In a series of posts, Ranch13 asked, "So how many here use 4f in cartridges? Fellers this was mostly posted in frustration of the tongue lashing I took from another forum for calling someone, who loaded 82 grs of the stuff into a 40-82 case, fired the damn thing, lost a primer and is now concerned about how much pressure bp generates, and is convinced that Lyman's data is "questionable", bullheaded."

Digital Dan responded, "Well now, whyn't you invite him over here for a little chat?"

JB said, "First off Ranch I want to say that you were right in what you said in your responses over at Goex. Me thinks Dick Gunn need his own Lab to conduct his own experiments away from the safe and sane world. What was his point about fine black powders the English used in the .303 Brit cartridge... ie apples to oranges. I read the same postings over at Goex as well as other forum boards that Dick Gunn associates with, I do question his reasoning for it.... Many shooters today just are not happy unless they are making their bullets fly at a supercharge or spiking their feet per second rate for flatter trajectory, and that is what he appears to be trying to attain. My Opinion Expressed. Now lets get back to talking about normal loadings of Fg, FFg and FFFg."

Ranch13 responded, "I think that clown needs to be identified immediately should he arrive at any shoot, it would not be a good thing to have some innocent bystander injured because his gun come apart at the seams on account of the possibility of the case being a little long. ( Never friggin mind the over charge of powder.)"

JB followed up, "Ranch13, Your exactly right, if he is identified should he attend the Quigley this next year, I want to know who he is because I sure don't want him shooting on the squad I'm shooting with."


Reading the foregoing posts, it would seem that I am a bullheaded clown whose sanity is questionable, who is trying to supercharge BP cartridges, and who cannot be trusted because he might bring dangerous experimental loads to a match.

While folks are certainly entitled to express their opinions, I believe that in this case the above statements, opinions, and misinterpretations are not supported by the facts. The facts concerning my 4Fg velocity tests were extensively aired on the GOEX board and the MSN site, and I would have been happy to leave it there. But since I did not hide behind an anonymous handle, my name has now figured prominently in disparaging posts on this site, so I figure I better defend my good name.


This whole discussion started when I asked if anyone had access to laboratory pressure test data for BPCR cartridges. I'm trying to work up an equation for estimating BP pressures, so I need a lot of data points. There's a bunch of published information about peak pressures generated by muzzle loaders, but not a lot about BPCR pressures. Also, there appear to be some minor but persistent discrepancies between the BPCR pressure data published by Accurate, Lyman, and Spencer Wolfe. While these discrepancies are not very large, the fact that they exist does present a problem when trying to decide which pressure data points to use when developing my pressure equation. Hence the inquiry re: possible additional sources of pressure data.

So far so good. Nothing in the above request should have caused howls of protest or gross insults.

Regarding the 4Fg stuff, when I was working up some equations for estimating BPCR muzzle velocities, I got most of my data by chronographing a series of cartridges loaded with 1Fg, 2Fg, 3Fg, and 4Fg. This velocity measurement process was done in what I regard as a reasonable, safe, and prudent manner.

There was no question that the test loads of 1FG, 2Fg, and 3Fg would be safe, but working with 4Fg was an unknown territory. Since Spencer Wolfe's testing had shown only a 20% increase in peak pressure when shifting from 2Fg to 3Fg loads, an additional pressure increase 20% or 30% was a reasonable expectation for the 4Fg loads. The British had used very fine grained BP in their .303 without any problems.

Even though the available evidence suggested that moderate 4Fg loads would be safe, I started low with a strong Siamese Mauser chambered in 45-70 and then worked up slowly. I also used a Mauser chambered in 375 H&H, the poor man's 38-90. After the 45-70 and 375 H&H 4Fg loads were found safe, 40-82 loads were tested in a C. Sharps 1875 action. The C. Sharps 1875 is a modern made replica that is at least as stout as an 1885 Winchester High Wall, and Winchester used standard Highwall actions for the pressure test guns in their laboratory.

I used CCI pistol primers for the 4Fg loads because those primers were made of lighter gauge metal than rifle primers and were reputed to show pressure signs at just 35,000 psi.

No one else was endangered during these tests because I tested the 4Fg loads on a weekday afternoon when I was the only one shooting at the range. No one else was there except for the range safety officer.

The 4Fg loads fired in the 45-70 and 375 H&H Mausers did not produce any excessive pressure signs or primer flattening. Also, the first 4Fg rounds fired from the 40-82 showed no signs of excessive pressure. Thus it was a surprise when I opened the 1875 action and found that the primer pocket had expanded. It turned out that the 40-82 pressures had skyrocketed because that particular cartridge case had been trimmed too long. Firing stretched it into the throat, tapering the case down onto the bullet and making it difficult for the bullet to be released from the case.

Of course, if a bullet doesn't move out quickly, the pressure goes way up. Given the excessive length of that cartridge case, pressures would have zoomed up if I had loaded the cartridge with 2Fg or 3FG. Powder granulation had nothing to do with that excessive pressure peak. It was a function of delayed bullet release.

Of course, all this was explained in the posts on the GOEX and MSN sites. Selectively quoting from these posts only gives an inaccurate picture of what actually transpired, and does a disservice to BP shooters who are looking for accurate information.

As I hope I made clear, I am not advocating the use of 4Fg in BP cartridge rifles. As my experience with the 40-82 shows, you have to pay attention to every aspect of handloading, including case length.

Just to set the record straight, I have no beef with Spencer Wolfe, Lyman Products, or Accurate Powder. Nor do I have a beef with anyone who made a constructive response to this inquiry. I'm not trying to supercharge black powder cartridge rifles. Those 4Fg loads only increased muzzle velocities by about 50 fps compared to the 3Fg loads. If anyone wants high velocity, they should try another game than BPCR.

Despite all the above safety precautions mentioned above, I do not recommend that anyone use 4Fg in a BP cartridge rifle.

In conclusion, it's real simple. I'm looking for lab tested data on pressure generated by BP cartridge rifles. If anyone has such data, or knows where I can find it, I'd like to learn more.

All the best,

Dick Gunn