Skeptical about Action Screw Torquing affecting accuracy

[BODAB]

I have a new Savage Model 12 Varmint with thumbhole stock in Ruger .204. Found the best powder and seating depth I could come up with and the rifle was shooting about .75 groups. Not bad, but not what I expected either. A friend told me about adjusting the action screws and how that could affect accuracy. Nothing to lose here so I tried it today. Set front action screw to 35 inch pounds. Started back action screw at 20 inch pounds and shot three shot groups adjusting the torque on the back screw each series by 5 inch pounds. Was prepared to go to 40 inch pounds. The attached targets show the patterns for each action screw setting.20 inch pounds grouped at .750. 25 inch pounds grouped at 1.385. 30 inch pounds grouped at 1.201 and 35 inch pounds grouped at .202. All were three shot groups. I am now a believer that playing around with the action screws on these Savages can take you from acceptable to excellent

[IMG]<a href="http://s1267.photobucket.com/user/EdBrodt/media/DSC_2521_zps0v6do65r.jpg.html" target="_blank"><img src="http://i1267.photobucket.com/albums/jj556/EdBrodt/DSC_2521_zps0v6do65r.jpg" border="0" alt=" photo DSC_2521_zps0v6do65r.jpg"/></a>[/IMG]

[IMG]<a href="http://s1267.photobucket.com/user/EdBrodt/media/DSC_2520_zpshpw9lx5r.jpg.html" target="_blank"><img src="http://i1267.photobucket.com/albums/jj556/EdBrodt/DSC_2520_zpshpw9lx5r.jpg" border="0" alt=" photo DSC_2520_zpshpw9lx5r.jpg"/></a>[/IMG]

[IMG]<a href="http://s1267.photobucket.com/user/EdBrodt/media/DSC_2519_zpsay4e88gp.jpg.html" target="_blank"><img src="http://i1267.photobucket.com/albums/jj556/EdBrodt/DSC_2519_zpsay4e88gp.jpg" border="0" alt=" photo DSC_2519_zpsay4e88gp.jpg"/></a>[/IMG]

[GaCop]

I guess I need to invest in a torque wrench!

[Steve Cox]

Not sure which brand stock your thumbhole is, but I just went through this recently on my Model 16, and everything I found including the instructions on my Hogue stock say 55-65 in/lb on the front and rear action screw and 15 in/lb on the rear trigger guard screw. I also wound up using blue Loctite on the action screws, and the scope rails and rings (except the ring to rail clamp screw). Really tightened up my groups; and the addition of the Hogue stock did away with the 5th round stray I kept getting at the range.

edit - Here's the torque wrench I use - https://www.basspro.com/shop/en/whee...crewdriver+Set

[Texas10]

I start lower on the back screw torque, 10 in lbs for starters, and work up. Once I have a determined the best torque, I use a sharpie to mark the head of the rear action screw as a quick check in case it's loosened. I also keep a torque wrench in my bag.

Also, check around the rear tang for at least .005 clearance and remove stock material as necessary. I use a .005 "feeler gage". If it's hitting on one side, loosen your action screws and try to center the action in the stock. If it's been bedded, this step might prove useless, but sometimes it does work.

[mnbogboy2]

BODAB,
Did you check your factory torques before you started your test?
Just finished tuning a load for a friend, his model 116 accustock was less than 20 in/lbs on the rear screw and only 30 or 35 on the front screw. Groups dropped from 1 1/2" to just a tad over 1/2" by tightening to 60F 55R. All my after market B&Cs are torqued to 65/65 and my Boyds and Sav wood stocks are 60/50. Your groups seem to have tightened up considerably at your highest torque. The more a stock flexes the more likely the screws will loosen. My guess is your groups and torque will stay more consistent with more torque than you are using now.
The action screws will easily survive 65 in/lbs and as long as they are pillared maybe you should try to tighten even more than you already have. A wood stock however without pillars and bedding might distort or even crack using the higher torque values. And of coarse with lighter torques a wood stock most likely will not stay consistent.
All my rifles are hunting rifles so I don't want them to change or "loosen" in the field. For that reason I can't imagine running the lower torque values that some of you do. But what works for some is always not the best for others.
Let us know if you run more tests.
Randy

[SageRat Shooter]

I have a Pillared Boyds Pro Varmint... I have my action screws torqued to 60 inch pounds on both screws... 1/4 MOA shooter... Chambered in 260 Rem.

Also the same with my 22-250 in a Boyds Prairie Hunter... It will print 5 shot groups that I can cover with a nickel @ 100 yards.

[tobnpr]

Action screw torque is a bigger factor in rifles that don't have the recoil lug correctly bedded and lack pillars- but even in those circumstances it can make a difference, but not as dramatic. With a professional quality, stress-free pillar bedding job screw torque has much less impact on accuracy.

On an action that isn't in solid, even contact with bedding or chassis, torquing action screws will warp the receiver. This is easily observed with indicators on the action as screws are loosened/tightened. Natch, that's going to require finding the "sweet spot".

IMO, this article explains it well:

http://bisonballistics.com/articles/...bedding-issues

[Nor Cal Mikie]

"It will print 5 shot groups that I can cover with a nickel @ 100 yards."
I'll go even one better. Pillar bedded or mounted in a Whidden V Block, as all of my rigs are, my 5 shot groups @ 100 yards can be covered with a dime. And I don't bother to torque the action screws. And, I'am not about to start messing with a good thing.

[SageRat Shooter]

"It will print 5 shot groups that I can cover with a nickel @ 100 yards."
I'll go even one better. Pillar bedded or mounted in a Whidden V Block, as all of my rigs are, my 5 shot groups @ 100 yards can be covered with a dime. And I don't bother to torque the action screws. And, I'am not about to start messing with a good thing.

Nice... I wouldn't mess with that either... If it ain't broke.... don't fix it....