plumbs7 wrote:Hi Aaron , I'm a plumber ! So this advice is coming from no engineering background!However, many years ago when I was doing a engineering pre-vocational coarse for fitting and turning. We use a dye toothpaste like stuff to tell if we had filed down our piece of metal flat and square! It was a dark blue stuff that got all over ur clothes!
Is that the old prussian blue? When I did my bachelor of engineering at QUT they actually made do a few one day lectures/practicals in the engineering workshop at Gardens Point - welding, castings, machining etc. First one was hand cutting (hacksaw) and filing a 100mm set-square by hand out of some 4 or 5mm mild-steel plate. They did let us use a drill bit and press to relief the corner notch. We had to check the fit and prussian blue was use to mark to mark the high points. The were more than a couple in the class that only finished in the 3hrs we had let alone start the manual lathe job. Workshop supervisor told us this series of practicals was added to the course to stop engineers specifying tight tolerances for simple parts without some appreciation for the labour time and skill required achieve those tolerances. I still have the set-square in my tool box somewhere I think?
IMO , most factory bedding jobs a re poor. As u said earlier , re-bed it and I thinks it's 50 inch pounds on the recoil lug and 25 inch pounds on the rear tang screw!
In the past I've used Devon for bedding and white shoe polish as a release agent and play dough to fill up the holes. Worked well in my factory savage hspfcp. I'm sad that I had to sell it to fund a full on f class rifle !
Something else that I notice is that the loads stated are way down in the real slow area of the accuracy node , which to me is saying I don't like any pressure at all! Yep still sticking to my first comment if bedding and maybe poor barrel ( eg walking of poi as it heats up!)
Good luck let us know how u go after bedding etc.
Regards Graham.
The more I read -
http://www.snipercentral.com/fnspr.phtml the more I think FNH might have been a bit ambitious about their sub-1/2 MOA claim.
I agree with the loads possibly only able to reach the 2nd-top accuracy node, some chronograph readings would be preferable among other information. I also suspect there is a reasonable magazine restriction on overall length, but the chamber is relatively short-throated to work with 308W SAAMI OAL tolerances.
I've passed on the feedback to the owner and suggested he ask FNH to answer their sub-1/2MOA claim before tinkering himself or with a gunsmith. Either way I'll be interested in the results.
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