action screws

4

4runnerman

New member
I believe this has been talked about before. How many here mess with the tension on your action screws?. I read a few articles on it and gave it a try.
I borrowed the inch lb tool from another person. The results were amazing to say the least. Subject-Savage Model 12 FVSS in 308 with Dog Tracker Stock

Before messing with screws i could get 1 inch groups at 300 yards. I then set both screws to 5 inch lbs-5 shot group= 3 inches. set them to 10 inch lbs groups went to almost 4 inches. I kept going up 5 inch lbs at a time. When i got to 20 inch lbs my groups went to 1 inch again. I then went to 25 inch lbs in front and left back at 20. My groups at 300 yards were .623. This was the best i have ever shot at 300 yards. I have loaded 20 more rounds to see if this can be repeated again on Sunday. This is a pillar bedded action only. I was really thinking of getting it bedded,but have also read that bedding the action can sometimes harm accuracy as well. I have heard a lot of people say ( crank it to 50 to 60 inch lbs). As i have read this is a generic setting and does not work for all rifles. I did set it once to 50 inch lbs,but after the first shot,my bolt was very hard to open,Did not do that again.

Just wondering who else has played with the screws too

Thanks
 
Played with screw tension with my 10/22 custom rifle. A few times with Yugo Mausers and Lee Enfields. It does effect poi and group size. Wished I had time to do more with it.
 
On my wood stock bolt guns I usually set the action screw to 30 in.lb. and on synthetic stocks I usually set them to 60 in. lb. I have noticed before that the increase or decrease in tension will change the POI but no noticable change in group size.
 
The owner's manual with my 700 Ti calls for 60 inch-pounds (5 foot-pounds). Synthetic stock. The rifle is reliably sub-MOA.
 
One of the top National High Power Champions did some tests years ago with his wood stocked Winchester 70's clamped in a machine rest. Receivers were epoxy bedded and the barrel was totally free floating. Best accuracy happened when all three stock screws were torqued to 60 inch pounds. This was with the .308 Win. and 30 caliber magnums.

Other top scoring high power competitors using epoxy bedded Remington 7XX actions with the .308 and 30 caliber magnums got best accuracy with 45 inch pounds of torque on the front and rear stock screws with wood stocks. The middle (smaller) one was torqued to 30 inch pounds.

Anschutz smallbore match rifles' instruction manuals say to use 44 inch pounds for wood stocks but most top scoring competitors get best accuracy with somewhere between 20 and 25 inch pounds.

As far as I know, there's no difference between wood and synthetic stocks; use the same torque in each for a given action.

While a given barreled action will vibrate at the same frequency every time it's fired, the direction it starts out at and how much angular movement the bore axis at the muzzle makes is somewhat controlled by how hard the receiver's held in the stock.

Folks using the Optimum Charge Weight or other forms of Ladder Testing for best accuracy with their home made ammo might want to consider the effect stock screw torque has on the results. Most of them probably don't consider this at all. I'm convinced that differences in stock screw torque is just one more reason why there's so darned many "most accurate" loads for a given bullet in a given cartridge.
 
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I have a 7.62 NATO 40X Repeater in a McMillan A5 with a Whidden bedding block installed and the torque on the action screws makes no difference at all! I had heard that accuracy could be affected by this so I went ahead and bought a $100 inch-pounds torque wrench and tested the theory. I went through torque settings in increments of 5 inch-pounds from 40-70 inch-pounds and shot 5 shot groups at each. The groups were consistently 1/2 MOA or better so I did the test again to see if any settings were better than another twice... Nope!

I don't know if it's the bedding block or what.

Any thoughts???
 
My Ruger 77 MkII all-weather used to be in the paddle synthetic stock and they recommended (I believe 60 inch/lbs torque on all three bolts). It was a tackhammer. Also had slight pressure near the end of the forearm. I hated that ugly stock so bought a pre-inletted (drop in?) Boyds laminated stock and it wouldn't group for jack. I finally gave up and had Gander Mountain's gunsmith pillar and glass bed it and free float it. Shoots better then ever but I'll be darned if I'm gonna mess with the torque to see what they put it at. At least until I have to tear it down to clean it. The gunsmith didn't remember what he torqued it to either. By Ruger's recommendation was all he remembered. :)
 
I don't know if it's the bedding block or what.
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Could be, but I wouldn't suspect so. Probably just the rifle is consistent with any torque setting, some are. They're all individual animals, some will shoot damn near anything with the same consistency, others are picky as hell.

I don't see the bedding block as doing anything more than pillars, steel-on-steel contact, with a proper epoxy bedding job accomplishing the same thing.
 
One of the top National High Power Champions did some tests years ago with his wood stocked Winchester 70's clamped in a machine rest. Receivers were epoxy bedded and the barrel was totally free floating. Best accuracy happened when all three stock screws were torqued to 60 inch pounds. This was with the .308 Win. and 30 caliber magnums.

Other top scoring high power competitors using epoxy bedded Remington 7XX actions with the .308 and 30 caliber magnums got best accuracy with 45 inch pounds of torque on the front and rear stock screws with wood stocks. The middle (smaller) one was torqued to 30 inch pounds.
Click to expand...

You sure you didn't get the Win and Rem results backwards? My Remmy 700s only have two action screws, but the Winchester rifles that I've worked on have three, one of which is only "snugged up."

The Remmy rifles with the aluminum bedding blocks (mine are HS Precision) are the only ones that call for 65 in/lbs of torque.
 
I'm curious about this myself. I have never paid any real attention to the action screws. I tighten them in the order specified in the manual but have always just tightened them to what seemed "right". Of course, I've never had a gun that shoots 1/5 MOA at 400 either. On the other hand, my Ruger M77 in 204 shoots 1/3-1/2 MOA all the time at 100 and around 1/2-3/4 at 400 with a cheap Mueller scope and bone stock except for a Jard trigger. I'm not really sure *I* can shoot better than that.

Anyway, I'll be curious about your further testing.
 
eldorendo, all four Rem 700's I've shot had a smaller diameter screw in front of the trigger guard and it went up behind the magazine. That's the third one I'm referring to. 'Course that was some years ago and the newer ones may not have it.
 
Just reviewed a schematic! I stand corrected! Pretty sure that I don't torque the center (small) screw, just snug it up.
 
Well it repeated it self again. 25 inch lbs front and 20 inch lbs rear. Managed to get a few rounds in today before the sky opened up on me. just got a new scope today mounted and sighted in. Had about 15 rounds down barrel before the hail and wind and rain ruined my whole day. I was able to repeat the accuracy of the last time out. I know it is a no-no,but the action screws will be lock-tite in now (blue lock tite,) This is unreal and im not going to mess with it. I have never sahot this good,Thats 2 times out at range in a row now. The 4th shot i pulled on so im throwing that one out. 300 yards here.
 
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