Question for 7mmRUM shooters

James Jones · #1 07-11-2006, 06:34 PM

How fast do you think its possible to drive a 160gr calss bullet?
what about the 180's??

this will be from a 28" 3 groove Lilja 1-9 twist

sambo3006 · #2 07-11-2006, 08:19 PM

I have a 26" LSS and I was able to get 3500 fps with the 140BT and 3400 fps with the 150BT. Above these velocities I got extractor marks, flat primers and a big velocity jump for small powder charge increase. I would say 3300 fps with the 160AB in my gun.
Interestingly, I got the best velocity from IMR 7828. I also tried H1000 and got pressure signs at lower velocity.
With 2" more tube and heavier slugs, H1000 or RL25 might be just the ticket for you. I would think that you could safely get 3400 fps with the 160 from your 28" tube.

speedbump · #3 07-11-2006, 08:57 PM

JD, I've shot 156gr Cauterucio VLDs from a 30" tube with good results. Never chrono'd them, but SPEEEEEEEDY. They'll get to 1K in about one second flat. Literally.

My match load is with a 176 VLD from the same maker at 3,360fps. Both were fired with 5010 pulldown powder from www.gibrass.com . I've tried many powders, & 5010 does the best in THIS rifle, followed by Retumbo.

distantfoe · #4 07-12-2006, 04:40 PM

I've been wondering the same thing, except I'm leaning toward the 180-200gr bullets.

duckinalaska · #5 07-13-2006, 03:29 AM

I will tell you that if yuo use 94 grains of retumbo you will be at 3400+ fps with 160 grain accubonds.

257speed · #6 07-19-2006, 07:50 PM

180 bergers, retumbo, 28" Krieger, 3250fps (warm load)

ceg1963 · #7 07-19-2006, 08:26 PM

Sambo hit the nail on the head (IMR 7828 & 160 NABs)

In my rifle, a dose of 87g of IMR 7828 loaded at OAL 3.68" does the best with the 160 NABs. 87g of 7828 get me 3350 FPS and one hole at 100, 3/4" at 300, and 3" at 500 yds (with 2100 Foot pounds of Energy at 5).

Keep in mind that this is a carry rifle... not a heavy rifle: it has a S/S, #5 contoured, 27" fluted Shilen barrel, action is all trued up, a jewell, a McMillan Classic stock, a Zeiss Conquest at 4.5x14.

All total it only weighs in at 8.5 lbs.

With 140g NABs, and 91 g IMR 7828 it gets me comfortably 3600 FPS with very similar accuracy and has 2045 Foot Pounds at 5.

The difference between the 140 & 160 at 800 yds: the 140 g NAB retains about 1300 FP... whereas the 160 NABs retains 1400 FP.

I guess it is according to what you want to kill.

v/r