jimbo1096, Excellent question! I have the current Hornady and Sierra manuals and they still have many popular loads rated in CUP instead of psi. This means they haven't retested the published loads ... just reprinted old ones. Speer did a really good job on their #13 manual so I'm assuming #14 will be even better.
I use QuickLOAD software quite a bit but never as a single source for reloading data. It is great for doing "what ifs" with different loads and to see what happens when bullet seating depth is changed or a different style bullet is used. QuickLOAD seems to track quite well with the Speer manual but often disagrees with Sierra or Hornady manuals.
A lot has been learned in recent years since piezo transducers started being used for pressure testing. We now get actual chamber pressure in psi instead of pseudo pressure in copper units of pressure (CUP) in some "unreal" test barrel. The labs have a much better handle on safe limits for each cartridge and in fact have caused the Small Arms and Ammunition Manufacturers Institute (SAAMI) to change their standards on many loads. SAAMI likes to see cartridges rated at about 50% of a gun's "proof test". For example, a 357 Mag is now rated at 35k psi so you can expect the gun to hold up to at least 70k psi. Previous standards were way hotter ... well below the Kaboom point but high enough to cause considerable damage. The European CIP standards have the max chamber pressure for a 357 Mag rated at 3000 bar, which converts to 43,511 psi and is about the same as the older SAAMI ratings.
The worst reloading data comes from powder manufacturers. They tend to load "hot" .... maybe they are trying to boast. They seldom specify a primer nor do they specify a particular bullet or even seating depth. Believe me ... these things can make a huge difference. The foreign made powder companies (mostly from Australia and Finland) tend to follow CIP standards or their own agenda, which are often way hotter than SAAMI specs.
Speer takes those powders and their own bullets then charts them within SAAMI specs. They specify primers, bullet seating depth, and note other conditions like a compressed load. I like that. I don't want to be a "range dummy", I just want to safely shoot accurate loads at factory power levels. When you chronograph Speer loads, your results will mirror Speer's data very close (assuming you use the same barrel length). I always figure ... if my gun isn't powerful enough with SAAMI rated loads, I need to buy a bigger one, not push the envelope on my current cartridge.
There are two types of gun damage from hot loads. First is catastrophic damage which we commonly call the "Kaboom" factor. This is where chamber pressure exceeds the strength of the gun and causes the gun to blow up. The second is accumulated damage. This is from metal fatigue and other wear issues that cause the gun to shoot loose then slowly get worse until the gun fails or becomes unsafe to shoot. Most shooters only think of the Kaboom factor and believe if their gun doesn't blow up, it must be safe. As a long time gunsmith, I can assure you this is not a good agenda. I have seen many guns come in the shop that were damaged beyond the point of being safe. Some of these guns were repairable ... some would cost more to fix than to buy a new one. Some were fired after being stressed and resulted in catastrophic damage.
Here on the forum, I don't like to see folks post loads that are over SAAMI specs. If they insist on risking damaging to their guns or their body ... I guess I can't do much about it, however, the Ruger Forum is not the place for dangerous data.
Back to Speer ... Speer loads equal factory loads and maybe a little hotter, they are always within SAAMI specs. I like that and will continue to be a "Speer reloading manual pusher". It doesn't mean the other manuals are bad, just not quite up to par with Speer.
