Hey Guys/Gals!!

I need some help.

I have access to a range for one day only with steel set up at 200, 500, 800 and 1k. My issue is I'm out of my go-to 123gr SMK with only the 123 gr Lapua to shoot at this one day range event. Has anyone tried H4831 and IMR4064 with the 123gr Lapua HPBT in a 260 Remington?
My rifle is a VZ-24 Mauser 98 with a 27" 1-9" Shilen. All load development for my rifle was done with a 123 SMK and had my best accuracy with H4831 and IMR4064. These are the two powders I have on hand and would like to stick with them for now.

I appreciate all the help!!

You've been shooting 123g Sierras and now are going to use the SAME weight lapua ?
If I read you post correctly, I would drop down 2 grains, set up my die so the seated lapua is just off the lands using the same primer AND lot of powder as w/ the Sierra and see how it shoots. Work up in 1/2g increments til you find 'the' load w/ the lapuas.
I do it all the time. I do my load work up /w cheaper bullets, then switch. I worked up my GFs 260 /w 129g horn and then switched the load to 125g NP. When the NPs are gone, will do it again /w the 130g AB.
Good luck /w it.