lower powder charge for accuracy?

[kennedy]

Lees reloading book says to use 43gr of H4895 as a starting load for 150gr .308, what would happens if I use less, like 40gr? any better accuracy? or not enough to get the bullet out to 100yds?

 

[Steve H]

I would not go under the starting load. You could be asking for problems you don't want.

 

[dmftoy1]

You'll get it out to 100 yards but you won't get any better accuracy. (at least that's been my experience) I tend to find that 7-10% below max is where I achieve my best accuracy and I start with the starting load and work my way up until the groups grow. FWIW

 

[rcmodel]

40 grains of IMR4895 will give you about 2,400 FPS, and about 32,000 PSI according to the Lyman 47th. manual.
H4895 would be very similiar.

The risk of going to low with jacketed bullets is not that they won't go 100 yards, but that they won't go anywhere at all, and stick in the barrel.

If you want to load reduced loads, there are ways to do it safely, but going much below recommended starting loads with any particular type of powder isn't one of them.


rcmodel

 

[Owens]

Adjusting the charge up or down does change accuracy. It is actually manipulating the barrel harmonics and finding a load that causes a uniform harmonic oscillation.

Suggested loads, such as may be found on powder jugs (i.e. Hodgdon) are only a point at which the charge may need to go up or down.

Data from manuals will usually have a high and low, and is usually best to stay within those limits.

Use caution.