Savage 12 help needed

[toejamm]

I was helping an elderly friend from the gun club recently, who purchased a Savage 12 in 22-250. It is a varmint model with the heavy, ss, fluted barrel.

Here is the problem:
- Bore sighting (Looking down the barrel with the bolt out) the bore is on the target at 50 yards.
- Scope was put on target as well (We tried the Nikon Prostaff and Leupold VX-3)
- The bullet lands 12" right and 6" high
- Why?

Here is the kicker:
- The gun holds 1MOA at 100 yards, so it IS ACCURATE

The barrel crown and bore look fine.

Anyone have an idea on how this happens?

 

[farmerboy78]

When looking through the bore, you have to align the barrel like peep sights. Get the muzzle in the center of the chamber, and then center the target accordingly. Also check to make sure everything is good and snug.

 

[toejamm]

Farmerboy78,
The bore was aligned and the target was centered in the bore.

The scope was also centered on the target.

I can't count how many rifles I have sighted in using this method.

The problem is, that after aligning the two, the bullet lands 12" right and 6" high @50Y, and 24" wide and 12" high at 100Y.
AND the groups are 1MOA or less.

I can't figure out how that happens.

 

[rbernie]

I dunno that it's a problem - I've seen a significant difference between bore sighting and actual sighting a LOT. I've always considered this difference between a bore sight and downrange performance to be due to barrel harmonics - the barrel flexes as the bullet is travelling down the bore, and the bullet actually winds up going wherever the barrel is pointing as the bullet exits the muzzle.

https://www.youtube.com/watch?v=D33g-BsIF1s

This is why shorter and/or thicker barrels are generally more accurate than longer and/or skinnier barrels - they vibrate faster but through a smaller range of motion.

 

[Poper]

rbernie:
OP states it is a ss varmint configuration so should be relatively stiff.

I had a Savage M12BVSS in .243 Win. with a 25" barrel that would regularly shoot varmint weight bullets less than 1/4" at 100 yards. (Wish I still had it.) It, too, would be "off" with a "look through" bore sight. Use a laser bore sighter and it would be much closer but still significantly off. Can't give a rational explanation, but it may be a combination of barrel harmonics coupled with the longer barrel.

Who knows? Rifles are very distinct individuals.

 

[Sniper66]

I have eye-balled numerous scopes and most are off a bit...not usually a foot, but some.. You probably sneezed at some point in the process. So you got it zeroed?

 

[toejamm]

Thanks for the input so far guys.
To be clear, it is a heavy bull barrel (24" I would guess), with very shallow flutes. All factory.

I am not a gunsmith or engineer, but I do understand barrel harmonics. It is hard for me to wrap my head around how it could be off SO far (12" right and 6" high) at 50 yards.

The doggone thing shoots 1" at 100 yards though, and tighter at 50. Three different shooters had it shooting that 1MOA, myself included.

If the groups were erratic, I could understand the harmonic-hic-up, but I don't know....

I told my buddy, "So what if your target and the scope faces north and your barrel faces west. The bullet lands in the cross hairs @ 1MOA. It's all good!" He wasn't amused.

Any other ideas?