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Posted: 1/31/2016 7:35:29 PM EDT
The bolt pictured below was used in a new rifle last week.

Temps were at or slightly below freezing.  Possibility of lube / storage oils still in the chamber.
I had continuous failures to feed and extract, 3 rounds consecutive was the best I got that day.

Now, it could have been ice / slugish oils in the action, the gun was brought from inside and hiked out to the range and fired.
Plenty of opportunity for cold weather problems.

However, today I stripped everything down to clean it up and dry it out for another winter shooting session next week and found this - it appears that the chrome has flaked off on the tail.
I "think" the bolt is a stag, possibly rock river - I've had it for a few years and never used it until last week.
I had intended to add the improved extractor and strip the gun clean until I found this.
Now I'm wondering if this could have been part of the problem and if I should just use another bolt.

I'd bought the chrome as an upgrade, hoping for easier maintenance but it seems to have potentially shit the bed.


Thoughts?



ETA - That picture is after a bath in Hoppes #9 and the bolt has maybe seen 30 rounds.
Link Posted: 1/31/2016 7:51:25 PM EDT
[#1]
That looks like carbon to me. Take a sharp blade to it and see if the black comes off or the chrome has in fact flaked off.
Link Posted: 1/31/2016 7:54:50 PM EDT
[#2]
Looks like carbon buildup in the pic.
Link Posted: 1/31/2016 8:02:38 PM EDT
[#3]
Use something like this if it's carbon: CAT M-4 Tool

Link Posted: 1/31/2016 8:03:06 PM EDT
[#4]

Discussion ForumsJump to Quoted PostQuote History
Quoted:


Looks like carbon buildup in the pic.
View Quote




 
Link Posted: 1/31/2016 8:09:16 PM EDT
[#5]
That's Carbon.  Source: USMC Bootcamp.
Link Posted: 1/31/2016 8:19:48 PM EDT
[#6]
Looks like a chrome bolt with a little carbon baked on there. Put some lube on it and shoot it.

Do NOT use this:
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Use something like this if it's carbon: CAT M-4 Tool

http://ecx.images-amazon.com/images/I/31-VtP8VLXL.jpg
View Quote

Link Posted: 1/31/2016 8:28:51 PM EDT
[#7]
Hey, It's carbon.



I've been heating the parts to remove all of the moisture.
Just pulled that part again and the stuff scrubbed off.

Out of curiosity, Why not use the CAT tool ?
Link Posted: 1/31/2016 8:30:36 PM EDT
[#8]
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Looks like a chrome bolt with a little carbon baked on there. Put some lube on it and shoot it.

Do NOT use this:

View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Looks like a chrome bolt with a little carbon baked on there. Put some lube on it and shoot it.

Do NOT use this:
Quoted:
Use something like this if it's carbon: CAT M-4 Tool

http://ecx.images-amazon.com/images/I/31-VtP8VLXL.jpg



Gamma is right. Do not use this tool.
To clean that carbon use  bore brush and Hoppe's 9.
Link Posted: 1/31/2016 8:48:39 PM EDT
[#9]
Whenever that happens to one of my guns I just throw the whole thing away.
Link Posted: 1/31/2016 8:58:46 PM EDT
[#10]
Discussion ForumsJump to Quoted PostQuote History
Quoted:


Gamma is right. Do not use this tool.
To clean that carbon use  bore brush and Hoppe's 9.
View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Quoted:
Looks like a chrome bolt with a little carbon baked on there. Put some lube on it and shoot it.

Do NOT use this:
Quoted:
Use something like this if it's carbon: CAT M-4 Tool

http://ecx.images-amazon.com/images/I/31-VtP8VLXL.jpg



Gamma is right. Do not use this tool.
To clean that carbon use  bore brush and Hoppe's 9.


What's wrong with that tool? I use it and it won't remove all of the Carbine. It's very gentle on the bolt tail.
Link Posted: 1/31/2016 9:02:20 PM EDT
[#11]
Discussion ForumsJump to Quoted PostQuote History
Quoted:

Out of curiosity, Why not use the CAT tool ?
View Quote


its not needed.

I have never cleaned the tail of my bolts, as a owner of a m16that shoots steel an corrosive its a waste of time.

Im sure there will be some 100rd per decade shooters tell me Im wrong.  

Link Posted: 1/31/2016 9:18:57 PM EDT
[#12]
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Hey, It's carbon.



I've been heating the parts to remove all of the moisture.
Just pulled that part again and the stuff scrubbed off.

Out of curiosity, Why not use the CAT tool ?
View Quote


Because a .45 casing works just as well and is free.
Link Posted: 1/31/2016 9:35:14 PM EDT
[#13]
If it was actually flaked off I was going to ask if you were sure it was Chrome and not NIB since I have never seen a Chrome bolt flake off like that.  I have seen speckling and slight flaking in chrome bolts that were 50-60 years old but nothing like that.  Good call on the carbon build up - still not sure that is the cause of your problems though.  Unless it was really really freezing out I really doubt your oil gummed up.  I also concur with the above poster that there really isn't any need in scraping all the carbon off just clean it as well as you can with some sort of brush/bristle and oil.  

I would start with your extraction upgrade kit.  If you are sure your extractor is not wore too much and is working ok then just get the BCM bolt enhance kit with the HD spring.  You shouldn't need the o-ring especially with their HD spring.  See if that helps out, at least with your extraction issues.  And maybe try some different mags and ammo if you didn't on your outing.  Lots of things it could be, a better description of the jam itself or some pictures would be great in helping us figure it out.  And all the ARs/16s I have ever ran love to be ran wet.  A little squirt of oil on the bolt can make a world of difference, but a good running AR should run even when dry and dirty.

Just to toss this out there - some people are very anal about cleaning their guns.  I am a very practical person and understand the difference in clean and spotless.  I clean my rifles after they get dirty but I don't scrub them to get every little piece of carbon out.  In the Army that used to bug the hell out of me - I understand teaching discipline and soldiers how important it is to keep their rifles clean but they really go at it the wrong way like they do most stuff.  You could scrub on the rifle for hours and still not have it clean enough.  Something I started doing after awhile was using a sink and water to clean everything - you'd be surprised how well it works.  I got a lot of weird looks by doing this and even some telling me not to do it but all the smart old timers would do the same thing knowing how anal the armorers would be.  It really wouldn't take no time to clean out all the carbon with a little bit of water and a drop of soap washing them in the sink.  Just make sure all the parts are lubed up afterwards and it is good as new - without all the wear and tear that over cleaning will do.  Those poor rifles in the Army probably get twice the wear and tear on the parts as a rifle that is just cleaned normally from all the over cleaning and scrubbing they do.  And another bad thing about this is, a lot of people would be afraid to put lube on their rifles after cleaning them because it would be a lot more likely that a piece of carbon would work itself out for the armorer to find.  Therefore getting a rifle that has been in storage that has no lube on it and likely to even rust in some spots.  As a civilian I do not use the sink to clean my rifle parts but if something was really dirty I would, I just spend a few minutes cleaning and oiling in between uses so it doesn't get built up too much.  
Link Posted: 2/1/2016 12:00:13 AM EDT
[#14]
Is your bolt chrome plated or Nickle Boron? They look similar but have different properties. NiB is more common lately, but may have some issues compared to chrome.

I've read that Hoppes 9 is not compatible with nickle. I will probably start a thread soon to ask other peoples experience with this since so many bolts and carriers are NiB plated.  I looked up Hoppes webpage, and they state to not use it with nickle coatings. Hoppes is OK for chrome bores, but I too have bolts and triggers plated in nickle boron, so if the hoppes 9 is not compatible I will have to find other options to clean the bolt and action to protect the nickle finish.
Link Posted: 2/1/2016 12:12:51 AM EDT
[#15]
That's carbon and isn't a problem. The jamming is being caused by something else.
Link Posted: 2/1/2016 2:45:38 AM EDT
[#16]
Discussion ForumsJump to Quoted PostQuote History
Quoted:


its not needed.

I have never cleaned the tail of my bolts, as a owner of a m16that shoots steel an corrosive its a waste of time.

Im sure there will be some 100rd per decade shooters tell me Im wrong.  

View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Quoted:

Out of curiosity, Why not use the CAT tool ?


its not needed.

I have never cleaned the tail of my bolts, as a owner of a m16that shoots steel an corrosive its a waste of time.

Im sure there will be some 100rd per decade shooters tell me Im wrong.  



It may not be needed for the absolute function of the rifle, but neither is actually cleaning it after ever range session. I still do both.

It works as described, it doesn't scrape the finish off either as it still leaves a very thin layer of carbon on the bolt tail. It was a cheap item that gets used.
Link Posted: 2/1/2016 10:16:27 AM EDT
[#17]
I must be weird, I clean the carbon off the bolt tail by wetting with some Hoppes #9 or CLP, let it soak till the next commercial and then rub it off with 0000 steel wool....
Link Posted: 2/1/2016 11:00:01 AM EDT
[#18]
You can use the case neck of a .308 or 30.06 round to clean carbon off an AR bolt.  No need to use a steel tool or purchase anything.
Link Posted: 2/1/2016 11:05:27 AM EDT
[#19]

Discussion ForumsJump to Quoted PostQuote History
Quoted:


You can use the case neck of a .308 or 30.06 round to clean carbon off an AR bolt.  No need to use a steel tool or purchase anything.
View Quote




 
Cool trick. I wish I knew about that years ago. lol. And the brass won't harm the bolt.




Anyway, did OP use something to degrease the bolt? Cause it looks like it aint got a single bit of clp on it. And others have said, from the looks of the bolt, it's not the bolt that's the issue.
Link Posted: 2/1/2016 11:07:45 AM EDT
[#20]
So the issue of reliability for next weekend hasn't really been addressed.  I have never used Hoppes 9 on an AR o don't know how it acts in cold.  But slip 2000 gun oil or even CLP do well in the cold.   A lot of people use slip 2000 EWL on their AR, it is thicker then gun oil and great for an AR bolt, although if super cold with cycling concerns I would use the gun oil,  I also use gun oil not EWL on handguns year round.  

stand the bolt up an exercise the ejector and extractor to be sure they have strong tension and no inconsistent spot in their area of travel.  Also, you have more then one mag, right?  Could be that.  although not my first guess on your issue,  but easy to check.

Link Posted: 2/1/2016 11:34:00 AM EDT
[#21]
Maybe I am the odd man out, but I rarely clean the carbon off the tail of my bolt.  When I clean my gun, I will strip it down and use a copper brush, but never feel the need to get all of that off.  Never had any issues.
Link Posted: 2/1/2016 11:42:53 AM EDT
[#22]

Discussion ForumsJump to Quoted PostQuote History
Quoted:


Maybe I am the odd man out, but I rarely clean the carbon off the tail of my bolt.  When I clean my gun, I will strip it down and use a copper brush, but never feel the need to get all of that off.  Never had any issues.
View Quote




 
I don't think it's a big need either. It's not a bearing surface. It can get caked, several millimeters thick and it's not going to grind on anything.
Link Posted: 2/1/2016 12:07:09 PM EDT
[#23]
soak it over night in some gun cleaner.
Link Posted: 2/1/2016 12:07:59 PM EDT
[#24]
that much carbon from 30 rounds?  
Link Posted: 2/1/2016 1:08:00 PM EDT
[#25]
Discussion ForumsJump to Quoted PostQuote History
Quoted:

  I don't think it's a big need either. It's not a bearing surface. It can get caked, several millimeters thick and it's not going to grind on anything.
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Quoted:
Quoted:
Maybe I am the odd man out, but I rarely clean the carbon off the tail of my bolt.  When I clean my gun, I will strip it down and use a copper brush, but never feel the need to get all of that off.  Never had any issues.

  I don't think it's a big need either. It's not a bearing surface. It can get caked, several millimeters thick and it's not going to grind on anything.


I gave up a long time ago worrying about the carbon on the tail of the bolt.  It is an exercise in futility or pointless because the next time you go shoot it will come right back.
Link Posted: 2/1/2016 1:12:56 PM EDT
[#26]
Quoted:
Temps were at or slightly below freezing.  Possibility of lube / storage oils still in the chamber.
I had continuous failures to feed and extract, 3 rounds consecutive was the best I got that day.

Now, it could have been ice / slugish oils in the action, the gun was brought from inside and hiked out to the range and fired.
Plenty of opportunity for cold weather problems.
View Quote


You likely have a gas system issue.  It sounds like your gun is under gassed slightly, not enough to cause issues in warm weather.  Try a lighter buffer, bolt carrier, and/or spring.
Link Posted: 2/1/2016 1:13:10 PM EDT
[#27]
Discussion ForumsJump to Quoted PostQuote History
Quoted:


its not needed.

I have never cleaned the tail of my bolts, as a owner of a m16that shoots steel an corrosive its a waste of time.

Im sure there will be some 100rd per decade shooters tell me Im wrong.  

View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Quoted:

Out of curiosity, Why not use the CAT tool ?


its not needed.

I have never cleaned the tail of my bolts, as a owner of a m16that shoots steel an corrosive its a waste of time.

Im sure there will be some 100rd per decade shooters tell me Im wrong.  



I mostly use mine on my DI .45, because steel case bulk .45 is nastay.
Link Posted: 2/1/2016 1:23:36 PM EDT
[#28]
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Is your bolt chrome plated or Nickle Boron? They look similar but have different properties. NiB is more common lately, but may have some issues compared to chrome.

I've read that Hoppes 9 is not compatible with nickle. I will probably start a thread soon to ask other peoples experience with this since so many bolts and carriers are NiB plated.  I looked up Hoppes webpage, and they state to not use it with nickle coatings. Hoppes is OK for chrome bores, but I too have bolts and triggers plated in nickle boron, so if the hoppes 9 is not compatible I will have to find other options to clean the bolt and action to protect the nickle finish.
View Quote


Came to post this about chrome. It does strip it over time
Link Posted: 2/1/2016 1:48:05 PM EDT
[#29]
If you need some good oil to use before your next outing and don't want to wait on some Slip 2000 or whatever then just go to your local automotive or big box store and pick up some Mobil 1 synthetic oil.  Works just as well as most gun oils out there.

Also as mentioned, perhaps your gun is undergassed.  Or not sure if you mentioned what buffer weight you are using but if you are using a heavier H2 or H3 then consider trying a Carbine buffer.
Link Posted: 2/1/2016 8:08:23 PM EDT
[#30]
Discussion ForumsJump to Quoted PostQuote History
Quoted:


Came to post this about chrome. It does strip it over time
View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Quoted:
Is your bolt chrome plated or Nickle Boron? They look similar but have different properties. NiB is more common lately, but may have some issues compared to chrome.

I've read that Hoppes 9 is not compatible with nickle. I will probably start a thread soon to ask other peoples experience with this since so many bolts and carriers are NiB plated.  I looked up Hoppes webpage, and they state to not use it with nickle coatings. Hoppes is OK for chrome bores, but I too have bolts and triggers plated in nickle boron, so if the hoppes 9 is not compatible I will have to find other options to clean the bolt and action to protect the nickle finish.


Came to post this about chrome. It does strip it over time


Follow up post: Similar question about Hoppes previously, and guys confirmed that it was not recommended for nickle. You could still use the solvent just to clean the bore, and wipe down the bolt and trigger parts (I recently got a few trigger groups in NiB) with CLP or some other cleaner.

http://www.ar15.com/forums/t_3_7/599838_Hoppes__9_on_a_NiB_BCG.html
Link Posted: 2/1/2016 11:31:39 PM EDT
[#31]
What kind of lube were you using? sounds like you have a gas problem.
Link Posted: 2/2/2016 3:29:17 AM EDT
[#32]
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Looks like a chrome bolt with a little carbon baked on there. Put some lube on it and shoot it.

Do NOT use this:

View Quote View All Quotes
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Discussion ForumsJump to Quoted PostQuote History
Quoted:
Looks like a chrome bolt with a little carbon baked on there. Put some lube on it and shoot it.

Do NOT use this:
Quoted:
Use something like this if it's carbon: CAT M-4 Tool

http://ecx.images-amazon.com/images/I/31-VtP8VLXL.jpg




I can't disagree more with this.
I've been using the Cat M4 tool for years.  So many years, I can't count.  Rifles with many thousands and thousands of rounds.  This tool has been nothing but beneficial to me.
Have you used one Gama?  You will notice it's not actually scraping the finish of the bolt's tail, it only scrapes enough to clean off raised carbon build up that's raised above the surface.



Link Posted: 2/2/2016 3:41:13 AM EDT
[#33]
dtap
Link Posted: 2/2/2016 3:44:14 AM EDT
[#34]
Discussion ForumsJump to Quoted PostQuote History
Quoted:


its not needed.

I have never cleaned the tail of my bolts, as a owner of a m16that shoots steel an corrosive its a waste of time.

Im sure there will be some 100rd per decade shooters tell me Im wrong.  

View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Quoted:

Out of curiosity, Why not use the CAT tool ?


its not needed.

I have never cleaned the tail of my bolts, as a owner of a m16that shoots steel an corrosive its a waste of time.

Im sure there will be some 100rd per decade shooters tell me Im wrong.  




You're wrong  
Seriously though, yes,  the gun will run with built up carbon as long as its well lubed.
But nothing wrong with the Cat M4 tool for people who like to take the extra cleaning step.
It will not cause any damage to the bolts tail, it wont even scratch the finish.
Link Posted: 2/2/2016 10:21:17 AM EDT
[#35]
Discussion ForumsJump to Quoted PostQuote History
Quoted:

Anyway, did OP use something to degrease the bolt? Cause it looks like it aint got a single bit of clp on it. And others have said, from the looks of the bolt, it's not the bolt that's the issue.

View Quote



Yes, when that photo was taken I had broken down the gun and cleaned the entire BCG in Hoppes #9 and then put the components on heat for an hour or two to bake off anything that remained, I wanted to start with a 100% clean slate.

I did the extractor upgrade w/ the BCM spring kit & O rings at the same time.

Just to address a couple of other items brought up in the thread -

I used 4 different magazines that day - 2 30 and 1 20 and 1 10 round - all P-Mags
Extractor, bolt & carrier are all new - in fact, the entire gun is unfired, NIB parts.
Gun has a carbine buffer installed
Ammo was all .223, a mix of WWB and S&B.
And yes, that much carbon in 30 rounds.

In addition to gumming up lubricants, I know the cold can impact propellants and this wasn't exactly "hot" ammo to begin with but it still seems out of the ordinary.
So now I'm down to undergassed, oversprung, too heavy of a buffer or possibly just weak extraction?
Link Posted: 2/2/2016 11:24:57 AM EDT
[#36]
Buffer spring.
Link Posted: 2/2/2016 12:14:11 PM EDT
[#37]
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Whenever that happens to one of my guns I just throw the whole thing away.
View Quote


Considering how cheap AR15s are going for right now, why not?

Cleaning sucks!
Link Posted: 2/2/2016 5:01:43 PM EDT
[#38]
I highly doubt you have weak extraction with both the BCM HD spring and o ring.  In my opinion that is probably too much force.  Not sure if it could be causing your issues, probably not but worth a try.  Take the o-ring out and see if anything changes since that's free to try.  I don't think I have ever heard anyone else say this but from my limited trials I have found out that my bolts with just a regular extractor spring not even the HD one that they go into battery much easier when riding forward.  The guns that have a regular spring and o-ring will never go into battery if I ride them forward - which is no big deal I rarely do this and can get it to go into battery by using the forward assist.  The only thing I am getting at here in your case is that if you have even more tension then I do by using both the HD spring and o-ring and your rifle is dirty on top of it or not well lubed then perhaps that is the issue?  I really doubt it is but just try it out and see.  I am surprised I have never read another person bring this up about the extractor tension and the bolt going into battery.  

But the more likely cause of this problem is using weak 223 ammo in the cold weather on a barrel that is slightly under-gassed.  Or perhaps it is a combo of things and your barrel isn't under-gassed.  Meaning between the weak 223 ammo, the cold, lack of lube, excess extractor tension, and added carbon build up that it all went together to cause your issues.  I have never heard of an under-gassed GM barrel, and most of the time even barrels that have a lot smaller port size then the standard will still cycle all ammo reliably if it has a carbine buffer.  Since you have a carbine buffer it can't be that causing it.
Link Posted: 2/2/2016 5:40:47 PM EDT
[#39]
I agree that the issue is probably just the combo of the cold weather which reduces pressure and velocity, the relatively low velocity ammo to begin with, and perhaps an undergassed port size.

I'd not change anything beyond simply trying some standard 5.56 velocity, M193 or M855 and see if it runs smoothly.   It may be as simple as avoiding the low velocity ammo in cold weather, rather than experimenting with buffers or other equipment issues.

As an aside, has anyone use the Otis B.O.N.E?   I have one and have never needed to use it.  My NiB BCG just wipes clean.  No carbon buildup --- so far.   Just curious about how this small tool carried in my range bag for years, might work, should I need it.
Link Posted: 2/2/2016 7:24:17 PM EDT
[#40]
Discussion ForumsJump to Quoted PostQuote History
Quoted:

You're wrong  
Seriously though, yes,  the gun will run with built up carbon as long as its well lubed.
But nothing wrong with the Cat M4 tool for people who like to take the extra cleaning step.
It will not cause any damage to the bolts tail, it wont even scratch the finish.
View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Quoted:
Quoted:

Out of curiosity, Why not use the CAT tool ?


its not needed.

I have never cleaned the tail of my bolts, as a owner of a m16that shoots steel an corrosive its a waste of time.

Im sure there will be some 100rd per decade shooters tell me Im wrong.  


You're wrong  
Seriously though, yes,  the gun will run with built up carbon as long as its well lubed.
But nothing wrong with the Cat M4 tool for people who like to take the extra cleaning step.
It will not cause any damage to the bolts tail, it wont even scratch the finish.

The bolt tail is part of the system that seals gas inside the carrier's gas cylinder.  Carbon buildup is unsightly, but it actually HELPS make the gun run better by ensuring a better seal for the gas cylinder.  It is self limiting too - once it gets thick enough that the carbon rubs on the carrier, the carrier rubs it off.

In any case, getting extreme in cleaning a bolt tail can damage the bolt's finish.  The guy with 0000 steel wool won't see it soon, but it will eventually remove the finish on the bolt tail.  In an armorer class, I was taught to use a little Kroil and a green 3M ScotchBrite pad to clean the bolt's tail.  The guy next to me actually POLISHED the tail of his bolt to a brilliant, silvery shine with this method.  That is certainly not "good" for the bolt.

Link Posted: 2/2/2016 8:59:03 PM EDT
[#41]
I like to clean everything after each shooting.  Just my old military mentality.  Shoot it.  Clean it.  I use CLP and a bronze brush on my bolt.  Works fine.
Link Posted: 2/2/2016 10:44:44 PM EDT
[#42]
Discussion ForumsJump to Quoted PostQuote History
Quoted:


its not needed.

I have never cleaned the tail of my bolts, as a owner of a m16that shoots steel an corrosive its a waste of time.

Im sure there will be some 100rd per decade shooters tell me Im wrong.  

View Quote View All Quotes
View All Quotes
Discussion ForumsJump to Quoted PostQuote History
Quoted:
Quoted:

Out of curiosity, Why not use the CAT tool ?


its not needed.

I have never cleaned the tail of my bolts, as a owner of a m16that shoots steel an corrosive its a waste of time.

Im sure there will be some 100rd per decade shooters tell me Im wrong.  



You don't have to clean your rifle ever for all I care, as long as I never have to depend on you or your guns; but where are you finding corrosive ammo and you must mean an NFA M16?
Link Posted: 2/3/2016 5:06:50 PM EDT
[#43]
Discussion ForumsJump to Quoted PostQuote History
Quoted:
I highly doubt you have weak extraction with both the BCM HD spring and o ring.  In my opinion that is probably too much force.  Not sure if it could be causing your issues, probably not but worth a try.  Take the o-ring out and see if anything changes since that's free to try.  I don't think I have ever heard anyone else say this but from my limited trials I have found out that my bolts with just a regular extractor spring not even the HD one that they go into battery much easier when riding forward.  The guns that have a regular spring and o-ring will never go into battery if I ride them forward - which is no big deal I rarely do this and can get it to go into battery by using the forward assist.  The only thing I am getting at here in your case is that if you have even more tension then I do by using both the HD spring and o-ring and your rifle is dirty on top of it or not well lubed then perhaps that is the issue?  I really doubt it is but just try it out and see.  I am surprised I have never read another person bring this up about the extractor tension and the bolt going into battery.  

But the more likely cause of this problem is using weak 223 ammo in the cold weather on a barrel that is slightly under-gassed.  Or perhaps it is a combo of things and your barrel isn't under-gassed.  Meaning between the weak 223 ammo, the cold, lack of lube, excess extractor tension, and added carbon build up that it all went together to cause your issues.  I have never heard of an under-gassed GM barrel, and most of the time even barrels that have a lot smaller port size then the standard will still cycle all ammo reliably if it has a carbine buffer.  Since you have a carbine buffer it can't be that causing it.
View Quote



The BCM spring and o ring were added after the fact as a part of the tear down this week.
They were not installed when I had the issues.
Link Posted: 2/3/2016 5:31:21 PM EDT
[#44]
I guess Im wrong too, been using the CAT M4 tool for years.

It takes 5 seconds, and necessary or not to have that part clean, its too easy to not use it.
Link Posted: 2/5/2016 3:41:23 AM EDT
[#45]
What oil were you using and how cold was it?

Some oils and greases will work fine in sub zero temps. Others will become too thick and will cause failures.
Link Posted: 2/5/2016 7:54:56 PM EDT
[#46]
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Quoted:


You don't have to clean your rifle ever for all I care, as long as I never have to depend on you or your guns; but where are you finding corrosive ammo and you must mean an NFA M16?
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no a home built M16, I filed down the firing pin, but thanks for checking the hall

5,45x39, a shitload of it.
Link Posted: 2/5/2016 8:06:47 PM EDT
[#47]
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Quoted:
That's carbon and isn't a problem. The jamming is being caused by something else.
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How in depth please go on..
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