Anyone used a carbon lower?
Any problems?

I just posted a similar question recently - you might try a search.  Someone responded to my post saying you can get Bushmaster carbon lowers for $189.  My take is the consensus on the Vulcan parts skews negative.  If you don't need a telestock, you might look at the Cavalry Arms Mk. II lower.  They are Nylon 6, not Carbon, but are light and have a good reputation.

the ones i have seen here have never reported back with problems



either they never had any, it turned out really bad, or theyare ashamed of their purchase.
bushmaster said they will be offering their lowers soon, one i would choose over the other options

I just saw a Wilson carbon fiber lower at one of the local gunsmiths shops.  I didn't get to ask many questions about it as he was really busy, and havenot tried to research it, but it may be another source for one.  It was definately stamped wilson on the mag well though.

I have a carbon 15 97 rifle from bushmaster, and have replaced the trigger (no problem), have added a collapsible buttstock (no problem), but I would say be careful here in general - while some folks have had good luck with the carbon, I have had nothing but problems with the material wearing too quickly, and the weight savings (say .4 lbs saved compared to aluminum lower) may not "outweigh" the reliability factor.

My rifle is on its 2nd trip back to the factory with misfeed issues.

If this is a "project" rifle which is for fun - go for it, but if you need it to work, stay with tried and true technology.

just called Bushmaster the other day inquiring about their carbon 15 model 97 and asked them about putting a collapsable stock on it and the rep told me it couldnt be done cause of different thread types. how did you do yours.  I was thinking of ordering thr 97 upper and a carbon 15 lower with collapsable stock to over come that issue.  is it feasible?  and any idea what a 97s upper goes for, it wasn't listed for sale on bushy's site

bushmaster offers the c15 m4variant which is a carbon copy of std alum m4variants which uses all std parts as any other would.




ask about that instead of the model 97's but even then i remember someone that had an ace socom stock on their model97 carbon rifle

I put a M4 style stock on a 97 and it went tighter then hell...The thread pitch is slightly different. I then bought a 22 complete gun and e-mailed asking If i could interchange the stocks...he said go for it...I did and snapped the receiver on the top of the ring. I got back to them and they said the guy should not have told me that....they replaced it for free.

There is no issues with the newer model 4 and the M4 carbons.....just be careful or better yet, have Bushy add the stock. That's what I had done on one of mine.

P.S....I love the carbon series.....mine run perfect, a couple have needed feed ramp elongating and polishing, but that is a 5 min. job with the dremmel.

This is my favorite

On my carbon 15 97 rifle, the thread was exactly the same as the bushy m4 collapsable stock - the only thing you have to do is dremel out the area where the detent is around the back of the receiver - there is already a hole there for the current stock, and you can continue to use that stock as well if you're careful as the detent is only 1-2mm deep.

I measured the thread depth of the standard black plastic buffer tube, then used the rubber washer from that tube to indicate the same depth on the alum m4 tube, and did not screw in beyond that point, but then tightened the nut on it. only used hand torque and it was not very much at all. good luck. I'd post a pic but BM has my rifle right now. . .

I have a Vulcan set (upper & lower) build without problems it has manny rnds on it I was done before I joined here & learned of the problems with Hesse but I have yet to have a issue

How well does the carbon lower accept standard aluminum uppers?

Quoted: I have a Vulcan set (upper & lower) build without problems it has manny rnds on it I was done before I joined here & learned of the problems with Hesse but I have yet to have a issue

You know at $80 each it wouldn't be the end of the world if a Vulcan upper or lower broke (as long as no one got hurt).  I'll have to do some more searching.  The photo I remember showed a Vulcan upper that broke at the bulge opposite the ejector port--apparently the cam pin hit the upper and knocked out a piece of CF.

I might buy a set.  If they work, great.  If I have problems, I can replace them with one of my forged pieces and chalk the cost up to tuition at the school of hard knocks.

I'm thinking about a maximum carbon fiber build--

* CF upper and lower
* CF wrapped barrel (ABS)
* JP low mass operating system & fire control components
* DPMS CF free float handguard
* Ace Ultralight Stock (too bad they don't make the CF one anymore)

All the CF components, low mass operating system and ACE stock would make it a very lightweight build.  Between the ABS barrel (w/Mike Rock bore) and the JP components, it would probably be an accurate one, too.

I have seen that photo as well I try to keep an eye on the parts.I have yet to see any sighs of trouble I now have other AR's that if there was any damage I would swap the parts this set may go to a ultra light weight build too

I did a little more searching.  The more troublesome posts are the ones that mention melting in the barrel extension area.  Makes sense.  It can get pretty hot in there if you are blasting away.  I know the carbon is supposed to transfer heat well, but what about the polymer (a/k/a plastic) nexus the carbon fibers are in?

While if you've seen some of my posts you know I'm not sold on the reliability of the material, I have no worries about melting. I think your barrel would be in pretty bad shape if you got the rifle hot enough to melt the plastic (carbon 15). The major difference I have seen is simply that the carbon 15 material is not abrasion resistant as an anodized aluminum surface.

I would buy the uppers and lowers if/when BM places a metal insert into the area where many ar's have m4 feed ramps. I think a nice thin layer of steel, with polished m4 feed ramps, would turn this into an awesome material.

BM has moved very fast with standardizing the uppers and lowers, and I expect that at the current pace they will make this a material comparable to aluminum soon.

I am unaware of any bad issues with Vulcan lowers.  They are not a Hesse product, and are made by a subcontractor.  I have built 7 rifles on them to date, and am happy with them.  

One issue, mags will not drop free from them without modification, but I don't want my mags to drop free, so that is not an issue with me.