Hi

I was hunting with a friend this past weekend and he used my BSA .30-06 to hunt blesbuck.
We checked the rifles zero on Wednesday at Sahara, before embarking on Saturday morning.
On the farm, I again checked the rifle at the farm's range. When sighted infor my friend, the rifle shoots about an inch left at 100 metres. As my mate was arriving later on Saturday afternnon, I fired two shots andthey were left but touching each otehr so the zero was perfect.
Saturday afternoon he used my .30-06 to shoot a ram at 100m and another at 196m, both heart/lung shots.
The next day another ram was headshot at 120m. the headshot was low but that is why I do not like head shots. No apparent problem with the rifle.
That afternoon he completely missed a ram at 140m aiming at the vitasl area from a standing position over shooting sticks, at 140m. He is a good shot so we were all suprised at this.
On day three things went wrong. Aiming at the heart of a ram at 120m, the shot went through the hindquarter and fortunately broke the animals hips.
This, combined with the previous day's miss lead us all to believe that the cope had lost its zero. I recall that the muzzle of the rifle hit the Land Cruiser's roll bar quite hard when we went through a ditch the previous day. At the time I did not thing that it was hard enough to cause the scope to shift zero.

The farmer's assistant took him to the range to check the rifle and I continued to hunt. He fired two rounds at 50m and the first one was about about five inches low and two inches right.
The second shot was also about five inches low but now four inches to the right The third shot at 50m was the right height but still left. He fired two shots at 100m and one was not on the paper and the other was a couple of inches right.

I plan to take the rifle to a range again sometime and test it further. It seems that the rifle is shifting zero each time that it fires, which leads me to believe that the scope may be faulty.
It is a Bushnell Banner 3-9x40 and is barely three years old. I have checked the bases and rings, and these do not appear to be the problem. The rear base is flush with the bridge and appears to still be flush. All rings were still tight.
The ammo is 165 gr handloads. Each load was electronically measured by myself. I don't think the ammo is at fault.

Could a clang against the rifle's muzzle case teh scope to shift zero? Even if so, surely i would shift and then stay there. Could the clang have damaged the scope which is causing the cross-hairs to move after the recoil of each shot?

I should also mention that there was a bit of rain while we were hunting and the rifle's wood stock may have gotten very slightly damp. Could this cause a problem such as this?

Any suggestions?

Thanks

as long as the rings and bases are tight i would guess that the 2nd plane lens is loose. not at all uncommon in the bushnell cheap scope line

If some of that rain made it into the bore before he fired the last good shot that would explain the shift. If the stock is wood the shift could be the result of the rain as well. The stock screws could be loose.

I would pull the bolt, wipe and examine the bore. Particularly the very end at the muzzle for any sign of damage or bulge. It could be very difficult to see. Could appear, with a good back light, as a shadow or ring.

Mount a different scope and recheck it.

I have had the same problem in the past and it was a bad scope. and yes it was a busnell scope too

quote:

Originally posted by Westpac:
If some of that rain made it into the bore before he fired the last good shot that would explain the shift. If the stock is wood the shift could be the result of the rain as well. The stock screws could be loose.

I would pull the bolt, wipe and examine the bore. Particularly the very end at the muzzle for any sign of damage or bulge. It could be very difficult to see. Could appear, with a good back light, as a shadow or ring.

I will check the guard screws. Good point.

Would the bulge near the muzzle be due to firing with moisture in the bore?

Thanks for the advice!

quote:

Originally posted by umshiniwam:

quote:

Originally posted by Westpac:
If some of that rain made it into the bore before he fired the last good shot that would explain the shift. If the stock is wood the shift could be the result of the rain as well. The stock screws could be loose.

I would pull the bolt, wipe and examine the bore. Particularly the very end at the muzzle for any sign of damage or bulge. It could be very difficult to see. Could appear, with a good back light, as a shadow or ring.

I will check the guard screws. Good point.

Would the bulge near the muzzle be due to firing with moisture in the bore?

Thanks for the advice!

Yes.

Inspect the crown with a magnifying glass to see if it is damaged as well.

I lost a red deer once due to Bushnell Banner scope - the optics had terrible glare from the sunset & I could not see the deer & so I lost the opportunity to shoot the deer.

Now I only have Leupold scopes on my hunting rifles except for a Swarovsky 2.5-10x.

Lifes to shot to hunt with cheep glass.

Leupold Minimum
Ziess if you can afford it

Leupold.

Your scope is not shifting zero. It has no zero.

Something is loose. Either you have some loose screws holding the rifle in the stock or holding the scope to the rifle. If those are all tight, then you most likley have a broken scope.

Life is too short to hunt with broken scopes or scopes that break.

Hi again,

went to the range yesterday to test the rifle, a month after the problem occurred.

At 50 metres:



I have a suspension that damp conditions caused stock warping which led to the erratic performance?

Any moisture in a barrel will spray shots all over. I have shot in the rain alot in competition. Shooting through rain is not a problem, but any moisture in the barrel will make your bullet take off. Yes, moisture could make a poorly sealed and cured wood stock move.
Butch

quote:

Originally posted by butchlambert:
Yes, moisture could make a poorly sealed and cured wood stock move.
Butch

Thank you, I think this is the culprit. The rifle stck has an oil finish. I will need to have it finished off with something which is more impervious to water or moisture. Any suggestions?

I am not a gunsmith - just a gun nut who hunts in wet weather in New Zealand. I would sand the entire stock and just finish it with Tru-oil - diluted 50% with Mineral spirit. Apply one thin coat and allow to DRY FULLY and repeat. The first coat can be rubbed in with a tooth brush into the barrel channel and the action mortise etc. Apply thin coats with your finger tip. Make sure you remove the recoil pad and treat the wood under the pad as well. Similarly the action screw holes & the sling swivel holes. Give a gentle sand with 240 grit sand paper and apply oil again. If you really have the patience you can actually rub in the oil with wet & dry paper. This forms a slurry of wood dust & tru-oil which just fills all the pores and dries hard.

I did my Mannlicher Schoenauer stock like this - took 20 coats for the outside and it looks great too. The inner areas need say 3 to 6 coats. The experts may please correct me on this.



Good luck