Discovery breech problem

Discovery breech problem

Joined: February 25th, 2011, 7:41 am

October 1st, 2011, 2:51 pm #1

I had problems cocking the Disco, for a while. Sometimes I was able to cock it, then, no matter how much I pulled the bolt, it wouldn't move far back enough. And I felt a lot of resistance.
It was way smoother at the beginning.
Later on, I saw few severe scratches inside the breech. I opened 'er up, messed that 4-48 screw, that was collateral damage, and I found that both bolt and inner side of the breech had a lot of scratches in there.
I tried to sandpaper them, with 600 grit. It helped a little, but they are still noticeable. I can cock the Disco now, it works smoother than before, but occasionally it gets hard. That's rare. Now my bolt has a little room to wiggle, its not snug, and I noticed that the bolt handle is scratching the walls of the breech on which it slides on.
How can I solve this? And how can a gunsmith help me? should I make a thicker bolt (but the top would remain the same size, the one that goes inside the barrel), and machine that inner space of the breech a bit, to remove scratches? But then the pellet might not load properly, because of the extra space? Or maybe a half a mm space wouldn't make a difference?
Also, since I'm a lefty, I was thinking of opening the other side of the breech, and make it a left hand breech. Maybe even to somehow close the right side.
Any help and advice is much appreciated!
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Joined: November 5th, 2008, 8:23 pm

October 1st, 2011, 7:44 pm #2

I would suggest this-
http://www.airgunsbbguns.com/cobra_veno ... breech.htm
They look awesome.
Ray
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Joined: February 25th, 2011, 7:41 am

October 1st, 2011, 10:45 pm #3

and getting one of these into my country, it requires permits and stuff, its way to expensive to do.
But thanks for the suggestion.
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Joined: May 11th, 2011, 11:36 pm

October 2nd, 2011, 11:22 am #4

I had problems cocking the Disco, for a while. Sometimes I was able to cock it, then, no matter how much I pulled the bolt, it wouldn't move far back enough. And I felt a lot of resistance.
It was way smoother at the beginning.
Later on, I saw few severe scratches inside the breech. I opened 'er up, messed that 4-48 screw, that was collateral damage, and I found that both bolt and inner side of the breech had a lot of scratches in there.
I tried to sandpaper them, with 600 grit. It helped a little, but they are still noticeable. I can cock the Disco now, it works smoother than before, but occasionally it gets hard. That's rare. Now my bolt has a little room to wiggle, its not snug, and I noticed that the bolt handle is scratching the walls of the breech on which it slides on.
How can I solve this? And how can a gunsmith help me? should I make a thicker bolt (but the top would remain the same size, the one that goes inside the barrel), and machine that inner space of the breech a bit, to remove scratches? But then the pellet might not load properly, because of the extra space? Or maybe a half a mm space wouldn't make a difference?
Also, since I'm a lefty, I was thinking of opening the other side of the breech, and make it a left hand breech. Maybe even to somehow close the right side.
Any help and advice is much appreciated!
I would try to find out the reason it got scratched up.

The easiest thing to do would be install a new breech, Used they can be had for around $25.00.

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Joined: December 29th, 2009, 3:08 pm

October 2nd, 2011, 2:03 pm #5

I had problems cocking the Disco, for a while. Sometimes I was able to cock it, then, no matter how much I pulled the bolt, it wouldn't move far back enough. And I felt a lot of resistance.
It was way smoother at the beginning.
Later on, I saw few severe scratches inside the breech. I opened 'er up, messed that 4-48 screw, that was collateral damage, and I found that both bolt and inner side of the breech had a lot of scratches in there.
I tried to sandpaper them, with 600 grit. It helped a little, but they are still noticeable. I can cock the Disco now, it works smoother than before, but occasionally it gets hard. That's rare. Now my bolt has a little room to wiggle, its not snug, and I noticed that the bolt handle is scratching the walls of the breech on which it slides on.
How can I solve this? And how can a gunsmith help me? should I make a thicker bolt (but the top would remain the same size, the one that goes inside the barrel), and machine that inner space of the breech a bit, to remove scratches? But then the pellet might not load properly, because of the extra space? Or maybe a half a mm space wouldn't make a difference?
Also, since I'm a lefty, I was thinking of opening the other side of the breech, and make it a left hand breech. Maybe even to somehow close the right side.
Any help and advice is much appreciated!
reason being if you have put it back on the wrong side it can cause problems.

I completely stripped and reasembled my AS the other day and when I got it back together I tried to test fire it. The bolt was jammed up and wouldn't operate properly. I unscrewed the handle and spun the probe 180 degrees and screwed it in on the other side. Hey presto! Smooth as silk!

If you have been messing about with it pulling stuff apart then you may have done the same thing. I also found that some breeches don't like some bolt handles. Check for burrs, there has got to be a simple reason.

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Joined: March 12th, 2006, 8:58 am

October 2nd, 2011, 5:48 pm #6

I had problems cocking the Disco, for a while. Sometimes I was able to cock it, then, no matter how much I pulled the bolt, it wouldn't move far back enough. And I felt a lot of resistance.
It was way smoother at the beginning.
Later on, I saw few severe scratches inside the breech. I opened 'er up, messed that 4-48 screw, that was collateral damage, and I found that both bolt and inner side of the breech had a lot of scratches in there.
I tried to sandpaper them, with 600 grit. It helped a little, but they are still noticeable. I can cock the Disco now, it works smoother than before, but occasionally it gets hard. That's rare. Now my bolt has a little room to wiggle, its not snug, and I noticed that the bolt handle is scratching the walls of the breech on which it slides on.
How can I solve this? And how can a gunsmith help me? should I make a thicker bolt (but the top would remain the same size, the one that goes inside the barrel), and machine that inner space of the breech a bit, to remove scratches? But then the pellet might not load properly, because of the extra space? Or maybe a half a mm space wouldn't make a difference?
Also, since I'm a lefty, I was thinking of opening the other side of the breech, and make it a left hand breech. Maybe even to somehow close the right side.
Any help and advice is much appreciated!
The hammer striker pin that rides on top of the hammer. One time I had put a pistol of mine back together and that floating pin that rides on top of the hammer striker was not fully seated all the way down and it was causing a bind and it was not smooth when cocking. That or if you have some kind of bur on the back edge of your bolt that could cause some problems you could always slightly round off the face of that bolt and take off the sometimes sharp 90 degree edge which might help. You could also get a new bolt and then polish the inside of the breech with very very fine sandpaper. If you smoothed it all out and used a drop or two of automatic transmission fluid or some non detergent oil it would have to be smooth. You just done want to open up the breech to much as you dont want that bolt to slop which will probably make binding worse hence why I would slightly round the back side of the bolt to take off the sharp 90 degree edge.

Best of luck to you.
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Joined: February 25th, 2011, 7:41 am

October 2nd, 2011, 6:53 pm #7

mess with the bolt and bolt handle. That probably caused the problem in the first place. I did sand it with fine sandpaper, inner side of the breech and bolt too, but I found new scratches again. I ll take it to the gunsmith tomorrow, to see what can be done.
I also can see with my bare eyes that edges in there are not flat - on some places its a bit curved. I ll try to make a macro photos of this.



edit: here are the pictures













i hope you can see scratches, and those curved lines inside breech, and on the place where you load the pellet.
Last edited by UlicniTrkac on October 2nd, 2011, 10:05 pm, edited 1 time in total.
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Joined: December 29th, 2009, 3:08 pm

October 3rd, 2011, 7:01 pm #8

...I would just get a new breech and bolt and start again. Looks like you got a friday afternoon 5:15 job. Unless its an optical illusion, it looks like there is a wobble in the bore of that breech. It shouldn't have passed QA IMHO

Just replace it and you will be sorted. Inspect the new one carefully prior to installation. Now you have messed with it I doubt that Crosman will still guarantee it.
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Joined: February 25th, 2011, 7:41 am

October 4th, 2011, 4:41 am #9

for the opinion. I'll try to sort this one out a bit, but I found a way to get new one. And ordered a custom bolt and handle :D
Now I have to be patient, it will take time to get it here.
Thanks again to all!
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