Is newer reloading information “wimpier” than the older stuff?
Friday, October 05, 2007 (04:06:41)

Posted by Pumpkinslinger

Is newer reloading information “wimpier” than the older stuff?

Every so often when I am talking to folks about reloading I hear that the loads printed in current reloading manuals are much milder than the loads in older manuals. The most common reason given is legal liability, that the various companies have “wimped out” due to legal pressure. Since I had a variety of manuals on the shelf I decided to check some loads for myself to see if there really was that much difference. Also, if I found differences, I wanted to try to understand why there was a change.

The oldest bullet manufacturer’s manual on my shelf is a Speer #8, printed in 1970. I also have a Speer #14, printed in 2007. Obviously these would be a good place to start as they come from the same source and use the same bullets. I picked two very common cartridges to use for comparison, the .30-06 Springfield and the .45 ACP. The procedure was pretty simple. I just went through both manuals, found the loads using the same powder and bullet weight in each and wrote down the maximum recommended load. Then I determined the difference between old and new loads, both as grains of powder and as a percentage of the load. I did not list any muzzle velocities because different guns, with different barrel lengths, were used in the tests and I didn’t want to muddy the water with that variable.

I took the .30-06 first. I used three different bullet weights: 165 grain, 180 grain and 200 grain. I found five powders that were used with those bullets in both manuals. The results are in the table below.
.30-06 Springfield
Powder Bullet 1970 2007 Difference % Difference
H414 165 58.0 56.0 2.0 3%
H414 200 52.0 53.0 -1.0 -2%
IMR4064 165 51.0 50.5 0.5 1%
IMR4064 180 50.0 50.0 0.0 0%
IMR4831 180 59.0 59.0 0.0 0%
IMR4831 200 58.0 56.0 2.0 3%
IMR4350 180 56.0 56.0 0.0 0%
IMR4350 200 53.0 54.0 -1.0 -2%
IMR4895 180 50.0 47.0 3.0 6%

When you compare all the loads you see that the older ones averaged about 0.6 grains more powder, a difference of 1.1%.

Switching to the .45 ACP I picked two bullets, the 200 grain lead SWC and the 230 grain FMJ. I found five powders that were used in both manuals. The table below shows the results.
.45 ACP
Powder Bullet 1970 2007 Difference % Difference
Red Dot 200 4.5 4.5 0.0 0%
Red Dot 230 5.5 5.3 0.2 4%
Bullseye 200 4.0 4.6 -0.6 -15%
Herco 200 6.2 6.0 0.2 3%
Unique 200 6.0 5.4 0.6 10%
Unique 230 7.0 6.5 0.5 7%
700-X 200 4.3 4.2 0.1 2%
700-X 230 5.0 5.1 -0.1 -2%

Again comparing all the loads the older ones averaged 0.1 grains more powder, a difference of 1.2%.

We can see that, while there is a small difference between the older and newer data, it’s not significant. There are a couple of things that can account for the changes. Different lots of the same powder will vary a little. You’ll note that sometimes the older charge weights are higher; sometimes the new ones are higher. I think another likely reason for any changes is that we now have better ways to measure the actual peak pressures. Electronics give us more accurate pressure readings than the “crusher” systems that were used before. To quote Alan Jones, editor of the Speer manuals #12, #13 and #14, “Sooner or later the old crusher system will be obsolete. We started the transition from crusher to electronic pressure measurement with the handgun cartridges in Number 12. Now we are converting the rifle data as time permits.” All Speer loads are kept at or below the standard industry maximum pressure.

It looks to me that the recommended loads today are no “wimpier” than the old loads. They should be safer, given the better pressure measuring equipment now available. One thing I would like to say is that these reloading companies have much better equipment than we do measure the pressures for the various cartridges. Personally I think it is foolish to try to exceed the maximum loads they have printed. I won’t risk the chance of damaging a gun, or me, to try to boost my velocities by a few feet per second. Let’s enjoy our hobby of reloading but keep it safe!