Blackhawk Knoxx-mossberg 500 help

[StratoWack]

hi people. i just installed a blackhawk knoxx specops gen2 on a mossberg 500, and im not sure if i have issues per se or not.
if i tighten the stock bolt down all the way, the trigger on dry firing feels sticky and requires more pull. after dry firing it also doesnt have that few millimeter return forward i assume is normal. it stays tight to its rear most position. if i then loosen the stock bolt, the trigger clicks forward a few mm to its normal position.
similarly, if i back off the bolt so theres a little bit of play in the knoxx/mossy joint, the trigger on dry fire feels like it did when the pistol grip was on. smooth, effortless, and returns forward a few mm to its out of battery position.
i wont get a chance to fire it for a while, so i thought i'd get some feedback from people at this point. (i think valkman has one of these).
I'll post some pics/vids that are iphone compatible. but i can convert the to mpeg or wmv if anyone needs.
thanks!

 

[StratoWack]

this is the package photo. the stock sits flush with the rear trigger guard. mine doesnt, but its likely more related to the package photo being of a different weapon. maybe a 590 or a rem 870.

 

[StratoWack]

this photo shows the tight top joint but the gap in the lower joint. the grey thing in between is the flush right side of the sling attachment.

 

[StratoWack]

https://vimeo.com/175063239
this vid shows the play if i back off the stock bolt so the trigger feels/acts smoothly. am i wrong to think if it feels good and (when i live fire it) shoots good i shouldnt worry about it?

 

[StratoWack]

this vid shows what i call the 'normal' return to non battery position, after firing, that I can only get if i back off the stock bolt a few of millimeters.https://vimeo.com/175065560

 

[StratoWack]

https://vimeo.com/175071670
heres what happens if i tighten the stock bolt so the knoxx is in place without a gap at the bottom of the joint, and i dry fire. the trigger stays rearward. in the vid i gently back off the bolt and the trigger returns to its non battery position.
if i was a missberg armorer i would probably know exactly why tightening the bolt affects the trigger. but i dont.

 

[StratoWack]

by the way, to see if it made a difference, i reinstalled the knoxx with the stock mossy bolt, and it seemed to allow me to get the joint tighter without binding the trigger rearward, but if i tighten it ever so firmly, it binds. funny, the mossberg bolt is almost 1/2 inch shorter than the knoxx bolt, but it seems to aalliw for a better fit of the knoxx than the knoxx bolt.

well, i gave a lot of material. hopefully It'll help you guys.
thanks people!

 

[danez71]

Ive seen a lot of similar Amazon comments/questions on 2 different ATI stocks for the 500 too.

To the effect of 'tighten it too much and the trigger has problems'.

Answers/follow up replies seem to say use a shorter bolt or add washers.


It the case of the ATI stocks (1 or both models, I forget) some complained about the stock not coming with a new bolt and that the stock bolt was causing the problem.


Either way, it seems to be the same issue and confirms what you're saying... too long of a bolt causing trigger problems.



I only 'know' this because Ive been searching through Amazon and thinking of buying a pistol grip stock even though I generally don't favor them.



Question: Did the trigger reach get longer or shorter? I'm not asking about LOP, Im asking about how much your index finger has to stretch out to reach the trigger face.



Thanks for all the info you posted!

 

[StratoWack]

thanks for all that info danez. it helps to know that my experience is relatively common. and it's interesting that the consensus is that it's the bolt length, rather than the tightening itself. i was thinking it was the latter, cause i figured the recess the bolt travels into doesnt communicate with any part of the trigger/firing mechanism.
for the record though, i cant understand why either tightening or bolt length or both would create a stress that affects trigger/firing. again, I'm sure an armorer could easily explain it. im gonna shine a light into the bolt recess in the receiver to see if theres anything in there that would explain it.
to answer the question, i'd say no, the length of the reach of the trigger finger needed to pull it isnt any more/less than with the stock pistol grip. i have relatively sizable hands so it would have to significant to notice. it didnt shorten the reach, thats for sure.
so you gave me an idea when you mentioned some people add washers. the knoxx bolt comes with one. the mossy comes with two. but when i used the mossy bolt i only used one. i have three total, of course. so im gonna try the shorter mossy bolt with two and then three washers. if it is the bolt length combined with the knoxx dimensions that is the issue, maybe using three will back off the bolt so that it still mounts the stock effectively, but completely relieves the interference with the trigger/firing; cause even with the shorter mossy bolt, i still have to back it off. I'll post my results.
thank you!

 

[StratoWack]

OK. Well, So much for that idea. I can't use more than one washer with the stock bolt because it makes it too short to screw into the receiver. and with the Knoxx bolt, even with two washers, it's too long. so I'm just using the stock bolt with one washer, and I back it off about a half turn, and it works better then the Knoxx bolt. the trigger works fine, and there's virtually no gap or play in the joint between the stock and the receiver.
another weird thing I'll say just for the record is that if you use the Long end of the quarter-inch Allen key to tighten the bolt, as you bare down to fully tight the angle of the bolt changes such that the Allen key presses against the inside of the plastic of the Knoxx stock making it impossible to remove the key. The only way to remove the key is to back off the bolt so that the key angle straightens the key comes out fine. if you use a smaller metric key that grabs but not perfectly, or you use the short end of the quarter inch key, you are able to get the key out fine. I don't know if this is due to poor design of this stock or something else but it is real.
aside from all that stuff, I guess I'll keep the stock because it appears otherwise very well-made and super comfortable.
thanks man.

 

[danez71]

Could have misinterpreted the amazing chatter that the bolt was too long vs over tightened 'as a consensus' but I do remember some saying that specifically.

But it's amazon chatter so I take it with a grain of salt.

Thanks for trigger reach info. I have short fingers and that's a big issue for me.

The ATI non adjustable I looked at, at a gun store, seemed like it might shorten the reach a little.

Thinking about it more, I don't remember if those trigger issue comment were only about the 500 or if any were for the Maverick 88 which is the same thing but does have a different trigger group.

 

[StratoWack]

ah. yeah. may not have been comments about a 500.
for the record, the instructions that came with the Knoxx do make a very explicit cautionary statement about checking the trigger and firing after installing the stock and then advise, if any issues are noticed, to back off the bolt a little. so whether it would be the length of the bolt or the tightening, they may have experienced issues when they were proving their product, or they are responding to comments on Amazon and elsewhere like here. what's funny though is that the stock bolt on my 500 that was holding the pistol grip on was cranked down tight enough that I mightve had to use a little Chi gong to get it cracked. and I had come across other forum comments regarding getting Schwarzenegger or hulk hogan to crack the threads. i'm not sure if that was due to some factory Loctite or if it's because they had it cranked down tight, but if it's the latter, I would wonder why it wouldn't cause trigger/firing issues like with the knoxx.
interesting learning/knowledge database expefience.

 

[Valkman]

Interesting - I bought my Knoxx stock before they were taken over by Blackhawk I guess. I bolted it on and have never had a problem.

 

[StratoWack]

yeah. maybe tolerances changed.

 

[danez71]

ah. yeah. may not have been comments about a 500.
.

No no no...

There were definitely those comments types of made about the 500.

But I'm not sure if any of those type comments were made about the Mav88. There may have been, but I 'm not sure.

 

[StratoWack]

ah. thanks for the clarification.