GC Inch Actions

[WazzaG]

I would like some feedback on GC Inch actions. I have been looking at the action and the fact that they have a rear locking bolt
and thought that may be the way to go but was talking about them yesterday (at our club) and a southern visitor shooting
with us suggested that they have a tendency to stretch cases.
I am wondering if anyone has experience with this action and if this problem does happen.

Wazza

[BATattack]

Are they cheaper than a Barnard?

[WazzaG]

Not sure if they are cheaper, have found out today they are not available unless
you find a second hand one.

[Longranger]

I use one and there is no issue with stretching cases. Very robust action made out Bohler Uderholme K600 stainless alloy hardened to HRC 52. Very happy with it. Has a very nice trigger as well.

[Jase PTRC]

Im just about to receive this weekend a new rifle i had built using its brother action the "CG Delta" aluminium housing front locking action with a tool steel insert.

[Mick_762]

I also use a CG Inch - no more of a case stretcher than any front locker that I have found.
The three locking lugs on the action are well. . . quite substantial.

Very nice triggers, the anodising does have a tendency to chip slightly though.
Very positive lock up and fast lock time - beautifully machined as well (I own rifle 006).

Mick

[Paul Janzso]

Hi WazzaG
Just stick with a Barnard P action
You will not be disappointed
Cheers
Paul

[Robert Chombart]

I would like some feedback on GC Inch actions. I have been looking at the action and the fact that they have a rear locking bolt
and thought that may be the way to go but was talking about them yesterday (at our club) and a southern visitor shooting
with us suggested that they have a tendency to stretch cases.
I am wondering if anyone has experience with this action and if this problem does happen.

Wazza

To reoy to the case stretching question, a survivance of the spongy SMLE era, I can only quote the following, from the 'Shootinh Shed Journal:

The MYTH of CASE STRETCHING In Match Single Shot Rear Locking Actions
Posted on May 14, 2013 by David (The Shooting Shed Jpurnal).
Robert Chombart emailed this to me today and I have decided to publish the article in its entirety as it covers some interesting points on the differences between modern rear locking rifle actions, specifically the M41 CG INCH action compared to the military rear locking action specifically the SMLE.

‘’The MYTH of CASE STRETCHING In Match Single Shot Rear Locking Actions
Robert Chombart
Bolt compression resistance:
I have calculated the compression resistance of the INCH Bolt.
The cross sections of the Bolt decreases in steps from front to rear. At 11 mm ahead of the Lugs bearing abutment (against the counter-lugs in the Receiver), it is still over a total of 35 tonnes before any compression could occur (Yes, 35,000 kilograms or 77,260 pounds). This represents some 7 times the total pressure against the Bolt face of a Magnum-sized case head, 9 times a .308 and 19 times those of a .223, and still 6 times those of a .338 Lapua Magnum. This is for the total pressure exerted on rear thrust. Converted to the .308 bolt face, with its surface of .175 sq/inch, it represents 395,500 lbs/sq inch of capacity.
Comparing to military or sporting Rear Locking Actions: In the case of an excessive pressure exerted axially against one end of circular solid (the bolt body), is heavy enough to create a reduction in length, this solid increase in diameter (or bent if the force is not fully centred, or the solid, itself eventually not symmetric in shape). This phenomenon is called ‘Buckling” or ‘Flambage’ in my mother’s language.
But if contained with close tolerances within another solid, thus preventing the radial expansion, any eventual reduction in length is impossible to occur because the cylinder cannot expand or flex. This is the case for the INCH (and other rigid rear-lockers) in which the generously dimensioned bolt is maintained straight at close tolerance in the Receiver, with limited openings and generous cross sections.
This is different in the military or some sporting repeater rear locking actions, the example being the SMLE, in which the small sectioned Bolt (1/3 those of the INCH) is not maintained due to the large and long openings for magazine well and loading/ejection port. The Bolt is only slightly maintained (with generous tolerances too) at front and rear… with also a threaded junction in between (non-rotating bolt head screwed in the bolt). There is nothing here to contain the central buckling of the bolt. Also the receiver flexes under stresses on those actions as well because of their asymmetric construction and horizontal locking lug arrangement. The SMLE’s lugs bolting is the only of its kind being horizontal when closed.
Choice of materials: The choice of material and treatments used in the construction also play an important role in general compression resistance. The material and treatment used for the INCH (as it was for the Millenium) has a Rm of 185 kg/sq.mm @ 52HRC (363,130 Lbs/sq.inch) as compared to the 120 kg/s.mm @ 38 HRC (170,680 Lbs/sq.inch) of a hardened 4140 receiver.
Conclusion: One important conclusion which can be drawn from the above is that, the smallest cross section of the Bolt being the only one to consider and being only 11mm (.433’) long, this distance being inferior to those Bolt Recess / Rear of Lugs of a Front Locking action, it is a nonsense to attribute any case stretching tendency to a well designed Match Single Shot Rear Locking Action, notwithstanding the superior metal characteristics.
To repeat the main important aspect, the Bolt being fully enclosed in the action, the later acting as a super-strong outer sleeve/collar preventing any inflation or flex (buckling) of the Bolt.
R.G.C
01/2010).

Production of the C.G whole range will resume shortly .
R.G.C

[DannyS]

Don't you just love this forum ie when Robert Chombard the designer of the action comments.

[Robert Chombart]

Don't you just love this forum ie when Robert Chombard the designer of the action comments.

Danny,
I love this fprum and nisit regularily.Always interestng..
Yours
Rpbert Chombart
c-g-designs.blog4ever