*stands on soap box*
You know what... I'm just going to poo poo all over the USMC's decision for a wide adoption of the M27.
Honestly I just think its the USMC just trying to be special again. They are the smallest "branch" within the armed services
(in quotes because they're part of the USN so technically there are 3 branches of the US Military, NOT 4). Everyone else is sticking with either M16s already in service or moving towards M4s and M4A1s. Why the USMC wants to go down another path is beyond me. First the USMC went with digital camouflage
(with great success however. Though what was wrong with everyone using the same pattern and basic uniform layout?) then everyone wanted to go down that path
(damn trend setters. Though now I think the US Army has the better pattern and overall better battle uniform). Then they wanted to hold onto their Mk.318 while most everyone moving towards the M855A1
(even the SOCOM was moving away from the Mk.318 to the M855A1). No we have their M27...
First they tried to pitch it as an alternative to the M249. Which is ridiculous if anyone understands the concept of sustained suppressing fire as well as fire and maneuver. Then they pitched it as a DMR. Which is another dumb idea because there is already another DMR in use
(though no longer being procured) that is also in 5.56 and is purpose built for the job; the Mk.12 SPR. They've been trying to sneak this through the back door for years. Now they just said "F it!" and want to introduce it as a service wide weapon. I stated how this was a bad idea both economically and practically IMO.
Its not economical because the M27 cost 3k per unit. An M4A1 costs roughly $700 for the US Military. The Mk.12 SPR is roughly 2000-2200
(at least civilian builds made by Daniel Defense and Centurion Arms). Another reason why I think this is not economical and as well as practical is because the M27 has proprietary parts. The last thing you want in a large force is to have a weapon system with proprietary parts. Smaller units in SOCOM however can get away with this because they are a smaller force and have their own budget
(they spend their funds more wisely). Proprietary parts means more long term costs when it comes to service life. This would also be more difficult down the road if they want to improve the M27 because there isn't that many CoS parts for it.
The US Army
(despite its numerous and awful stumbles) had the better decision to upgrade current M4s in service to the M4A1 standard rather then going for a completely new weapon
(which they tried and failed because nothing out there substantially outperforms the M4A1. They unfortunately also cancelled their M4A1+ program... however something interesting popped up. http://www.thefirearmblog.com/blog/2017 ... -carbines/). USMC was already procuring the M4s, why not modify it to the M4A1 standard the US Army uses? USASOC is looking to improve their M4A1 SOPMODs through a new Upper Receiver Group that uses readily available CoS parts
(US Military as a whole would be wise simply to let USASOC do their thing with it then piggy-back off of it later on). One of the improvements that stand out is going from a carbine length gas tube to a mid length gas tube in their carbines. This is a great idea because the open civilian market has LOTS of mid length gas systems for the AR-15 and by all accounts improves the overall reliability of the rifle/carbine. This cannot be said of the M27s H&K short stroke gas piston system. If one looks at all the short stroke gas piston systems for AR-15s on the market, they would fine that no two are truly alike nor can you swap out parts. The US Military can take existing M4/M4A1s and with existing and more readily available CoS parts upgrade those weapons and it would still be cheaper then the M27 and would be a improvement over what is currently issued.
Now we come to another wrinkle for the M27, the adoption of the M855A1. The USMC finally adopted the M855A1 after the US Army has been using it since 2010
(perhaps they just wanted to burn through their stock of Mk.318...). This presented a challenge for the M27. The M855A1 was tailored more for the M4 and M4A1 as well as the DI gas system that they use. The M855A1 showed that the M27 had feeding problems with the round
(gen 2 and 3 PMags fixed that. M4A1s also had issues with the M855A1, again newer magazines fixed that) and that the M855A1 actually decreased its service life further then that of the M4A1 and M16s. Because the M27 is essentially an over gassed system, this creates more strain on parts. Matter the fact US Army testing showed that the M4A1 had the least amount of class 3 stoppages/malfunctions over piston driven counterparts using the M855A1. Originally the M855A1 had a chamber pressure as high as 62k PSI. From other people who are still in and have a finger on the pulse say they reigned it down to 55k psi. That is still a higher chamber pressure then the original M855 but lower then original M855A1 specs. This higher chamber pressure with the over gassed system of the M27 means a lower service when compared to the M4A1.
This isn't like the USMC procuring the F-35B which will significantly change their doctrine and how they fight when it comes to air power. The M27 offers no significant benefit over current M4A1s or M4A1s with CoS upgrades/parts. M27 will not have a significant effect on how the Marines fight their current and future conflicts but mainly just a restructure of their fire teams. Also a loaded M27 is roughly 2lbs heavier then a loaded M4A1. 2lbs and $3K for something that isn't significantly better then what is currently being used now.
To sum up...
> M27 will likely have a higher service life cost
> M27 has no major parts commonality to what is out there in the civilian market means limited path of future upgrades
> M27 when coupled with M855A1 will have a lower service life cycle
> M27
IS NOT WORTH THE COST