Inch - Metric - Israeli - differences

[ricochet]

I've looked in the FAQ's and tried to answer as much of this before asking, but:
I know a metric upper/lower seems to work with an inch upper/lower.
I know that internals (trigger,hammer,sear) cannot innerchange between inch/metrics.
I know that the stock parts (grip,buttstock) cannot innerchange.
The gas piston on an inch is longer, but a metric will work. Correct?
As far as barrel threading and recoil devices, what innerchanges and what can be made to work?
Can the mag release from an inch work on a metric and visa/versa?
Is Hesse the only maker (currently) of U.S. parts for an inch trigger group?
The gas plug works from one FAL to another. Any exceptions?
At what point is my assembled rifle considered a rifle? Do I legally need to have 6/7 U.S. parts before assembly, or is it not considered a complete rifle until I insert the dreaded magazine?
In a nutshell, what are the main differences in metric,inch, and Israeli? (can this be asked in simple terms?)
Legally, how many can I (and my wife) assemble for personal use, per year. I have gotten several answers, and this is only referring to those I plan to put in the safe. I do not want to sell ANY, I am selfish and want to keep them all for myself.
Any or all answers will be appreciated, I do not want to cross the BATF boundaries, and intend to be informed. Again, these are questions that have and are to be asked again. Thanks guys.

[ July 24, 2001: Message edited by: gary.jeter ]

[Dan at VOW]

Ok I answered some of these in another post. Here is a link; http://www.fnfal.com/forums/Forum1/HTML/006279.html
Gas piston- metric will work in inch.
barrel threading, muzzle devices, as long as they are not a flash hider, you can thread the muzzle, but must permanently attach through one of several means. This can be done by silver soldering (1100 degree solder required), blind pinning, 4 spot welds, or welded all the way around.
Mag release-yes you can use an Inch mag release on a metric or vice-versa.
Heese is only inch t/h/s maker at present, but there will be quality made out soon (hopefully no more than 6 weeks)
Gas plug-can't use Izzy gas plug in metric, it's different length. inch is for inch
When is it a rifle? If the recvr is attached to the barrel, it can be considered a rifle, if all other parts are present (BATF's idea, not mine)
Differences in type; Inch-these have a lower that has 'tangs' or wings at the base, where the butt stock joins the lower. The pistol grip is different, in that the grip on an icn is secured with a screw that you remove from the top of the lower, instead of unscrewing a nut form the stud that projects from the lower on a metric. The trigger setup is also different, the Inch has the trigger return plunger as part of the grip, though it is removeable, this can make working on trigger pull more of a challange. They will also have a taller rear sight, the leaf or blade will fold down. The safety selector is larger and more easily used than a metrics (Izzy is my favorite though). The mag release is also larger and easier to use, especially one handed. the British Inch rifles did not have the forward or "auto" position marked on the lowers, while the Australian model does. The Inch dust cover has 2 small tabs on the rear, which are designed to help keep it in place. The Inch also has the folding charging/cocking handle (mistakenly referred to as the operating rod by the ATF) this is a desireable feature, in that it won't gouge a big hole in your back if carrying on a sling. The inch also takes a different mag, in that it has a large lug at the front, instead of a small 'beak' as on the metric. It also uses a different floorplate, with edges that fold over the outside lips of the mag. This is done so that mags with dents or dings could be straightened out easier, with a large block of steel cut like a mag inserted inside. the Inch rifles also used a breeching washer, in place of the shoulder that is found on metric barrels. Breeching washers of different thickness are used to set head space, as well as the locking shoulder. The gas adjustment ring is different on an inch rifle, these do not have the grooves as on the metrics, though they are numbered, it is a different set of numbers. The front sights on the inch are also different, the soights have open ears (some Izzys and Argintine did also) and use a different front post, set screw type with locking screw in front of gas block.

As for how many can you assemble in a year. Well how many can you afford? As long as you are building them for your self, and there are no local or state restrictions on the number of receivers that you can purchase, then build all of them that you want. I hope I have answeresd some of the questions that you have. Any mistakes I might have made will be pointed out by others who are more knowledgeable than I am. I also apologize for the spelling errors. Dan at VOW.

[ricochet]

Thanks Dan,
I know that these have been asked before. Thanks for the answers. I was told that it is not consisdered a rifle until the mag is inserted. That is why I ask. I appreciate the answers, that clears up a lot for me.

[W.E.G.]

moved to FAQ