Navy trigger group shelf

[Buddymack]

Does anyone have a good tutorial on that little shelf that goes in place of the pin on a Navy TG ?, I am going to be putting one together soon.

[Perro Del Diablo]

on the navy, you trim the metal plate in front of the grip frame to just sit on top of the shelf. There is a square cutout in front that must be made to match up to the shelf on the magwell.

then, you need to epoxy a plastic block inside of the lower in front to prevent the installation of a full auto fire control box. it should be close in shape to the one in the steel grip frame.

on the steel lower, the block is what holds the front of the grip frame to the receiver

on the plastic lower, the square hole in the metal plate in front is what holds the front of the grip frame to the receiver.

so - to make a navy grip frame work, you need to take some precise measurements from bottom of receiver to the square hole and cut it to fit tight. make the rough cut shy of the correct deminsion, and work up to final dimension taking light passes on your finishing cuts.

without the block epoxied into the navy lower, it would take me 5 minutes with a dremmel tool to make it full auto - can never be too careful with the whole "readily restorable" thing

[Buddymack]

on the navy, you trim the metal plate in front of the grip frame to just sit on top of the shelf. There is a square cutout in front that must be made to match up to the shelf on the magwell.

then, you need to epoxy a plastic block inside of the lower in front to prevent the installation of a full auto fire control box. it should be close in shape to the one in the steel grip frame.

on the steel lower, the block is what holds the front of the grip frame to the receiver

on the plastic lower, the square hole in the metal plate in front is what holds the front of the grip frame to the receiver.

so - to make a navy grip frame work, you need to take some precise measurements from bottom of receiver to the square hole and cut it to fit tight. make the rough cut shy of the correct deminsion, and work up to final dimension taking light passes on your finishing cuts.

without the block epoxied into the navy lower, it would take me 5 minutes with a dremmel tool to make it full auto - can never be too careful with the whole "readily restorable" thing

Can I just use the cut out of the FCG box as a rough estimate of the material I need to start with?

[Perro Del Diablo]

Can I just use the cut out of the FCG box as a rough estimate of the material I need to start with?


not sure what you mean exactly

if you mean to size the block you are going to epoxy into the grip frame then yes, use the size of the cutout on the fire control box as a reference to size of the denial block.

if you mean as a reference for the part of the grip frame that will sit on top of the shelf behind the magwell, then no, me personally i use a dial caliper to measure from the top of the shelf to the section on the bottom of the receiver that the FCG box touches when mounted. Then i add the measurement from the top of the grip frame down to the top of the FCG box to that number.

with that measurement, then measure down from the top of the grip frame and scribe a line across the front with a straight edge - cut to the line and test fit - will most likely still be a bit tight - now make light finishing cuts until it fits perfectly.

hope that helps? if i have lost you, tell me where and i will try and explain better

[Buddymack]

So yes I think you are understanding me, I will try to make a block equal to the missing square on the FCG box.
Is that secured with epoxy? or maybe gel superglue?
and I am still kinda foggy on the shelf, I have CAI Cetme that has the pin ears clipped but is the shelf the same?
............

I might cheat and have one of them done so I can look at it and go oooohhh, once an aircraft mechanic always one I guess I need another tail number in the hangar to look at lol.

Thanks Perro BTW!

[Perro Del Diablo]

So yes I think you are understanding me, I will try to make a block equal to the missing square on the FCG box.
Is that secured with epoxy? or maybe gel superglue?
and I am still kinda foggy on the shelf, I have CAI Cetme that has the pin ears clipped but is the shelf the same?
............

I might cheat and have one of them done so I can look at it and go oooohhh, once an aircraft mechanic always one I guess I need another tail number in the hangar to look at lol.

Thanks Perro BTW!

the steel grip frame has that block welded into it, or if you get a big50 pack, then it is silver soldered onto the metal frame.
on the plastic lower, if you heated it, it would melt of course so you want to affix it to the lower somehow - jbweld, 2 part epoxy, super dooper super glue or whatever.

it's only purpose in the navy lower is to prevent you from installing a full auto fire control box easily. it serves no other purpose.

I was a jet mechanic once myself :wink:

If you need pics, i would be happy to help, but im sure someone else here already has the pics on hand - i would actually bet a dollar that Blades, or Holes have those pics already.



Mike

[Perro Del Diablo]

better yet - i searched google images and found a premade picture that should answer your question about enlarging the front of the navy lower to sit on top of the shelf

http://i71.photobucket.com/albums/i123/ptoguy2002/FRAMES.jpg
that one doesnt have a denial block epoxied in it, but it should give you a good example of what the front of the square hole is going to need to look like to work for you

[Perro Del Diablo]

this is the PTR navy lower - you can see how they cut the sides of the ears to fit around the sides of the shelf - a very nice touch

but also no denial block

[Buddymack]

Thanks Perro! a version of that PTR one looks really doable to me.

[Daffy]

I guess I better post since this seems to be the thread where all the ex-aerospace, jet,etc, mechanics are posting.
I'm just about to do the same on mine. I was thinking also that you could spot weld something on that sheet metal for the denial piece. I cut my shelf slot like PTR's. Mine's from black market parts. Theres a great glue called zap-a-gap that should work if you're going to glue a block in place. It can be had an any hobby shop or place that sells radio controled cars. It should melt the 2 plastics together. I have some, and will give it a test.

[Buddymack]

Now that I re read this I realize what I was missing and that is that the sheet metal is already there on these thus making them easier to do than the metal ones...
Perro must of have been wondering about my sanity :icon_neutral:

[Smokehouse69]

I don't think the denial block is a must, since my C93 doesn't have one and neither does the PTR91 with a plastic lower that a buddy of mine has.

[Daffy]

Smokehouse: that was crossing my mind as well. I think the denial block was an HK idea, not the feds. So everyone just assumed....
Think I'll put one in anyway. I like to error on that side of things. I learned from the IO confisgation some years ago that companies don't always get it right.

[Buddymack]

When you look at it like this, that shelf does not keep you from converting the rifle into FA at all, but the denial block does, but only with that FCG, so really either you have intent or you don't, I personally feel if it's legal it's legal, if they decide they don't like you for some reason they will find something anyway that is why there is a tax code weightier than the bible on codes
"IMHO anyway" :icon_neutral:

[Smokehouse69]

That's a valid point, dealing with the Alphabet boys I think a lot of it just depends on how they interpret things rather than the intent of the law or the gun owner.