Problem with groupings after drop.

[Hullensian]

Could us some help from the smart guys.

Got a TC 300WM synthetic stock stock gun vortex 30mm picatiny rings mounting a vortex diamondback 4-12x40 scope.

Last hunt I dropped it a couple times scrambling across hillsides. Nothing that felt like a big drop but it seems off now.

Always shot the same ammo and could count on sub 1 inch groups at 100 but even off a bench with a lead sled I can’t seem to get em under three inches now.

So the question is where do I start with the troubleshooting? 

 Thanks all.

 

[pvreb]

I would suspect the scope. Maybe try another one and see what happens.

 

[Jack Dupp]

Agree with above. First check scope and mount screws. Second check the barrel crown for damage.

 

[smithers599]

I would suspect the mounting system.
Phase 1: Check for loose screws.
Phase 2: Remove the scope from the rings/base, and the rings/base from the rifle. Reinstall everything.

 

[Harrier]

Like everyone else said...the scope would be my first suspect.
IIRC the Dimondback line is the bottom tier of Vortex offerings- made in China IIRC, so if it is the scope I'd send it back for replacement if they have the same lifetime warranty as the higher models.

 

[TheJediknight]

I agree with re mounting the scope and rings even....

Bring the target in to 25 yards...

 

[Hullensian]

Thanks gents. Everything is tight and within specs. Once all this craziness blows over I’ll send it in to Vortex.

 

[Kingjoey]

Check the crown too, if you dinged it you'll have accuracy issues

 

[felixm24]

Check the Crown it don't take much

 

[Elk34]

If you really want to find out for a fact. Put your rifle in a vise and shoot a target. I would use a chamber laser to get lined up. Shoot without looking through scope. After look through scope and see how far off it is. Then adjust scope.

 

[Ballistic Therapy]

If you really want to find out for a fact. Put your rifle in a vise and shoot a target. I would use a chamber laser to get lined up. Shoot without looking through scope. After look through scope and see how far off it is. Then adjust scope.

What vise should he use where a 300WM won't move the gun from recoil ?
He would not only need a good vise but a pretty good table to mount it too.

 

[Elk34]

Yes I would make a l shape rifle mig out of a 2x8 that way the but has something to recoil against. We are all red necks here. Maybe not. It can be done and used with other rifles as well.

 

[792mauser]

A shooting buddy has a lead sled and loads it up with 2 35# weights.
Strapped in my Winny Laredo in 300 win mag dont move much at all.

 

[Ballistic Therapy]

A shooting buddy has a lead sled and loads it up with 2 35# weights.
Strapped in my Winny Laredo in 300 win mag dont move much at all.

It doesn't have to move much.
To do what Elk34 is proposing it would have to be almost welded into the vise.
There are vises that are made to hold a high powered rifle solid , but the gun is not in the stock when put in the vise.
The table it is mounted too has to be very solid and heavy or bolted to the floor for this to work also.

 

[shooter444]

It doesn't have to move much.
To do what Elk34 is proposing it would have to be almost welded into the vise.
There are vises that are made to hold a high powered rifle solid , but the gun is not in the stock when put in the vise.
The table it is mounted too has to be very solid and heavy or bolted to the floor for this to work also.

Yup,... I remember talking with a sniper, many years ago, how he would concentrate on slowing his heart beat, and take the shot in-between beats. I'm sure this had to to with VERY LONG DISTANCE shots,... but, it goes to show how little, a movement needs to be, to throw a shot off!

 

[Elk34]

A shooting buddy has a lead sled and loads it up with 2 35# weights.
Strapped in my Winny Laredo in 300 win mag dont move much at all.

It doesn't have to move much.
To do what Elk34 is proposing it would have to be almost welded into the vise.
There are vises that are made to hold a high powered rifle solid , but the gun is not in the stock when put in the vise.
The table it is mounted too has to be very solid and heavy or bolted to the floor for this to work also.

The concrete tables at Rio Salado would work. I could weld you up a light sled that would hook.to the front of the table and hold your rifle still with no problem

 

[Elk34]

Could us some help from the smart guys.

Got a TC 300WM synthetic stock stock gun vortex 30mm picatiny rings mounting a vortex diamondback 4-12x40 scope.

Last hunt I dropped it a couple times scrambling across hillsides. Nothing that felt like a big drop but it seems off now.

Always shot the same ammo and could count on sub 1 inch groups at 100 but even off a bench with a lead sled I can’t seem to get em under three inches now.

So the question is where do I start with the troubleshooting? 

 Thanks all.

I can build you a rig that will take care of your problems

 

[Delfuego]

If you "dropped it a couple times" there are a bunch of thing that could have happened. I would pull it completely out of the stock and clean it. Make sure there is no rocks or gravel between the barrel and stock. That could cause big issue. verify the crown. Remove, clean and re-torque the scope base, rings and action screws. Then shoot it again with a few flavors of ammo (if you dont reload). If it's still squirrely, try a different scope. Still not better, send it to Thompson.

You could also take it to a reputable rifle smith locally and have it looked over and tested. Probably cheaper and a much better option than building some cockamamie vice like suggested above. A quick peak from a trained set of eyes (and maybe a bore scope), could give you much better info than an untested contraption recommended by somebody on the internet.

 

[redj]

I would have to agree with the above comment.
If someone say's you need a vise like that to sight in a rifle , I would say you need to ask someone else.
Then again it would be kind of humorous to see what kind of a contraption he comes up with.

 

[Markhpb01]

I’m certain that you would have checked all the bolts already to make sure everything is snug and tight. If that is indeed the case I would try a different scope. When I was 10 years old I dropped my hunting rifle through a cattleguard and it actually broke the reticle loose inside the scope.