I have fired all the listed items, but I don't claim to be a military expert or competition shooter, so I'll just make some general observations and offer some political/legal info (I accept no responsibility for your actions because this is not legal advice and I expect you to verify any legal information with your own attorney or a suitable firearms owners group, such as the NRA or CRPA).
1. Trigger action: M1A has the best trigger, right out of the box on standard models, and it's even better on Match rifles.
2. Ergonomics: depends on user, but many people have trouble with HK91 variants.
3. Accuracy: all can be very good, but it is easiest to find match barrels and match or combat gunsmithing for the M1A.
4. Reliability: all are thoroughly proven in the field. Note that I have heard several people (3 of 7 owners) in my circle complain about the reliability of their AR-10's, indicating that they may not be debugged yet.
5. Scope mounting: expensive for all, and some bases/adapters are not too good. Be sure you get a base that is solid (i.e., don't get a base for the M1A that only attaches with the original single screw--it WILL shoot loose--get an A.R.M.S.#18 or Brookfield, instead).
6. Magazines: stick with OEM/GI mags, not aftermarket. FN mags come in at least two incompatible patterns, so be sure to get the one that matches your rifle. M1A/M-14 GI mags should have a stamped U.S. mfr. proof mark on the lower rear face, approx. one inch above the baseplate--but it might be rather faint (Chinese and others will not have the mark). You should get a minimum of 1/2 dozen mags of 20 rd. capacity, but even more would be better. 6 mags will probably be enough to get you through this lifetime, however, since all 3 rifles use strong steel mags. Due to the political climate and law enforcement overzealousness, and possible hunting use, you should also have one or two 5 round mags. They are legal for hunting (check your state laws) and they are relatively inconspicuous. They don't have the "AW" look, for times when you want to practice in public places without drawing attention to yourself. Keep in mind that some "sport" SHOOTERS still don't like "AW" users and they might be sufficiently offended that they would report you to the local gendarmes or BLM rangers. To say nothing of the hikers and bird watchers and mountain bikers who might pass by your campsite.
7. Parts: since you live in California, it would not hurt to get a basic set of spare parts for whichever one you buy. You never know when the shows and even the shops and mail order might be shut down. As a minimum, get a couple of op-rod springs, a couple of firing pins, a hammer and spring, extractor, ejector, non-captive pins and any other parts that have any record of wearing out (go to the specialized web sites for that info). I do not know if all HK parts are compatible, but I know that FN has both inch and metric parts, and the M1A has GI and Chinese parts (avoid these).
8. Political/legal considerations: In California, and possibly later nationwide, you will need to "adapt" your firearms to comply with the law if you wish to avoid registering them as "AW's" (and I can think of no reasons why you would want to be forced to register them when you can comply with the law and simultaneously not register them). Get a copy of bill SB 23 at
www.sen.ca.gov and print out the page which states the features which cause a firearm to be classified as an "AW" requiring registration. Make copies of that page and keep one in the butt trap of ANY firearm which might be even remotely considered to be an "AW" (beware: some pistols and shotguns are also "AW's"). Note which features (careful--might need to remove or modify more than one) you will need to remove or modify to ensure that you do not possess an "AW". This can be a bit tricky, so contact the NRA HQ in Sacramento to find out how the law is currently being interpreted and enforced--916-446-2455. You have until Dec. 31, 2000 (not 1999) to decide if you want to register it or modify it so that it is not an "AW". Some companies will be making legal adapter kits to replace the "pistol grips" on HK and FN types. If anyone has older models, you may also need to remove the flash suppressor, bayonet lug, grenade launcher, etc. There is nothing in the law which states that you cannot simultaneously own those parts, but they may not be installed on the firearm. As a bit of practical advice, I would not store the removed parts in the same home as the firearm because in a previous case involving SKS's, the separate parts were taken into custody and miraculously found to be assembled and working in an illegal manner at a later date--and since the law enforcement officers couldn't explain how the parts came to be assembled, it was presumed to have been done by the owner. (;> ) The current M1A only needs to have the cage of the flash suppressor removed in order to be a non-"AW", and for that, you might want to buy an aftermarket (cheaper) flash suppressor or muzzle brake and cut it back to the base of the front sight. Note that muzzle brakes will be technically legal and non-"AW", but it is unlikely you will be able to explain the difference to some police officer who knows little about firearms--so just avoid the risk and make sure it doesn't extend past the base of the sight.
9. Psychological factors: it is much harder to make the HK or FN look like a traditional rifle if you want to avoid undue attention. Here, the M1A has the clear advantage, if low-profile is what you want.
I apologize for the long post, but many of these points had not been previously covered, as far as I could tell. If anyone would like to contact me, e-mail me at largebear@earthlink.net.
[This message has been edited by largebear (edited December 09, 1999).]
