What is the difference between an L1A1 and an FAL?

An L1A1 is a variant of the FAL.  The L1A1 is an "inch" version which means certain parts are not compatible with with the more common metric models.  Other variants that you will hear about commonly are the Imbel (Brazilian), STG58 (Austrian), G1 (German) and R1 (Rhodesian).  Those are all metric variants.  They are all FAL rifles but have some minor differences.  All Metric variants can interchange parts and all inch types interchange between eachother.  There are some parts that can go either way but don't ask me what those are.

L1A1s is inch pattern, FAL is metric pattern.Which doesnt mean metric thread sizes.What it really means is there ate some major diffrences yet some parts interchange.The magazine in a metric will fit in an inch gun but not vice versa.A metric mag is a cresenct shape punched out of the mag body itsself.The inch mag has a piece welded on to the front and is larger.The metric reciever has a crescent cut into the magwall to lock in the like shape on the metric mag.The inch has a larger rectangle cutout to accept the larger tab welded onto the mag.The inch has a folding charging handle the metric a knob.The inc has a cut in the charginging handle rails to accept it.The metric has a detent to hold the charging handle.[handle does not move back and forth with bolt and carrier]The inch usually has sand cut on the carrier and inside the reciever.Metric lowers are completly diffrent than inch lowers but will interchange as long as complete units are used.Buttstock on metric is straight were it meets the lower,inch is stepped .Internals dont interchange except the saftey with a little work.Inch saftey is much larger.Sight on inch usuall fold down metric doesnt.Top cover on inch has nothes and will not fit a metric unless trimed.Metric and inch do have the same english thread sizes.However India and Isreal do have metric threads.Isreal for the most p0art interchange with metric except the barrel threads which can be chased and made to work.India is a mismatch and combo of everything.Hard to tell what they were thinking.There are exception on some models like pratrooper models will have folding cocking handels ect.but they are rare.  

Also L1A1s are NOT F.A.Ls since F.A.L stands for Fusil Automatique Leger wich means light automatic rifle. L1A1s do not have full auto or burst capability, seems that the brits didn't want a full auto 7,62x51 rifle so they designed their rifle to fire in semi ONLY. there's more, the handguards and flash hiders are a little bit diferent as well.
I just thought i'd add this.
HUNTER.

The L1A1s had a semi-auto selector. All that was necessary to convert them to select-fire was a slightly different selector.

Quoted: The L1A1s had a semi-auto selector. All that was necessary to convert them to select-fire was a slightly different selector.

Then if it needed somethingELSE to have full auto capapbility IT DIDN'T have full auto capability out of the box as the british troops used it, right? an AR15 can also have FA capapbility if the right parts are swapped, and that applies for most semiauto rifles, my point was that the L1A1 as it was used, WITHOUT ANY MODIFICATIONS, didn't have a FA selector.
HUNTER.

The HB versions of the L1A1 did have full-auto
capability.
Also some L1A1s did have F/A capability.

Canadian and Australian FALs were inch also.
The Indian FALs were half inch and half metric.

The L1A1s are FALs they are they are essentially
the same rifle, with a few differences, just as the
Belgian, Izzy, Brazilian, Dutch and Argy FALs
are.

Quoted: The HB versions of the L1A1 did have full-auto capability. Also some L1A1s did have F/A capability. Canadian and Australian FALs were inch also. The Indian FALs were half inch and half metric. The L1A1s are FALs they are they are essentially the same rifle, with a few differences, just as the Belgian, Izzy, Brazilian, Dutch and Argy FALs are.

And HB versions were Heavy Barreled versions, right?
Because if so that's exactly my point HEAVY barreled versions of the FAL are not "FALs" but the same receiver on a much heavier barrel.
Like i said b4 FAL stands for Fusil Automatique Leger and a HB version is not leger. We have that version down here to but instead of FAL (F.usil A.utomatico L.iviano in spansih) is called FAP (fusil automatico PESADO), get the point now?
HUNTER.

I see what you meant now. L1A1s were called SLRs (Self Loading Rifle?)by the Commonwealth folks, if I'm not mistaken.

Quoted: I see what you meant now. L1A1s were called SLRs (Self Loading Rifle?)by the Commonwealth folks, if I'm not mistaken.

That is correct!
HUNTER