Bullboss shenanigans...again. :(

[VaporTrail]

Previously, on Days of Our Bullboss...

Had an issue with cocking the Boss; hammer would go back, but stop right before the trigger sear. Maybe about 3-5mm shy of the sear. It's like it ran out of room? Thought it was the Hammer Debounce (or hammer sear), so I ordered that part. Then I thought it was the auto-indexing lever, so I ordered a new one along with the spring.

Installed the HDD and spring, same issue. Installed the new auto indexing lever and spring, same issue.

Thought something might be wonky with the collar, hammer and that other part (can't remember the name, it goes on the valve side collar, where the valve screws into); so I sanded them all smooth (there were nicks from the HDD). Wiped the inside of the hammer tube as best I could. There's nice patch about 3/4 of an inch long where the hammer scraped away some of the wall of the tube. I smoothed that one down as best I could as well. Sanded the bottom corner of the legs of the HDD so that it's a slight round to help it not get caught on the hammer.

All of this stuff didn't help either. 

By this point, I had disassembled and reassembled about 4 times and fiddled with internals for about 3 hours. I was sooooo done.


So....any thoughts as to what it might be?

[Back_Roads]

 It sounds to me like the hammer spring is reaching coil bind 
If not I'm stumped also. 

[redlined_b16a]

If I try to get more preload out of my bullboss I encounter the same issue.

Sounds like coil bind to me as well.
My Boss is the first generation one.

Also try trigger adjustments.
Trigger adjustments effected mine too.

[Nomadic Pirate]

Told ya to buy a Sumatra before buying those Hatsans  LOL 

[Rallyshark]

Make sure the plastic plug at the rear of the trigger tube is pushed as far forward as possible, before tightening down the bottom screw and the top screw that goes though the rear of the breech.  The HS is pushing that piece toward the rear of the trigger tube when you reassemble the gun.  I've had that cause the same issue you're experiencing myself  

[VaporTrail]

It sounds to me like the hammer spring is reaching coil bind 
If not I'm stumped also. 

I've tried with the HS at max preload and also at minimum preload. It still won't go the last 5mm.

And to make matters even more interesting, I forgot to mention one little thing:

when the trigger/hammer tube is not attached to the upper block, the hammer will go all the back and engage the sear. However, when I attach the tube to block? No cock. 

[VaporTrail]

If I try to get more preload out of my bullboss I encounter the same issue.

Sounds like coil bind to me as well.
My Boss is the first generation one.

Also try trigger adjustments.
Trigger adjustments effected mine too.

I thought it could be coil bind, but I also tried it with preload at zero. Still the same. As for trigger adjustments, I suppose I could try it out, but the hammer won't even go back far enough to engage the trigger sear. 

[VaporTrail]

Told ya to buy a Sumatra before buying those Hatsans  LOL 

Lol...that you did, my man. I can't say I regret it, though; I do love me a nice bullpup. Almost reminds me a KSG. Just not as violent. And loud.

[VaporTrail]

Make sure the plastic plug at the rear of the trigger tube is pushed as far forward as possible, before tightening down the bottom screw and the top screw that goes though the rear of the breech.  The HS is pushing that piece toward the rear of the trigger tube when you reassemble the gun.  I've had that cause the same issue you're experiencing myself

I'll loosen it up and try that again. I did remember what you told me, so I took a look at it. The screw holes seem to be lined up nice. I did knock it a little with the allen wrench but it went too far. I pushed it back from the other side and lined up the holes again. Still no love.

Oh...did I mention? when the tube isn't connected to the upper block, the hammer will go all the way back and engage the trigger sear. When it's attached to the block? No love.

Stumped. 

[Rallyshark]

Make sure the plastic plug at the rear of the trigger tube is pushed as far forward as possible, before tightening down the bottom screw and the top screw that goes though the rear of the breech.  The HS is pushing that piece toward the rear of the trigger tube when you reassemble the gun.  I've had that cause the same issue you're experiencing myself

I'll loosen it up and try that again. I did remember what you told me, so I took a look at it. The screw holes seem to be lined up nice. I did knock it a little with the allen wrench but it went too far. I pushed it back from the other side and lined up the holes again. Still no love.

Oh...did I mention? when the tube isn't connected to the upper block, the hammer will go all the way back and engage the trigger sear. When it's attached to the block? No love.

Stumped. 

That is odd?  It really makes me feel like something is up with the de-bounce getting in the way of the hammer moving all the way back.  Try taking that de-bounce out of the gun and put it back together without that.  If it cocks then, then you know something isn't sitting in there right with the de-bounce.

[VaporTrail]

Make sure the plastic plug at the rear of the trigger tube is pushed as far forward as possible, before tightening down the bottom screw and the top screw that goes though the rear of the breech.  The HS is pushing that piece toward the rear of the trigger tube when you reassemble the gun.  I've had that cause the same issue you're experiencing myself

I'll loosen it up and try that again. I did remember what you told me, so I took a look at it. The screw holes seem to be lined up nice. I did knock it a little with the allen wrench but it went too far. I pushed it back from the other side and lined up the holes again. Still no love.

Oh...did I mention? when the tube isn't connected to the upper block, the hammer will go all the way back and engage the trigger sear. When it's attached to the block? No love.

Stumped. 

That is odd?  It really makes me feel like something is up with the de-bounce getting in the way of the hammer moving all the way back.  Try taking that de-bounce out of the gun and put it back together without that.  If it cocks then, then you know something isn't sitting in there right with the de-bounce.

Got it. I did sand down the lower corners of the legs of the one piece HDD to help the hammer slide past it. When I look at it, it doesn't seem like the HDD is getting in the way, but I'll give it a shot.

I was also thinking that maybe the collar is out of round? Or is catching somewhere? The uniform scrape on the tube wall is telling me that it has to be either the hammer or the collar that is causing that scrape.

Oh...I also put in an AT44 HS. Definitely feels stiffer than the one that's in there. Could possibly be because the AT44 spring is new, though.

[Rat Sniper (AKA: PaulT58)]

Did it cock before you swapped the hammer spring?  Have you checked to see if the AT44 spring is longer when fully compressed and that's causing the issue? If it's stiffer it could have more coils per inch would would prevent it from compressing as far as one with less coils per inch.

[VaporTrail]

Did it cock before you swapped the hammer spring?  Have you checked to see if the AT44 spring is longer when fully compressed and that's causing the issue? If it's stiffer it could have more coils per inch would would prevent it from compressing as far as one with less coils per inch.

No sir...it didn't. That's when I thought it was the HDD. So I ordered that, along with an AT44 hammer spring to try out. When the parts came in, I installed it, but it still did the same thing. So...I figured maybe I stretched the debounce spring a little too much, so I ordered that. The auto-indexing lever also looked like it was taking a beating, so I ordered that as well since I recall reading that a wonky AIL might also prevent it from cocking. Those parts came in and I installed them...but it still wouldn't cock. 

I have an extra AT44 HS, so I'll measure OAL compared to the Boss spring and count coils. It's like the hammer is hitting a wall.  At this point in time, I think I've assembled and reassembled the Boss so many times I can probably do it with my eyes closed. Like literally, with both eyes closed.  Lol...as I'm typing this, I'm picturing it in my head, feeling around and taking things apart.

I have no regrets, though...I love this gun. 

[Back_Roads]

  Could something in the trigger be messed up, perhaps a sear?

[VaporTrail]

trigger sear works fine. That's what makes this a tad annoying; when the hammer tube is separated from the upper block, I can use a t-handle and push the hammer all the way back to the trigger sear and the sear will engage. Attach the tube to upper block? No love.

It's like the hammer is hitting a wall somewhere, and it's about 5mm away from the sear. So I tear down the gun, fiddle with the hammer tube and it's components, cock it so that I can access the screw underneath the bolt/pellet probe, then release it so I can access the rear screw above the trigger assembly. Reattach the trigger and sidelever linkage...and no love. Won't cock. 

[Rat Sniper (AKA: PaulT58)]

Since I don't have the rifle in front of me anymore, I'm going completely from memory, but I recall running into the same problem with one of the refurbed BB's (before Hatsan sent me the new one you now have).  I mixed up a couple screws that went somewhere and one was just a tad longer than the other and it caused that problem since it went too far.  I wish I could remember which 2 screws, but recheck all your screws that may interfere with the hammer and try backing them out a bit to see if it frees it up.  If it does then find a shorter screw and try that.

[VaporTrail]

Hmm...that makes sense. I'll go over the screws again and see if maybe I made them a little too tight. Maybe it's making something off-kilter and that in turn is causing a bind somewhere in the hammer tube. Looks like I have a bunch of stuff to try out this weekend.

Thanks, bro! I'll give it a whirl. 

[kbstingwing]

I just looked at mine, and with in the last 5 mm it looks like that's when the auto safety is engaged, you might check that to make sure nothing is binding, also make sure the bolt is clear to slide back, maybe it is in upside down? not sure but worth it to check out, you did say with the upper block removed it will cock, so it sounds like something in the upper block is the problem and the bolt and the magazine index lever are there or maybe a screw is to long and obstructing the bolt? just some Ideas that might help find the problem

[VaporTrail]

hmm...that's also something to think about. Thanks, kb!

Maybe I need to go over the whole hammer assembly with a fine tooth comb. And do it slowly too.

It has to be something simple, since nothing appears to be broken.