Maverick 88 mod.
 

Ok, I have a Mossberg (Maverick) 88. I recently replaced the forend and stock with a Blackhawk Knox recoil reducing set, to replace the forend I had to put a new action slide tube assembly on, that of a mossberg 500. It all went flawlessly, but now that is all back together, when I fired it the bolt came open and the pressure of the fire pushed the whole pump action open. I was hoping someone could tell me what was going wrong.... maybe i got the bolt back in wrong were it can't lock IDK. I'd hate to lose a hand though.

Please help, post above has info. Thanks in advance for the help. =]

Can you pull the pump back fter its shut wo hitting the pump release?

God didnt make all men equal colonel Sam Colt did

Also you might try shooting lighter loads through it to see if it still does it.

God didnt make all men equal colonel Sam Colt did

My 88 will do the same thing if I don't have my hand on the foregrip,but it doesn't take much pressure to keep it in battery... it sounds like yours is doing it even though your holding the foregrip in the forward position right? If not and it only does it when not being held in place I wouldn't worry about it,I still have all my appendages.

Ok I'll bite on this one. If the mossy is working properly you should be able to rack back the slide when the firing pin has been released with out pressing the slide release. When it is chambered and ready to be fired the chamber should be LOCKED and not be able to slide back until the trigger is pressed.
So do a quick function check like this
1 make sure unloaded
2 cock the mossy and go forward with the pump all the way
3 see if when in the forward you can pull the pump back
4 squeeze trigger
5 see if you can rack the mossy like you are putting another round into it

After you squeeze the trigger the pump should be unlocked so you can pump with out pressing the pump release. When sent back into full battery it should lock until you fire or press the pump release to eject the live round.
I have experanced what you have once before on an well used 870 and it was not that it did not work properly it was that is was so "slick" that the recoil "helped" you pull the pump back.
I hope this helps you because I have a hard time explaining my thoughts on paper so to speak sometimes. Try the test and let us know what happens.

This what im askin and supplying the fixes for

God didnt make all men equal colonel Sam Colt did

Does the new forearm allow it to go to battery? Have you tried the old forearm?
If it worked before the mods and if it works after you put the old forearm back on, then I would suspect the new forearm.

Ya it will lock into place, you have to hit the slide release everything is completly normal function wise, up until I fire it.
On the lighter loads note, I've been shooting target loads.

The old forend broke that's why I just did the mods.

Then its so smooth now it is helpin you eject the hull

God didnt make all men equal colonel Sam Colt did