Using a 170 Speer Deep Curl in a 30-30 with W748 shows a min of 28 and a max of 32 (Speer data). Hodgdon's online data also shows a max of 32 (and no min) with the 170 Sierra. I will not be using my Lyman data of 32 grains START with 35.6 max.

So, I have 27 pieces of brass. That is 9 three shot groups. I can either load incrementally in 0.2 grains for 30.4-32.0 or 0.3 for 28.8-32.0.

Or should I just go with .5 grain increments for the full range of 28-32? I know I want at least 2000 fps, which puts me at the upper end of the data, so that's why I want to start a bit higher and keep the increments closer.

I suggest you go with an increment around 2-3 percent of the max load. Yep, percent. Reason is that a 2.7 gr load of Bullseye is vastly different than a 70 gr load of 4831. One wouldn't use the same increments for those two situations. I shudder when people say they work up in ___ gr increments, because it really depends on the size of the powder charge. If you only have a published max load, then be sure to start low - no less than 10% below max.

Don't get hung up on velocity. I'll take a 1800 fps load that shoots good over a 2100 fps load that doesn't any day. Bullet placement (accuracy) far more important than bullet energy (velocity).

I would not load all the loads at once. You may end up taking some apart if you do that. I would go with 5 shot groups, too.

I just want to match factory velocity with decent accuracy for large hogs. Velocity is needed for getting through the shield on these things.

And 2% would be .6 grains. I'll go with .4 incriments then. That should be plenty.

It's been my experience that expanding bullets penetrate less at higher velocity. It causes them to open up faster and to larger diameter. Solids are another matter. There, more velocity does equal more penetration.

Another option, you could do a 2 or 3 set ladder test with each load increment fired sequentially. You could do the entire range in 2 sets of .3gr increments or almost 3 with 4gr increments.

I use the following method to determine increments for initial testing.

M = maximum recommended load
m = minimum recommended load
D = M - m

1: m
2: m + 0.25 * D
3: m + 0.50 * D
4: m + 0.75 * D
5: m + 0.80 * D
6: m + 0.90 * D
7: M

I load a few of each. I start at the lowest load and work my way up paying attention to any signs the load is too much for the gun.

In that specific range of powder weights, I would just work on 0.5 grain increments and especially for the the caliber and for a hunting application.

As was stated, if it was a 38 wadcutter load then you would be trying much smaller increments. And for a 460 Weatherby larger increments. Or for a target gun you would be trying smaller increments.

And I would load at least 5 of each if I could. The three shot works if you get the load you want. I have done that. But I have also wished when I only had three, that I could go back and fire another couple of those to confirm what I saw. Or if I maybe pulled one wide.

What does the current factory load you are using show in actual velocity versus what its published velocity is shown to be?

I'm a believer in the Dan Newberry's Optimum Charge Weight link

To me every load work up is best viewed as a somewhat unique effort
without adherence to any set of strict rules. You want a full power
handload with a 170 gr bullet using W748 powder for hunting use in a
lever action rifle. Looking at a variety of data sources shows that W748
can easily equal factory velocity while developing less pressure than
most other powders. Having seen charges as high as 37.0 grs used
with 170 gr bullets in manuals and magazine articles about loading
for a Win md 94 I would do the following if I were in your shoes.
I would load five rounds with 32.0 grs and chronograph them.
Depending on how close the velocity was to factory, say 2100 fps,
I would load five more with the charge I would guess would yield
2100 fps and chronograph them and repeat this process until I got
2100 fps and stop. You have your hunting load. Settling for a load
that yields less than factory velocity because it groups better on
paper is absurd. You're using a lever action carbine to hunt large
game in the woods at fairly close range, not hunting paper targets
at the shooting range with sand bags and a bench.