308 150 Core-Lokt Varget Question

[WildCard]

Hello Everyone! I've been reading through the boards for a while now, but this is my first post. I'm pretty new to reloading (less than 100 rounds so far) and just got started on loading my first ladder series for my .308 Win (Savage 12FVSS, 1:10 twist). I decided to go with Varget powder, as it seems pretty popular for the 308 and also should be decent in my 223. I also picked up some Remington Core-Lokt 150 grain bullets to get started.

However, I have a couple of questions: First, looking through my reloading manuals, Lyman says that the max charge for a generic 150 grain PSP bullet is 47.0 grains, Nosler says 48.5, and Hornady says only 44.9! I understand that they may all be using slightly different bullets, but unless I'm reading something wrong, this seems like an awfully big range. What gives - is this just our nation's lawyers at work? Seems like I've read before that Hornady is often pretty conservative.

I loaded a series of 5 each from 42.0 to 45.0 grains of powder in 0.5 grain increments, with about 20 extra at 42.0 grains just for some practice reloading. I'm trying to figure out how much higher to go and may base my decision on how the groups and pressure signs (if any) look at 45.0 grains. So far I've only had a chance to fire the 42.0 grain loads, which grouped about 2" at 100 yds. I admit I'm not the world's greatest shot, but how much do you guys typically see your groups drop during load development?

Sorry for the book - I appreciate any feedback you guys can give me!

Thanks,
Dave

[darkker]

Dave,
There is ALOT at play here. First of all is the powder it's self. Hodgdon does not build their powders, and depending upon who is building a paticular powder; the speed may move slightly. Therefore depending upon when someone got the info for publishing, there is a difference. Also as you mentioned the specific jackets have different "Slickness" values, and that affects pressure.
The biggest improvement I have found in all of my Savages(15+ years of Savages) is the COAL. Savages tend to have long throats. The FP's in paticular have VERY long throats. If you don't have one, go and buy a inertia bullet puller(looks like a hollow hammer). Take and EMPTY, resized case and seat the bullet, WAY far out. Drop it in the chamber and close the bolt. This will force the bullet in the lands, and seat it farther in the case. Then open the bolt, take the cartridge out and stick it in the calipers to measure the COAL. Now you know where THAT paticular bullet contacts the lands. The general area that MOST bullets shoot really good is with about 1/32" jump to the lands.

I think you will be surprised how much longer the cartridge for your gun is than standard.

[WildCard]

Thanks! I just measured and came up with an overall length that was about 0.050" longer than the recommended COAL in my reloading manuals. Is that pretty typical? Since my last batch was reloaded to their suggested length, I guess I really should work up another that is about 0.020" or so shorter...

[Uncle Jack]

Just as a matter of reference, I start all my load developement with bullets .010" off the lands and then work back and forth in .005" increments after finding a decent powder loading. In MOST cases, I find my best results are around .008" to .015".

uj

[LHitchcox]

Some other factors causing the different powder recommended max loads would be chamber size(the first chamber cut with a reamer will be slightly larger, getting smaller til the reamer reaches minimum) , throat length, case capacity, bore diameter, and lot to lot variation of the powder.

Good reasons to follow recommendations to start low and build up to your rifles max load.

[darkker]

Jack,
I do as well. But for a relatively new loader I figured I give a helpful starter, that wasn't super close.