Impact Precision: 737R Short Action, RH - .308
The Nucleus Gen 2 Short Action has a tab style bolt stop similar to the Mausingfield, but on the opposite side (the 3 lug bolt head necessitates a different design than the 2 lug Mausingfield). The tab is pressed down to remove the bolt and a spring returns it to the locked position when the tab is released. "We test our bolt stop designs by slamming the bolt into the bolt stop as hard as we can hundreds of times to ensure it will always stop the bolt. During normal use no one typically slams the bolt open nearly that hard, but if you do the bolt won't come out" - American Rifle Company
FeaturesKeyed rail interface
For scope mounting, Nucleus G2.0 uses a Picatinny rail that now has a tapered slot that engages a similarly tapered key machined into the top of the receiver, just like those of the Archimedes. So, in addition to the five conical head screws that were used on the original Nucleus, the key provides an additional constraint for maintaining alignment between the rail and the receiver and for resisting the forces imparted on the rail by the recoil lug during barrel installation.
Bayonet style bolt shroud
The striker assembly of Nucleus G2.0 can now be removed by depressing the bolt shroud locking pin and then rotating the bolt shroud with respect to the bolt by one-quarter of a revolution, enabling tool-less take-down of the bolt for cleaning and for bolt-head exchange.
80 degrees of bolt rotation
In order to improve the smoothness of the bolt cycle, maintain an appropriate level of cocking effort, and still provide adequate clearance between the shooter’s hand and the scope during bolt cycling, Nucleus G2.0 has 80 degrees of bolt rotation. The original Nucleus had 72 degrees.
Smoother cocking and closing
Nucleus G2.0 slightly over-cocks when lifting the bolt handle and then de-cocks by a tiny bit when closing the bolt, thus no cock-on-close will be the standard offering. Moreover, the cocking piece never falls into the cocking cams when closing the bolt thus eliminating any bump-on-close that would otherwise result from a slight amount of re-cocking. The cocking behavior of Nucleus G2.0 is now essentially identical to that of our current Mausingfield action.
Optional cocking pieces
To accommodate variations among triggers that will be used within Nucleus G2.0, we now have an inventory of cocking pieces varying by 0.25mm (0.010 inches). Additionally, those wishing to enable their action to cock-on-close can do so by ordering a cocking piece that will provide that functionality. Cock-on-close cocking pieces can also be modified by a competent gunsmith in order to eliminate any de-cocking and cocking-on-close.
The smartest bolt knob in the industry
Nucleus G2.0 comes standard with our short barbell knob which we believe is the smartest and most ergonomic bolt knob available. The knob boasts a function driven design that makes high-speed cycling of the bolt as easy as possible.
Improved fully-retracted bolt guidance
The receiver of Nucleus G2.0 cradles more of the bolt body than did its predecessor, thus making it a bit easier to avoid binding while cycling a bolt that was already easy to cycle. An incremental improvement at best, is was essentially free to implement and therefore we included it.
FFL Requirements & Magazine Restrictions
This item has to ship to an FFL. Please read the attached information. Shipping Rules & Magazine Restrictions.