I have a 5 month old S&W mp-15 with a round count at about 1100. The whole bolt with the exception of the extractor is covered with pits and grooves. I had thought it was carbon that was bonded to the metal, but after a long soak in slip 2000 carbon disolver I was could see it was eroded. I shot mostly M193 and M855. No corrosive rounds were used. The bolt passes all of the BCG tests and it has been lubed as Pat Rogers reccomends. The rifle runs great, but I am concerned about its life. Should I buy a new BCG and keep this one for a spare or buy 2 new BCG’s and retire this one comppletely? I have larger pictures available if needed.
Thanks for any help provided.
There is no corrosion/erosion going on.
We see this from time to time from many manufacturers. If it bothers you, contact S&W and ask for a replacement.
C4
Looks fine to me.
Looks normal, just curious, what does the bolt face look like? Can you post a pic?
Thanks for the replys. I emailed the pic to S&W also I post the results from them when I hear back from them, although I don’t expect more than “Send it to us for replacement”. I’ll keep shooting it for now, until I get a new BCG and then make this one the back up. I’ll post a bolt face pic, but it dosen’t seem to show the same pattern as the bolt body.
I can’t tell that anything is wrong with it. If you do buy a backup BCG, shoot this one until it breaks and leave the backup for that–backup. Why leave a partially used BCG laying around?
Hey just curious but what gas rings are you using?
Thanks,
Looks like there is still some carbon on the bolt causing the appearence of pitting. Try using a Scotch Brite Scouring pad on it and see if the rest of the carbon comes off.
Yeah looks terrible, ship it to me and I’ll find a good home for it. 
All,
Thanks for all the help you have given. To answer the questions asked so far. The gas rings are stock from S&W. I tried a scotch brite pad and a chore boy copper scouring pad and the only thing removed from the bolt was some of the phosphate. The pits are still there. I’ll just keep shooting this bolt until it breaks, and keep a new one in reserve. I have higher resoloution pictures available if anyone would like to see them. PM with your e-mail and I’ll send them out.
Did you use any other cleaning products previously?
I would call S&W you might get a free replacement out of it. 1100 rounds isn’t much for it to be looking like that.
Ive seen this on a few bolts and carriers etc…In fact I have a parkerized Rem 870 that had similar finish to the parts.In fact the 870 I mention tended to continue to pit over a period of time(particularly the receiver) even when heavily covered in CLP.
I was told by the gunsmith that the surface degradation was due to the parts not being properly washed after parkerizing.Gun oil and CLP just does not have the chemistry to deal with the park and or bluing salts.
On the 870 in question the smith washed/hot tank the parts and the problem was solved.
Since the bolt has been cleaned in a water based carbon cutter I’d say if it is related to the parkerizing the salts are now gone.I’d just run the bolt and replace it if and or when it fails.Or if the mood strikes you,install a BCM,LMT or DD bolt and keep the original as a spare.Thats my preference at any rate.
I have been using hoppes elite cleaner and lubing with tetra gun lube. I had not thought of the phosphate salts causing the pitting, but it makes allot of sense. I’ll monitor the pitting as I shoot this bcg and if it keeps getting worse I will put this one to bed and get a new bolt.