I cannot seem to find either the dram equivalent or any type of chamber pressure reading on these new non-toxic shells. Does anyone know or have tested or had tested the chamber pressure in Kent’s Tungsten Matrix of the new Hevi-Shot classic doubles shells?

I get the impression from the advertising (not a particularly good source) that the Classic Doubles Hevi-shot may be low pressure, but that the Kent T/M and all the rest of the Heavy-shot offerings are pure Saami spec. loadings not suitable for our old guns...Geo

Geo. I think you're right on that but even with a dram equivalent I can get some idea of where the pressure is or at least a range of pressure. But all it said on the box of Kent's Tungsten Matrix is 'MAX'. Anyone call Kent to see where their chamber pressure is? Granted I know dram equivalent is not the best way to do it but with that number and the weight of the shot charge I can at least back into a range of chamber pressures using a reloading manual...or can I???

I just buy Bismuth sporting loads when I can find'em; and I think they're probably high pressure as well. But I don't shoot them in my damascus guns or in any of my pre-1930s guns...Geo

Which of your guns do you shot them in?

Post 1926 Foxes, Parker, Ithaca NIDs etc. Nothing magic about the date; just figure that by 1930, all the US makers had adapted their products to the Super-X type shells by then. As far as the damascus barreled guns go I guess I'm just careful...Geo

I expect that the RST nice-shot loads are ok, but I've not tried them; still saving up to invest in a box.

Kent Impact Waterfowl 1 1/4oz 9900 psi, 3/8oz 11,400 psi, and my pure poison 20ga load for anything flying: three-inch 1 1/8oz, 10,100.

King B what guns do you shoot those shells out of?

I shoot Kent 12ga 1 1/4 out of 1911 VH Parker, 1938 LC Specialty, 1913 Army and Navy, and 20ga SKB o/u Model 500.

I bismuth-handload half my duck-and-geese shells, and use 7,000-range with 12ga 1925 Sterlingworth and 1899 Francotte for sentimental reasons.

I'm no poster boy of risk assessment and believe I have reasonable instincts for safety. I honestly think good old guns will handle most anything.

Dram Equivelent has never been an indicator for "Max" pressure, only the velocity of the load. Several factors in addition to shot wt & velocity, play important roles in "Max" pressure.
If you fire a given shot wt to a given velocity then the same work has been performed, but the pressure curves can be entirely different, thus a totally different max pressure. The Max pressure is just one small point of that curve. What you gain at one point, you lose elsewhere.

Miller, couldn't I back into that chamber pressure range using a reloading manual if I had those two numbers, dram equivalent and weight of charge? I think I can at least get into the ball park.

Too many variables with shotshell loading for me. I think I will stick to reloading rifle and pistol.

In their Gamebore line, Kent offers a 12ga Tungsten Matrix load in a 2 1/2" paper hull with a fiber wad. (Pure tradition there!)
30 gram/1 1/16 oz of 5's or 6's. Perfect in old doubles. Not sure whether those are American or Brit shot sizes. Their Gamebore lead loads go by Brit shot sizes, so it'd be good to inquire with Kent before you buy.

What means "back into that chamber pressure range"?

I'm afraid I don't understand the question or the goal. Seems you're concerned about the pressure. That imnplies you want or are interested in "lower" pressure. Any new factory ammo can reasonably be expected to be operating near the SAAMI max recommendation unless specifically stated otherwise. There is no way to guesstimate what peak chamber pressure a load might generate from the measured velocity and payload, much less the crude and antiquated DE term. DE is virtually useless these days in light of the fact that SAAMI specs allow a variance of +/- 90 fps from the associated average velocity. and A quick glance at any reloading manual will show you many recipes with identiacl velocities for a given payload and pressures that vary from 6,000-11,000 psi.

The only guesstimating that's justified is interpolation of velocty & pressure when everything else remains constant. Extrapolation is never justified. Even the powder companies sometimes become aware of unexpected pressure excursions and revise their data accordingly.

IF pressure concerns you at all, the ONLY way to alleviate those concerns is to test. For $15 Tom Armbrust will tell you what the pressure is.

How do I get a hold of that rascal, Tom Armbrust???

A 3 dram equivelent with 1 1/8oz shot in a 12ga is supposed to produce a muzzle velocity of approximarely 1200 feet per second. Look in any realiable loading manual see how many loads with 1 1/8oz shot pushed to that 1200 FPS you can find. Look at the assortment of powders used & also look at the range of max pressures listed, probably from around 6K up to about 11K. No! dram equivelent tells one nothing about the max pressure, only the approximate amount of Work done.

Well, so much for that idea.

Tom Armbrust
Ballistic Research
1108 W May Avenue
McHenry IL 60050-8918

815-385-0037