JP Enterprises LMOS Carrier
I have been interested in the JP Low Mass carrier for a while, and I decided to purchase one and see what I thought about it. I am going to share with you my input about this carrier, and what purposes it should be used for.
First off, this is not an in-depth overview of the technical specifications of the carrier. If you are looking for that information, I would suggest looking at JP Enterprises website for that information.
First Impressions: The very first thing I noticed was how light the carrier is. It makes the standard mil-spec carrier feel like a brick in terms of comparison. The outer walls of the carrier are much thinner where the hammer travels through during the cycle of operation. However, this carrier does not feel cheap!
Bolt Carrier Group Assembly: The bolt fits very nicely into the carrier. You can feel the nice tight fit of the bolt, yet it moves around effortlessly. The cam pin also rotates with ease and no sticking at all.
BCG Functions Check: I honestly expected the same feel performing this check with a standard mil-spec BCG. However, the difference in feel of the carrier during assembly proved to be true during the functions check. I pushed the bolt in and gave it a quick snap. The bolt moved in and out so noticeably smoother that you'd have to feel it to comprehend it.
Shooting Test: I also ordered a Syrac adjustable gas block at the same time I ordered the low mass carrier. Therefore, without doing a direct carrier swap and adjusting the gas block for each carrier, it's hard to say how much of a difference in felt recoil the carrier makes. Although, the rifle does shoot very smoothly! In my opinion, it's how an AR15 should feel when you shoot it.
Noted Issues: I found out that under certain circumstances that the BCG would not fully chamber a round. For example, I loaded a magazine with 30 rounds and racked the bolt; the round was not fully chambered. You could see the gap in where the bolt was not fully seated. So I tried the same magazine with the same rounds with the mil-spec carrier and it chambered the round with no issues. I tried this several times and the JP carrier would not fully chamber a round.
I tried 29 rounds with the same magazine and ammo which then it chambered every time. With some magazines it would chamber a fully loaded magazine while other magazines required 29 or less for reliable chambering. With the mil-spec carrier, none of those issues happened using the same magazines and ammunition.
From time-to-time I have bad reloads which causes me to have to "pogo" the rifle to eject the round. This usually happens because I wasn't paying attention to the feeling of the primer being seated when I am cranking out rounds on the Dillon XL650 press. With the JP carrier, it took me a few times to "pogo" the rifle to eject the round. Whereas the mil-spec carrier rips it out on the first attempt.
In my opinion, I think that the weight of the carrier is the reasoning for the two issues noted. In other words, the carrier isn't moving with the same amount of force or mass (I am not a physics major) that the mil-spec carrier is which causes these issues.
Conclusion: With the exception of some bad reloads, the rifle hasn't had any malfunction issues with the JP carrier installed. To be fair, JP does not recommend this carrier to be used for duty use and I 100% agree. With the chambering issues and the added pogo strikes, I would not put my life in the hands of this carrier.
I see this carrier best used for precision rifle applications where less reciprocating mass would be a benefit, the cool factor, light-weight rifle build, or competition use. If you were thinking that this could be something to add to your defensive rifle, I would say to save your money.
Overall, I am happy with my purchase of this carrier. It makes shooting the AR15 even that much more enjoyable.
