OH but MD...............whatever happened to "all other things being equal?" when it comes to things you DON'T push.
LIKE the 4-1 "rule" (very weak guesstimate that originated in the 60s by Homer Prowley with the ALSO antiquated "Prowley Computer" where it DID actually give SOME information because IT WAS APPLIED TO CAPACITY INCREASES MADE IN THE CHAMBER OF THE SAME RIFLE, WITH THE SAME BARREL, WITH THE SAME BULLET JUMP, SAME SEATING DEPTH, SAME EVERYTHING......EVEN THE SAME POWDER")
Back THEN........it was "about", "kind of close", "in the area of"........this much increase in velocity. Comparing rifle to rifle? Cartridge to cartridge" Regardless of ALL OTHER FACTORS that make UP a rifle.......is ludicrous.
Until EVERY rifle shoots the velocity given IN the compared load data used in the aborted version of the "4-1 rule"........it is entirely, absolutely, and without a doubt.............POINTLESS.
Going from factory barrel to a decent custom barrel can give you up to 100 fps........or more, alone, depending MUCH upon the very, very, very small changes/differences in bore/rifling diameters. Being BETTER barrels as far as accuracy goes is NOT the only differences.
Anyone doubting this please compare Nosler's load data pages to the Hodgdon reloading data site. Compare the same powder, same bullet (you have to look some), same barrel length and see how often (almost always) the Nosler data is way more (often 100 fps plus) than the Hodgdon data. They look at the name NEXT TO the barrel length on the Nosler site. Nope..........."all things are not equal".
Comparing two rifles...........THEY ARE NEVER EQUAL. There does not exist a "rule of thumb" on how high or low the velocity/pressure/accuracy/anything else compares. Trying to create one is a waste of your time and thought processes. Your rifle, your brass, your powder and primers, your efforts as a hand loader, make every combination an entity of it's own right. No one, no data, no arbitrary "maximum pressure" applies. It's safe in your combination........or not.
The information given here in the OP is OLD...........OUTDATED..........and NOT comparing primer to primer fired ALL OTHER THINGS BEING AS EQUAL AS POSSIBLE..........makes it all worthless..
No, all things cannot be equal.........ever, but handloaders SHOOT FOR such for low ES and low SD, (as consistent as possible) and DO use primers as a half decent high pressure sign.............because it is when the person loading makes all efforts to properly load rounds (as close to identical as he/she is able) , firing them in the same chamber (that they KNOW is clean and dry) .
Every long range competition shooter KNOWS the "weak link" in high pressure loads............is the soft (by comparison because it is not SOLID metal and not the same thickness as case base material) and it is PRESSURE FIT into the case. What gets pushed IN can get pushed out.......if there is "room" (bad sizing) but if not..........the primer TRYING to push out enough to deform it......IS HIGH PRESSURE.
Many studies have been done by competition long range shooters on primer hardness and size for that very reason.
Proper primer fit, proper case to chamber fit, headspace etc etc is a "surely you are doing that" kind of thing because experienced hand loaders know this is the main key to consistency along with the same components. They are not mentioned because it would be an insult to the other person asking them if they knew what the H they were doing...........just not saying it straight out.
What also gives "high pressure signs" in loads/chambers/ etc concerning improper care or loading............is moot and does NOT take away from the fact that ...............if you get primer deformation in loads you know for a fact are as equal as possible........and then you back off a half grain and you DON'T have primer deformation.......................IT WAS HIGH PRESSURE. (Talk about a no-brainer).
*******A short word (oops.......too late for that,eh? LOL) to those here that can think for themselves. READ the pages before and after SAAMI "Maximum Average (repeat AVERAGE!) Pressure" charts. I'm not going to tell you what they say. I have complete faith that those who understand the English language and will take the time to read through it all..........will see some BLATANT differences in what is tossed about. Special attenton to WHO SAAMI IS, What they can and cannot do.......and do not set!, How testing is done. What factors can cause errors in their tests (any anyone else's!!).
On pressure..........look ESPECIALLY for a statement on "97.5 percent of the service rounds will not exceed WHICH Maximum? and last but oh so far from the least.......Look for the STANDARD OF DEVIATION for their MAP findings. AND ALL THE OTHER PRESSURES within their report!.
Take the "Maximum Average Pressure" out of context and deciding what it is or is not, is like reading the 10 Commandments ( Exodus 20 KJV version) and seeing "Thou Shalt Not Kill" ..............and deciding to sell all your firearms because of what that "means".
Forget what you've been told.......read it all and read it again. Then give thought to this....... When you understand what the REAL maximum pressures THEY PREDICT are within FACTORY ammo, recall how often you have seen a rounded or flattened primer using them (it happens.........rarely) ...........then rethink what pressures WE are at when we sneak up on max (FOR OUR RIFLE) but back off when we get to pressure signs. Especially when you realize where your pressure MIGHT be when you see for yourselves the standard of deviation on chamber pressure ESTIMATES. And yes........all means of measuring chamber pressure have one. And yes............the Piezoelectric testing is considered one of the most accurate.
That's why SAAMI uses it. (I'm sure SOMEONE will huff and puff about the "strain gauges" now........oh well. YMMV?)
I'm not attempting to get people to load hotter............I'm trying to get people to think and decide for themselves. (Yes MD we KNOW........."You load to velocity"...........gimme a break.)
MODERATORS! While I would love to have a decent conversation on this, I will not return to reply on this post. The blatant disregard for controlling insulting, idiotic ramblings on this site make it of no interest to me ..............what-so-ever.
Hint.................
My apologies to those having a true interest in finding out for themselves (aka thinking) for my poor writing abilities and the mis-spelled words. I don't have multiple people proof-reading my work, plus it's just past 2AM. I only hope I've reached............at least a few.
YOU GOT THIS! You don't need MY or "anyone else's" help.
Have at it bashers. I can insure you that, I for one, will not waste my time reading them.
Oh.........MD? YOU owe Homer Prowley a public apology for aborting something he offered us into the lunacy you've stated as any kind of useful information. I mean............come on. Buy five rifles, all in the SAME caliber and they won't often shoot within a 50 fps span of each other. Guesstimating velocities CARTRIDGE to cartridge ALSO in differing rifles?..............zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz.
God Bless. Hunt safe.
Steve
