I've been reloading for many years & have followed the start low & work up to max on powder charges for safety. The rule use to be take the max & reduce it by 10% for a starter min load. Magnum cases are worked up to max in 1 gr increments. Med capacity cases ~.5 gr increments. Small cases in <.2 gr increments. Most load data is now specified in min/max numbers. Are there any adjustments for other factors to consider? What rules do most reloaders follow getting to max?
Pertnear -
Howdy !
My rifle re-loading has mainly been performed to provide dedicated ammo for rifles that
are/were chambered for “ wildcats “ of my own design. I have performed a lesser amount of reloading for a couple of .35 Remington, but for those ….. I develope accurate loads that feature “ reduced charge “ weights, and not loads that operate near max pressure.
My safe process:
To ensure I developed loads that operate w/ safe pressures, I first review case capacity and loads for known cartridges of the same caliber; that bracket the case capacity of my wildcat.
I’ll pre-load my wildcat test charges at home, then identify, label; and segregate them in separate storage containers. Focusing on one particular bullet/bullet wt….
I start my wildcat’s load development w/ a powder/charge that has shown to be safe in the smaller capacity case ( mentioned above ). This starting point charge wt is typically within * 2gr of the final charge wt I’ll finally adopt ( once range testing is completed ) for shooting that powder in my wildcat case. IMHO - a 2gr span for potential final powder charge wt to be adopted is already pretty close to the maximum point. For this reason,
* I approach max charge wt by going up in charge wt from the starting point in first in .2gr increments, and watch for pressure signs as I fire each test cartridge….. starting with the lowest charge test cartridge first; and then and go on to the next incremental charge.
Once ( or if ) I have advanced a total of 1gr in test cartridge charge wt and have not topped out on pressure, * I slow all remaining powder charge wt increases to just .1gr increments…. aiming to find the max, safe charge. I have often found ( while testing new powders out ) that I don’t even get to fire the last 4 or 5 pre-loaded test cartridges….
as I have crept up on the max charge carefully; and the max charge was soon determined.
After finding max charge wt:
For safety sake, and as an accommodation to my eventual use of these wildcat cartridges on groundhogs in warm/hot humid weather: I’ll write down the max charge wt for the powder & bullet in my loading book as being .1 or .2gr below the proven safe max charge wt shown in testing.
Accuracy:
* With the max charge wt for that caliber & bullet recorders, I thereafter assemble my next batch of test case charges… were I reduce charge wt down in .1gr increments…
until best accuracy is achieved, shooting 3 shot groups @ 100. When one of these charges gives the accuracy level I’m looking for, I verify by shooting a 5-shot group.
With my .224” cal and 6mm cal wildcats, the accuracy charge is often not very far below the max pressure charge. In my “ DEEP 6 “ wildcat, best accuracy was found ( for all bullet weights I tested ) to be right @ or very close to max charge wt, when shooting
s-l-o-w-e-r “ burn rate “ powders like RL-22, IMR7828 ( and 7828SC ); and RL-26.
( DEEP 6 has 51.2gr H2O capacity ). I also was using FED Magnum Rifle Match primers.
For the reduced loads in .35 Remington ( Marlin M-336XLR and CVA “ Hunter “ ) I first very thoroughly read up on “ Secondary Explosive Effects “.( S.E.E. ).
What I learned by reading magazine and book articles years ago, was greatly augmented by the wealth of information one can pull from the web; especially by conversing w/ those knowledgeable on the subject of S.E.E. @ this website.
YRMV
With regards,
357Mag
