Shooters of the M-16/AR-15...have you ever experienced the "Vietnam Jam"?

[Grump]

No. Civilian experience only, and I live in a VERY dry climate.

I wonder what the velocity differences were between M193 with ball powder and M193 with stick powder?

At 78 or whatever degrees farenheit, none. The standard was and still is 3xxx fps at 78 feet, +/- 30 fps, for all ammo without regard to powder type. Because my experience with ball powders is up to 1 fps per degree F temperature change, I would estimate that at 110 F, the ball powder stuff would be 32 fps faster than "standard", while the stick-powder ammo would be about 16 fps faster than "standard".

I think we're also mixing metaphors here. The carbonate fouling from early ammo (excessive stabilizers) caused gas tube restrictions that led to *inadequate* extraction and failures to eject. That's the opposite of the rusty-chamber problem, which was compounded by the ball powder ammo giving a bit too much port pressure.

Those batches of ball powder caused two opposing problems--high port pressure/fast cycling when the tube was open, and plugged gas tubes after many rounds were fired.

 

[Byron]

I was in the 4TH Inf as a grunt 68-69. My rifle never jammed. I kept it clean as any rifle in combat should be. Byron

 

[DMK]

My first clue to the solution to the problem came from talking to the Battalion Armorer. He had an M16 that worked under almost all conditions. I asked him what he had done to it, and he replied that he had taken a ¼" drill, attached a couple of sections of cleaning rod to it, and put some "crocus cloth" through the slotted tip (like a patch) and run it into the chamber and turned the drill motor on. He "horsed" the drill a bit and apparently relieved the chamber dimensions just enough to ensure positive functioning.

(from Grendalizer's link)

That's interesting. I did the same exact thing to a Yugo SKS to fix a cronic FTE problem it had.

 

[cordex]

Actually yes I have...multiple times. I have a DPMS lower and Model 1 upper.

I had the same problem with a Model 1 upper I had once. Tight, rough chamber was the problem. Worked fine until you got a few rounds through it, then started failing left and right - just like that. Happened a few times in the Jim Crews carbine course I took. Got rid of that and picked up a new upper.
This is one of the reasons I don't buy from Model 1.

chrome lined bore and chamber.

You sure? Back when I used to buy from Model 1, they never had chrome lined barrels.

 

[fix]

I'm sure this will bring an onslaught of folks defending their kit guns, but I must point out the old adage...

Buy cheap, buy twice.

 

[cordex]

I'm sure this will bring an onslaught of folks defending their kit guns, but I must point out the old adage...

Buy cheap, buy twice.

True enough. I bought what I could afford at the time. I've moved on since then.

Which is not to say that I'd agree a kit gun is necessarily any worse than a factory weapon. Properly assembled by someone with sufficient experience from good components and chances are it'll be superior than factory products.

 

[Destructo6]

I've had this sort of jam with my pre-ban Eagle CAR-15. The chambered case would tear about 1/3 the way from the case head. The case head would be ejected and the next round would be rammed into the forward section of the stuck case. It was a bear to get apart. I usually waited for the gun to cool, then pounded the butt against a table while pulling on the charging handle.

The problem only occured with some loosely-packed Israeli 5.56 that was purchased at a gunshow. Unfortunately, this was the first batch of ammo that I'd put through the gun, which didn't give me warm fuzzies in the reliability department.

I haven't had the problem since switching to another brand. I think I still have one of the cases around somewhere.

 

[Grump]

I've had this sort of jam with my pre-ban Eagle CAR-15. The chambered case would tear about 1/3 the way from the case head. The case head would be ejected and the next round would be rammed into the forward section of the stuck case.

Same *sort*. Yours are/were case breakage rather than rim rip-off.

Hmm... Rim rip-off. Has a ring to it, eh? Do we have a new name for a specific jam here????

Anyways, I've had a heap of broken cases in an AK action like what you describe. Most ejected the front 2/3 or 1/2 okay. Those that didn't--immediate action always cleared them. The new round acted like a broken case extractor, even though it was rammed close to a quarter-inch into the broken case body.

 

[thumbtack]

Nope

 

[RevDisk]

Nope. Mostly just double (or triple) feeds, some problems locking back the bolt, some cycling problems time to time. I did see two M16's that bent a round into the shape of an L. Ugh. Immediately handed those off to the armorer.

To be fair, the problems were mostly with battered magazines and battered rifles. These rifles were used very heavily for testing, probably more heavily than most combat tours. Lightly used rifles and new mags seemed to have few problems.

If you keep an M16 surgically clean and use new(ish) magazines, you'll be fine. Be mindful of which lubes you use, and keep lube handy when firing.

 

[chieftain]

Yes, sort of.

I followed Col Culver in to the hill fights at and around Khe Sanh.

Luckily I had been issued a M14. Because I worked in small detachments, I made sure I never went to my administrative rear in Danang with the M14.

But with that said, I policed up many a Marine body because of that POS.

My M14 went bang every time I pulled the trigger, as long as I kept bullets in it.

Can't say that for the POS.

Oh and our brass didn't cling to the chambers because of rust or corrosion either. We cleaned our rifles at least twice a day. I cleaned my M14 twice a day. Better safe than sorry.

During the last year we had troops in Iraq die because the M16/M4 refused to function. Once again many excuses were forwarded.

Dump the POS and get something that works. I can stand the caliber if I must. Maybe the new 6.8 will work better. If it works, great, if it doesn't we will write more ordinance history with the blood of dead American troops.

Lets use what we KNOW works. experiment between wars, not during.

Or how many more troops must die, to maintain egos here and at the top?

Worst yet many, folks will swear by their AR15/M16, and tell me well mine works. Go to the wall in DC and tell them. Take your weak cheese there. It is hollowed ground, and many, not a few men's names are on that wall because of that POS.

There is a book out now, "The Hill Fights", the first battle of Khe Sanh. Read it and the epilogue about the POS. That was similar to what I experienced. Then bring it to me.

Semper Fi

 

[iamkris]

cordex

Yes, Model 1 has just started offering chrome lined bores / chambers.

And, fix, thanks for insulting my choice of uppers.

I've found the Model 1 to be of decent quality and have had NO problems other than with the Santa Barbara ammo. All other ammo (Wolf and various forms of Winchester) have run without a hitch.

I have a DS Arms STG58 that won't function with Indian surplus worth a crap...but I don't think anyone would say that it is the rifle's fault.

 

[blue86buick]

Not an AR-15 owner....but yes.

With any other ammo I've tried I don't have this problem but with Santa Barbara (Spanish) SS109 NATO surplus, I get this EXACT problem about 1x per mag.

Examination of the case (once I've run a brass rod down the barrel to dislodge it) is that the rim is severely gouged out by the extractor.

I have a Kel-Tec SU-16, and don't have problems with any other ammo. However, with S|B (Santa Barbara) SS109, I DO have this problem. This was more than 1x per mag though, this was more like 100% of shots fired (when shooting S|B SS109).