Originally Posted by
versifier
Understand that with the specific brass, bullet, primer and OAL in the specific firearm that Accurate used to generate their data it was a MAX load. It may or may not be MAX with different components and a different gun. Taffin used different components and firearm, but as far as I know he has NO access to to a PBL with a strain gauge for actual pressure measurements. I enjoy reading John's work, but he is a writer (and retired hs math teacher) with a LOT of loading experience; he is not a machinist, not a chemist, and not an engineer. He may be correct, or not, but either way there has to be a good reason why Accurate's MAX is so low, and I would want to know what that reason is before ignoring it. Just because it is in a popular magazine does not mean that it is correct, that the data was entered correctly by the typist, that a proofreader caught the error, that the data is safe. Remembering their published disclaimer, I would trust it no more than I would any data I found on the net from a non-industry source. The difference between the two MAX levels is so great that there is a definite possibility of an error somewhere. (It is also possible that the error is in Accurate's data, too. I have found a number of errors in loading manuals over the last 35 years - they are written, transcribed, proofread, and edited by human beings, and we all make occasional errors.) After having seen more than one revolver blown up by overpressure and the resulting damage and injuries to the shooters, I would prefer to err on the side of caution and could not advise otherwise on a public forum.
When anyone publishes data that is so contrary to that of the powder manufacturer, I would want to be doing a lot more research before even considering using it in any handgun. The main reason is that unlike for instance, a bolt action rifle, pistols and revolvers very often show no pressure signs on their primers at all, even far in excess of MAX. Sometimes the only noticable sign is difficult extraction from a cylinder that normally has no problems, but even that is no sure indicator, and it only works with revolvers, and not every time. With pistols, there are often no signs at all before a KABOOM. (You were talking specifically about a revolver, but you should also be aware that loading too hot for a blowback operated semi-auto can damage the gun by excess wear and strain on parts that were designed to function within a specicic pressure envelope. Firing a lot of very hot loads even if not above MAX isn't overly healthy for a revolver over time, either.) Even if you saw no pressure signs, that does not necessarily mean the load is safe. The only reliable ways to tell if you are too hot with your handgun loads is by using a strain gauge on the chamber or by carefully micing the solid part of the case heads before and after firing.
The first thing to do is to check several other current manuals for loads with the same powder and bullet weight to see if they agree with Accurate's data or Taffin's....
This is the data I have on hand:
Sierra says .44spec 240gr Jacketed 10.3-11.5MAX AA#7. Lee says .44spec 245gr lead 7.8-8.7MAX AA#7. Lyman doesn't list the powder with cast or jacketed bullets. This isn't enough data for me to make a safe determination, even with the AA and Speer data added in. At the very least, I would next want to be looking at both Hornady and Nosler data before proceeding to see if they could settle the question.
You may be safe at that charge level, but if it were me, I wouldn't be shooting any more of them until I had more definitive data. Putting both our data together, two sources say low and two say high - so far there is no clear trend one way or the other for me to make what I would consider a safe or an informed decision. It is easy to assume that John is correct, and personally I might be inclined to trust him if it were a wildcat for which no data were available, but the round has been with us for long enough that there should be plenty more data out there, enough to KNOW. Life is to short for me to bet mine on an assumption, even with those awesome 1" groups tempting one.