What prevents a cocker bolt from getting blown back?

[nicad]

As the subject states, what exactly prevents an autococker bolt from being blown back while firing a ball? Im focusing this to the setups which claim to operate at like 35psi recocking or thereabouts. this is only about 1 or 2 lbs of force at the shaft -> holding bolt.. very light cocking force.
I have tried placeing an air ram at this same pressure directly behind a bolt tip and firing, but the bolt will get blown back by the propelling air.. unless i crank the ram pressure way up.. well beyond chopping point.
About the only thing i have decided holding the bolt in place is sticktion, mass, and slight binding (bolt -> backblock -> recocking arm). By the same token, how do shockers manage, since they are line-drive behind the bolt with an air ram..? all sticktion??
And i guess a follow up question is how much pressure pushing back typically does the bolt see (cocker, shocker) when firing?

[FutureMagOwner]

the reason why cockers have no blow back normally(they shouldnt unless if you screwed with the pumping arm) is because it is a closed bolt which means the breach you fire from is sealed so when you shoot all the gas gos down the barrel and then the gun uses the ram to push the back block back which recocks the gun and aloows another ball to feed in. then the ram(via 3-way) pushes the ram back(not sure how but i had a theroy on that) sealing the breech for firing again.

[FreshmanBob]

The pressure in the ram holds the bolt back in a normal cocker
pressure on the bolt? my guess is less than 70 psi, because thats about what is put onto the paintball.

If you really want to make a LP recocking cocker, find out about the old sheridan guns that used to have a thing on the back that made it so the same wouldnt happen if you didnt hold the pump forward, but would when you pumped it.

lemmie see if i can describe it..
basically the pump arm was connected to a second peice at the back of the bolt. When it was pumped back, the second peice went back and drew out two ball bearings holding in the bolt and then recocked. When pumped forward the ball bearings came out again.

This made it so you could put immense pressure on the bolt and it wouldnt budge, but just tap the pump arm back and it would open up the ball bearings.

Hope that helps

[nicad]

:) thanks for the input guys, but FutureMagOwner your a little, er, waaay off in another ballgame from what im talking about. :)
I guess i wasnt all too clear... :-/
FreshmanBob- i think your getting my drift. and yes i understand your description of the two locking balls.. makes sence!
Now, how does a cocker/shocker get away with not "locking" the bolt in place while firing? i can see how the higher (80-90psi) recocking setups could possibly supply enough pressure, but they will chop also if they catch a ball.
Im just wondering how the 2-3 LBs of force on a "low-cycle-pressure" setup cocker VS. the ~25 LBs of force the bolt sees (~70psi * area of .68" bolt).. seems like the bolt would physically get blown back with each shot.. but it doesnt.

simply put, we have a small boar ram holding forward at low pressure VS. a large boar (.68") bolt getting a burst back with high pressure.. yet it does not move. why? :)

[SLICEnDICE]

BOLT

WHAT HE IS TALKING ABOUT IS THE OLD COOPER-T BOLTS.

[Minimag4me]

its because paintballs are a tiny fraction of the weight and friction of the bolt and back block. If the air takes the path of the least resistance, the ball is out of the gun and the bolt sees almost no force.

[nicad]

.. try turning your LPR off, pull your bolt pin out, and fire.. just make sure noone is standing behind ya.. :-)

[xatle]

i see what your saying nicad, good question, kinda curious to see a good answer that takes into account equal and opposite reaction and all that jazz.

could someone with a cocker disconnect the cocking rod and fire it and tell us how far the bolt blows back? its a place to start if nobody already has a good answer.

[nicad]

yeah.. just make sure your backblock isnt throwin the bolt out. thats why i said to turn the LPR off, so the backblock dosnt move.
Iv seen it happen before.. a guy was at the chrono range and his pin fell out and the next shot the bolt went flying back and almost hit a kid behind him.. twas kinda funny... :)

so anyways back to the question. :-p

[FreshmanBob]

yes, thats what they're called!

cooper-t bolts had that feature, you should check them out and i'm glad you understand what i mean

[FutureMagOwner]

your questions needed some puncuation and a little grammer check to tell exactly what you wanted so i could answer only what i saw that looked like a question

[nicad]

LOL.. :) too lazy..
more important things to do.. like eat!

[AGD]

Nicad,

Are you the old Nicad member? Anyway, you are perceptive in discovering there is not much holding the bolt in place when fired using a low pressure LPR. I suspect that it is moving backward when firing but since your trigger pull almost instantly actuates the 3 way it all seems like one movement.

If you find that the bolt does move back from the air pressure but does not cause blowback up the feed tube there is an explanation. The air blast to the ball is almost instantaneous and is gone in only a few milliseconds. By the time the bolt moves back and opens the breach the pressure is all gone. Think of the air blast like a cue ball hitting another ball. The ball being hit reacts but the cue ball bounces off and is long gone before the ball getting hit moves very far. Got it?

AGD

[Vegeta]

Tom, you said that the air is out ot the bolt withing a few miliseconds... would this volume of air travelling down the barrel have some sort of downforce vacuum effect on the balls in the chamber as the bolt was opening? i.e. ball suck? or would the air be too far down the barrel to cuase any effects on hte feed tube? Kind of like an airbrush efeect; high pressure air moving over a tube that goes into a canister of paint pulls hte paint up and sprays it out.

I know the issue has been discussed before but I never head of a conclusion.

[xatle]

ok, i think the air pressure in the ram manages to hold the bolt in place in the same way that i can drive around in a 700 lbs car on 4 tires with 30 psi in them...this doesnt mean i understand or can explain how this works, just that they prolly have a whole lot in common.