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Posted: 2/3/2016 3:55:30 PM EDT
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I have been carrying an AR 15 Rock River brand for years at work. So I decided I am a mechanically inclined guy to build one myself for fun. In the past I have rebuilt motors for cars, motorcycles and atv's.
I have read lots of blogs, forums and watched YouTube videos on actually building ar's. So I purchased all the parts for the build (tools also, love tools) and built it. I did my first test fire and cycle with a .22 conversion CBG. Worked great so I then tried a 5.56 CBG from my Bushmaster and them from my RR. All of these worked great with no problems. I did more research and decided I wanted to try a boron nickel CBG. I located one at MidwayUSA. It is a APF Armory CBG. I am using a .223 Wylde SS barrel. I changed the new bolt and my PD had given us some Hornaday steel case with a finish on it to use as practice ammo. Not a fan due to how dirty it makes my gun. I ran probably 5 rounds and the gun jammed. I could not pull back the charging handle with my hand. Took it back to the shop and was able to get it out. I checked all of the possible wear surfaces and did not see anything out of the normal. I tried it again and got the same results. I contacted APF and told them what happened. They said they make about 10,000 a month and might have gotten out of spec. I sent it back and it had the same problem with the new one they sent me. I then used a brass 5.56 and put about 30 rounds through it. I felt my barrel after shooting the Hornaday and was warm to the touch but not hot. Has anyone experienced a problem using a nickel boron CBG with a SS barrel? Could the chamber heating up expand the steel and create the problem? Thanks in advance for any knowledge you can give. |
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Why the kindergarten sized print? The correct term is BCG. Stick with standard ones, forget the snake oil of the fancy coatings. Clean the snot out of the firearm paying close attention to the chamber. Use a good chamber brush made for the task. Use only CLP. Dry it when clean. Inspect the chamber for toolmarks or burs, it should be baby butt smooth. Never use anything Hopps. Keep the BCG well lubed, shoot good 5.56 ammo for the first hundred or two rounds. Welcome to the site. |
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So the rifle works fine with a couple of normal bolt carrier groups.
You put in a replacement and it starts malfunctioning. This would probably be a clue. What are you using for lubrication? Nickle platings have the characteristic of shedding lubricants so this can be problematic. |
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Sorry guys for the bold typing this is my first post and comment. Excuse the CBG, I meant "bolt carrier group" I was at work and had to many irons in the fire while trying to post this.
I am going to try the nickel boron BCG in my RR this weekend and see how it goes with the Hornaday I was using. If it sucks all the way around I will send it back and go back to basics. Thanks for the input. |
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So, everything worked fine, until you paired a new BCG with steel cased ammo - but somehow the barrel is at fault?
Basic troubleshooting logic doesn't follow. FWIW I've seen more compatibility problems with steel case ammo than anything else. Generally, it has to do with lower powered charges in the steel cased ammo. |
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Quoted:
Why the kindergarten sized print? The correct term is BCG. Stick with standard ones, forget the snake oil of the fancy coatings. Clean the snot out of the firearm paying close attention to the chamber. Use a good chamber brush made for the task. Use only CLP. Dry it when clean. Inspect the chamber for toolmarks or burs, it should be baby butt smooth. Never use anything Hopps. Keep the BCG well lubed, shoot good BRASS-CASED 5.56 ammo for the first hundred or two rounds. Welcome to the site. |
| Also, what exactly is a "jam"? Are you talking about failures in extraction? feeding/locking? double feeds? what is the actual "jam" that is occurring? For someone who says that they went so far into reading and watching videos to learn about the system, I would expect a better description of the problem than just a "jam". |
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I think I would advise the OP to stick with one of his standard BCGs and regular brass ammo until he has the rifle broken in some (300-500 rounds)
Then after another round of cleaning/lubing try the new coated bolt (with lube and proven ammo). I expect there is really nothing wrong but having a brand new tight gun , brand new tight BCG and some kind of steel possibly lower powered ammo is asking to have a malfunction . I don't claim to have much of any experience with coated BCGs but it just seems the standard BCG that runs fine as a full auto with proper care and cleaning/lubing should be just absolutely fine loafing along in a semi auto gun . |
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What buffer do you have? Does the new coated BCG have an extractor O-ring? Does your old one? The bottom extractor in this picture has an O-ring.  I would pop the extractor off your bolt and check for one. How did the steel case looked after you got it out? Any damage to the rim? Did you have to drive the fired case out, or did it extract after a really hard pull on the charging handle? |
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The imminent problem may be the steel cased ammo; the AR was not designed for steel cased ammo, with different expansion characteristics from brass, which affects extraction, mostly.
It is possible to get the AR to digest steel cases but it often takes playing with lots of parts such as extractor/ejector, looking at chamber size (5.56 vs Wylde vs .223), buffers, springs and different BCGs. You have found yourself in an interesting area of AR study. Generally we all have to find a way along that works and repeat. Generally speaking, steel cased ammo is NOT your friend in an AR. There are many here who have more experience than I and who have figured this out. Welcome to the site. Rick |
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Hopps leaves a film that turns to a gooey residue in an autoloader. Quoted:
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Never use anything Hopps. Why not? Hoppe's is a solvent that can damage the finish of NiB. Never got goo in my autoloaders from it... WD40 yes. |
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Generally speaking, steel cased ammo is NOT your friend in an AR. There are many here who have more experience than I and who have figured this out. If your in-spec and broken-in rifle won't cycle cheap steel cased ammo, there is someting wrong with your rifle. Yes it's dirty and not as accurate, but a proper AR pattern gun should eat it up without problem. Didn't one of the internet video guys, Nutvuursomethingorother, do a multi-thousand round steel cased ammo torture test? |
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If your in-spec and broken-in rifle won't cycle cheap steel cased ammo, there is someting wrong with your rifle. Yes it's dirty and not as accurate, but a proper AR pattern gun should eat it up without problem. Didn't one of the internet video guys, Nutvuursomethingorother, do a multi-thousand round steel cased ammo torture test? Quoted:
Quoted:
Generally speaking, steel cased ammo is NOT your friend in an AR. There are many here who have more experience than I and who have figured this out. If your in-spec and broken-in rifle won't cycle cheap steel cased ammo, there is someting wrong with your rifle. Yes it's dirty and not as accurate, but a proper AR pattern gun should eat it up without problem. Didn't one of the internet video guys, Nutvuursomethingorother, do a multi-thousand round steel cased ammo torture test? Except BCM and DD make their gas ports small so that they are "softer" when shooting M193. The result is most of them won't cycle weaker steel case. |
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Quoted: Except BCM and DD make their gas ports small so that they are "softer" when shooting M193. The result is most of them won't cycle weaker steel case. Quoted: Quoted: Quoted: Generally speaking, steel cased ammo is NOT your friend in an AR. There are many here who have more experience than I and who have figured this out. If your in-spec and broken-in rifle won't cycle cheap steel cased ammo, there is someting wrong with your rifle. Yes it's dirty and not as accurate, but a proper AR pattern gun should eat it up without problem. Didn't one of the internet video guys, Nutvuursomethingorother, do a multi-thousand round steel cased ammo torture test? Except BCM and DD make their gas ports small so that they are "softer" when shooting M193. The result is most of them won't cycle weaker steel case. This incident is a sticking case/failure to extract though, which is much different from a short stroke. |
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Quoted: Except BCM and DD make their gas ports small so that they are "softer" when shooting M193. The result is most of them won't cycle weaker steel case. Quoted: Quoted: Quoted: Generally speaking, steel cased ammo is NOT your friend in an AR. There are many here who have more experience than I and who have figured this out. If your in-spec and broken-in rifle won't cycle cheap steel cased ammo, there is someting wrong with your rifle. Yes it's dirty and not as accurate, but a proper AR pattern gun should eat it up without problem. Didn't one of the internet video guys, Nutvuursomethingorother, do a multi-thousand round steel cased ammo torture test? Except BCM and DD make their gas ports small so that they are "softer" when shooting M193. The result is most of them won't cycle weaker steel case. |
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Quoted:
If your in-spec and broken-in rifle won't cycle cheap steel cased ammo, there is someting wrong with your rifle. Yes it's dirty and not as accurate, but a proper AR pattern gun should eat it up without problem. Didn't one of the internet video guys, Nutvuursomethingorother, do a multi-thousand round steel cased ammo torture test? Quoted:
Quoted:
Generally speaking, steel cased ammo is NOT your friend in an AR. There are many here who have more experience than I and who have figured this out. If your in-spec and broken-in rifle won't cycle cheap steel cased ammo, there is someting wrong with your rifle. Yes it's dirty and not as accurate, but a proper AR pattern gun should eat it up without problem. Didn't one of the internet video guys, Nutvuursomethingorother, do a multi-thousand round steel cased ammo torture test? http://www.luckygunner.com/labs/brass-vs-steel-cased-ammo/ Tula and carbine gas doesn't get along very well due to the pressure characteristics of the powder they use. Wolf is loaded a bit weak but not weaker than say PMC Bronze 223. IME, due to the difference in obturation between steel and brass, part of the cause of issues with steel is the fit of the case body in the chamber. This has nothing to do with the throat design. Most tend to think a loose chamber = reliability, but with steel case I haven't found that to be true. |
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