CAPT I use the 444 brass all the time, for makeing the JDJ cartridges in my TC Contender hunting pistols. I have a 411 JDJ now and have had two 375 JDJs, one a contender, and the other a Valmet 412 375 Win barrel set, re-chambered for the 375 JDJ, makeing a very good 375 JDJ double rifle. I had no trouble with any of the brass except the bending of the case head out of line with the case body. That wasn't caused wholey by the stringth of the brass, but was exasorbated by the springiness of the action on the contender. I had the same problem with 30-30 brass in the contender. I most likely will never build either the 6mm/7mmR or the 243 simi-rimmed but it is a thought! I will, however build another 243 Jakal (256 Win Mag necked to .243 with a 87 gr sp)a wildcat of my own, double on a good 410 ga action!