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Hi all
I bought a second hand bsa r10 super carbine 177.
For some reason the loading bolt keeps unseating itself when firing the gun but not all the time.
I've searched the ne t and some say the probe is to long and some say the bolt needs turning another 10 degrees.
Does anybody body have a definitive answer for what the gun does this.
Any help greatly appreciated

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The gun does not do it all the time
The bolt lever with the ball on was resting on the stock.
I've moved the lever back so it's in what I think is correct position.
Its helped abit but not cured it
From what I can gather the cut out in the probe housing is bigger than the locking pin on the probe and apparantly this is the cause.as it's a pig in a poke.
I shall strip it down and have a good look what's happening.
Blowing air through the hollow probe like some crosman probes is maybe also adding to the problem or may well be the cause.
I got the gun cheap so all is not lost and hopefully I can sort it out
Thanks for the replies I will let you know what I find boys
Thank you
 
How difficult is it to exchange these parts? Any special tools required?
Hi orangeokie
Waiting for parts to arrive
But I'm positive this cures the fault
I got gun Thursday and went to the range Friday and noticed the problem.
The top half of the gun is more or less the same as the coyote and I've stripped that right down without any problems
And from what I can gather the r10 needs no special tools.
I'm sure theres 3 things maybe going on 1 the probe locking pin is undersized.
2 the locking pin needs few more degrees of turn in the housing?.
3 the air coming from transfer port is sandwiched between the pellet and the wall of the probe and forces the probe back on itself
They have modified the probe and swapped indent ball bearing for delrin type
I may also swap probe bearing for fac type as one is steel and one is delrin if its worn.
I will let you know how I get on orangeokie sometime this week hopefully 👍
 
Hi orangeokie
Waiting for parts to arrive
But I'm positive this cures the fault
I got gun Thursday and went to the range Friday and noticed the problem.
The top half of the gun is more or less the same as the coyote and I've stripped that right down without any problems
And from what I can gather the r10 needs no special tools.
I'm sure theres 3 things maybe going on 1 the probe locking pin is undersized.
2 the locking pin needs few more degrees of turn in the housing?.
3 the air coming from transfer port is sandwiched between the pellet and the wall of the probe and forces the probe back on itself
They have modified the probe and swapped indent ball bearing for delrin type
I may also swap probe bearing for fac type as one is steel and one is delrin if its worn.
I will let you know how I get on orangeokie sometime this week hopefully 👍
I ordered two kits, one for my R10 and the other for my Scorpion. I guess we will see together! When this malfunction occurs, do you get a loud puff of air coming back out of the breech?
 
My Ultra SE doesn’t do it but I’ve had this problem with other guns when the poppet pin is too short. I cut another poppet and don’t press the pin in as far and the problem goes away. Over travel of the hammer is what causes the problem. Hope you guys get things sorted out. Those R10’s are nice guns.
Hi orangeokie
not really but I did notice it's worse with heavier pellets.
Some fellas over here replace the 12ftlbs probe bearing with the fac type and remove more metal from the probe pin cutout so it travels further and shorten the pin and cone the end of it " the use a dremel ball bit to redo indent on the probe.
I shall try new probe on it's own first if problem still there replace probe bearing before removing any metal whatsoever.
With barrel housing off the gun look at the indent hole and see if it lines up when cocking handle fully rotated to closed position?
Hi vetmx does the ultra have a hollow probe like the r10 and thanks for your input

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The gun has been at my dads house for probably 10 years but I believe it does. I regulated the gun with a much lighter hammer spring so this may have helped because I’m not hammering the valve very hard. It’s just a little .177 shooting about 830fps. When your hammer travels too far into the stroke it bumps the part of the bolt used to cock it. It’s been so long since I was inside my BSA but you can test this by backing your hammer spring off and seeing if the problem goes away. If it does, lengthen the poppet stem.
 
The gun has been at my dads house for probably 10 years but I believe it does. I regulated the gun with a much lighter hammer spring so this may have helped because I’m not hammering the valve very hard. It’s just a little .177 shooting about 830fps. When your hammer travels too far into the stroke it bumps the part of the bolt used to cock it. It’s been so long since I was inside my BSA but you can test this by backing your hammer spring off and seeing if the problem goes away. If it does, lengthen the poppet stem.
Hi vetmx
I know there's a lighter hammer out there aswell.
I know where this gun came from and its fired probably a few thousand pellets and it's in imaculate condition so it's not a wear and tear problem as you would expect.
What i would expect is bsa to rectify a fault that they know exists with the r10 besides the regulator.
Maybe they should of sneaked over to the gamo bench in the dinner break lol
Bjesus
 
I wasn’t talking about a wear and tear item. I’m talking about a design flaw when a gun is cranked up and the hammer starts to strike the valve harder than the manufacturer intended. That’s when cocking bolts start jumping when you shoot.
Hi vetmx
This r10 is doing sub 12ftlbs so not cranked up its exactly as it came out the factory and not ever being adjusted in anyway so god only knows vetmx.