Thumbhole Stock Modification

[Addax]

Hello Folks,

I am working on a project to fill in a thumbhole stock to make it a solid stock.

What are the legal definitions (if any) on how a stock can or should be modified?

I do not have pics yet since I only have a sketch of the plan on paper only.

The plan is to fabricate 2 pieces of thick plastic with a aluminum bracket/frame, 2 bolts and nuts and a sponge foam insert or solid foam insert.

I am going to bolt the two piceces together through the Aluminum bracket / frame and this frame would sit inside the foam and the foam placed inside the thumbhole in the stock. So bascially the thumbhole would be filled and covered on both sides with an internal reinforcement using the Aluminum bracket.

The rifle does not have a normal stock mfg. for it, only a thumbhole stock is available.

Please provide me your ideas or opinions on this.

[Jicko]

As long as u completely fill the hole and there is no indent and no way a thumb can poke thru.... then you are fine.... it is no long a thumb hole stock... it is just a regular stock...

[Addax]

Thanks JickoRicko.

That is what I was thinking too.

Yes, the plan is to cover the thumbhole completely on both sides.

[paradox]

Read this thread:

http://www.calguns.net/calgunforum/showthread.php?t=36279

The oar stock rises!

[Addax]

Much appreciated Paradox.

Yeah, I am building me an oar!

Does it matter if the thumbhole plug is filled using a polymer or glueing it in place, or can the pieces be bolted together and still be considered passable?

[Blacktail 8541]

The alteration should be non reversable without tools. So an epoxy type filler would be adviseable.

[RANGER295]

I have been thinking about making something like this. I have a full wood shop and my idea was to put a standard A-2 buttstock on and make a wooden pistol grip type thing that would taper down as the buttstock gets wider. It would screw on where the pistol grip screws on to the receiver and in the rear it would screw to the butt stock where the sling swivel normally would screw on. Might be a bit more work than the other but I didn’t know that they made a thumbhole stock for an AR. I also thought about getting a thumbhole AK stock and filling the hole. Here is my question. Do you all think that it would be ok to have a hook that screwed into the right side of the stock to push your thumb against so that you could get a little more support? Or even just have a peg stick out the side to rest your thumb on.

[blkA4alb]

I have been thinking about making something like this. I have a full wood shop and my idea was to put a standard A-2 buttstock on and make a wooden pistol grip type thing that would taper down as the buttstock gets wider. It would screw on where the pistol grip screws on to the receiver and in the rear it would screw to the butt stock where the sling swivel normally would screw on. Might be a bit more work than the other but I didn’t know that they made a thumbhole stock for an AR. I also thought about getting a thumbhole AK stock and filling the hole. Here is my question. Do you all think that it would be ok to have a hook that screwed into the right side of the stock to push your thumb against so that you could get a little more support? Or even just have a peg stick out the side to rest your thumb on.
http://www.calguns.net/calgunforum/showthread.php?t=39534

[bwiese]

Some incorrect information was given out above.... instead,


There is NO legal requirement for permanence of modification for a 'filled-in' thumbhole stock, just as there is no legal requirement for permanence of affixation of a fixed mag.


There is also no requirment to avoid an indentation; you just can't have a *hole* your thumb can go through

CCR 5469(e) "thumbhole stock" means a stock with a hole that allows the thumb of the trigger hand to penetrate into or through the stock while firing.




[Again, the only permanence in CA AW laws + regulations relates to permanent capacity reduction of hicap mags (and possible triggering of the alternate "fixed mag with over 10 rounds..." definition of AW).]

If you have a thumbhole stock and you can 'fill' the thumbhole with two wood disks held together with a nut & bolt, you are fine.

Of course, you don't wanna take the screw + plug out while the rifle has a open mag well/detachable magazine!!

[Addax]

Hi Everyone,

Thank you for the input and additional information, it is very helpful and reassuring that I am planning on doing the right thing.

This is going to an interesting project.

More details to follow soon.

[RANGER295]

Thanks. I saw the other post a while back but was not comfortable that it would be sufficient. Besides I don’t have any of the stuff needed for kydex. But based on the responses I take it that we all agree that a thumbstud or thumbrest of some sort would probably be ok?