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Problem with groupings after drop.

Posted: March 16th, 2020, 11:52 am
by 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.

Re: Problem with groupings after drop.

Posted: March 16th, 2020, 12:16 pm
by pvreb
I would suspect the scope. Maybe try another one and see what happens.

Re: Problem with groupings after drop.

Posted: March 16th, 2020, 12:50 pm
by Jack Dupp
Agree with above. First check scope and mount screws. Second check the barrel crown for damage.

Re: Problem with groupings after drop.

Posted: March 16th, 2020, 2:11 pm
by 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.

Re: Problem with groupings after drop.

Posted: March 16th, 2020, 3:26 pm
by 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.

Re: Problem with groupings after drop.

Posted: March 17th, 2020, 5:20 pm
by TheJediknight
I agree with re mounting the scope and rings even....

Bring the target in to 25 yards...

Re: Problem with groupings after drop.

Posted: March 30th, 2020, 4:46 pm
by Hullensian
Thanks gents. Everything is tight and within specs. Once all this craziness blows over I’ll send it in to Vortex.

Re: Problem with groupings after drop.

Posted: March 30th, 2020, 5:21 pm
by Kingjoey
Check the crown too, if you dinged it you'll have accuracy issues

Re: Problem with groupings after drop.

Posted: April 2nd, 2020, 5:03 pm
by felixm24
Check the Crown it don't take much

Re: Problem with groupings after drop.

Posted: April 18th, 2020, 2:41 pm
by 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.

Re: Problem with groupings after drop.

Posted: April 18th, 2020, 2:53 pm
by Ballistic Therapy
Elk34 wrote: April 18th, 2020, 2:41 pm 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.

Re: Problem with groupings after drop.

Posted: April 18th, 2020, 3:01 pm
by 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.

Re: Problem with groupings after drop.

Posted: April 22nd, 2020, 10:29 pm
by 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.

Re: Problem with groupings after drop.

Posted: April 23rd, 2020, 7:06 am
by Ballistic Therapy
792mauser wrote: April 22nd, 2020, 10:29 pm 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.

Re: Problem with groupings after drop.

Posted: April 23rd, 2020, 4:01 pm
by shooter444
Ballistic Therapy wrote: April 23rd, 2020, 7:06 am

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!