Delrin head ‘discovery’.
It would appear that the nozzle on the Delrin heads I’m making and using (the bit that sticks into the breech) expands upon firing such that it grips the breech firmly enough to stop it shooting forward at all, which is advantageous for a number of reasons. An accidental/fortuitous by-product it seems.
This also explains why the floating heads were still coming off the stem even when the bore was 6mm all the way through both stem and head. Now the heads are screwed onto the stem my rifle has never shot better.
I have a good shoot on this afternoon and evening, so it’ll be getting a good workout. On the last shoot the breech was being shot forward so hard it was deforming the new knob against the lock-off notch in the frame and causing it to jam in the slot on the next cock, necessitating much chiselling with a screwdriver.
R&D can be such fun. 😆
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Viewing 6 replies - 1 through 6 (of 6 total)
Breech smaller ID toward the tank and bigger toward the barrel.
Just ever so slight of a taper, the breech still fits over the TH, upon expando, ya get a lock, positive, no leaky 8) 8) 8) 8)
SAW
It seems to be working without the need for a taper, though that’s a fine idea in it’s own right. 🙂
Top hat towards tank, smaller od slightly tapered to bigger od at the tip.
Breech smaller ID toward the tank and bigger toward the barrel.
Just ever so slight of a taper, the breech still fits over the TH, upon expando, ya get a lock, positive, no leaky 8) 8) 8) 8)
SAW
if it’s a slight taper, i think the expanding tophat will push the breech away, exactly what he wants to prevent
Or how about a slight taper on the mating surfaces, just enough for the 2 to engage, when the shot is taken the expando factor locks them together for an airtight seal, The breech is small to big front to back and the head is oppisite, somewhat like a dovetail joint
SAW
Lang-
I think ya are on to something there, expandind TopHat,
seal has gotta be much better, no leaks 😛
Think about this, the TH has a rim and the breech has a groove, when a shot is fired the ring and groove mate up for a super seal.
Man, I’ll tell ya it sounds good, with or without the rim/groove
SAW
Viewing 6 replies - 1 through 6 (of 6 total)
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Breech smaller ID toward the tank and bigger toward the barrel.
Just ever so slight of a taper, the breech still fits over the TH, upon expando, ya get a lock, positive, no leaky 8) 8) 8) 8)
SAW
ooooooooooooooooooooooooooooooooooooooooooooh now i get it, yeah that would work
i thought you wanted to put a taper on the part of the tophat the breech slams against