questions about the newer 2 action screw Accustocks
Has anyone noticed a change in accuracy after removing the action from the Accustock? I've googled quite a bit but can't really find a consensus. I thought I'd ask Accustock owners about their first hand experience with this issue. To adjust the Accutrigger, the Accustock needs to be removed. Even a simple trigger cleaning means removing the Accustock. The accuracy issue seems to come from the action screw torque. Assuming they are torqued at 45# at the factory. I read a post somewhere about the retorquing procedure and it seems pretty straight forward. Front screw, rear screw in increments until you reach 45#. I'd really like to lighten my Accutrigger pull but I don't want to do it and find that the rifle doesn't shoot as well after putting the Accustock back on. Comments welcome.
AccuStock torque settings test (tuning)
Hey, guys, this is exactly what I was playing with last Saturday :-)
Sorry for the post length.
TRIGGER:
I've adjusted the trigger as low as possible and there's been no bump/slam-fire yet.
(Just for you guys who are stuck in "should I adjust it or not" as I've been for a while...)
STOCK TORQUE:
Past few days I googled a lot and found two sources of interesting information:
[1] http://www.accurateshooter.com/techn...torque-tuning/
[2] http://forum.snipershide.com/snipers...accustock.html
EQUIPMENT etc:
I have a Savage 10TR (308Win in AccuStock) with 20" barrel and cheap muzzle brake. Factory ammo - Sako 168gr HPBT Sierra RaceHead.
I shot 4-rounds groups adapted to 4-rounds magazines. I let the barrel cool down before shooting another group whenever I couldn't keep my hand on the barrel easily.
Also used mounted harris bipod and sock shooting from prone position on a 100 metres distance.
For particular torque description I used values in lb.ft, set by a (brand new) F.A.T. wrench.
As a "front screw" I mean the screw just in front of the magazine release, as a "back screw" I mean the screw UNDER the bolt release.
I use the format "30/10" meaning front screw torqued to 30lb.ft and back screw torqued to 10lb.ft...
DISCLAIMER:
Let me state that I don't claim this method nor results as the right one ;)
I just tried with my setup - and there was for sure a plenty of room for shooter's error - obviously your mileage can vary.
But enough chatter...
First, I tried something similar to the
METHOD [1]:
Beginning with action seated into stock carefully and having the lug "bumped" against the stock a little, both screws were torqued to 10/10. Then I tightened front screw to 30/10.
I tried a few groups with various torque settings of the back screw: 30/10, 30/15, 30/20, 30/25, up to 30/30.
As this was the first (wide) comparison of torque settings effect on accuracy, I tried only 2 groups on each settings. (Eventually 4 groups when I was uncertain about my shooting.)
See the groups below (column on the right excluded, that one belongs to method [2]) ;)
http://imageshack.us/scaled/large/607/q4pw.jpg
http://imageshack.us/scaled/large/4/m2z1.jpg
The second test method I used was alike linked
METHOD [2]:
I loosened both screws, "bumped lug" and started to tighten both screws as equally as possible (in 5lb.ft increments at most).
Unfortunately these are only 3 or 4 groups as I wasn't amazed by the results.
I used "30/30~" format for description and went with 30/30~, 35/35~ and 40/40~ settings.
You can see the results above in the right column.
In the end, I came back to 30/30~ settings which I tested a few more - but I am not sure if the average results (0.6-0.9MOA) weren't caused by my fault (getting dark, having tired eyes and shouldered already 60+ rounds which I am not used to).
You can see the results below:
http://imageshack.us/scaled/large/820/fz9c.jpg
CONCLUSION?
IMHO it DOES matter in case you're trying to achieve best possible accuracy. (Almost all groups under 1MOA anyway - does it matter for you might be the question.)
I'll try to find my sweet spot between 25/25~ and 30/25 which seemed to be the best.
You have to try for yourself with your rig, I suppose different ammo, brake or barrel length could significantly matter.
If I were you, having AccuStock re-assebled after trigger adjustment - I would start with 30/20, 30/25, 30/30 settings.
Hope this helps anyway.
The test was very demanding on shooter's concentration and abilities (and I am no great shooter at all).
Feel free to comment and share your own results! ;)