Am just about to charge my .303 British cases with Varget, my powder of choice, and I am torn between two lots of load data. (NB: BEST EFFORT FOR ACCURACY MADE, BUT NO GUARANTEE ON TYPOS; CHECK ALL THE LOADS FOR YOURSELVES BEFORE USING.)
If I believe Hornady (9th edition manual), their 174 grain bullets (both the .3105" FMJBT and the .312" RN SP) are good for a minimum charge of 31.6gn of Varget and a maximum of 39.1 grains (Hornady/Frontier case, Winchester LR primer).
If I believe Lyman, the Hornady 174gn RN is good for 38gn of Varget as a minimum and 42gn as the maximum but data are not given for the FMJBT. These are also the high and low points given in the Lee Loader data sheet IIRC. In addition, ADI powders report their AR2208 (basically Varget in a different bottle or as near thereto as makes no difference) with the same minimum and maximum loads (38-42gn).
Lyman specifies Remington cases and Federal LR primers, and the same COAL as Hornady. Neither Lee nor ADI make any specification as to primer or case, and ADI doesn't even care which type or make of bullet you use as long as it's jacketed and assumes milspec COAL wherever there isn't a cannelure. The only other generic loading books I have predate Varget - in fact one of them was written when IMR was still Dupont, Nobel's powders were still in use, and reduced loads were listed as using shotgun Ballistite.
Turning to Hodgdon's site, the Hornady heavies don't even get a look-in, but they do offer loads for the Sierra MatchKing in that weight (38 to 42 grains; sounds familiar, doesn't it?) and for the 150gn Hornady SP, which I have a box of. That load runs 39 to 43 grains (ADI's loads for AR2208 are exactly the same), while Hornady says 33.0 to 40.8; Hodgdon, like Lee and ADI, does not specify case or primer type. Hornady and Hodgdon give COAL within 0.003 of each other, which might easily be within the margin of error of some reloading presses.
We have a problem here. I know that switching cases and primers can cause pressure variations, and the proper thing to do is to drop back down to minimum and work up again. But surely the variations aren't that steep? And whose minimum do I use, especially if I can't match the primer and case combinations found in the specific manuals? Hornady's load range is way, way down on everyone else's and the manuals warn you not to underload by too much, while everyone else's minimum is so close to Hornady's max loads it's almost scary (especially in an SMLE).
I suspect that Hornady are making allowances for the fact that the base of the 174gn FMJBT protrudes much further down into the case than does the base of the RN of the same weight when both bullets are seated to their cannelures. But it doesn't explain the marked differences in the 150gn data (unfortunately Lyman didn't shoot the 150gn SP with Varget, but other powders that the two books have in commmon show similar underloadings on Hornady's part).
*sigh* Life was easy when I lived in Australia and all I had was ADI powders, which didn't seem to give a damn about whose bullets, primers and cases you used so long as you worked up from minimum every time you changed something.
(EDIT: I have Winchester large rifle primers and a combination of Privi and Remington brass.)
If I believe Hornady (9th edition manual), their 174 grain bullets (both the .3105" FMJBT and the .312" RN SP) are good for a minimum charge of 31.6gn of Varget and a maximum of 39.1 grains (Hornady/Frontier case, Winchester LR primer).
If I believe Lyman, the Hornady 174gn RN is good for 38gn of Varget as a minimum and 42gn as the maximum but data are not given for the FMJBT. These are also the high and low points given in the Lee Loader data sheet IIRC. In addition, ADI powders report their AR2208 (basically Varget in a different bottle or as near thereto as makes no difference) with the same minimum and maximum loads (38-42gn).
Lyman specifies Remington cases and Federal LR primers, and the same COAL as Hornady. Neither Lee nor ADI make any specification as to primer or case, and ADI doesn't even care which type or make of bullet you use as long as it's jacketed and assumes milspec COAL wherever there isn't a cannelure. The only other generic loading books I have predate Varget - in fact one of them was written when IMR was still Dupont, Nobel's powders were still in use, and reduced loads were listed as using shotgun Ballistite.
Turning to Hodgdon's site, the Hornady heavies don't even get a look-in, but they do offer loads for the Sierra MatchKing in that weight (38 to 42 grains; sounds familiar, doesn't it?) and for the 150gn Hornady SP, which I have a box of. That load runs 39 to 43 grains (ADI's loads for AR2208 are exactly the same), while Hornady says 33.0 to 40.8; Hodgdon, like Lee and ADI, does not specify case or primer type. Hornady and Hodgdon give COAL within 0.003 of each other, which might easily be within the margin of error of some reloading presses.
We have a problem here. I know that switching cases and primers can cause pressure variations, and the proper thing to do is to drop back down to minimum and work up again. But surely the variations aren't that steep? And whose minimum do I use, especially if I can't match the primer and case combinations found in the specific manuals? Hornady's load range is way, way down on everyone else's and the manuals warn you not to underload by too much, while everyone else's minimum is so close to Hornady's max loads it's almost scary (especially in an SMLE).
I suspect that Hornady are making allowances for the fact that the base of the 174gn FMJBT protrudes much further down into the case than does the base of the RN of the same weight when both bullets are seated to their cannelures. But it doesn't explain the marked differences in the 150gn data (unfortunately Lyman didn't shoot the 150gn SP with Varget, but other powders that the two books have in commmon show similar underloadings on Hornady's part).
*sigh* Life was easy when I lived in Australia and all I had was ADI powders, which didn't seem to give a damn about whose bullets, primers and cases you used so long as you worked up from minimum every time you changed something.
(EDIT: I have Winchester large rifle primers and a combination of Privi and Remington brass.)
