Having retina problems and can't shoot heavy recoiling loads, so want to use some Sierra Pro-Hunter and Hornaday #3232 150gr soft points in the stash for whitetails in my 8x57. Since this is the East Coast, we're talking pretty small animals at 100yards or less in the woods. A .30-30 equivalent load sounds about right.

Rifle powders seem sorta available around here on a hit-or-miss basis, so several choices might be useful. Looking at 150 gr. .30-30 loads gives me a starting point, but I'm not well informed about the effect of case capacity and bore diameter on using duplicate loads.

I would appreciate some advice, please?

Try the Hodgdons website, look for H4895 reduced loads, very helpful information.
I also just looked in the Sierra manual which lists 6 powders that run a 150 grain bullet around 2400 fps which might be mild enough.
I would stay with published 8mm data and not try to interpolate 30/30 data into an 8mm load. Just me...

Shoot factory ammo, it chronographs about 2000 FPS last I tried..I think it was Rem. ammo??

If it is 30-30 velocities you want, you probably are looking at something around 2400 fps.
Here are loads doing that, out of a manual
40 grains RL15
42 grains RL12
50.5 grains H4350
56 grains H4831
43 grains BL-C (2)
43 grains H4895

Should anyone see an error in this data please speak up.

Originally, pre-WWI, when the "S" loading came out in 8x57 it shot in a 29" barrel a 154 grain bullet at a then unheard of 2,9950fps muzzle velocity.

German powders being just that so much better than any American powders at the time. A nice loading would be to use a fairly bulky powder and re-create the old 303 British 150 grain bullet loading.

I am lead to believe that Trail Boss can, in fact, be used for jacketed bullets and that that might be your answer?

Interesting idea. The Trail Boss loading guide for rifles shows a 30-30 load for 160grs at 1000-1200 fps with pressures in the 20,000-30,000CUP. It might be an interesting experiment if nothing else looks good.

I think the "starting" loads listed in most manuals will provide the sort of thing you are looking for.

Lyman's book lists this interesting lower pressure "starting" load:

150gr Speer SP bullet, 47.5 gr of 760 powder, 2316 fps, 28,200 psi

I have used this load successfully on whitetail. My son has I should say.
Syrian Mauser 20" 185 Remington 1800 fps SR-4759 22gr CCI 34 Win brass 2.984 OAL
a load copied from elsewhere:
8x57 Mauser - 150 grain Speer SP bullet, 21.5 grains SR 4759 powder, WLR primer, Winchester case. COL 2.945". MV 1960 fps in 25" test barrel. MAP 37,000 CUP. (Based on the IMR Smokeless Powder Reloader's Guide, April 2004.)

Good load for that 185gr.
I was sent another good one, also from an older Hodgdon manual. 150gr SPR SP, 36gr IMR4895, 2310fps (probably less in my carbine barrel), 37000cup. I loaded 20 of these and tested them today: they are low recoil, acceptable group at 50yds off a rest - probably more accurate than my old eyes with my express sights beyond that. This will be a great load for my woods hunting this year. Thanks everybody for suggestions.

12~15gn of trailboss in my 8mm mauser kicks like my 22-250ai.