20 Gauge Damascus Pressure

[Jay Oliver]

I have searched the reloading forum and probably missed this, but what it the maximum pressure for a Damascus 20 gauge? Specifically a 20 GH 28" with Damascus barrels on an 0 frame. Would it be 8000?

I have a Mec 600 Jr on the way. I would like to load Cheddite 2 1/2" both 7/8 and 3/4 ounce shells. Also I am hoping I can find some Alliant 20/28 as that seemed to have some lower pressure recipes. It looked like Green Dot, Unique and Herco were good powders too.

Thanks!
Jay

[Garth Gustafson]

Jay, here are the service pressure limits from TPS.

[Bill Murphy]

Difficult as it may be to find loads with low pressure 12 gauge equivalents in the 20 gauge column, keep trying until you find one you like. I'm saying not to accept an 8000 psi load just because it is hard to find a 6500 load. Keep looking until you find one, or invent one.

[Jay Oliver]

Thanks Garth and Bill. It really looks like Alliant's 20/28 powder would be perfect for this. However, I have spent a week trying to find some 20/28(even on GunBroker with those soul crushing prices) without any luck.

It looks like I can use Unique and keep pressure in the mid to high 7000psi range for 3/4oz and the low 8000psi range for 7/8oz loads. With velocities for both in the 1100-1150fps range.

That will get me started since I have some Unique until 20/28 is available again. In my research I read where the burn rates on these two powders were close.

[Matt Buckley]

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.

[Bruce Day]

This is what I use :

Reasonable costs.

[ED J, MORGAN]

Me also

[Richard Flanders]

That's what I load all my 20ga to Bruce. It's the perfect load for any type of clays and for hunting.

[Dean Romig]

For me it's load my own to known low-press recipes or buy RST.





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[Jay Oliver]

Thanks for all the replies they are helpful. I have been meaning to send a few loads to get pressure tested and I am going to follow through this time. I think it would be enjoyable to come up with some new low pressure loads. I am down to my last few boxes of 20 gauge RSTs and what I like is not currently in stock.

As a somewhat related follow up question. Do you see having to be a little creative with reloading in these challenging times when shelves are empty and online retailers are out of stock? I not asking for permission to be careless, I just can't find the shells and/or the reloading components I would like to have...

[Jay Oliver]

Bruce are you using those shells in damascus barrels?

[Bruce Day]

Yes.

[Bruce Day]

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.

[Drew Hause]

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.

[Bill Murphy]

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.

[Jay Oliver]

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!

[Harold Lee Pickens]

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

[Don Strelioff]

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

[Dean Romig]

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





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[Jay Oliver]

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.

[Dean Romig]

Sorry, thought we were discussing “20 Gauge Damascus Pressure”





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[neil steven]

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.

Jay, did you ever get round to having the 20G Unique loads tested for pressure and velocity?

[Jay Oliver]

Hi Neil,

I never did get them tested, but I use them all the time. I have stepped the powder down for a 1/2oz. load that has been both effective and remarkably fun to shoot(practicly zero recoil).

[Craig Larter]

Here is a 20ga load I made up and had tested using Unique. Shot it in my damascus 20ga DH.