Brownells 601 issue.

As mentioned elsewhere, got a Brownells 601 Retro, lightly used, at a local gunshow. Put it on my 16A1 lower; nice fit, nicely made. It is the 16" carbine; using an LMT BCG.
One problem; it won't run. Took it to get a quick zero; empties eject, but the bolt isn't picking up the next round from the magazine.
This sounds like the classic 'undergassed' issue that the original 601 carbines had (not enough dwell time beyond the gas port).
Anybody else experience these issues? Suggestions?
The vendor I bought it from had it on consignment for a buddy; he's to check with him (tho' I'm suspicious of a straight answer).
Thanks,
Moon

Have you called Brownells?
They’ve been awesome for me with any concerns or problems.

cz, I'm a longtime customer, and get a price break due to my C&R FFL. They are indeed great people to deal with. I will give them a call tomorrow.
BTW, I've done business with the vendor, and he's a straight guy. Not so sure about his buddy.
Moon

Okay, curiouser and curiouser.
-Contacted Brownells; because I was not the original purchaser, they were unwilling to stand behind it.
-Maybe Brownells wasn't the issue. I was using a spare, new, LMT BCG. It seemed an uncommon tight fit, so I tried the vintage Colt BCG that usually resides in my Colt M16A1. There probably weren't 500 rounds thru' the NOS upper.
-In any case, the Brownells upper ran just fine with the Colt BCG.
So the LMT BCG was the culprit, tho' it does appear the gun is a bit undergassed, as this BCG had run just fine in the original Colt upper.
Moon

Does not compute, the 601 has a 20" barrel, you state this has a 16", if it has rifle gas then it is a 605 or a cut down 601.

Quote:

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Originally Posted by mack7.62

Does not compute, the 601 has a 20" barrel, you state this has a 16", if it has rifle gas then it is a 605 or a cut down 601.

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This. What do you really have here?

Also, if you are buying a retro to modify and update with modern components you are doing it wrong.

Sorry, misused the number. I suppose it is a 605. It has a 16" bbl, rifle gas system; if you read my original post, I made it clear it was indeed a 16"
It also has triangular handguards, pinned and welded three-prong flashider, and A1 sights.
Brownells markets it as a retro carbine; I realize there is some discussion here about whether it should have a forward assist (it does).
The lower is a 15 year old NoDak M16A1 clone; the usual upper is a 20" (601?) NOS Colt M16A1.
The buttstock, pistol grip and handguards on the 20" are nearly 40 years old, as is the rest of the upper.
My original plan was to build a clone of the rifle the Gummint was kind enough to give me in 1970, and I achieved that. The lower was $160; the Colt upper was $579, brand freaking new, never issued.
The early carbines were of interest to me, but I never encountered them in the service.
"Dissy" style carbines have long appealed to me; I like irons, and a full sight radius makes sense; hence the interest in this 605 clone.
Moon

Quote:

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Originally Posted by halfmoonclip

Sorry, misused the number. I suppose it is a 605. It has a 16" bbl, rifle gas system; if you read my original post, I made it clear it was indeed a 16"
It also has triangular handguards, pinned and welded three-prong flashider, and A1 sights.
Brownells markets it as a retro carbine; I realize there is some discussion here about whether it should have a forward assist (it does).
The lower is a 15 year old NoDak M16A1 clone; the usual upper is a 20" (601?) NOS Colt M16A1.
The buttstock, pistol grip and handguards on the 20" are nearly 40 years old, as is the rest of the upper.
My original plan was to build a clone of the rifle the Gummint was kind enough to give me in 1970, and I achieved that. The lower was $160; the Colt upper was $579, brand freaking new, never issued.
The early carbines were of interest to me, but I never encountered them in the service.
"Dissy" style carbines have long appealed to me; I like irons, and a full sight radius makes sense; hence the interest in this 605 clone.
Moon

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M16A1 - Model 603, not 601. The XM16E1 also used a 603 upper (w/forward assist). For a 1970 M16A1, the upper receiver would have had no forge codes, only proof marks in front of the port door. The XM16E1 was the same way.

As for the Model 605, some had 603 uppers and some had 604 uppers (slickside). There were a few that had 603 upper forgings that had the forward assist area milled off. These were used when there was not enough 604 uppers to use at the time. Some refer to these as 605 uppers, but that is not necessarily true although they only appeared on a few Model 605s. I built my 605 clone with a 604 upper (original Colt) and a cut-down original Colt barrel that was worked by John Thomas of Retro Arms Works.

https://i.imgur.com/OO2gvn0.jpg

https://i.imgur.com/2tE0UN0.jpg


This is also my clone of a late 1967-1970 M16A1.

https://i.imgur.com/a99Sgjk.jpg

https://i.imgur.com/5UZ5KTu.jpg

https://i.imgur.com/7lmiWbC.jpg

Thnx, Renegade.
I'd seen your pictures elsewhere here. Your M16A1 is the twin of mine, including the barrel markings. When I first put it together in November '05, I couldn't wait to try it out. -8 windchill and all, got a 5 shot group at 50 yards; 0.855". I had better eyes then.
Whatever is 'just right' with the carbine, I'm happy with mine, and a bargain price ($300 for the upper).
Oddly, I've another 16" carbine with full length handguards; a Colt 6536 CHPs that was made specifically to fit their gunracks. It's a heavy barrel, so it's not as handy as it might be.
Moon