I read (and re-read) the article linked above by Ledsinger. Then got out some of my old info on my DE.
I bought it in 1991. Bought the 440CorBon bbl for it in 1993. It was an older,origional MK1. Serno was 323XXX.
I put aftermarket sights on it. Bright orange adjustable rear and orange blade style front. Unknown brand. I also put aftermarket Hogue grips on it.
Re. the article - - -> It does not say what brass it uses. However it does mention 50A&E. It "looks" exactly like a 440CorBon to me. Simply necked down from 50 to 429. My 440 was fast,but that was coming from 10 inches of bbl.
The article states that only two bullets are offered,with 240gr being the heaviest. Hmmmmm . . . wondering why no 265,275,300,etc ??
Do not have any of my 440 loading notes anymore. Had chrono data also at one time . . but gone now.
IMO - - -> If the bullet speeds in the artical are true,my guess that this "new and better" chambering is either a 440 rebranded or 50A&E brass with a thicker web.
We'll see when this gets out into the public domain. --- SAWMAN