New Lot of Powder

A

akinswi

New member
When ever you get a new lot of powder, do most of you start at your current charge and shoot a few groups at .2 or .3 grains around that charge too see if anything changes? Or is it a moot point and just stick with your current charge

The powder is IMR4895

Thanks
 
I drop down a few tenths then rework the load coming up .1 grain at a time. Sometimes the old load is good, others times may need adjusted up or down a tenth or two
 
I load and shoot a few with my previous load. If there's no significant change down range or in the appearance of fired brass, I call it good to go.

If there is, I'll start adjusting, depending on what the change is.
 
I load a few, shoot a few over the chrono, Shoot a couple groups, see if anything changed. Tweak it if needed, and keep on loading.
 
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The only times I download and work back up is if the load is already at the maximum recommended level. If the initial load is well below maximum and the new powder shoots the same I leave it alone.
 
With stick powders in standard calibers, I don't worry about it. Shooting my 7mmRM at max is the most accurate in my rifle, so I come down a couple of grains of RL22 or 25.
 
akinswi said:
When ever you get a new lot of powder, do most of you start at your current charge and shoot a few groups at .2 or .3 grains around that charge too see if anything changes? Or is it a moot point and just stick with your current charge

The powder is IMR4895

Thanks
Click to expand...
I keep loading my load from lot to lot. Only powder I have seen dramatic differences in is Rl 22, thats why I now use Norma MRP. Same powder but consistent from lot to lot.
 
reynolds357 said:
I keep loading my load from lot to lot. Only powder I have seen dramatic differences in is Rl 22, thats why I now use Norma MRP. Same powder but consistent from lot to lot.
Click to expand...
Got caught years ago with RL22 in the 257 wby because of case lot differing. One of the main reasons started buying larger quantities of the most used powders.
 
For typical 30-06 Garand loads, QuickLoad thinks ±1.0 grain should cover you, plus wiggle room. I don't usually bother to increment less than 0.2 grains, as most scales are ±0.1 grains, so you need an increment of at least 0.2 grains to be sure your next load is actually different from the last. But if you have a higher resolution scale or just want to try it, that's up to you. The underlying assumption here is burn rate controlled to ±3%. Hodgdon does that with all their powders except some years ago they said it was ±5% for IMR powders. Since then, though, the processes have changed, so I would expect they've tightened up the IMR range. You can always call to ask. If it is 5%, then go to ±1.7 grains to be sure to cover it.

For safety, it is always best to assume your last batch of powder was at the low end of the burn rate range and that your new one is at the high end. In other words, to reduce at least 10% for a powder that is ±5% in burn rate. And it doesn't hurt to do that for at least one shot anyway.

Code: 
4895, 168-grain SMK, 24" Barrel, 68.2 grs case water overflow capacity, 3.290" COL

Constant Velocity; about ±0.8 grains:

Ba=0.5044; 48.27 grs; 43847 psi; 2633 fps; 1.311 ms   

Ba=0.5200; 47.42 grs; 44157 psi; 2633 fps; 1.308 ms

Ba=0.5356; 46.63 grs; 51051 psi; 2633 fps; 1.304 ms



Constant Barrel Time; about ±0.9 grs:
 
Ba=0.5044; 48.35 grs; 44046 psi; 2637 fps; 1.308 ms  

Ba=0.5200; 47.42 grs; 44157 psi; 2633 fps; 1.308 ms

Ba=0.5356; 46.53 grs; 44251 psi; 2628 fps; 1.308 ms
 
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