For example, and I’m talking about 6.5x55 Swede here, say you like Hornagy’s GMX recipe, but it may be hard to find the prescribed primers in your area, so you gotta sub. (1)
People obviously do this regularly with success and safety. (2)
Then there’s some data that just makes no sense... for example the Barnes 127 LRX recipe using H4350. It calls for a max charge of like 8+ grains less than other recipes for other similar weighted bullets. That makes no sense. (3)
See warpig62’s recent post about load testing this LRX bullet in his Swede. He’s using powder charges that obviously worked out fine, and accurate, but are WAY too hot according to the Barnes manual. Yet look at the Hodgdon data for a 129 gr. bullet and he’s just fine. How’s a newbie to make sense of this! (4)
Then there’s the issue of a lot of load data being based on use in old mil surp rifles, yet mine is a modern bolt rifle. More inconsistencies. (5)
So I counter that it’s nearly impossible, and certainly impractical, to following reloading manuals to a tee. You pretty much have to use some creative license, yet common sense must also be applied liberally. (6)
(1) See above and read more from John Barsness and the many other fine and experienced writers as well as Brownell on Pressure Factors and other academic studies. There are primer substitutions that are about as safe as any shooting sport can be and primer substitutions that are highly risky.
You seldom or never, gotta sub. You do gotta find a book load with available components. Wartime expedients of match heads and chopped movie film excepted. Most places in this country a book load that will do the job is possible. It may not tickle the fancy but it will do the job. Say you like Hornady's GMX recipe but you can't find the prescribed primers. Then either make a safe substitution - not arbitrary but safe or put it aside until supplies change and move on to something else. I'm not listing generally safe substitutions here but anyone with average google fu or broad reading will have seen them.
(2)
If you’re unlucky, the rifle’s action can come apart all at once. This happened a few years ago to a friend who was fond of loading rounds beyond normal velocities—and hence pressures. He got lucky. The right side of the action blew, sending the heavy scope over his left shoulder and into the side of a building over 30 feet away—instead of into his face. HE OBSERVED NO “PRESSURE SIGNS” BEFORE THE RIFLE CAME APART but had been shooting hot loads in the same varmint rifle for over a year. John Barsness again
Might even speculate about folks on this board with similar experiences. There was a similar experience with .30-'06 bolt coming back with a SAAMI spec load in a previously abused rifle. Some choices are safe, some are unsafe, is dangerous is gun is always true.
(3) It makes perfect sense. See my mention posted above that once upon a time bullets were - mostly - of similar cup and core construction so that bullets of about of the same weight had a lot in common.
Today similar weight but different construction and shape means bullets can be and often are different enough to make a major difference in the load. data A monolithic or varied alloy lead free bullet will tend to be longer for the same weight and so have a different bearing surface and often be harder. Much like the difference between cast and jacketed pushed to an extreme. Notice this implies different engraving force and often implies different seating with respect to the throat. Similar weight with a variety of other characteristics quite different the similar weight does not thereby imply similar charges. Rather the differences all combined imply different charges.
(4) Perfect example of the above discussion. Barnes LRX are pure copper 129 GR. HDY SP per Hodgdon have a solid one piece lead core. Which leads into
(5) Data for 6.5x55 may be intended for a 19th century military surplus rifle or a recent Ruger or Remington Classic.
The SAAMI Maximum Average Pressure (MAP) for this cartridge is 51,000 psi (351.6 MPa) piezo pressure (46,000 CUP).
I would not hesitate to exceed this SAAMI maximum myself. I might even blur distinctions as between the .270 and .280 in a modern bolt rifle figuring the .280 introduced in a gas auto can handle a little more pressure in a bolt gun. I've also got some interesting almost torn rims from high port pressure but reasonable max pressure book loads in a gas gun.
Similarly there is data for .45 Colt at three different pressure levels commonly from black powder Colt Peacemakers to new downsized Rugers to loads that might best be used in a revolver chambered in .454 Casull up where the highest pressure .45 Colt load is pushing no limits in the gun. Oddly enough about the highest pressure generally accepted as safe loads in a .45-70 are for an old military surplus the Siamese Mauser. Here again there are gradations from trap door Springfield loads to Ruger #3 loads with assorted revolvers and lever actions someplace in the middle.
I wouldn't say inconsistencies but I would say incomplete or abbreviated information. And all information is incomplete. Again is gun is dangerous and a little knowledge is dangerous. When I picked up an original flat top Ruger Blackhawk back when they were new on the market I looked at the frame mounted firing pin, analogized it the Colt 1911 I had training on and assumed with all that implies that the firing pin was floating like the 1911 - unlike the Colt hammer mounted firing pin - so I comfortably but mistakenly loaded 6. Don't do that on an original.
(6)So I contend that it is perfectly possible and relatively easy to follow loading manuals to a tee - all the more with the quantity and quality of lab tested data available today. I started with a Lyman 310 tool loading 9x19 - one dipper load at a time. Today I may amuse myself showing off interesting performance as with heavy bullets for the cartridge in a 9x23 with SP2 based on shared experience more than published lab tested data but that's not a good starting place or I'd have
Super Face.
