OK, the new 300 WBY barrel is going to be here in another 10 days or so, and Wyojeepeer and I are having a bit of a debate on the best way to develope a load.
First off, somewhere, he read that a good way to find a starting load is to shoot one shot @ (say) 78 grains, the next @ 79, the next @ 80... until they start to group. ie, the 80, 81, and 82 are in a fair group with the 79 and 83 out of it. Take the middle charge (81) and start fine tuning from there. Sound like it would work to you?
FYI, I'm planning on keeping close tabs on case web expansion, etc. in the process.
Next, from a thread on some board or another, I'm going to build 5 shot groups with .010" staggered seating depths using that (theoretical) 81 grain charge. Whichever of those works best, build another 5 groups staggered in .5 grain increments around the (81 grain?)charge used to find the seating depth.
I have it on mediocre authority that this method gets you to a sound load that will take lots of work to improve upon.
Yes, No, maybe?
Any recomendations on a better way?
Here is a little mental reminder of what not to do:
"Just one more grain."
BOOM. As you recover from recoil your nostrils suck in a smoky, acrid smell that shouldn't be there. As you look down white smoke leaks out of the bolt shroud and your mind says "You're freaking lucky you still have eyes - you IDIOT!"
Your right hand goes to the bolt handle - it doesn't lift like it usually does. Matter of fact is doesn't lift at all. "Welded shut" comes to mind.
You tap the bolt open, holding your precious rifle steady with your left hand while trying to smack under the bolt knob with an RCBS plastic cartridge case block. The bolt lifts bit by bit until it is all the way up. You draw it back and more smoke comes out of the chamber - more stink. "How the hell could there STILL be smoke inside that barrel?" you think to yourself.
The cartridge case doesn't eject, it is stuck in the bolt-head. You wiggle the case until it comes free. The primer drops out onto the bench. The base of the case has a bright, shiny circle that obscures some of the printing, and of course a black hole where the primer should be.
You look at the bolt face - it is smudged with a nasty black circle around the firing pin hole. Ooops, the ejector plunger is stuck below the bolt face and the extractor is gone, clean missing.
You check the bench - no extractor. Frantic, you tip the rifle upwards and are rewarded as a tiny hooked extractor and coil spring fall out of the recoil lug recesses.
Time to head to the gunsmith... Damn.
Just made all this up, of course. Pure fiction...
Thanks Darryl & Ian. FYI, I do plan to shoot over a chrono and not exceed 3250fps (assuming all goes well up to 3200) with my 180gr Sciroccos and new 30" tube. Measuring the case web in addition to the chrono and watching primers etc should insure that my Encore (no bolt) doesn't fill the shed at the range with smoke or flying gun/face parts.
I'm planning on starting off with RL-25 and Fed 215s if anyone has some starting loads they'd like to share.
By the way, it was waiting for me when I got home from work today. Now all I need is for my rings to get here.
Like you, I use my chronograph when working loads so that I can watch the velocity gain per grain of powder. Seems to drop right off when accuracy goes bad. I shoot the Encore quite a bit, have never shot it in a big magnum tho. Find it to be an amazingly versatile rifle.
My .300 Weatherby seems to like RL-22 best with 180 grain bullets - Darryl hit it right on for a starting charge. No doubt RL-25 will also be a good choice, haven't tried it myself yet.
You should not have any problem getting 3250 with a 30 inch barrel. I also found great accuracy and excellent velocity with a Winchester ball powder called Magnum Rifle Powder, not sure if it is still available.
Good luck finding the optimum overall length - seems to be a matter of testing lots of variables until you get the right combination. I am hearing that Winchester magnum primers are worth testing vs 215's.
I would have to second Ian's suggestion about looking at other primers. I've been doing some testing lately with my 338 Lapua Imp. and have got the min/max muzzle velcoity variations down in the single digit range from 45-55fps when using the Fed215M primer. I started testing GM210M using R25 (90+gr worth) and didn't have any troubles even in temps as low as 40F. I know some guys that are giving the CCI BR and Win LR primers a serious go in competition and doing very well so far. CCI do seem to have a thicker or harder primer cup, because I do know of 2 rifles that mis-fired or hang-fire when using them. Normally a second blow on the same primer and they will go off.
In a 300 Weatherby you shouldn't have any trouble igniting powders with a standard primer and you might be surprised with the results. I got rid of the up/down in my group in my 300 Win Mag by going from 215 to 210 primers and going up 3gr using R22 powder. Then the groups shot consistantly round and th up/down tendenancy went away. I've found Federals magnum primer to be approx 2gr worth of powder in large magnum cases. So you will need to adjust your load accordingly to get your velocity/accuracy back to where it was.
Have you used the Winchesters yourself? If so in what cases and powders? Just curious.