What exactly does "The charts given are shaky to me" mean?
Every load table has a MAX load. If no start load is given, then the start load is a 10-12% reduction from the MAX load--unless otherwise specifically noted.
1) I always started any plated bullet load work-up with the starting load for the same weight lead bullet--just as all the manufacturer's used to recommend.
2) I prefer to check at least two sources and start with the lowest starting load.
3) Get a copy of Richard Lee's #2 manual. He compiled a lot of data from all sources (data is not copy-righted, only the formatting) and has it separate by jacketed, plated, lead, frangible, and, probably, monolithic.
4) It is safer to call the powder manufacturer than to take the word of anyone on the 'net.
So, pretending that I have the problem, I go to an Alliant or Western Powder Load Manual.
From the one I find on-line, I see the following:
*125gn Bar TAC: 5.2-5.8gn*
125gn Hdy XTP: 6.1-6.8gn
125gn Rem GS: 6.4-7.1gn
125gn Sie JHC: 6.1-6.8gn
125gn Rnr P-HP: 6.4-7.2gn
*125gn SF RHFP: 5.4-6.0gn*
For comparison, the Hornady #9 manual shows:
125gn FP-XTP and HP-XTP: 6.6-7.6gn
Accurate 2003 shows:
125gn Spr JHP: 6.1-6.8gn
Note*:
SF makes frangible bullets, so that data is not applicable.
Barnes TAC is a monolithic (all copper) bullet, so that data is not applicable.
I can not find any 120-130gn lead bullet data with AA5 powder, so can not use that as my start load.
So, the one and only plated bullet tested shows a start load of 6.4gn. Since I can find jacketed data with a lower start load, I would start with the lower charge.
So, that gives us start loads of 6.1-6.6 gn and MAX loads (which are dependent on the GUN, the LOT NUMBER of powder, the exact bullet used, the COL, and, to some extent, the primer and cases used—and you almost certainly don't even have one of those things, so your MAX load is completely unknown) of 6.8-7.2gn.
So, for safety, my load work-up would be 6.1, 6.4, and 6.7gn and see what I get.
I would retrieve all cases after firing (I like to retrieve the first round at each weight and, if it looks OK, fire the other four—then collect those four and inspect them all) and inspect for any pressure signs. With handguns, I like to compare the recoil of the rounds to factory rounds of the same weight of bullet and also where the cases land, compared to those same factory rounds—besides the normal primer appearance and case bulge just above the web (compared to those factory rounds) and any other signs of problems.
If there are no pressure signs and groups are getting smaller, I "might" test higher charges; however, I have no need for a max charge, so I am not going to chase it.
