David Bonwick Posted: September 19 2013
Today was a test day for the CG INCH Actioned M75 Chassis. I sent a few actions and barrels to the London proof house however I have not had a chance to shoot any since they returned, the plan is to head down to Bisley for a full days testing and load development in the next couple of days however I was keen to get at least one day at the range prior to Bisley to see how the M75 chassis felt under recoil.
Starting at 200m for zero was interesting and actually quite painless. I use an iPhone app from Aphelia called SightSet which told me how much I needed to correct and it is pleasantly accurate in its prediction so a good zero was set in three shots. We shoot at 990mm/38" targets which have caused some controversy in the past as this equates to 3.8MOA at 1000 yards which some feel is overly challenging, personally I reckon if you can see it then you can shoot it and frames are a lot lighter than full size frames.
These are the current ICFRA F Class target dimensions which means we are effectively shooting at an F Class target that stops halfway through the 2 ring so if you are in the black then you have to have scored a 2! It can be challenging on occasion
A quick dose of C2R and it was off to the 800 yard firing point. I was one of the RCO's for the day however as I needed to zero I was on the second stint which suited me. I had given everyone a lecture about the importance of hydrating throughout the day and also to keep loaded rounds out of direct sunlight however we were blessed with a cloudy albeit warm day with temperatures not exceeding 24C and a wind from the 10:00 at around 4 minutes, nearly ideal conditions.
I had already experienced one minor issue at the 200m point, the cheek piece position had felt perfect when I was setting things up on the kitchen floor (There is less chance of being mugged by an opportunist Weim from Hell if I am in the kitchen) Of course once on the firing point things changed and something caught me top of the jaw bone just below the ear, ouch!!! The good news is the cheek piece was moved back by 20,0mm in under a minute and I was good to go. I did a similar thing when I built the first cheek piece for my Accuracy International so note to self, keep cheek pieces set back, the good news is it was more comfortable in the revised position and I have to say there is a lot to be said for modular chassis systems that can be adjusted to suit the shooter, if it does not fit move it to a position where it does fit. On the subject of fit, the M41 Action is incredibly slick and the bolt is perfectly positioned within the chassis with quite a short stroke which makes operation an absolute delight.
Now on the subject of fit, it is well documented elsewhere that I prefer a low shooting position, ideally about a fingers width below the butt however today I chose to shoot with a rear bag in the spirit of F Class. This means the back of the rifle was raised up higher than I would have liked even with the adjustable rear bag rider in it's highest position, so the bipod had to be elevated to suit which in turn meant my neck was more upright and my back arched. Certainly such a position is the accepted norm for many F Class shooters but not for me and it was literally a pain in the neck!. Raising the rear butt pad made a difference however shooting through a 42X scope exaggerated movement and I suddenly noticed my reticle was moving in time to my heart beat, I did try the Viking trick of shooting between heart beats however soon gave up on that and squirmed around a bit until I was in a better position. We have commissioned some low rear bags for F Class which I really hope will show up soon so we can test them, they are just 25,0mm high to the base of the ears which should be a lot better.
Now on the subject of 42X scopes, it is a Nightforce BR Model that I hate with a passion, the glass is poor in comparison to the European scopes we have in the house and the turrets are back to front to the S&B PMII I am more used to, plus it is in 1/8 minute clicks and this did lead to some issues. Firstly I dialled in the wrong way on more than one occasion, secondly 1/8 minute clicks are certainly not the same as the 0.1Mils I am used to so I tended to under correct for the wind and elevation on occasion, operator error - it is a couple of years since I used this scope.
Ammunition wise I was shooting bog standard 155 Lapua Scenars in Lapua brass with N540 powder initially at a conservative 45.5 grains and then 46.0 grains in two batches of 15. The higher load returned an average MV of 2892fps with an ES of 49fps which was pretty grim and hardly did the rifle justice. At the 800 yard point I had struggled to hold half a minute of vertical dispersion however I was not unduly worried given pilot error and a brand new rifle so a quick dose of C2R and it was off to do some RCO work.
I had to call two STOP STOP STOPs today, one as a dummy exercise as we had new shooters with us and it is important they understand exactly how to respond to such an event. Second time was down to a loss of comms with the butts, minor delays however it is always important to keep safety at the forefront on the range.
After a pleasant time as RCO I was back to the rifle at the 1000 yard point. The barrel is super slick to clean and copper fouling was minimal with the C2R doing a good job of stripping the copper and carbon with ease, I do like the product and looking back at my days using alternative products makes me wonder how good a job I was really doing, one thing for sure is the barrel was *clean* and ready to shoot.
Look just how high that rifle sits on the bag and bipod, the sooner the new bags are built the better. On the subject of bipod's this is the Shooting SHED Støtteben, the bipod formally known as the RWBL (Really Wide but Light) This is the bipod I have been working on for a while and the prototypes were tested by the Viking and Tim Stewart, based on their feedback the new version is here, it extends to 780,0mm wide and weighs in at 677 grams, yes it could go considerably lighter however I wanted to keep the top section triangulated with minimal deflection plus some space to engrave the name is good. This was the first time out with the bipod for me and I really do like it, the ground is quite springy yet the bipod kept on target and tracked well, I think shooting off a mat would make things even better. This version lacks the locking handles on the top pivot point as it is my prototype. You should be able to spot a hole in the side of the bipod head, this is for an optional anti-cant device hence the additional cut out in the top of the leg for clearance.
Material is 6082 T6 vapour honed and black anodised with stainless fasteners on this version, the production model has some very minor refinements.
Looking at the plot sheet for 1000 yards I held better than half minute of vertical for the majority of the time which I am pleased with, I do need to sort the loads out and next time out will probably be with IMR4895 with Berger 155 Hybrids, that should bring things in somewhat. For me, shooting the rifle is very satisfying and the combination of M41 Action and M75 chassis works incredibly well, I have no idea how it will perform in the hands of a dedicated F Class shooter so it will be interesting to see how it performs over the next few months. This particular rifle is our demonstrator so it will be off to an F/TR shooter in the UK very shortly for testing.
So this is me holding the rifle however this is not all my work, in fact far from it and without the solid design input from Robert Chombart and the dedication to a dream from Chris Quatermaine this would never of happened, really I just sat in the middle and put things together so Robert and Chris, well done guys we have a good rifle here.
I cannot wait for the next outing, and yes that is me nearly smiling