280ai

[Brambles]

At the bottom I cut and pasted quick load data I found on another thread............

My rifle is a 23 1/8" long lothar Walther barrel
A 168 hunting vld loaded .006 off the lands is 3.435"
Federal 215 magnum primers

I want to get 2800 fps if I can

I have a good selection of the more common powders H4831sc, RL22, H1000, Retumbo, IMR 4350, IMR 7828 (not ssc)

I figured Retumbo was my best bet..

I loaded 3@63g to play around and a ladder load from 63-66 gr in .3-.4 gr increments...i.e. 63, 63.3, 63.6, 64

What do you think about starting load development .006 off the lands? Might show pressure sooner?

Should I continue the ladder load past 66gr...???....the powder comes half way up the neck at 66 and is crunching a good bit...the boat tail sits below the neck in the case.
........................................................................................................

Cartridge : .280 Ack Imp
Bullet : .284, 168, Berger VLD
Cartridge O.A.L. L6: 3.340 inch or 84.84 mm
Barrel Length : 24.0 inch or 609.6 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 84 50.40 2077 1610 22918 9056 84.9 1.831
-18.0 86 51.66 2135 1701 24415 9449 86.9 1.785
-16.0 88 52.92 2194 1796 26019 9832 88.7 1.739
-14.0 90 54.18 2254 1895 27739 10203 90.4 1.694
-12.0 92 55.44 2314 1998 29582 10560 92.1 1.650
-10.0 95 56.70 2375 2105 31560 10899 93.6 1.606
-08.0 97 57.96 2437 2215 33684 11217 94.9 1.564
-06.0 99 59.22 2499 2330 35968 11513 96.1 1.522
-04.0 101 60.48 2561 2447 38423 11782 97.2 1.476
-02.0 103 61.74 2624 2568 41072 12024 98.1 1.429
+00.0 105 63.00 2686 2691 43927 12236 98.8 1.383
+02.0 107 64.26 2748 2818 47012 12416 99.4 1.339
+04.0 109 65.52 2811 2947 50347 12561 99.8 1.297 ! Near Maximum !
+06.0 111 66.78 2872 3078 53959 12671 100.0 1.255 ! Near Maximum !
+08.0 113 68.04 2934 3211 57878 12745 100.0 1.215 ! Near Maximum !
+10.0 116 69.30 2995 3346 62136 12807 100.0 1.176 !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 105 63.00 2854 3039 54129 11798 100.0 1.261 ! Near Maximum !
Data for burning rate decreased by 10% relative to nominal value:

 

[PGJPJ]

That's kind of the down side of Retumbo, you may end up with a compressed load. I use RL26 in my 280ai, but your powder selection looks great. I think RL22 and IMR7828 would be where I'd look.

0.006" off the lands is fine. But I believe the Berger guys may suggest playing with seating depth before dialing in the charge. They have a suggested method for finding the proper seating depth, I think I saw it here in this site, but certainly on the Berger site.

2800 fps should be no problem! You'll be able to get more than that with the powders you have.

 

[FEENIX]

That's kind of the down side of Retumbo, you may end up with a compressed load. I use RL26 in my 280ai, but your powder selection looks great. I think RL22 and IMR7828 would be where I'd look.

0.006" off the lands is fine. But I believe the Berger guys may suggest playing with seating depth before dialing in the charge. They have a suggested method for finding the proper seating depth, I think I saw it here in this site, but certainly on the Berger site.

2800 fps should be no problem! You'll be able to get more than that with the powders you have.

+1! Also, H4831/SC and VIHT N-165.

 

[reeldawg]

A friend was running 62.5 Retumbo and was in the mid 2800s. It was shooting in the .2s and .3s. He recently tryed RL26, it is shootiing in lower 3000 fps are with hte same accuracy. I think he has a 25 in barrel.

Jay

 

[BEEMAN]

I use H4831SC in my Cooper 280AI. It has a 24" barrel and shoots the 168 classic hunter at 2880 fps. I could get more speed out of it but it shoots really good at this velocity.

 

[Brambles]

So it looks like quick load must be a little conservative with their velocities by the reports you fellas have with your loads. Which is great cause I was having a little doubt I was gonna reach my goal....

Just gonna find some good weather to shoot.

 

[blacktail 8541]

+1! Also, H4831/SC and VIHT N-165.

Both great powders in the 280 AI

 

[cowboy]

I use H4831SC in my Cooper 280AI. It has a 24" barrel and shoots the 168 classic hunter at 2880 fps. I could get more speed out of it but it shoots really good at this velocity.

Sent you a PM - don't want to hijack this thread.