I have, wasn't real impressed. Left a lot of carbon on the curved part of the bolt,
and was sporadic in the cleaning of inside of the carrier.

Too bad, had high hopes.

I'm glad to know this because I was planning on getting one.

I have not used it on an really dirty BCG but I agree it does not get all of the carbon off.  Just the heaviest.

I have not had the results I had hoped for using mine.

Are yall using the older version or the new "improved" version that was released sometime in 2012?

Ive got a MSR kit that has the newer version B.ON.E.,but haven't used it yet.

Can't say that Ive had much of a carbon issue on the bolt,FP or in the carrier that was enough to need to use the tool.I keep the BCG fairly wet with a CLP type product,and do quick PM after use, so most of the fouling wipes off,no accumulated carbon to speak of.I do soak the bolt, tail down in a jar of Hoppe's No.9 while I clean the rest of the rifle to soften/remove what doesn't wipe off.Helps get the fouling out of the gas rings,and bolt ring groove too.

Maybe you guys clean much deeper than I do but I was pleasantly surprised using my b.o.n.e tool.  Got a lot of crud from my carrier that I didn't think was there.  I consider it a field tool though.  Scrapes the worst away so you can keep shooting.  I agree about the bolt.  I can definitely get it cleaner using a brass brush.  Firing pin would have to be in pretty bad shape to benefit from the pin scraper.

This owns all other BCG cleaning tools

I just tried the Otis BONE Tool that UPS delivered yesterday:

I used Break Free CLP as a "cutting oil", first on the inside of the bolt carrier, yes took out a lot
of carbon that I could not get to with picks, Q-Tips, etc. Left some behind, but should be no problem.

Next, I used it on the bolt's "tail". Scraped off most of the build-up, yes did leave some, but
still met my expectations.

If you want "immaculate", then you have no choice but to either soak in some kind of carbon
dip, which involves taking extractor, spring and "donut" off, or use some kind of polishing compound
which will certainly remove bluing/phosphate finish.

I think the Otis BONE Tool will keep your rifle running, and cut down on cleaning time.

I like it.

I had thought about picking one up as they are now carrying them now at my local Academy, but reviews like these have turn me off to it. I think most people still recommend the CATM4 tool over the Otis BONE

I bought a B.O.N.E. tool last week. I'm an admitted clean freak when it comes to my firearms. The two parts I can never seem to get completely clean are the bolt tail and the rear inside of the carrier...I still try like hell to though. I bought the Otis tool hoping it would help. I decided to test the tool on a BCG that I had already cleaned the best I could with my normal methods. The tool was able to remove a decent amount of fouling that I hadn't gotten. Did it leave some fouling behind? Sure but not as much as I do after working on each piece for 10mins each. I assume it will clean a fresh from the range BCG just as well as it did the one I had that I already removed most of the fouling from. My opinion is it's a good tool and will decrease the cleaning time significantly. Well worth the $25 to me.

Mine came today. The paper says this tool fits many bolts flawlessly. It may fit some bolts better than others, due to the manufactures variances. It does not fit my S&W M&P15 all that great. I wound up using brass brush. The firing pin scraper also does not work all that great either. Then again, I did not have enough rounds through. The Otis MSR/AR kit is nice though. According to the box my kit was made 9/13, so I assume I have the newer BONE tool. But, for the most part you can still get your rifle clean with this kit.

I am pleased with the bone tool, for me it works fine. Like somebody already mentioned, I too see it as a field tool. On my bolt it removes almost all carbon just leaving a light bit of darkness behind in some places. After a scrape with the bone tool, a brass brush and 30seconds of scrubbing, spotless (as close as it can be anyhow).

I bought one for the guys on my unit to try and they like it, but don't expect it to clean the bolt perfectly, you also need to push it of to one side as you twist it to get a better cleaning action. i cleaned several pool weapons that hadn't been cleaned in about 3 years and had many thousands of rounds through them and in those cases where the carbon was real caked up it made cleaning go quite a bit faster. I don't think carbon on the bolt is a big deal and I've never seen it cause a stoppage but I do like clean rifles.

Get a CAT M4 tool instead.

These work very well on my Colt's bolt.

I have both and like the BONE better, the CAT M4 didn't seem to work as well on my Colt BCG.

The NRA American Rifleman has named the Otis BONE tool the Accessory of the Year.

Since I bought the CAT 4, I don't know which is better.