Aim NiB BCG

[Sticky]

$130 free shipping...

http://www.aimsurplus.com/product.aspx?item=XAIMNiBBCGV2&name=AIM+NiB+.223%2f5.56+AR%2fM16+Bolt+Carrier+Group&groupid=723

One of my AR's just gotta upgrade.. lol

 

[Kingjamez]

I bought one earlier today. Apparently the bolt is not mil-spec steel, but I don't know if that is good or bad. AIM has always treated me well and offer a lifetime warrantee on it, so it's worth a try, I think.


-Jim

 

[ObsceneJesster]

I bought one earlier today. Apparently the bolt is not mil-spec steel, but I don't know if that is good or bad. AIM has always treated me well and offer a lifetime warrantee on it, so it's worth a try, I think.


-Jim

A lot of manufactures are actually using 9310 for bolts. It isn't Mil-Spec however the material can be as hard and in some cases even harder than C-158. I've read that 9310 has a very narrow threshold when it comes to heat treating. In order to be as good as C-158, it needs to be heat treated properly and some manufactures aren't.

Personally, I don't think you will have a problem. It should last as long as a bolt made with C-158 as long as it came from a reputable manufacture.

 

[Sticky]

I think it could be an upgrade when properly treated.. at least JP thinks so too...

"JP EnhancedBolt™
9310 Bolt assembly with standard extractor. Available for .223 and .308 (DPMS LR-308 application).

To satisfy customer requests, we now offer the new JP EnhancedBolt™ with great life expectancy while utilizing a standard configuration extractor.
The truth is, the standard Mil-spec C-158 (Carpenter 158) bolt has a number of factors limiting its performance, not the least of which is that the life expectancy of such bolts is only about 6,000 rounds. In fact, standard bolts will start to show stress cracks on the locking lugs adjacent to the extractor cut after only 3,000 rounds. Cracking at the cam pin hole and weak extractor spring tension only add to the problems of the Mil-spec bolt.

Typical bolt failure mode next to extractor cut.

The material used in these standard bolts is also not the best choice by today's standards, but if you remember the old story that explains why “Mil-spec never dies,” that applies here as well; they make them this way because they’ve always made them this way.
The latest edition JP EnhancedBolt™ is made from SAE 9310 high-grade steel. This material makes for an extremely hard surface with a tough, ductile core resistant to structural failure and a life expectancy far exceeding Mil-spec C-158 bolts. SAE 9310 is the same type of steel used in the transmission gears of Formula One racecars, and the high-load application of a bolt assembly is ideal for this state-of-the-art material; the results of actual full-auto endurance torture tests prove it.
The design of the JP EnhancedBolt™ addresses many other fine points, the most important of which is the utilization of a standard configuration extractor. Most users want the ability to replace extractors and other parts with commonly available Mil-spec parts instead of being dependent on proprietary parts that can be difficult to acquire. Therefore, this new bolt will accept standard extractors, pins and springs.
The JP EnhancedBolt™ will now be standard equipment on all JP .223 and .308 rifles and uppers, and we highly recommend it as a complement to your JP High Performance Bolt Carriers or any rifle system. The .223 version of the bolt is compatible with any AR-15 platform using a Mil-spec bolt carrier and subcomponents. The .308 version is compatible with the JP LRP-07 and the DPMS LR-308 platforms (or clones thereof) only and cannot be used to replace bolts in the Armalite AR-10 platform (or clones thereof)." (From JP Rifles Website)