Originally Posted By jbntex:  I have an M2 carbine machinegun.  My personal M2 is a WW2 USGI (Quality Hardware) M1 registered receiver.  While I am  RKI I wouldn't profess to be an M1/M2 expert by any means.

In my mind there are essentially "5" types of M2s out there including the registered part option.

- Factory WW2/USGI manufactured and marked "M2" guns from Winchester and Inland.

- Factory WW2/USGI M1 guns that were reported to be factory made Inland and Winchester as M2s but just not marked as such.

- Factory WW2/USGI M1s that were converted to M2s via drop in parts after the fact.

- Commercial made M1s converted to M2s

- Registered M2 conversion part(s).  The most common registered part seems to be the M2 disconnector lever.  Although I have seen registered M2 hammers and trigger frame bodies as well.  Can't say I have ever seen a sear, selector, or any spring as the registered part over the years.

For me the sweet spot in price was a WW2 USGI receiver that had been converted and registered as an M2.   I didn't want to pay the "factory" M2 marked Carbine up-charge, the commercial guns don't have the best reputation, and the registered part option which was most commonly the disconnector seemed fragile to me and were almost as expensive as the factory M2 guns.  Ultimately I figured how often am I really going to move a registered disco from one gun to another....probably never.... so why pay more for what appears to be a more fragile part that I am never going to move to another gun.  

However for you it sounds like you want to put a registered part in a new Fulton Armory production gun so maybe that makes more sense for you vs. what I wanted.  The registered M2 trigger frames are considered the most "desirable" registered part due to durability but there is some argument if a M2 trigger frame should really be a registered machinegun conversion part.  Personally I think its fine as while its legal to have an M2 trigger frame on an M1 its still an M2 specific part even if its not considered one of the "7" M2 restricted parts.

As mentioned above mags are one of the things that need to be taken seriously.  I originally bought aftermarket mags (Korean I believe) that were reported to be good to go but in reality were marginal.  I ultimately sucked it up and bought a bunch of USGI WW2 20rd mags and a handful of the USGI 30rd SEY "hardback" mags (which are like ~$100+ each) and my gun has run like a champ ever since.  My advice is to just be patient while your F4 is in transfer and cherry pick the best USGI mags from gunbroker, etc. as you can find them.   (You can always take solace in the fact it could always be worse and you bought a Reising with $300 factory magazines)

Also find a type of ammo you gun likes and when it available for a reasonable price buy a shit-ton of it.  There was a period of time recently where there was close to zero 30 Carbine for sale at almost any price short of gunbroker gougers at $2+ per round.  Even today 30 carbine isn't cheap as it starts at around 80cpr with shipping/tax to your door and quickly goes up from there.  Buy a couple boxes of few different types of ammo, find the ones your gun likes  best, and then buy however many cases you think you will need for years and just cache it away.

If  you do end up going the USGI/WW2 M1 converted route keep in mind there are two types of "M1" receivers.  The ones with a recoil spring tube and others with the recoil spring tube as part of the receiver.  Theoretically the spring tube receivers are not as strong and were never meant to be full auto M2s, but I have never heard of a spring tube receiver failing but I guess its possible.  As an FYI, my personal Quality Hardware M2 is a spring tube gun and I have never seen any issues.

My personal take is they are not the best shooters in the world, especially for the somewhat anemic "rifle" round they shoot but you have that experience with your buddies postie so you know what you are in store for.  Ironically I probably shoot mine more in semi-auto than full auto. The USGI guns are a cool piece of history and I shoot mine maybe once a year-ish (a couple hundred rounds) for something different or bring it out for somebody who has to shoot an M2 carbine.

Good lock with whatever you decide.

Originally Posted By Silverbear_51:  FWIW:

When you thread your cut-down barrel, make sure you thread "on centers".  When I had a flash hider installed on my chopped M2, the gunsmith noted that the bore was nowhere near centered in the barrel at the new (shorter) muzzle as the drill had wandered a bit while making the barrel.  It was wartime and nobody cared as long as the rifle would shoot "minute of Nazi".

Watch out for the barrel band as you handle a hot gun.  It gets just as hot as the barrel does after a few magazines, which I found out as I was putting my M2 into a vertical rifle rack after shooting it.  I kept clear of the barrel, but the web of my hand contacted the barrel band- ouch!

The old GI "recoil check" or muzzle brake does really work to keep the front end down in full auto.

I have a few left-over parts from my M2 days (a couple of hammers and a sear) that I want to be rid of.  If you PM me with an address, I'll send them to you.

Originally Posted By backbencher:  Order a Criterion bbl, chop it?

Originally Posted By Landric:
I finally made it to my dealer's place to try the M2 kit (it has been almost a month since the form 4 was submitted).  The BRP-Suomi I bought just arrived there last week, so I got to try them both out.  The M2 kit works perfectly and the BRP was huge fun.  Definitely more interesting than the STEN Mk. II and the M10/45 I sold to help fund this.