I have a theory that is ready to be confirmed or dashed

I have been working with my Weatherby Mark V Deluxe in .257 Weatherby off and on for most of a decade now. The only bullet I have found to shoot acceptably on a consistent basis is the 115 grain Combined Tech Ballistic Silvertip. Bullet selection for caliber aside, this is the one that performs consistently. For reference I have tried Partitions in the 100 and 120 grain versions, 110 grain Accubonds and 100 grain Barnes TSX's as well.

My load consists of a charge of IMR 7828 that boosts the bullet out at around 3,400 fps (chronoed). It shoots sub-moa all of the time.

This is where theory comes in...or out. I have about 7 lbs of H1000, 3 lbs or RL25, 5 lbs of RL22, 8 lbs of IMR 4831 and only about 1 lb of IMR 7828 left.

I would like to utilize some of the other powders I have (H1000, IMR 4831 or RL25 specifically as I don't have a current application for them right now)to work up a load that is comparable to the one I have with IMR 7828. I know that the gun will probably not like some of the applicants and may like one or more better than the IMR 7828, but I don't want to go to extensive testing with each individual powder if I can't get equal or better results.

Here is my question/thought. I thought I would load up 4 or 5 cartridges with each powder, starting with a starting load and working up in one grain increments. Fire them over the chronograph for recorded velocities as well as watching for excessive signs of pressure. This will take approximately 20-25 rounds of ammunition. This will get me to where I can find the powder charge in each of those powders that will give me 3,400 fps, or excessive pressure signs before that. If I have pressure signs prior to achieving that velocity I know I don't want to deal with that powder any more. If I reach 3,400 fps safely then I thought I would load up several 3 shot groups of that powder charge and test for accuracy. Does this sound like a good way to accomplish what I am trying to do without burning a barrel out?

Secondary question...If a bullet/powder combination gives desired performance at a certain velocity, can a person expect to get reasonably similar results from a different powder if velocity and all other variables (bullet,primer, case, o.a.l. etc.)are the same?

Considering you know that 3400 fps is obtainable with 7828, a quick look at some load manuals should be a reasonable indicator of whether you'll be able to duplicate the velocity with one or more of the other powders you have. I'd say most likely without even looking. If you believe the Optimum Bullet Time theory, then yes, you should be able to duplicate accuracy also. Can't say that I believe or disbelieve it as I haven't had the time to try it.

quote:

Originally posted by 300winnie:
...Does this sound like a good way to accomplish what I am trying to do without burning a barrel out?

Nothing wrong with trying it. If you simply follow the never improved upon Creighton Audette Load Development Method, you will be doing what you describe, plus be able to see if you are achieving a Harmonic Convergance of the Points-of-Impact at the same time.

quote:

Secondary question...If a bullet/powder combination gives desired performance at a certain velocity, can a person expect to get reasonably similar results from a different powder if velocity and all other variables (bullet,primer, case, o.a.l. etc.)are the same?

It could possibly happen, but the chances of the barrel hitting a similar resonance with a different Powder is slim to none. Dosen't mean it can't happen though.

Best of luck to you.