Torque for bedding bolts

[Cumbrian]

1. Am I correct in thinking that 6 foot pounds is the best torque setting for the bolts on a .22 rifle in an aluminium stock? Or could one advantageously go higher?

2. I have read of one experienced shooter that re-torqued his .22 every time before use, otherwise it would not group. Was/is he unusual/unlucky or is it generally good practice to re-torque frequently? I leave my bolts alone for months at a time, but, since I am barely an averagely good shot, the variable results that I achieve could be attributed to many other causes.

[Th.]

Anschutz recomends 6 Nm = +/- 4.4 foot-pound

[Tim S]

1. Am I correct in thinking that 6 foot pounds is the best torque setting for the bolts on a .22 rifle in an aluminium stock? Or could one advantageously go higher?

2. I have read of one experienced shooter that re-torqued his .22 every time before use, otherwise it would not group. Was/is he unusual/unlucky or is it generally good practice to re-torque frequently? I leave my bolts alone for months at a time, but, since I am barely an averagely good shot, the variable results that I achieve could be attributed to many other causes.

Roger,

You're confusing your units.

6ftlb would be rather excessive. Anschutz recommend 6 Newton Metres for their alu stocks, and 5Nm for the 1800/1900 wood stocks with spring washers under the bolts. 6Nm and 5Nm equate to 53 and 44in lb. 6ft lb is 72in lb. I know of some Gemini owners who torque the bolts much tighter than 6Nm, but I'd be leery; Dave Phelps springs to mind, but don't quote me.

I don't think you need to retorque frequently with an alu stock. If you take the barrel out of the stock, then re-torque, but otherwise forget about it for club shooting. In years past, owners of wood stocked rifles often loosened the bolts after shooting, and re-torqued the next time to avoid compressing the wood under constant torque. There is a school of thought that this risks damaging the receiver threads.

That's all moot though, as your Gemini stock is crush-proof, and won't warp in hot or humid weather.

[Cumbrian]

Many thanks to both of you for straightening me out about the units. My torque wrench is calibrated in Nm but away from it I tend to think in rather old fashioned terms. I'll follow your advice, Tim, and not push it beyond 6 Nm.

Roger

[Martin Catley]

Many thanks to both of you for straightening me out about the units. My torque wrench is calibrated in Nm but away from it I tend to think in rather old fashioned terms. I'll follow your advice, Tim, and not push it beyond 6 Nm.

Roger

These numbers seem to be around where most work. I have heard of over torqued bolts stripping the thread in Anschutz 54 actions,

[Modena]

Personally I use 3.5NM

[streetglide]

i use 6Nm and re-torque it every time i go.

[DavZee]

I torque to 6nm using the Anschutz torque wrench before starting a match or practice session.
I loosen before putting my rifle back in the case when I’m done. I have the 1918 aluminum stock.
I’ll take the rifle out of the case and let it get acclimated to the temperature of where ever I’m shooting be it indoors or outdoors. Then I torque.

[40xguy]

The following "in my opinion:" use a beam type torque wrench calibrated in INCH - pounds. Most people I know have a torque setting for bedding screws (for this type rifle) in the neighborhood of 30 to 40 inch pounds (nothing above 40). The torque setting can and will, affect group size. Try different settings, 20, 25, 30, 35, 40 inch pounds, to see what setting gives you the best group size. A friend of mine just experimented with his inexpensive Anschutz benchrest rifle and found that 10 (ten) worked best for him..... never heard of anything that low, but at 50 yards, all the holes are touching each other while using one lot number of mediocre ammo..... can't argue with these results !! Remember: we are talking about one "lot number" of ammo... you can't expect the same results from different ammo lots. One caveat here.... be positive that the bedding screws are not contacting the action !!! Look at the action to see if there are any screw marks from the bedding screws and please, don't ask me how I know this !!!

[Cumbrian]

The following "in my opinion:" use a beam type torque wrench calibrated in INCH - pounds. Most people I know have a torque setting for bedding screws (for this type rifle) in the neighborhood of 30 to 40 inch pounds (nothing above 40). The torque setting can and will, affect group size. Try different settings, 20, 25, 30, 35, 40 inch pounds, to see what setting gives you the best group size. A friend of mine just experimented with his inexpensive Anschutz benchrest rifle and found that 10 (ten) worked best for him..... never heard of anything that low, but at 50 yards, all the holes are touching each other while using one lot number of mediocre ammo..... can't argue with these results !! Remember: we are talking about one "lot number" of ammo... you can't expect the same results from different ammo lots. One caveat here.... be positive that the bedding screws are not contacting the action !!! Look at the action to see if there are any screw marks from the bedding screws and please, don't ask me how I know this !!!

Now that is interesting. Does this apply to aluminum stocks? 40 inch pounds = (approx.) 4.52 Nm, which is appreciably lower than the usual employed for aluminium stocks.

And there is or was a set of test results available online in which a real expert (from Bedford, I think) using increasing pressure, up to 5 Nm if I remember correctly, with a wooden Anschutz stock obtained better and better groups as the pressure increased. The results were quite graphic. From this test I have always inferred that, within reasonable limits, more pressure on the bolts would produce better results, whether the stock was wooden or aluminium. But perhaps that 'ain't necessarily so'.

[Tim S]

Roger,

What you're thinking of was part of the "Brookwood" articles in Target Gun magazine by Chris Fordham, then owner of Bedford Target Supplies. I've got the original, May '95 edition. The targets were shot by a fellow club member at Bedford RC PJ Andrews, with an 1813 and Tenex. If I remember correctly, only the tension on the front bolt was changed; the rear stayed at 5Nm throughout. The uneven tension may have caused the dramatic difference. I wonder what the groups would have been if bolt bolts had been tensioned equally.

I get relaxing the pressure on a wood stock after shooting, but why alu?

[Cumbrian]

Thank you very much, Tim, for the precise reference and details. I hadn't noticed that the bolts were under different pressures. That does rather muddy the waters.

Roger