Breech #2, in brass.
I’ve been having the exact same problem with the alu breech I made that Pablo was/is experiencing with the two Sean made for him, very difficult to cock. I’m pretty sure it’s caused by a form of galling, even though I had oil in there (silicone). I tried the knob in three different locations (fore, aft and middle), no difference. I reduced the diameter down from a nicely snug 25mm to 24mm (per the stock item), no difference. If the breech was pushed evenly from behind it went forward very sweetly, but using the knob tipped it forward slightly and that was enough to bind it in the tube.
So, thinking it had to be the afore-mentioned galling I figured either nylon or brass would work best. The stock item is nylon and works very nicely.
I’ve turned out a brass version and it works as well as the stock one, if not a little more smoothly, and that’s with zero lube. Hoorah! It looks pretty trick too. 25mm OD for a snug fit.
I’m bloody well pleased with that. 😀
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Wouldn’t the main effect of the brass breach be to slightly increase lock-time by slowing acceleration of the breach/hammer mass. I’ve gone down the strong spring/lightish hammer /standard breach route to minimise a lock time which is not really helped by a 24″barrel.
I don’t think moving the breech is an issue, and if anything brass is probably better than a lighter material. The energy from the hammer is transfered through the material into the top-hat. I think I’m getting slightly better FPS with the brass breech, though the difference is very small. Probably to do with the denser material being more efficient at transfering the energy.
I actually suggested that on the other forum way back when. Nobody really seemed to jazzed on the idea. I suggested that I believed it would transfer more energy to the valve stem and waste less of it moving the mass of the breech.
Voltar actually said he might play around with the idea. Maybe he will chime in and let us know if he came up with anything.
Why everybody doing breech as a one solid HEAVY part?
Make It from two parts – inner with O-rings to hold a pressure. And outer – piece of tube – to transfer hit from hammer to valve.
LOL, You got it Walt 😀 😀
We are the knights who say “Ni??”
What can i say? 😀 😀
Last thing on list is bushings, and i think thats it. Have i missed owt??
A small shwubbewy.
Lubberly jubberly thanks Blod.Problem is me! I’m happy the barrel is doing its part, its just me messing things up! Breech is working fine,getting a decent scope for it by Friday so will know what shes like at the longer ranges. Getting a good flat power line for 30 shots with a 2500 fill. New hammer u did is working a treat.
What can i say? 😀 😀
Last thing on list is bushings, and i think thats it. Have i missed owt??
Just took a bit more out from the bottom of the “O” ring groves by hand with the “groover”.
Baz has idetified a problem also for me.
It seems that because the tophats on my valve is only a few mm proud of the face of the valve, The breach is allowed to come a little further off of the barrel when seated on the tophat.
In future i’ll make em 10mm longer than standard to acount for this extra travel.
😳 ( my bad )
Hows the .25 ?
I was busy doing other stuff…probably! To be honest, i can’t remember. I do know he gave the o-ring seats a de-burring ( i think he said de-burring) Also he tapped a new hole further back on the breech to stop it rocking forward so much,though it rarely needs that since he sorted it,looks nice though as i use a small,low sunk allen bolt for the rear cock.
Sean whips around his shop so fast, its difficult to keep track 😀 He has found a use for me though, i’m quite good at finding mis-laid tools!!
Hey Sean, what did u do??!! It seems i had my head up my jumper at the time!!
Pablouk, what was the problem? What was the tweaking that was done?
Has anyone studied the US equity markets today and yesterday????
….this is actually Talon related, you know; if I guess right on some crucial stock purchases at tomorrow’s open, I’ll be able to buy more Condors 🙂
aloha,
walt
YAY !!! 😀 😀
Good work Lang, lets see some photos then…
I nipped into Seans the other day, he tweeked the breech and it works a treat now 😀
Cheers Blodders 😀 😀
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I suppose it could, but I’m pretty clueless about all the possible variables involved. My main understanding is that the mass of the breech is largely irrelevant to the functioning of the shot. Maybe a bit more or less air gets out, but all I know is the FPS seems to be pretty much the same with a stock, alu and brass breech, maybe a tad higher with the brass. And the brass is smoother. Same dimensions as the alu one I made, same width, depth and position of o-ring grooves, but the alu one jammed up and the brass one doesn’t.
I suppose I should be more scientifically rigorous and tabulate shot count/fill-pressure/FPS etc but I was knocking birds down at 50yds all weekend so I’m kind of “that’ll do me”. 😆