oops double post.....DV......
That is correct - straight blowback (non-locking bolt) plus a regular gas system with a very close tolerance tube. I am wondering now if any gas system at all was needed. Have a notion to weld the gas port shut in the block, and try it that way, just to see. It might still cycle with the pneumatic 'suction' in the gas tube, but definately slower. Never thought I'd want to 'slow down' a semi, but I'm afraid the super-fast stroke could wreck the feed mechanism. And to think I was sooo concerned it wouldn't have enough pep to cycle..........best laid plans. I have no doubt it could be built in 9mm, but x25 is half the cost. 9mm would probably fit in the links too, frontwards. I'm not home yet or I'd already know
I've had many x25 casings seperate (none in this one, yet) probably because my chambers weren't kept as clean as they should be. Residue builds up, a (cheap surplus) casing sticks/breaks, then I'm pulling it out with a turned-in drill bit. In the process, the chamber receives a tiny nick; now the likelihood of a stuck or broken casing has increased. So I'm keeping 'EC' super clean - 9mm chamber brush on a long rod, in a power drill. I have shot ALOT of x25 and it's been educational, for sure - my first experience with anything corrosive. 8mm was next - same lessons apply
Today I bought an Egyptian Hakim Always wanted one.
I had alot of case separations on the MPK-25 until I welded the bolt head to the carrier. With the loose bolt head and the powerful cartridge it was allowing the headspace to open up when firing. I havent had a single separation since I made the carrier/bolt combo 1 piece.
Thanks Dvann -
I WILL TRY THAT! A small weld to join them could be cut with a dremmel, if it needed removed later (extractor, firing pin). It has a TINY bit of fore-aft play between the B & BC. I can see how that small inertia slap could rip some. Also need to do that in the x25 carbine. It has about 1/64" of play and has had the most seperations.
Here are a few pics which show some details
Feed Ramp - the link/belt guide keeps the cartridges from nosing up. The original guide was ground off since the belts are fed backwards
The 'spanners' beneath the feed tray are the same width as the rcvr. They need to rest on something, so they straddle the upper rails. The trunnion is notched and the rails insert into the notches. The right side (ejector rail) is free-standing, but the feed tray keeps it compressed it into position. This is like wood-working
Here's another shot which shows how both rails interlock into the trunnion ears. With a SLIGHT bevel on your bolt cup, it will center on the cartridge rim every time
You could call this a show-off pic. I'm happy with how the stock fits into the rear of the rcvr, but my welding needs some work
Another show-off pic
That little lower cap was a couple hours work
Here's the stock mount w/ recoil spring tube. I could've ground it off purdy for the pic, but it works the way it is. All metal, but epoxy would've helped the fit. May add some later
The skirts on the HG were peened over so it snaps into place and no longer slips up. There are 3 trunnion screws on each side, since it's straight blowback, and the trunion is what takes the beating
Tomorrow I shoot her again - I plan to drill and tap the gas block, to make a primitive gas regulator, using a cap screw. This little cartridge has more pep than I would've guessed
Steve & El Cheapo, in El Paso
Last edited by cntrailrider; 07-20-2008 at 12:33 AM.
Your builds are very innovative. I am very impressed with the build you are turning out. I would be hard pressed to come up with something new that equals your builds.
P.S. Wish I had your T.I.G. machine.
What size tubing did you start with on the receiver?
Whoops - double post and I can't find the delete function
It's 1.5" x 1.5" and 1/16" wall. The sections on top are 1/2" x 1/8" steel from Lowes. Those sections are visible in this pic of the front trunnion and TC hinge bushing. That's probably my nicest tig weld so far
Need to get some oil on that barrel
The handguard locks into the upside-down bayo lug up front, and the back snaps down over the trunnion screws
Folded bipod doubles as an adequate lower handguard. That's rationalizing, but I didn't have a better plan. I don't know yet if ejected casings will clear the leg or not
Here she is wearing the right amount of make-up, dressed in black, and ready to play. And wouldn't you know it's been raining here in the desert, for 3 weeks straight
Last edited by cntrailrider; 07-19-2008 at 07:55 PM.