Home Forums Reloading Big Game Rifles High pressure sign with 51 grains Big Game 120 BT in 7mm-08?

I shoot the 120 gr. BT over 48.5 gr. of Big Game in Lapua brass for a velocity of 3100 fps. When I switched to Lapua brass from Remington, I had to reduce the load from 50.0 gr. which was also 3100 fps load in my rifle. You should chronograph your load as you may still be a little stout in Lapua brass even though you see no pressure “signs”. And I’ve never had a problem with Big Game shooting “dirty” and my loads are all a little shy of maximum.

Yes, in Nosler brass. How does its capacity compare to the Lapua you're using?

Did you fully cure the DBC, or just fire the one shot before cleaning the bore for the first time?

In reference to Mathman’s question above concerning case capacity, I went searching. I can’t seem to lay my hands on all of my records, so I weighed the water capacity of five pieces of Lapua brass and five pieces of Remington brass and averaged each group of five. Average water capacity of each is as follows: Remington brass held 56.1 gr. of water
Lapua brass held 54.3 gr. of water

That is almost two grains difference in 7mm-08 brass of different manufacture. Sorry, but I don’t have any Nosler brass to compare. I think this unscientific experiment shows a couple of things. 1) your problem is probably powder quantity related due to substantially less volume in Lapua brass causing high pressure, and 2). The need to start low when loading with different components (especially brass). And one other thing.........a chronograph is a better indicator of high pressure than flattened primers or stiff bolt lift.

That's what we use in my daughter's 7mm-08 and it is 0.1 grain less than the max shown in the Western Powder load data that I have. ( However I use WLR primers.) It is very accurate. She and her kids have killed mule deer, Coues whitetails, feral hogs, pronghorns and one elk using that load. Can't find the chronograph data, but it runs around 3,050 fps, as I recall.

as some said work up. Lapua brass is heavier ie thicker.. if you want to shoot 51.5 switch to remington or Winchester brass

I did fully cure it, it actually cured for a few months as I didn't have a chance to get out and shoot. I don't think the bore coat had anything to do with it. I treated several rifles with the bore coat at the same time and had no issues. It has to be the lapua brass having less capacity. I checked the water capacity and the lapua was a little under a grain less capacity vs nosler. In this case, as others have mentioned, I should've started lower instead of starting at a mid range load.

My first two 7-08s couldn't handle the Nosler load max. Despite the pressure signs, the loads shot extremely accurately. I reduced to 50 grains of Big Game and pressure went away and accuracy was similar. My third shoots the same leftover loads very well, so I stuck with it.

Hopefully, I've learned to stop selling these rifles!!

Still haven't seen any velocity readings. If you're trying to figure this out, without a chronograph, it's just groping in the dark.

Just checked Quick load for fun, it says 51.5gr of Big Game is about 72,524 PSI. Maybe why bolt is a little sticky.
Quick load says 48.4gr is 58,000psi wit the 120gr BT at 3120fps.
RL17 with 50.4gr and 120gr BT at 58,000 should give about 3198fps and I would start a little lower.
RL16 with 50.1gr and 120gr BT gives 56,981PSI because that all you can get in the case. at 3165fps.
Ramshot Hunter 51.9gr 120gr BT gives 58,000 PSI at 3138fps.

Check Lastrounds load above. a lot safer.