Hybrid 100v and the 280 Ackley Imp?

[TOM H]

UPDATE! well i have had some time and have been shooting my new 280ai and have had some questions. I have loaded retumbo, h4831sc and hybrid 100v. I thought i was going to get more velocity out of the h4831sc and the retumbo but not as much as i wanted. the real suprise was the hybrid 100v. I have a sako 75 LH in a Mcmillan sako 75 stock with a 25" benchmark 3 groove 1:9 twist. Im using new nosler brass, cci BR primers, and 168gr berger hunting vld's. so here are the max loads i tested and what i found:
Retumbo:
started at 61gr
63gr 2800fps
64gr 2840 slightly flattened primers but bearly noticable
H4831sc
started at 54gr
59gr 2768 fps no pressure (this is a max load for 160gr accubonds in the nosler data and they say this gets 2990fps)
60gr 2790 fps bearly see any flattening at all of the primer
61 gr 2835 fps little flatter but nothing alarming

With both of these powders i thought i would be getting 50-100fps more? i have a 25" #5 contour so its not a barrel lenght issue, so what gives?

then i just tried some hybrid 100v since its loaded in the 280 rem and the pressures were low with good velocity so i thought i would strart low and see what happened.
Hybrid 100v
started at 51 gr sinve thats the max load for the 280 rem and the pressure as stated was low.
worked up in 0.5gr increments and didnt see any pressure
57gr 2966 fps
57.5gr 2972 fps
58gr 3014 fps (primers started to show slight signs of pressure, nothing alarming)
58.5gr 3042 fps flatter primers
59gr 3064 fps hot load flat primers this is too much for me to want to load.

I wanted to use an extreme powder for the temp sensitive but i just am not getting the velocity with them as i am with the hybrid 100v. Am i doing something wrong here? any tips or suggestions would be good. I know i could use a magnum primer but i have 3k benchrest primers so i really dont want to buy any more.

I think setting how far from muzzle to chronograph should be in the instruction for your chronograph if you don't have that give them a call. I have the Oehler 35p and the distance on mine is 10ft.

I wasn't overly impressed with the velocity in the Kreiger 1/9 twist 25.5" long barrel 280AI with 150gr TSX but it is a very accurate load. My wife likes that rifle so didn't get alot of load testing with that 280AI.

I got a new 280AI last summer used a 27" long Lilja 1/9 twist barrel had it throated alittle longer and I figured that rifle should do 3000fps plus with 160gr bullets and it's done that with R-17 and IMR-7828ssc good accuracy with both powers. I have some Berger 168gr VLD I want to try in that rifle now that weather getting better and I figure in the 3000fps range with those bullet.

I like to get my accuracy first then chronograph just works best for me that way just one less thing I have to worry about. I load at the range so if I get a good load I'll come back shoot it at different yardage and I may shoot it for a week or two get comfortable with the rifle and load. I have more than one rifle so didn't bother me not getting everything done on the 280AI last year.

wish I could be of more help