OzFclass

bruce moulds wrote:I am putting a large part of the Australian victory in raton down to opposing teams having viewed that stock...

Its funny you should say that. At the last range of the individuals in the FCWC, I got down on the mound and next door was Charles Ballard, US Team member and winner of the US Nationals a couple of years ago. He's a pleasant chap with a broad Texan accent. He noticed my rifle and made some complimentary remarks, but he was probably having a chuckle to himself. I picked a condition and started shooting first. 10 minutes later it was all over - I got up with a 99.8 for the 20 shots, and Charles had his worst range of the competition with a 93.4!

battleship grey sends a strong message.
keep safe,
bruce.

Here is some glasses that will stop the battleship grey from affecting your scores- quick all other states jump on them before they sell out!
http://www.ebay.com.au/itm/like/3605635 ... e&lpid=103

Alan, what does your complete rifle weigh?

Obviously it shoots really well. I'm interested in its performance characteristics.

Does it torque much?

Does the barrel ever touch or come close to touching the front bag as it vibrates after the shot?

Although less than the Mastin, how much does the forend flex? Can you still squeeze the barrel and forks together with one hand?

I know you didn't like the crude test of squeezing the barrel and forend together.
The test could be standardised to give an actual result and figure for comparison between stocks by sitting the rifle on its rest (normal shooting position), the barrel overhanging a bench and the butt held down. The muzzle could be pulled down using a cheap spring scale. The result would be forend deflection per kg. Eg. my front rest/stock/barrel configuration may have 1 mm/kg of flex at the forend.
Done over a dozen configurations it may be an educating way of identifying an acceptable level regarding "How much flex is too much flex to consistently hold the X ring"............. so to speak.

Obviously there are other factors in stock design, but this certainly an important one I feel.

DenisA wrote:Alan, what does your complete rifle weigh?

Its 9.9Kg.

DenisA wrote:Does it torque much?

Definitely less than the Mastin. I put that down in part to the low profile, and the balance point is much further forward. I should also mention that I have a very heavy rear bag (8Kg), which I believe counteracts some of the sideways forces resulting from stopping the torque effect.

DenisA wrote:Does the barrel ever touch or come close to touching the front bag as it vibrates after the shot?

That was a problem I noticed immediately, and kept having to dent the middle of the front bag to prevent it. However the solution was to use a couple of cable ties pulled very tight crossed over the middle of the front bag.

DenisA wrote:Although less than the Mastin, how much does the forend flex? Can you still squeeze the barrel and forks together with one hand?

A little more than half the force to get the same deflection (as the Mastin) vertically. The forks cannot be squeezed vertically with one hand even a mm. There was too much horizontal flexibility with the forks until I fitted the aluminium bag stop across them. It is now negligible.

DenisA wrote:I know you didn't like the crude test of squeezing the barrel and forend together.
The test could be standardised to give an actual result and figure for comparison between stocks by sitting the rifle on its rest (normal shooting position), the barrel overhanging a bench and the butt held down. The muzzle could be pulled down using a cheap spring scale. The result would be forend deflection per kg. Eg. my front rest/stock/barrel configuration may have 1 mm/kg of flex at the forend.
Done over a dozen configurations it may be an educating way of identifying an acceptable level regarding "How much flex is too much flex to consistently hold the X ring"............. so to speak.

Obviously there are other factors in stock design, but this certainly an important one I feel.

I'd like to see a fore-end deflection tool manufactured and marketed. When you see some of the useless stuff that Sinclairs and others try to foist on shooters, this could be of real value to stock builders.

Alan

I'd like to see a fore-end deflection tool manufactured and marketed.

Alan,

You can do it by clamping a dial indicator to your barrel, and measuring the deflection of the stock.

I'm sure you'd have some mild steel left over from your stock making ventures to make up a clamp, along with some grey spray paint to finish it off

So once you see how much it deflects, then next thing will be to determine what is the range of acceptable deflection of the stock to barrel.

Not sure if this has been tried in Oz. I have an idea someone was using this type of setup at Raton.
I see 2 advantages if it is legal.
1 - Stiffen the forend like a brace or truss.
2 - Help reduce torque

See pic

http://img543.imageshack.us/img543/6420/ml05.jpg

I have heavy tuners on all my 7mm barrels. When researching I came across this link http://www.varmintal.com/aeste.htm

Note the various models magnified during recoil.

Cameron Mc wrote:Not sure if this has been tried in Oz. I have an idea someone was using this type of setup at Raton.
I see 2 advantages if it is legal.
1 - Stiffen the forend like a brace or truss.
2 - Help reduce torque

See pic

http://img543.imageshack.us/img543/6420/ml05.jpg

I did see that setup at Raton Cam. The one I saw was actually a tube gun with a "key" protuding from the bottom, and the front bag was made to match it exactly. It seems to be legal from my knowledge of the front rest rules - there is no resistance when it is lifted vertically, contact is only with the sand bag, and 76mm width is not exceeded. However if the key was made too long, then it may be seen as giving an unfair advantage.

I actually scored for this rifle in the Nationals - Nice guy and quite innovative. However a lot of conjecture was raised and no one protested as all agreed it was 'within' the rules as Alan mentioned. But all also agreed it effectively was the same as a conventional rest wrapping over flat stock on the right (WHICH WOULD BE DEFINED AS CLAMPING AND RIFLE COULD NOT BE LIFTED SO AGAINST THE RULES). It certainly controlled torque extremely well.

For that matter there is no limitation on height of contact with the bag in F open class (There is in F standard) so we could really have a deep vetical "key" of any height. Really the stock could just be a deep rectangle (as per my original thinking with the cf sandwich stock - the vertical surface helps control torque too) thus actually getting away from the low rider all together and going for a high stock but good side support - it certainly works.

Interesting challenge for the rulemakers ahead.

I recall seeing on BR Central that Seb or some enterprising person like him designed a 3" wide butt stock channeled in the centre for a single eared sand bag. While that was to be used for short range benchrest, it apparently gained approval.

Maybe a 7.62mm front & rear fitted bag contact for F class .......?

Didnt Rod Davies experiment with a wide rear rest and butt stock? Pretty sure it was him and he changed back to something more conventional.

I think the problem with the wide rear bag rider is getting enough weight over the rear of the stock to stop bounce, IMO the surface area is just to big in a 10 kg rifle.
Matt P

Kinda off base here but am considering going for a 7mm barrel to complement my 6x47L. How easy is it to add weight to the McM F-Class stock? Recoil is fine for the 6mm but wouldn't mind a tad more weight when I run a 7mm barrel.

Not much room upfront in the f class but I milled out the cheeckpiece and added tungsten powder and resin. That way I could lighten easily by removing cheekpiece and changing barrels to get under the HG benchrest weight. Of course this all messes with the balance so you need to think about that as well (worked kinda nicely with a lighter shorter barrel and taking out rear weight). I sold this setup before really getting to play in that configuration though.