Switching powders, where to start testing groups?

[Bayourambler]

Currently using rl-22 for testing in my 300 wm. Found a load that is ok but not great. It consist of 73.4 grains in fed case ,cci 250 primer with 200 grain sgk on top set at 3.350" OAL . I'm getting average of 2925fps . I do have h1000 I would like to try. Conventional wisdom says work up a load,( from low end of course) till I get to that velocity, and then load a few and try groups. I'm i on the right track? I don't like the thought of starting from scratch!! This 300 is eating powder like crazy!!

 

[Englishmn]

Unfortunately there are no safe short cuts in reloading.
If you are trying to keep at a certain velocity you can do that. Sometimes a little faster or slower can close up the groups but it does use a lot of powder looking for those points.

 

[horsey300]

Currently using rl-22 for testing in my 300 wm. Found a load that is ok but not great. It consist of 73.4 grains in fed case ,cci 250 primer with 200 grain sgk on top set at 3.350" OAL . I'm getting average of 2925fps . I do have h1000 I would like to try. Conventional wisdom says work up a load,( from low end of course) till I get to that velocity, and then load a few and try groups. I'm i on the right track? I don't like the thought of starting from scratch!! This 300 is eating powder like crazy!!

Yes, start at the bottom, and I'll tell you right now, as I said in the other thread, h1000 likes a full case. Period. Your first few groups will look like you're patterning 00 buck and it can be disgusting. Hodgdon actually used two bullets for this weight because of it. The partition and the accubond. One is a boattail, the other is not. Use the accubond data for that Sierra. Hodgdon seats to 3.34" and that's where I'd start. Work up in 10% of charge weight increments, for this load that means .7 gr. That means that somewhere between 76.3-77 gr, the light will shine down and show you the glory of the h1000 for heavy bullets.

 

[Big7]

4895 is your friend with larger cases..

 

[Bayourambler]

Yes, start at the bottom, and I'll tell you right now, as I said in the other thread, h1000 likes a full case. Period. Your first few groups will look like you're patterning 00 buck and it can be disgusting. Hodgdon actually used two bullets for this weight because of it. The partition and the accubond. One is a boattail, the other is not. Use the accubond data for that Sierra. Hodgdon seats to 3.34" and that's where I'd start. Work up in 10% of charge weight increments, for this load that means .7 gr. That means that somewhere between 76.3-77 gr, the light will shine down and show you the glory of the h1000 for heavy bullets.

. Good info to start on.

 

[forestswin]

Take a look at this method for load development

http://optimalchargeweight.embarqspace.com

 

[Laphroaig]

^ I think something like the OCW is a good idea when starting from scratch.

Sometimes I do the old Creighton Audette ladder test (one round each from min to max charges in .3 gr increments) when starting from scratch. However, it can be a pain to differentiate shots thru a spotting scope especially when testing at ranges longer than 100 yds. which is best for this method. But I can check for pressure signs with a new load and accumulate some chrono data with a minimal number of shots. If I get some "nodes" (and I always do) it points me in the right direction for some further group testing.

 

[Sunray]

When you change powders or any other component, you must start all over again. Max and likely about mid range H1000 loads will be compressed. Nothing to worry about though.
3.350" is too long. 3.340" is the SAAMI max OAL for .300 Win Mag. Forget the whole off-the-lands stuff until you have worked up the load. The whole off-the-lands stuff is an unnecessary load tweaking technique.
73.4 grains of RL 22 is .4 over max. Not enough to hurt anything though. Normal differences in manuals will do that.
Anybody's ladder test does not test the accuracy of a specific load. It only tells you the POI in relation to other loads.