dj_fatstyles wrote:those look great. how thin are you guys able to get the tubes with this process?
Thanks! We're excited about them. It's taken a lot of development to get here.
Our tube is 17-4 PH stainless steel. We billet machine the tube and spacers. We could go really thin and very lightweight because the 17-4 is at least 3 times as strong as 316L stainless steel, but we don't, because we know some of the durability of a suppressor is derived from mass that allows it to soak up heat, so it isn't hitting 900F in 30 rounds or something ridiculous like that with a paper thin tube.
Our tube at the thinnest point way up front is .055" thick when the suppressor is finished. I think an M4-2000 for example with it's 316L SS tube is about that thick up front (.035" spacer and about .02" of outer tube), so our can is stronger by virtue of the same amount of a material that is at least twice as strong all the way up to 1600F and 3-4 times the strength at room temperature. The KAC NT-4 uses 625 inconel tube .035" thick throughout. 625 is 2-2.5 times as strong as 316 at room temperature. Originally without the girdle KAC's can was probably in the arena of 15.5 ounces in weight. It heated up too fast and welds holed through (this is because 625 derives its strength from cold reduction and welding removes about 50% of it's strength in the heat effected zone) so they wrapped the suppressor in a 6-8 ounce perforated "girdle" that sucked heat away from the core and also improved surface area for cooling. So the ~15.5 ounce can became 22 ounces to obtain the level of durability the government required.
That tube KAC was using they had a lot of, from what I understand, so they couldn't economically justify selecting another tube wall thickness, so the girdle is an engineering workaround. Our tube is machined so we can select the ideal thickness for the parts and our M4SDK weighs 14.5 ounces and M4SD II (new model) weighs 17.3 ounces and each is exactly where we feel the optimum weight to strength, performance, and durability point is achieved.
You might think, "Why not just use the cheaper 316 that is already in tube form?" Well the problem with 316 is that while it is optimal for 5.56mm and 7.62x51mm, a guy might want to use his 5.56mm can on a .223WSM, or his .308 on a .300Win Mag, and that's where 316 can bulge and fail because it is operating so close to yield strength in its optimized 5.56mm or 7.62x51mm configs. Using a material that is 3 times the strength we get away from those problems. So we have a 17 ounce can that behaves like a 22 ounce tank of a can in 316.