c-g-designs

A DIFFERENT CONCEPT.

C .G 85 MINI- INCH ‘Tube’ rifle Chassis/Recceiver.

            I have been asked long time ago to imagine a rear-locking action of the Remington XP100 size, but as a repeater using an easily avaiable detachable magazine .

            The initial project was for a classic action, but this quickly changed for a Tube version, using the Chassis/Receiver as the central part of the rifle.

            The AR15-M16 magazine range seemed the right choice, as this magazine exist also in 10 and even 5  rounds capacity . Action dimensions and magazine lenght limiting the cartridge lenght to the .223 Remington-5,56x45 and Russian derived calibres (TCU , PPC, Grendel ,7,62x39, .30Blackout...etc).

            The above lenght limitation is walid for the repeater version but , as a single shot , longer calibres can be fed (such as 6mm Norma BR and derivates..).

            The C.G 85 ‘Tube’ has the receiver constitute  the  central part of a platform accepting all AR OEM and  aftermarket forearms and stocks. The model accept also the C.G 75 Match stock,forearm and accessories, such as the adjustable rear bag rider, front rider and accessory rails.

            A ‘classic’ version of the 85 Tube Receiver can also be proposed but is not included in this description..

            The C.G 85 is rear-locking,  with a genuine bolt guidance . The rear-locking principle allowed an extremely short bolt stroke of 70millimetre (2.746 inch). A front-locking system would have required a bolt stroke of at least 90 to 95mm (3.54 to 3.74inch), with the subsequent receiver and bolt lenghts dimensions increase. This stroke is just  2/3 of those of the standard Short Actions (105mm-4 . 134’’).

            The bolt is guided by a fixed bolt stop key. The system also perform the primary extraction. A further 35° rotation when the bolt is fully pulled backwards allow its removal from the receiver . This further rotation can only occur when the stock is removed first, this removal being accomplished in seconds.

            As the 85 receiver being bi-metal, the bolt is guided and bolted into a hardened  tool steel  guidance sleeve  (principle comparable to the AR bolt carrier). The counter-lugs and lugs rotation clearance  are machined at the rear of this sleeve.

            TheC .G 85 chassis/receiver is intended for the Remington 2 crosspins trigger fitting  system. The crosspins are screwed on the bolt carrier. This considerably ease the trigger removal  from the receiver.

            The firing mechanism is powered by a  new Belleville washers arrangement  making the bolt opening very smooth although keeping all its superior performance of the system. The short bolt body lenght  (123mm / 4.84’) however allow for a coil spring  system. Both options are totally interchangeable.

            The bottom metal is made for using the AR OEM  magazine release system making it a complete assembly in a housing . It also bears the handle and the rear stock latch.

General data :

            Bolt stroke :                                    70 mm (2.759’).

            Bolt diameter :                               18mm (.709’).

            Bolt lugs diameter :                      22,8mm (.898’).

            Number of lugs :                           3, Delta truncated shape.

            Total Bolting angle :                     over 170°.

            Lugs bearing area :                      55mm² (.0853sq/inch).

            Opening angle :                             60°

            Bolt face angle :                            120°.

            Barrel shank  :                                AR15 (11/16x16tpi UN)  with a   centering diameter added to the shank and cone washer to match the           120° bolt head angle to ease feeding .

85 Chassis/ Receiver diameter :           46mm(.1.81’).

            Chassis/Receiver lenght :          226mm (8 .90’’)

            Chassis/Receiver matterial :      7075 T6

            Bolt carrier material                     36NiCrMo16 (AISI 6F7).

            No further data or  illustrations included for pending legal protection of the concept

            05/2017        

            R.G.C