Too many points to easily address in one reply. I’ll do my best to cover a few:
1.) You’re citing pressure tests using a variety of wads and stuffings for Reloder 15 powder in 470NE loads. That is a non-sequitor to your follow up comments of IMR3031 being unsafe. I was asking for the data related to pressure tests on IMR3031 rather than RL15 to understand the logic leading from one topic to the other.
2.) Regarding single shot custom Ruger #1s, you can load them with about anything you wish. They are built to handle about anything you can throw at them, and they are single shot so regulation is of no concern. Speculation, why would someone recommend RL15 for that action? Because RL15 is a notoriously accurate and reliable powder?
Thanks if you can provide a table related to point 1 for IMR3031 pressure in 470NE related to a variety of stuffing options.
There is no article on the web dealing with chamber pressures measured while working up large caliber double rifles loads using IMR 3031. This would be expected since I doubt anyone would have the time, money or inclination to do this for a powder introduced in 1934 which has been sidelined by newer powders that don't carry its negative cachet.
I would posit that while no quantitative data exists, qualitative findings might be substituted. Loads that have been submitted here by reputable shooters could be a reasonable substitute provided they regulated at appropriate velocities, with appropriate powders and exhibited no extraction problems which would indicate elevated pressures. Let me step out on the teleological limb to say that medium burn rate powders and slower could be suitable for working up loads if standard precautions and procedures are taken. This is also stated by Wright. My bottom limit is Varget and his is RL15. RL15 is not my “go to” powder. Those now are Varget, H4350, RL17 and IMR 4381.
Graeme Wright chose powders readily available in Australia which includes the same powders as marketed under the Hodgdon Extreme series. To that he added IMR 4831 and RL15which have become classic. He chose not to try IMR 3031 for his stated reasons. Maybe someone can underwrite Wright to do this or even better, fund a 4th edition of this book to include IMR 3031. Maybe a debate at SCI might be a worthy venture? Any takers?
Ross Seyfried published two articles using the Hamilton Bowen Ruger No.1 in 470 NE. I am including photocopies from the 1990
Guns and Ammo article. I have the second 1995 one about using RL15 but this is not available as I write this as it is ensconced in Alaska. Note that in1990, he was using 4831. Yes, the falling block Ruger does not have the constraints placed on it that a double has; no regulation of two Siamesed actions and with better extraction from the falling block lever. However, please note he gave loadings below and equal to commercial ammunition. He reported no extraction problems with those loads. The second article also conforms to standard factory loadings with his use RL15 using dacron. Federal uses RL15 with a proprietary primer, the “216”, which doesn't require a wad. I have had access to those primers and they are hotter than 215s!
I called up Hornady today and chatted with them. Needless to say they use pressure testing as part of the work up. Considering the breadth of the loads tested by Wright, this was quite an undertaking. In my profession, “quoting the literature” that has been peer reviewed is mandatory. As such I am also submitting photocopies of small portions from his 3rdEdition, more to defend his position but also to show what the values are. Since the book is out of publication and I doubt anyone is going to sell theirs on the cheap for these “spoilers', I submit them here for reference as fair use.
Note that wads reduce the amount of powder needed and , from experience, improve ignition. Wright shows that wads have the equivalent value of 4 to 6grains of powder. I found this to be around 3 grains when I am using open cell backer rod. A one inch length of open cell backer rod costs about one penny US which is far cheaper now than 3 grains of powder.
As I mentioned in an earlier post, fast powders with small volumes can create problems such as belling. I submit the portion of Wright's book on that.
Finally, I have been loading and shooting 470 Nitro Express double rifles for 30years. I have used many makes of primers, at least 14 different powders, bullets from the major companies and all sorts of wads and stuffing from dacron , to speaker foam, backer rod and Kynock wads. My double rifles are still in one piece with the advantage of the benefits that newer powders give.
In summation, load what you want, but sage advice is out there from well respected members of the hunting and shooting society.
