B5 Systems Enhanced SOPMOD Stock
The original SOPMOD Stock was created by the Crane division of the Naval Surface Warfare Center (NSWC) in Crane, Indiana to help better serve America’s premier warfighters. It improved upon the standard collapsible M4 (AR-15) stock by increasing the cheekweld surface area and included water resistant battery storage compartments. This improved stock was originally made available to Special Operations forces and has since trickled into other channels including the civilian market. Anyone who has used a SOPMOD stock can testify to its comfortable use and tight fitment on Mil-Spec diameter buffer tubes.
While the first SOPMOD stocks were made in-house at NSWC – Crane, Lewis Machine Tool (LMT) later took up the job of manufacturing the stock for military as well as commercial consumption. LMT’s newer version stocks include quick-detach (QD) sling swivel mounts and a more secure lock up. LMT’s commercial MSRP for the stock is $199, making it a rather pricey option when compared to other aftermarket stocks.
In 2009, B5 Systems stepped in and won a contract with the US Army to produce the SOPMOD stock. Official named the B5 Systems Enhanced SOPMOD Buttstock, the stock is offered not only in Black, but in an industry standard Flat Dark Earth (FDE), Coyote Brown, Foliage Green, and hydro-dipped ATACS AU, ATACS FG, and MultiCam patterns. B5 System’s Enhanced SOPMOD is competitively priced at $120.
We are very familiar with the LMT versions of the SOPMOD so it was of great interest to see what the B5 Systems version is all about. At first glance, it is hard to tell them a part. We did notice upon further investigation that the texture of the B5 SOPMOD was a bit rougher than that of the LMT and the position adjusting lever has some slight differences. The LMT lever has a rounded trailing edge and a larger textured area than the B5. Another detail that separates the two is that the metal hardware on the B5 are color matched, while the rubber buttpad seems to be the same between the two manufacturers. We weighed the two stocks and found them to be nearly identical. The black versions both weighed 11.5 ounces while the various colored versions deviated by about half an ounce more.
We’ve read on a few internet forums that the early B5 stocks may have had fitment issues with Mil-Spec buffer tubes. It looks like they have solved this since those posts were made, because all five of the stocks we had the chance of testing fit well on the three different Mil-Spec diameter tubes we had on hand. Fitment was snug and there was no play or wiggle room. One feature that we actually don’t tend to use on the SOPMOD stock is the battery storage compartment. The stock needs to be removed from the buffer tube to store or remove the batteries. B5’s version requires this removal for battery storage as well.
One gripe from color conscious buyers about the LMT version of the SOPMOD is that their FDE color offered is quite a few shades darker than Magpul’s more commonly used FDE color. B5 addressed this complaint by going with an FDE SOPMOD stock that is color matched with Magpul’s popular line of FDE furniture. B5 says a new improved version of the Enhanced SOPMOD will include anti-rotational QD sling swivels is forthcoming. Their black and FDE stocks have not only been embraced by the U.S. Army, but by manufacturers as well. Freedom Group, LWRCI, BCM, and Legion are just a few that currently equip B5 Systems stocks with their rifles.
Priced at 40% lower than LMT’s version of the SOPMOD stock, the B5 version is a hard bargain to beat. It incorporates everything that we love about the SOPMOD style stock plus improvements such as a much more varied color selection. If you’re looking for a stock that can hold up to military grade abuse, look no further than the B5 Systems Enhanced SOPMOD Buttstock.