I've been collecting data on the weight of Brass versus Aluminum shells, both "full dress" and just the shell with everything else removed. Results so far suggest that for Suprasif full dress weight > 4000g then Brass shellif full dress weight < 3500g then Aluminum shellThat leaves a 500g zone where we can't be sure of a correct classification based on full dress weight alone. The one you are asking about is 4400g (9.7 lbs) which suggests Brass, but that is applying the full dress Supra formula to a SuperSensitive. That's an issue because the additional hardware associated with the SuperSensitive mechanism will make the full dress snare weigh a different amount. I don't yet have any SuperSensitive full dress versus shell only data to get an estimate of the difference being a SuperSensitive makes. If anybody does have data, it would help. Yes pre serial drums are very likely to have COB (chrome over brass) rims unless they have been replaced over the decades. And yes COB rims might add a bit to their full dress weight compared to COS (chrome over steel). I haven't yet pulled my drums apart and weighed all the components separately to try and learn more about the weight of individual hardware components. I'd recommend that you ask about buying it with a guarantee in writing that it has a Brass shell. Get a right of money back return (full money back or a lower agreed price) if it tests out as an Aluminum shell. That would protect you. You can do a definitive test by either removing all the hardware and doing the weight test on a bare shell, or contacting a metals testing lab and see what non destructive test they suggest. Be warned that sometimes the "scratch test" gives a false positive that a shell is Brass because the person making the test isn't experienced (let alone certified and calibrated). A home tester may interpret the intermediate layer of copper plating on an Aluminum drum as looking like Brass. The bare shell classification equation for 5" deep shells isif bare shell weight > 1100g then Brass shellif bare shell weight < 1000g then Aluminum shellThe zone of uncertainty is smaller for bare shell weights than it is for full dress weights because the variation in other hardware component weights (lugs, strainer, butt, rims, heads, snare wires) doesn't enter in to the equation. The reason for developing a full dress classification method is based on convenience. If it works, it is much easier to use. Note that these classification equations are subject to refinement as I get more data. Once again anybody who has any weights to contribute I'd be delighted to add them into my study.The other thing to look for is a B stamped above or below the tone control on a Supra. I don't know if this holds for SuperSensitives as well. [img]http://black.net.nz/cym2017/Brass-Shell-B.png[/img]Hope this helps.

There is a 100g zone between the cut points for the statistical classification function. It is not the average nor minimum difference in weight for 5" drum shells made from the two different materials. The cut points are chosen to minimize the number of classification mistakes (either false positive or false negative) given the weight of any particular drum. The 100g zone will change once we've got more data, but for now it is there to remind us that if a shell weighs between 1000g and 1100g we need to look at other evidence for shell material to make a reliable diagnosis. The heaviest Aluminum shell I've recorded is 900g bare shell weight. The lightest Brass shell I've recorded is 1264g and they go up to 1650g (Super 400) with a 1968 one at 1400g. I'm still trying to get more info on the thickness of different shells, but the level of variation in the older Super 400s (1254g to 1650g) already suggests that there is too much variation in late 50s early 60s ones to support a theory they were all the same thickness in the early days. Either that or the data I've got isn't measured accurately enough to get consistent results. My progress is limited by not having direct access to lots of these drums to measure. I have to rely on others because there aren't very many of them down here in the South Pacific.The only thickness info I've got is 1.6 to 1.8 mm from this site: http://slinkzdrums.awardspace.co.uk/shell.htmlI haven't yet replicated these findings, and I'm wanting to replicate before I go further into modelling the expected shell weight from the density of the alloy and the dimensions of the cylinders. But I have to replace my thickness gauge before I do. I've got a 2002 5" Black Beauty and a 5" 1970 Supra (Aluminum) to measure, so even then it won't be a full sample of all the different sorts of shells we want to know about. But it is a start.