Based on the excellence of the proven iRMT upper receiver and full ambi billet lower, the SP10 build kit offers unrivaled reliability, performance, and accuracy. This upper/lower/handguard trifecta is the perfect jump start to your next AR10 build.
The SP10 billet lower is fully ambidextrous having superior weapon controls such as the ambi magazine release and ambi bolt switch that allows the shooter to lock back or release the bolt with a single finger. Our ambi controls, and take down pins come installed and factory tested. All you will need on this lower to complete it is a grip, stock, trigger, and safety selector (we recommend Seekins, of course, http://www.seekinsprecision.com/parts-and-accessories/lower-accessories/sp-safety-selector-kit-1.html).
The SP10 billet upper features our Integrated Rail Mounting technology (iRMT) integrating the rail mounting points into the upper receiver retaining the stiffness of a true monolithic upper while allowing the rails to be completely modular. This new upper design is considerably thicker in the most critical area and will aid in squeezing all of the potential accuracy out of your rifle. The dust door is installed so all that's missing is a charging handle, bolt carrier group, and an accurate barrel like these (http://www.seekinsprecision.com/parts-and-accessories/barrels.html).
Coupled with the receiver set is the Seekins Precision 15" MLOK SP3R free float handguard. Flat on the bottom, the SP3R handguard provides stability when shooting off objects. Precision machined from 6061-T6 aluminum, this uniquely designed handguard also has a top picatinny rail and integral QD sling mounting points, designed for precision shooting.
What magazines should I use?
-Any SR25/DPMS/AR308 pattern magazine like the .308 Magpul Pmag will work well. The AR10 Armlite magazines will NOT work.
What pattern is the upper-lower based on since there is no "standard?"
-The SP10 is based on an SR25 pattern. However, we do not recommend interchanging Seekins receivers with other SR25 receivers to ensure the best receivers fit. Even in other SR25 receivers we have found differences confirming there really is no true standard.
What style of barrel extension and bolt carrier group do I need to use?
-The SP10 upper will accept any AR10 style barrel extension and bolt carrier. In today's marketplace, it's virtually impossible to find a manufacturer making both the complete barrel and bolt that you may want, and even if you do, ALWAYS check the headspace when you purchase a barrel and carrier assembly. Yes, you can use a DPMS bolt in an Armlite barrel extension and vice versa. When building anything other than a .308 we recommend using a bolt with a smaller firing pin that will take a high pressure round. Larger (standard) firing pins tend to pierce primers on 6.5 Creedmoor rounds. We will have our own .308 BCG available soon.
*NOTE ON EXTENSION TO UPPER FITMENT- Like everything else ".308," it's hit and miss for an extension diameter to fit perfectly into .308 uppers. While ALL will fit and function, we have sized our upper to fit the barrel extension that we use, as perfect as possible. What does this mean for you? You may use whatever you like, however it may fit more loosely than you expect and may require extra attention to get it to fit properly. If that's the case we recommend taking the barrel and upper to your favorite COMPETENT gunsmith i.e US.
*NOTE ON ASSEMBLY- Read the instructions thoroughly and don't shear the barrel extension pin. Don't forget the lock screws for the barrel nut. Neither will be covered by our warranty.