Need Comprehensive low pressure reloading how-to
 

I have just gotten a Parker 1879 uplift hammer 2 1/2” 12 Ga, with Damascus barrels, restored. Gunsmith proofed it with RST and said it was ok to use low pressure shells. Problem, as most know, RST, Polywad, etc., are out of stock and supply chain issues make it possible it will be a long time before they are back in the game. Reloading was suggested, but it looked like those components have supply-chain issues.

However a recent thread mentioned people now finding supplies at Brownells, maybe other sources. So, I want to consider reloading for this gun.

Sometime ago, I reloaded pistol and rifle cartridges, but I have never dealt with shotgun reloading. It’s clear from reading posts here that reloading for these vintage guns is a critical process to keep pressures low; and many variables, such as wads, shells, crimping, powder, and primers can make a big, and perhaps dangerous, difference, so it is not as simple as following cookie cutter reloading tables with standard materials.

Given the above, while I guess I could piece together parts of the science from various threads on this forum, I would like to find a resource that would comprehensively educate me on the process and materials for doing it safely without my missing a critical factor.

Can anyone point me to such a specialized resource that is reliable and clear to a newbie?

Thanks!

John, I'm sure a number in this group would be willing to share low pressure "secret recipes" that have actually been sent to testing labs, myself included. Your biggest problem is that components is a whack-a-mole deal right now. Stuff appears and disappears in hours. With shotshells a seemingly minor substitution can make big differences in pressure, especially wads, so caution advised! My best advice is to start with published or borrowed loads you can find components for, back off the powder to the 1150 to 1200 FPS range, and spend some time and $$ having them tested. Tune to your needs. This is a bit time consuming but time and money well spent.
Some of my Bismuth duck loads that have been tested. I substitute lead and bismuth in loads, cannot tell the difference in pressure. I shoot these in fluid steel barrels NOT Damascus (AGAIN, REDUCED POWDER TYPICALLY REDUCES VELOCITY AND PRESSURE). MODIFY AND USE AT YOUR OWN RISK!

These are more 12 ga. loads.
I've been working on low pressure 10 ga. loads for Damascus guns recently. Longshot powder is currently available and I have had very good success with it. Clean burns and low pressures according to the testing I've had done. You might want to try it.

Keith, it is late night as I see your post, so I would like to explore later; however, it just confirms how much I need to learn before I could even consider taking advantage of your generous sharing of load info. I need elementary school!

Don't be scared to ask questions here. This probably the best group I've ever associated with about sharing knowledge on our common passion.

The group has already been very kind!

Like I said, I have some experience loading brass, but none with shotshells.

Before I could even begin to talk about loads and testing, I need to learn a lot about such basics as even what reloading equipment works best, what accessories are needed, etc. The question of even what wads to use seems bewildering as I look at the plethora of options I saw on the site of just one dealer that seems to have stock. Which are compatible with low pressure? Then there is understanding hull materials, shotshell crimps, what powders are slow burning, primer differences, etc. These are some of the issues I have seen from perusing the forums; and I am not sure about what I don’t know that I don’t know.:shock:

It may not exist, but it would be nice to have a resource that took me through each essential, one by one, and covered all the bases systematically. :confused:

But I appreciate the group and will take all help offered!

I would recommend looking at the powder manufacturers website. All have extensive load info. Alliant and Hodgdons make a large proportion of the shotgun powder a lot of us shoot and have literally hundreds of loads published with primer, wad, hull, and powder combinations.

Keith, I did notice two of your loads are identical except for the primer. One 12g 2 1/2" load uses Fed 209 and one uses Cheddite. The difference between the two was an average of 10 FPS (?) and pressure of 100 PSI. That is not much of a difference. The reason I comment is some guys had higher pressures with Cheddites and some did not. Some recipes needed to drop an average of 2g of powder if using Cheddites to lower their pressures to levels consistent with the domestic primers. Since I don't load "hot" shells I don't really worry about the primer, but I see how some guys may need to have some testing done especially if they are loading something "snotty". Thanks for posting those recipes. :clap:

Yes, I got some 10 ga. results that differed only in that some had factory primed Cheditte, some I primed with Cheditte 2000s. They were 1Kpsi different! There was a thread speculating on what came in factory primed Cheditte hulls, we still don't really know. That's why I tested identical loads factory vs. Cheditte 2000 (that's what we're all buying). Surprised me. Now, those loads were 4200 PSI vs. 5200PSI for my Damascus guns, Ho-hum, but on the "snotty" end, might matter.

Which criteria
 

Keith,

I was looking at your reports. I assume that the red ratings were your conclusions based on the report values.

What are you basing the evaluation on? Velocity, pressure; average, standard deviation, or extreme spread of one of them? What made one "Best 12 Ga", 2nd, "Good", or "Very Good"?

What is your target for velocity and pressure; and I guess that these are for your fluid steel barrels? Would you target ~5,000 psi or something else for Damascus?

Thanks!