Pressure loads for Damascus barrels
 

I know this has been discussed here ad nauseum but it seems I have heard/read some really different numbers.

If barrels have been examined and measured to be .025 or more MWT what is the accepted pressure for loads.... high end ?

Thanks for your time.

Bruce, that .025” MWT only applies to the forward half of the tubes. The first half or rather the first 10” - 12” from the breech is equally, probably more, critical in barrel wall thickness as we should all know is where pressures are extreme. We’ve all seen the pressure curve charts and know the pressures begin to drop off drastically after exiting the chamber. Personally, I pay closer attention to the thickness at the juncture of the chamber and the beginning of the cone.






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There is a good article in this issue of the DGJ on low pressure loads including a loading chart, for all guages.

Right Keavin, and it also has the pressure curve chart I had mentioned earlier.





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Wall thickness is great, with .130 in both barrels at the end of the chamber, .121 at the end of each forcing cone. The minimum wall thickness is .038 and .036, 5” from the muzzle....

I do not have access to DGJ since they stopped offering it at "book store" outlets. If someone could scan the article and and send it to me I would appreciate it.

Thanks

Bruce, I'm not giving advice here but with wall thicknesses like those I would think you could shoot most off-the-shelf stuff except heavy turkey or waterfowl loads.

Bruce, the wall thicknesses cited here seem excessively thick at the front of chamber and forcing cone (.130/.121") and I ask how they were measured?

The DGJ is copyrighted and in effect you're asking someone to pirate the content for you. Not a big deal considering the society values of today but it’s still not right. DGJ will be delivered to your mailbox 4X per year for < 1/2 the current cost for a flat of shotgun shells. And even if it were available at a book store you'd have the added cost of gas and mileage depreciation. Just sayin.

The measurements were taken by Breck Gorman so I suspect they are correct. It is a #2 frame and barrels marked "4".

As to DGJ; Sorry about that. I guess my age has me thinking without thinking. Nuf said, I retract my request.

I found this information from Dr. Drew posts.
From the German proof house:
minimal wall thickness at end of chamber, regardless of length, for 12, 16 & 20 gauge guns should be 2.3mm (.0906") for 'ordinary good steel' or 2.1mm (.0827") if a 'Special Steel' was used. For the 24 & 28 gauges, due to their higher pressures, 2.4mm (.0945") was recommended.
Minimal wall of .6mm (.0236") was recommended in the "forward third" of the barrel.

I measured my O frame Parker 20ga and it measured .096 in front of the chamber and my Fox CE 20ga .098.

All my Parkers are Damascus 20ga to 8ga. 99% of my clay target shooting is not for score so in 12 ga I shoot 3/4oz at 1200fps Clay Dot powder @5600psi. If I miss some clay targets due to the reduced load, I could give a dam, because the reduced stress on the gun is more important to me than than my score. But then it comes to live birds I use the max load for which the gun was originally built.

Craig;
What is your ClayDot load for the 12ga.? I recently ran out of Extra Lite and switched over to Clays, which I understand is similar to ClayDot.