M4/M203

[recce_o]

Guys,

Two questions:

1. Is there a special M203 that mounts on the M4, or can you mount a standard M203 on an M4?

2. Is there a special quadrant sight for the flat top receivers, or do you simply have to rely on the leaf sight? But how would you mount the leaf sight because you can't use the 203 handguard on the M4?

Thanks in advance,

Recce

[SWO]

Both the standard and "Product Improved" versions of the M203 may be mounted to the M4/M4A1. The lower rail of the RIS/RAS is removed and the grenade launcher is attached in the usual way. Only real change is with the barrel mount attachment, which now has a quick detachable feature (quick detachable mount is manufactured by Knight's Armament Corp., I believe).

I am not aware of the quadrant sight being used with the M4/M4A1 (as I'm not aware of any quadrant sight designed for "flat top" M16 variants). However, there is a special leaf sight that mounts to the upper rail of the RIS/RAS (also manufactured by KAC, I believe).

[Kolt]

There is a new model of the M203 called the M203A1 for the M4. I'm not sure if that is what you were refering to when you said 'product improved' but that is what the TM says for the M4. Just some added info.

[recce_o]

Ok, here's another question:

Does the front sling swivel mount and bayonet lug get ground off before mounting the standard 203 on the M4, because there isn't enough clearance otherwise?

[SWO]

14" M4 barrels that I've seen have either the side swivel attachment or no permanent swivel attachment at all (have never seen the below-the-barrel swivel on an M4 barrel), but the bayo lug is completely intact (not ground-off or otherwise removed). Because the barrel release lever on the "standard" Colt M203 is on the left side, the side swivel must be attached on the right side (outboard for a right-handed shooter). If the side swivel is attached on the left (as some barrels leave the factory), then the side swivel interferes with the barrel release lever for the M203.