Thoughts on these??

http://www.aimsurplus.com/product.aspx?item=XAIMBCGNIBE3&name=AIM+Evolution+3.0+AR%2fM16+.223%2f5.56+NiB+9310+MPI+Bolt+Carrier+Group&groupid=6

I wish they would chrome it instead of NIB.  Should work find and the price isn't bad.

I would rather have a Melonited version.

Melonite is acceptable as well.

like this?


 

eta: i really like that these dont have the AIM logo plastered all over them, sick of ARs looking like billboards

Yep, that looks pretty nice.  

I ordered a melonite version the other day will report back once I receive it.

Followed your Lead here and ordered Melonite Evolution bcg.

DID send AIM an email regarding: Is this the heavy duty version similar to the sold out V2 AND Steve responded to say indeed it was hduty with the difference being C158 for the V2 bolt and 9310 for the Evolution bolt being 9310.

Lots of opinions & facts on c158/9310 for bolts .... did buy a leigtner wise Revised bolt fir my most used platform

...but with a C158 bolt.

Do want.

Got it today its really slick no machining marks anywhere a steal at 99$ shipped!
Will post pics shortly.

 
Hate to break it to you, but the LW bolt you bought is the exact same thing I sell, only his is twice the price. I know this because I manufacture them.

Then why am I the one bringing it up :D (yes, smiley Face for my bolt face)
Link, please sir.

Revised bolt - not just a coating or treatment ... I am interested.
Bought Evol. 3.0 to try ... what do you have I am interested ...

Yours has these improvements addressing high stress areas of the bolt?:

Failure experienced with the Original Stoner Bolt... from LW blog, link below:

Finite analysis of the original bolt design had shown high von-Mises stress distribution around the fillet, or root, of the locking lugs and even higher stress concentrations were present in the two locking lugs immediately adjacent to the cartridge extractor. All of the failed bolts had fractured at these specific locking lugs. The design of the original bolt is such that the extractor cut-out in the bolt body creates an asymmetry, or imbalance, in the bolt. When the rifle is fired the pressure of the cartridge forces the bolt rearward and the lugs transfer this energy to the matching locking lugs of the barrel extension. The bolt flexes at the rear inside corner of the lug during this process. Because of the extractor cutout and resultant lack of symmetry, the stresses are unevenly distributed and the deformation is greatest in the area of the two lugs immediately adjacent to the cutout. A series of engineering analyses suggested that the two lugs on either side of the extractor, of seven total lugs, each receive a disproportionate amount of the total recoil load: approximately 20% of the total load each while the remaining 5 lugs each carry approximately 12% of the total load. The integrity of the bolt is further compromised by the fact that these overloaded lugs are undercut in order to accommodate the extractor claw, lowering their yield strength relative to the under-loaded lugs by 48%. Most bolts will start to exhibit small cracks before they reach 3,000 rounds fired with terminal failures occurring between 6,000 and 8,000 rounds.

The improved design also incorporates a fully supported bolt face. The original bolt has a substantial area of the bolt face removed to accommodate the extractor claw and therefore a combination of the bolt itself and the extractor claw support the cartridge head. This arrangement leads to further flexing of the bolt assembly during firing and increases stress on the bolt lugs adjacent to the extractor claw. By fully supporting the bolt face, a significant reduction in bolt flex was achieved in this area. Additionally, the undercuts in the lugs adjacent to the extractor accommodating recess were removed, and instead a radius transitions from the side of the lug adjacent to the extractor accommodating recess into the fully supported bolt face. The omission of the 48% undercut beneath each of these locking lugs has increased the strength of these lugs from around 24% of the strength of the uncompromised lugs to approximately 85% of their strength. Finally, the locking lugs were held to the maximum tolerance indicated in the Technical Data Package for the original bolt design so as to provide as great a surface area as possible without altering the barrel extension.

http://www.leitner-wise.com/blogs/news/19142491-combat-match-bolt

I paid $85. for the LWise Enhanced Bolt with revisions on high stress areas & with original Stoner designed pin (not cotter pin), but not the entire bcg.
Shoot me a link on your bcgs, bolts and cool things...  Thank you !

Still waiting on my Evol 3.

Free shipping takes awhile ...

Great option would be for AIM to offer a choice between the burro and paying for UPS/FE.

cast parts you say?
I'll pass when i can

Have investment cast gas keys been problematic?

 
I've had less problems with the thousands that I've built with MIM/cast extractors over billet ones.


 

Truth be told, the average user is going to have a hard time breaking or wearing out either.

I always thought the biggest problem was gas keys coming loose, which good staking addresses.  I am thousands of rounds into both types of gas keys, all properly staked, and can't see any performance difference.

CrN is the best of both, chrome nitride is where it's at. I don't know why this isn't offered by more companies.