Was at Camp Dodge, Iowa this weekend training for this summer where I will go to USMC OCS in Quantico, VA. We were all issued rubber duck rifles to train with. The majority were just the new plastic M4 red rifles, but some candidates received older rubber duck rifles that have the real upper receivers filled with rubber on a fake rubber m16 lower. One candidate received one with a 601 barrel. I first noticed a cast front sight base on it and then upon looking between the FSB, I saw the W that indicated Winchester. Of course everyone thought I was nuts when I told them all about the barrel . I could not see any markings near the muzzle since they placed a strip of orange tape there.

Even though it was just an old rubber duck rifle, I cringed when I saw the candidate hit the rifle against shit and scratch up the cast FSB

I have no knowlege on these rubber ducks that incorperate real parts but do you think the barrel was filled with rubber too or just the inside of the receiver and possibly the barrel extension? If that was the case there would be hope for that barrel but since it's a Government Property item, I doubt that it will ever be saved if it can be.

i've owned a couple and the only part{s} that could be removed were the F/H and washer.
its generally accepted the barrels were surplus / ruined / shot out and i believe at least one person tried to salvage a barrel only to find it permanently obstructed,
could have been M1-Sniper, i don't remember, anyway it was a nogo.
it would have been nice to have pictures documenting the "W", the rubber goo would be too thick to tell about anything else.

Many remove the cast FSB and use on builds or sell.  I've never found one looking through 100's but I always look anyway.  Good luck on OCS.

If you get a chance, go to the Gold Star Museum on base.  They have one of the Winchester Lightweight Military Rifles that was the AR-15's initial competition in the 1950s.

http://ww2.rediscov.com/spring/VFPCGI.exe?IDCFile=/spring/DETAILS.IDC,SPECIFIC=10448,DATABASE=objects

Mine has an MP barrel and my cleaning rod runs the entire length of the barrel.
Maybe it is missing a barrel extension or has holes under the handguard, but I kinda doubt it.
IIRC Someone had an obstruction within the first few inches.
I'll leave my M16A2 rubber duck alone.
I don't need the MP barrel.
I wish I had an M16A1 rubber duck.