So...
If a patriotic gun company is going to be hanging on to the conversion parts and keeping them squirreled away in a secret location from which they will only be released in the event of open war or totalitarian regime, why not use that effort to just lock away a bunch of "real" guns?
Why not manufacture individual gun parts in your production facilities and then have committed patriots assemble them in secret, then store those now finished firearms in your bunkers?
I don't know about the costs associated with converting a bolt action to semi-auto but I wonder if it wouldn't be cheaper and easier to just come up with some sort of polymer and stamped PDW type weapon that can accept a suppressor and optics and has an effective range of about 200 yard.
The P-90 uses a straight blowback system, doesn't it? (been awhile since I've read about them), Maybe come up with something along those lines only utterly, crudely, spot-welded and pinned together simple.
Think of a Liberator on steroids and maybe you'll get a mental image of what I'm picturing.
It does have couple strong points:
1. Could be made utterly simply. Look to the Sten or Soviet SMG's for inspiration. It should be simpler to produce than something firing a more powerful cartridge because you can omit a locking mechanism and engineer it to fire from an open bolt with the firing pin just machined into the bolt face.
2. No foresight on the part of the owner is necessary. For the current idea to work, a bunch of guys who would actually potentially use their rifles to oppose a dictator have to buy one of your rifles. No special rifle made by your company = no easily converted weapon. And since they're sitting around planning to keep their AK's and AR's, why would they buy your bolt action? So they can convert it later... But not if no one is telling them that there is a plan in the works to allow these rifles to be converted to military style weapons later.
Seems like kind of a Catch 22.
3. More immune to any law or confiscation. Your secret bunkers are secret and so is what's in them. Just seems that if your going to go to such lengths to keep your conversion parts a secret, why not hide a whole gun? Then if a total ban ever were passed, all the sporting rifles in the nation could be confiscated and destroyed and you'd still have something.
4. Angry populace needs weapons - OK, great!
Now what do we arm them with?
Well... These guys were OK with the gov't. right up until the "agents of the state can rape you, your wife, and your kids any time they want" act. As such, they didn't feel the need to own a gun so they didn't buy one of your rifles. Now, they're willing to take up arms.
Would you rather be passing out conversion kits to guns they don't own or simple little SMG's or carbines that any buffoon can learn to use in ten minutes or less?
Don't get me wrong here - your reasons for trying to work this out are admirable. I actually kind of hope there are some extremely wealthy patriots out there stashing weapons right now in case the need for them should ever arise.
And my points might not even make much sense at all when I read this thread again in the morning.
Just some random thoughts...
Hope you can think of a way past them.