Action screws loosening while shooting

[Kroberts]

I'm having an issue with the action screws of my rifle loosening. The rifle is a savage short action with a laminate stock with steel pillars and is bedded up to the sling stuf to take some stress off the action, the barrel is a 32" #8 contour pac-nor in 284win. I had the screws torqued to 55" pounds. I noticed they had loosened when I was playing at 1000 yards and noticed a 2 Moa poi shift, so I figured I would torqu down the screws a little and see if that would help. I was going to bump it up 5 pounds but the screws turned about 1/4 turn before started to get back to original torque. I tested this the next day by torquing then down then firing two groups then torquing then again, and the screws moved a little before the wrench clicked. I'm thinking it might be some residual wax on te screws from when I bedded the stock so I cleaned them with alcohol. Here in a few minutes I'm going to see if that helped. I'm hoping that the screws slacking off is the reason for the less than acceptable groups I've been getting with the new barrel.

All advice on their issue is appreciated. I'm hoping that cleaning the screws and torquing then down to 65" pounds will fix the problem.

Thanks
Kyle

 

[dig]

I have one Remy that tends to back out the back bolt, odd. A little bit of blue lock time handled it. Sometimes vibrations are hard to figure out.

 

[Dosh]

K, did you use Locktite?

 

[dig]

Yes, lock tite. Stupid Apple spell checks got that.

 

[Kroberts]

I'm thinking about using locktite myself. Do you seem to have any issues using it on the action screws? After an alcohol scrub the screws held better. But still loosened a little after 15 shots. But the good news is that switching powder shrunk the groupings in half. With 7828 the groups were larger than I wanted with the best being about 1 Moa, though it had great velocity and potential for good speed spread. The 4831 held every powder charge within 1moa with the best being under 1/2 Moa. I just did a quick speed check and it looks like it will be about 50-75 fps slower.

Kyle

 

[gohring3006]

I use blue lock tite and a small correct fitting washer. It doesn't necessarily have to be a lock washer, though that would work, just a good washer, it evens out the surface area and grips both the screw and pillar. Any high vibration ares usually has a washer on it bolts and screws.

 

[dragman]

Something is wrong with pillars or bedding. At those kinds of tourqe numbers they shouldn't come loose. Are the screws stopping on something, giving you a false positive?

 

[sable tireur]

Kroberts,

Something is wrong with pillars or bedding.

This is correct. Action screws might loosen ever so slightly over an extended period of time with hard use but not such as you are describing. I would be all over the bedding and pillars with magnification and seeing if there even the very tiniest of movement when you put the barreled action in the stock. Check side-to-side as well as front-to-back and diagonally. Capture the stock in a padded vise so you can use both hands to check the barreled action movement. Go slow and look for minute movement around the recoil lug also. Check for pieces of dirt or tiny chips of bedding compound.

Regards.

 

[WildRose]

I'd put some black magic marker on the end of the screw, torque them down, then remove them to see if they are bottoming out. If they are the ink will be scratched or scraped off.

 

[Kroberts]

I think I've got the issue fixed.i think it was just wax still on the threads, after cleaning them firing a few shots and retorquing, it's holding fine now. At the same time I think I found a load I'm happy with. About 1/2" at 100 yards with a 5 shot SD of 4 and ES of 12. It's too few of shots to know for sure if it will be consistent across a long string, for a non competition play thing, I'm happy.

Kyle