doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Low pressure loading manuals

In the past I have relied on RST for most of my vintage shells. Just for ease. I haven’t actually called them, but the site is usually out of everything I use. My stock is about gone….

I reload for Trap at times, I have various powder handbooks, from the manufacturers but, there isn’t anything in that 5k psi range.

What are some good manuals out there that have a good selection of low pressure recipes these days? From Precision Reloading? Or off Amazon? Lyman?

I’m looking for 12ga 2.5” loading data.

Thank you!

Go to the Hodgden and Alliant websites. There are a number of good lower pressure loads listed. 7/8 oz 12 gauge loads using ClayDot powder are around 6,000 psi. Good luck though finding components

lymans shotshell hand book has lots of load formulas that fall in the 6 to 7000 psi range...

can data for 2 3/4 hulls be used for 2 1/2 " hulls?

and if not, why not/

Ballistic Products reloading manual has various loads for short shells.

For low pressure 12 loads I bought up a large stock of PB and 800X, both are hard to find as they are discontinued. Clays, International or Tightwad come to mind as possible powders. Alliant powders seem just a memory these days with only a few seen in scattered places. I bought 8 pounds of Unique a few weeks back but had not seen any in two years.

It comes down to what components you have available. I keep a ridiculous number of powders on hand, along with six different primers, many different wads and enough different empty hulls to fill a pickup truck completely full. And still I come up short on too many combinations. Locate what you can buy, then go to Hodgdon and Alliant online reloading guides to see what works. Also Trapshooters.com has a reloading section with a decent number of tested and verified loads for currently available powders, primers and wads. Does you no good to find the perfect load which uses Remington Primers when none are available and last seen were north of $100.00/1,000.

Also you might need to be flexible in what low pressure load you are after. 1 ounce/ 1,100-1,150 fps works for me while other might like a 7/8 ounce load for clays in the 5-6,000 psi range. Do watch many older published loads were in lup not psi and that makes a real difference.

Where is the line drawn between low pressure and high pressure? I recall a discussion years ago when the late Miller explained that the pressure curve was more critical in the barrel and was as important, if not more critical, as the peak pressure number. Seems I recall his referring to an old graph comparing pressure curves along the barrel length of various loads. I've seen loads which were listed as "low pressure" having psi in the mid 7K psi; others in the 5-6k psi range. Gil

smokeless loads that duplicate black power pressures could be considered as low pressure?

Gil is absolutely correct. To attain a common velocity two different pressures still have to generate similar energy. One can attain that in a very short distance in front of the chamber. The other, a lower pressure load, stretches out its energy creation further down the barrel. So, if I’m shooting an older gun with thick chambers but tapers quickly I choose a higher pressure load, keeping the stress in the strongest portion of the barrel. If the chamber is marginally thin, as many very early breechloaders were, then I’ll opt for a slower powder to distribute pressures into the bore. Common sense.

I think these were on doc drews site

I prefer to load smokeless powder using fibre wads and finding recipes for low pressure loads has been a challenge. I'm wondering about the relationship in pressure if I were to take a load listing a plastic wad and interchanged it with a fibre wad. Would I get more or less pressure or would I be going into the dark realm of loading where I shouldn't be?