Answers? OK so here are the responses from those closest to the issue. I was fortunate enough to get a response from the Quickload (QL) developer, the bullet manufacturer and the powder manufacturer. That pretty much covers all the bases, if anyone thinks they know more than these folks, you are in the wrong job. Here are their answers to my question... "Do you think the Barnes .338 Fed data with Accurate powder is reasonable?" Here are the answers. The info may or may not be applicable to your situation, so please do NOT apply without doing your own research. I am amused by the difference between which ones actually understand what�s going on inside the barrel, and those that just read a gauge. You make your own call.
I have no doubt that Barnes runs each of their loads through a test barrel. The fact is �things happen�. Barnes has pulled several loads from the current manual. I am not suggesting that they are any more �reckless� than any other manufacturer. On the contrary, at least you can easily find the updates on-line. I suggest that ALL load manuals have errors � I just prefer not to find them in my gun.
As you can tell some in the industry use QL � some don�t.
From the developer of QL:
�Even Accurate seems to change the manufacturer of their powders (formerly from Czech Rep.) to different origins. So the powders will be different, because they cannot manufacture equal types -they have to mix the powders to obtain the old specs.
To my knowledge, Barnes is testing the loads in rifles equipped with the Oehler Ballistc Lab. strain gage system. This allows no direct pressure reading, only comparison with reference loads with well known pressure curves.
75000 psi will not (always) exhibit high pressure signs. When you browse QL manual, page 114+115, I put some pictures of proof load case heads. They have been pressure tested before and their pessures are well known. With proper=small headspace there are minimal flattend primers. With weak brass primer can be popped.
You should try to email to ballistic lab guy of Accurate�
From Barnes Ballistician:
�Powders will vary from lot to lot by as much as 3%. Not to mention all the other variables such as chamber dimensions, brass thickness and seating depth or distance from the lands. That is why every manufacturer suggests a 10% reduction from the max charges, starting low and working the load up as is customary in the reloading process.
There are also anomalies that we can't explain. You'd think that one more grain will give another 50fps as it had done for the last three 1 grain increases but sometimes pressure spikes and the velocity goes down. These are the type of things that Quickload can't predict.
The AA 2230 powder we use is the same stuff you get. We don't get a special lot from the manufacturer
I'd contend that our data is if anything a bit conservative. We use some of the tightest SAAMI spec barrels to simulate a worst case scenario.
Velocity is a good indicator of the best powder for a given scenario. And because AA2230 gives the highest velocity and best fills the available space (load density) with several bullets weights in the 338 Federal, I'd suggest it is one of the best choices.
So you see, just when I think I have it figured out I learn something new that just can't be calculated. We must test and go with actual data.�
From Western Powders Ballistician:
�The only TSX bullet we actually tested was the 185grain. (Our measured data indicates 45.5grains vs 49.0grains of Barnes).
So it its higher than our test. However, I do not think it will be a serious increase in pressure that will cause problems. Calibers such as these tend to form a plateau (point of diminishing returns) in performance, and can actually at some point deliver reduced performance if more powder is added.
The issue with large expansion ratio calibers such as the 338Federal is that because of the high loading densities, a condition we call �premature shot start� occurs, which is very difficult to simulate. This �effect� can be amplified because of the reduced bearing surfaces (such as the TSX design) or special slippery coatings applied to some bullets.
Because the projectile moved away at a much earlier stage than normal, the effect is that the dynamics is �skewed� producing lower pressures because of a larger initial combustion volume.
Also the Freebore/leade dimensions of the barrel will be even more critical in such a case.
You can come close in QL by changing the shot start pressure to Zero and usually adding extra cc�s in case capacity to simulate the effects.
In such a case, it will important to measure the actual velocity, and adjust QL to suit the velocity value. The resultant pressure of QL pressure will be very close to the actual pressure.�
