark BBL.

 

[muleman69]

Have been messing with primers and powder for a week ,h414,h4350,4831sc and ended up going with straight IMR 4831 and 215 primers. 3192 average with 131 hammers. ES 10 and SD 2.6. Have not tried Retumbo or Hybrid 100 v but from what I have read folks are having good luck with both.

 

[Butte Sink]

Thanks all for getting back
I too have heard some good stuff coming with guys trying Retumbo, just would feel a little more comfortable with proven data before jumping in, thinking about bitting the bullet and splurging into QuickLOADS, just to have for later on down the road
The H4831 SC has been real good along with the 22

 

[L.Sherm]

If you have had good luck with RL22, I think RL23 is even better.

 

[DHuffman]

I've got an older 700 with a Shilen barrel. It shot a lot of the above mentioned powders alright but really tightened up with IMR 4831

 

[Dusty Stevens]

I use a drop tube to get to my load.

No problem getting powder in it, it was the getting it to shoot good was the issue

 

[Zero333]

Thanks all for getting back
I too have heard some good stuff coming with guys trying Retumbo, just would feel a little more comfortable with proven data before jumping in, thinking about bitting the bullet and splurging into QuickLOADS, just to have for later on down the road
The H4831 SC has been real good along with the 22

The only way it would make sense to use Retumbo in the 280ai is with heavy bullets seated far out to make more space for powder.

here is the QL prediction. Note the longer COAL with the 180 Hybs.
Even tho QL shows 59,490 PSI with 68.34 gr of Retumbo, I predict you will start getting pressure signs in that area because every time I load Retumbo with a heavily compressed load it spikes up in pressure faster than predicted.

Line in bold is what I assume the max might be.
In reality you don't know till you test.

====================================

Cartridge : .280 Ack Imp
Bullet : .284, 180, Berger Hybrid #28407
Useable Case Capaci: 66.587 grain H2O = 4.323 cm³
Cartridge O.A.L. L6: 3.570" inch = 90.68 mm
Barrel Length : 26.0 inch = 660.4 mm
Powder : Hodgdon Retumbo

Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-20.0 87 53.60 2257 2037 27660 9728 93.8 1.821
-18.0 89 54.94 2319 2150 29588 10042 95.2 1.771
-16.0 91 56.28 2382 2267 31661 10334 96.4 1.723
-14.0 93 57.62 2444 2388 33893 10601 97.5 1.676
-12.0 96 58.96 2507 2511 36294 10840 98.4 1.629
-10.0 98 60.30 2569 2638 38883 11050 99.1 1.579
-08.0 100 61.64 2631 2767 41678 11228 99.6 1.527
-06.0 102 62.98 2693 2898 44695 11372 99.9 1.477
-04.0 104 64.32 2754 3031 47958 11482 100.0 1.429
-02.0 106 65.66 2815 3166 51494 11568 100.0 1.382
+00.0 109 67.00 2875 3303 55327 11648 100.0 1.338 ! Near Maximum !
+02.0 111 68.34 2934 3441 59490 11725 100.0 1.294 ! Near Maximum !
+04.0 113 69.68 2993 3581 64016 11797 100.0 1.253 ! Near Maximum !
+06.0 115 71.02 3052 3722 68960 11864 100.0 1.212 !DANGEROUS LOAD-DO NOT USE!

 

[Butte Sink]

Thanks Zero for the info
I’ll give it a shot and see how it turns out

 

[Zero333]

You're welcome.

If possible keep us updated after testing.

Good luck, be safe, and most importantly HAVE FUN !

 

[jdlouie]

Reloader 26 is the powder for 280 & 280AI.

 

[muleman69]

Reloader 26 is the powder for 280 & 280AI.

Like to try some but can't find any

 

[L.Sherm]

Like to try some but can't find any

Try some 23, I couldn't get rid of a flyer with 26.

 

[SeabeeKen]

I tried a number of powders in the 280AI and the best were RL-22 and H-4831SC with midrange bullet weights. .25" groups. I didnt test the heavy bullets.

 

[Bindi2]

Don't compress Retumbo and use Magnum primers. Compression creates pressure very quickly.