Parker Gun Collectors Association Forums - 20 Gauge Damascus Pressure

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- - 20 Gauge Damascus Pressure (https://parkerguns.org/forums/showthread.php?t=32078)

Bruce are you using those shells in damascus barrels?

Yes. All a person has to do is look at the Parker service load tables and recommended loads to realize that these barrels , whether they be fluid, twist, laminated or Damascus , have way enough hoop strength to use sensible loads. I’m not talking about Black Cloud Prairie Storm guaranteed kill at 100 yards cartridges that manufacturers love to sell at premium prices.

The real issue is whether the barrels have been honed excessively , or if they have deep rust pits , or been whacked hard and cracked. Those issues require a careful examination by somebody with some expertise , not necessarily a gunsmith.

A usually more pertinent issue is recoil and how hard you want the gun to whack the stock or your shoulder. Some 100 year old stocks are solid , others not. And you know that chamber pressure formulas and the recoil formula are related , often confused but very different.

So here are cartridge boxes that I use on Parker small bores Damascus and fluid. The 16 ga ones can be instructive. Using the recoil formula and assuming guns of equal weight , which load produces the least recoil?

While I cannot put the math on here , the variable formula factors are the weight of everything that comes out the muzzle and the velocity of the ejecta. No cartridge length , no stock drop, no chamber angle , no favorite powder brand.

c. 1900 reported 20g pressures vary significantly
7/8 oz. 2 1/2 Dr. Eq. BULK Smokeless was 8000-10,000 psi.
7/8 oz. 2 1/2 Dr. Eq. DENSE Smokeless was 11,000 - 12,500 psi.

Up until about WWI the standard 20g load in the U.S. was 7/8 oz. with 2 1/4 Dr. Eq. Bulk or Dense Smokeless powder at 1155 fps.

As Bruce observed, assuming the barrels are without defects and with adequate wall thickness, using the load listed on the original hang tag would seem reasonable.

Jay, the next slower powder on the Alliant chart if you skip 20-28 is Herco. If you pick a Herco load that is similar to your Unique load, you will get the lower pressure you are looking for.

Thanks everyone, I feel better about this and see I have many more alternatives than I thought. I appreciate all the great suggestions. I should be making my own 20 gauge shells in a week or two. Thanks again for all of the help!

I use 20/28 for low pressure loads in AA hulls. Loads are listed in Alliants web site

Quote:

Originally Posted by Matt Buckley (Post 321580)

Jay, I would suggest sending in some of your hand loads to have the pressures and velocities tested. I have had an eye opener with having loads tested and being way higher pressures and velocities from published recipes. Precision reloading out of South Dakota is who I send my loads to.

Just as an example I just sent in a 12 ga 1 1/8oz that had a published pressure of around 7500 and velocity of 1175 and it came back 9400 psi and 1300 fps. I have been told there can be differences like this even from one batch of powder to the next. I was using 800x powder with this particular recipe.

Wow definitely a eye opener 800x is my go to powder for low pressure loads I use. 22.-23 grs 1 1/8 oz and 1 oz . Old AA hulls or GM . Not sure what to think now

1 1/8 oz. and 1 oz. loads in a 20 gauge?? What on earth for??

.

Dean, that post was just referring to Matt's experience with published vs. tested loads(and the importance of checking if concerned). I had assumed that was from a 12 gauge. In the next few weeks I am going to send a few 20 and 16 loads to be pressure tested, just so I know and I will share the results.

For the 20, I have settled on using Unique(which I have) until I can find some 20/28 powder.