Asymmetric Dialogue

Is the USMC Finally Replacing the M40 Sniper Rifle?

U.S. Marines with Regimental Surveillance and Target Acquisition Company
Photo by: RSTAC
After over 50 years of service, it looks like the Marine Corps is about to replace the venerable M40 Sniper Rifle. The USMC is set to purchase just over 350 new Mk 13 sniper rifles.
The .308 Remington 700 bolt action hunting rifle entered Marine Corps service as the M40 during the Vietnam War. They have since seen action all over the world and have seen a series of upgrades, the most recent being the A6.
The current iteration of the venerable M40, the A6, began fielding with Marine Corps back in June 2016. The M40A6 has a folding stock which is compatible with current M40 actions and barrels and a full-length Picatinny rail to accommodate optics and accessories. The Corps’ entire M40A5 inventory was upgraded by Remington, who were awarded a contract in 2014.
Members of MARSOC attend the Advanced Sniper Training Course near Jacksboro, TX on October 30, 2013.
Photo by: Catherine Deran/MARSOC
But Marine snipers have been calling for a new rifle with greater range and a larger calibre round for some years. It seems that they may be about to have their calls answered. The Fiscal Year 2019 Budget Estimates Justification Book for the United States Marine Corps procurement gives us some insight into the Corps small arms aims for the next couple of years and one of the line items is funding for the ‘MK 13 sniper rifle’:

Funding supports the MK 13 Rifle with associated optic, and principle end items (PEI) due to combat losses, wash-outs, and increases in AAO, as well as continuing product improvement and modernization of sniper and special purpose weapons, and support equipment.
The budget estimates justification books suggests that 356 rifles will be purchased during the 2018 fiscal year at a projected cost of $4.287 million. This puts the per rifle cost at $12,042.13. Currently, in use by the US Marine Corps Special Operations Command (MARSOC), the order is far too large to be earmarked for SOCOM Marines. A spokesperson for MARCORSYSCOM confirmed that the new sniper rifle “will be fielded to General Purpose Force snipers in both the Active and Reserve Components… The Mk 13 will augment the M40A6 in Scout Sniper Platoons and Reconnaissance Battalions.”
The procurement justification book does not state which Mod of the Mk 13 will be procured or if the Corps will create its own specification. But MARCORSYSCOM also confirmed that the rifle will be the latest configuration from NSWC Crane, the Mk 13 Mod 7.
It seems unlikely that the Mk 13 will immediately replace all of the Corps’s M40A6s but Marine snipers will welcome the greater range of the .300 win mag. The Mk 13 is made up of parts from a number of manufacturers but largely based on Accuracy International chassis and a Lilja barrel.
The Marine Corps is also interested in the US Army’s 7.62x51mm M110A1 Compact Semi-Automatic Sniper System (CSASS), with just under $1 million budgeted to procure 116 CSASS rifles. The relatively small order is likely for evaluation and to supplement the Mk 11 Mod 2s currently in service.
The budget justification book states that an award through NSWC Crane was due to be made in February 2018, although I could find no matching award notice, and delivery is scheduled for May 2018.

Sources: 
Fiscal Year 2019 Budget Estimates Justification Book for the United States Marine Corps Procurement Vol.1, Feb. 2018, (source)