I finished the conversion of the JSE 9mm blow back barrel to DI gas operated. I spent most of the time on it making the adjustable gas block for it. Here it is all set to ship out to it's new owner.
Thanks j427x, The only part that is remotely time consuming is the gas block. Most of the ones I've made weren't adjustable and went together faster. With the contour of the barrel a single piece gas block was out of the question. I'm already gathering parts for a 357max rimless build. Standard bolt, maybe even standard gas system. I'll need to modify the max brass to rimless and get a 358 barrel for the slower twist rate.
I sure do like these things!
M U S I B I K E
J427x, Here is the info on the 357 rimless. AR15BARRELS.COM - 357 Rimless Mag I have made a few straight walled 223 case and the longest useable length I could get was 1.450" and it was a chore to make. That site has ready to load cases for $25/100 which (after make a few) think is a steal. Looks like you'd just need a barrel and a set of dies to use it. I'm down to ordering a barrel for the max build. I'm looking at a .358 barrel with a 1-14" twist for it.
It runs great on Winchester white box, Win ranger HP, Remington UMC yellow, reloads (115fmj 5.2gr Win 231). It did not like CCI Blazer aluminum cased ammo which seemed very under powered. I didn't try opening up the gas adjustment for the blazer either though. The gas block was a two piece design because of the profile of the barrel and ended up being quite blocky. It did suprisingly fit under a car length handguard of mine that doesn't have any heat shields in it. The others I've made had a standard stepped profile of the barrel and a one piece clamp type gas block or a set screw type so they were much easier to finish. The one piece gas blocks are also slimmer, but may not fit under all free float tubes because of the straight gas tube. I think I have a solution to that problem, but I haven't had time to make one yet. Existing 9mm barrels may or may not work depending on length. The one in the pic started off at 16.25" but because of the way barrels are measured by bore length. By the time I got that barrel set up the boltface to muzzle measurement was only slightly over 16.1" although the outside measurement was over 16.25"