New to reloading, I started with the minimum load 8gr power pistol without any signs of over pressure. Can I increase charge .3gr or do I have to work up .1gr at a time. Book says max is 9gr. Any advice appreciated.

You appear to be safe to go up from the base in your .3 gr jumps. What I do quite a bit is to only load 2 or 3 or no more that 5 of a specific weight and shoot them to see what is happening. That way, if you do exceed the limit, you only have a couple of loads, not a box full of loads that are two hot and sometimes, you hit on a nice accurate load "on the way up"

Thanks. My inexperience makes me cautious.

You don't need to work up 0.1gr at a time . . . with a 9gr max 0.2 or 0.3gr is fine.

Dunno what caliber/bullet/firearm is involved here, but I'm going to assume that your initial 8gr load fed, ejected, and cycled OK (if pistol) or worked fine from your revolver.

I'd make up 3 to 5 rounds at, eg, (8.0), 8.3, 8.6, 8.9gr. I'd bring those rounds, some factory ammo I liked, and a rest to the range. I'd fire the factory rounds from the rest as a reference for recoil and accuracy at 10-25 yards. Then I'd fire the handloaded rounds in groups from the rest looking for accuracy, (ejection), and recoil.

Somewhere along that line you will find a load your gun and you like best for whatever purpose you seek . . . match factory, soft and accurate, hot, etc). While you are unlikely to run into too hot a round, you have recently fired factory ammo to give you a benchmark in addition to any other signs of overpressure.

Then you can go home and make more

That's fine, as long as you are below max .

The pistol is an m&p 40c . Using 155gr fmj. Gun cycled fine. Ejected case's about 10'
Found and inspected every case after every shot. Appreciate the information.

I generally use 0.3 grain increments for load workup. However, it's a good idea to determine how consistent your powder and powder measure combination is by weighing at least 10 individual charges. I consider 0.2 grain consistency OK (lightest to heaviest for 10 thrown charges).

The amount of increase is bullet, caliber & powder specific. Faster powders in smaller volume cases need smaller increases. PP is a Med-slow powder. So in service case, I am fine with 0.2gr increments. The closer you get to max, the smaller your increases should be.

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NRA Cert. Inst. IDPA CSO

The MOST experienced re-loaders have learned to always be cautious. Don't ever forget this.

Scott

.1 of a grain is hardly going to make a noticeable difference. Except that MIGHT be a good idea if you are going for max. load.

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"He was kinda funny lookin'"

If you look at any pressure curve, you see it obviously gets steeper as you get to the top. Faster powders have steeper curves, so yes, 1/10gr can make a diff with powders faster than w231.

__________________
NRA Cert. Inst. IDPA CSO

What you may find in doing you testing - "ladder tests" is as the powder charge changes, M.V. and accuracy will also change.

Pick the load that gives the best accuracy. You may find that as you approach the top end of the listed loads you will see the powder burn "cleaner" and may see you groups tighten up then open up as you pass the "sweet spot"

You will see the same effect when switching primers or changing crimp pressures or seating depths as well. When all the data is in, pick the load that best suits the need.

Good luck - load safe.