Powder Charge Increments for Load Development?

[Michael J. Spangler]

hey guys,

i'm working up a load for my remington 700 pss in 300 RUM.

i'm working with
fire formed brass, sized, trimmed, flash holed uniformed
H1000
Hornady 208 amax
Federal LRM primers
Harris Bipod
HS precision stock
leupold mk 4 3.5-10 IR Mil dot scope with 1/4 MOA clicks

i see a ton of load development threads, and OCW and ladder tests. It seems like the powder charge increments are pretty large, about 1% or more between loads.

should i stick to a 1% increase in between test cartridges or should i drop it to .5%
roughly 1 grain increments or .5 grain?

will the 1 grain be enough to get my close so where i can refine it later?

hodgdon suggested a starting load of 85 grains and max at 90.5

thanks in advance for the help

[Kevin Thomas]

Hey Michael,

One grain is just fine here, as it's pretty close to one percent with a 300 RUM. Thing to remember here is that a grain isn't just a grain, it's a percentage of the overall charge weight. One grain in a RUM is right at one percent. One grain in a 22 Hornet is about ten percent. In the Hornet, one-tenth grain increments make perfect sense, but they'd be pointless in the RUM. You're fine here, and moving up in half grain increments is pure fine-tuning in something this large.

[Michael J. Spangler]

thanks kevin.

i just loaded up a bunch in 1 grain increments.

now if i can get a nice day, i'll hit the range and see how they do

[Jeremybj]

In something with that large of a charge, I would go with 1 grain incriments. You could literally chase a load FOREVER if you tried it in .5 grains and really it is a small % incremental change overall.

[B-RAD]

I've never loaded anything but .223, but I have a post here - > Help with Cooper and AR-15 Loads

with load data, I basically went through the books and chose 5 loads, then from there I picked the best group and then picked a FPS reading from the book that was what my best load was and then followed that on loading with all my other powders. From there I then see what my best load was, and then went in .5gr increments + or - from there a few grains.

EX. My Cooper shoots best from 3200fps to 3600fps, I only loaded in that range - mind you it's a 1-14" twist

[Michael J. Spangler]

thanks guys.

i was going to try to hit the range tomorrow, but they have an egg shoot going on.

i'll wait till wednesday night and see if i can shoot through these load and narrow it down.

once i get a range ill work between the high and low with a .5 grain increment.

thanks again

[newmexkid]

When working up a load I always go in 1 grain steps until I start getting close the max load then I dropoff to .05 increment. That's for my big game rifles. For PD and coyotes I always work up in .05 increments. At times finding a, "load" can take time but, it's worth it. I have been reloading since around 1969 and have just twice found the best load for a rifle on the very first batch.