problems with my 280 26 inch barrel holding zero

[scbowhunter]

ok.where to start. im shooting a black  synthetic stock 280 with a 26 inch barrel.140 gr winchester supreme ballistic silvertip.i bought a BSA catseye scope 4x16 44mm scope.i took off a BSA deerhunter 3x9 50mm scope.the first scope i got was bore sighted by me and later by my local gun store.It wouldnt hold zero left and right would be completely off of a 12inchx 12inch target.So i sent it back.I got a new one the other day same scope 4x16 44mm.i laser boresighted it and got it dial in at 40 yards.about 2inchs low at 40.Then sighted in at 100 yards.after a few rounds and getting the rifle to hit bullseye and maybe a half inch low of bulls isaid thats good enough for me.so i went home and cleaned it.stored in a hard case.now a week later i went to go shoot it.The fist two shots hit 5 and 4 inchs high at 100 yards.so i adjusted for it 10 clicks on a 1/4 moa.next shot hit 2 inches low and one inch left.so i let the barrel cool.by the way im shooting off a bench with a vise and sand bag type rest.after cooling i shot without any more adjustments.the two shots hit 4inchs low 3.25 inches left,next hit 3inches low 3 inches left.frustrated i let it cool off.made no adjustments.next  shot hit 1inch low 2inches right.then the next hit 1 inch low and 1 inch left.I have noticed where the barrell meets the firing pin or stock it feels like it has a little play in it but not much.i am totally confused.havent ever had this much trouble sighting a rifle in.the reason i changed my scope was last year at 80 yards i missed a buck but then hit him at about 150 to 200 yards.but im starting to think its the rifle.i bowhunt more than i rifle hunt.so the past few years i havent really shot alot.now i getting back into it and i feel like im totally lost.

[sphingta]

you changed the scope but what about the mount? doesn't sound like the gun.

[scbowhunter]

no i havent changed the mounts.there the same ones i used on my 3x9 50mm deerhunter BSA.I didnt have a problem with them on that scope.1 inch mounts.

[scbowhunter]

 i really need some input.i have 30 days to return this scope and rifle season will be here oct 11.when i took it to the gun store they told me the mounts look fine and were on correctly.

[trotterlg]

You could check the screws that hold the scope rail to the rifle and see if they are tight and not bottomed out.  These rifles are known for vertical stringing but that does not explain the left right errors.  BSA is not a scope brand that inspires confidence, so it may still be a scope problem.  If you have any other scope to try just to check I would do that.  Larry

[scbowhunter]

i guess i will put my old 3x9 50mm scope back on and see if it will hold zero.im hoping its not the rifle.i guess you get what you pay for.

[Macphoto]

Typically, the cheaper the scope, the smaller the "sweet spot" where the adjustments are predictable.  If the scope is running out of vertical movement, scopes often have trouble holding windage zero.  A sure sign is when you make an adjustment and get a change that is diagonal rather than vertical or horizontal.  If that is the case, finding the optical center of the scope and then shimming to get it close, may be the answer.  That allows you to remain in the sweet spot and make minor adjustments with the dials.

[sphingta]

i didn't mean the rings that hold the scope but the rail that the rings attach to. See it the screws are tight and if they are i would still take the mount off clean underneath it and make sure it looks evenly mounted/milled to the barrel. than if it all looks good remount it and use some blue loctite on the screws

[Ten Ring]

You stated (I have noticed where the barrell meets the firing pin or stock it feels like it has a little play in it but not much.) If you feel movenent when the action is locked you need to check this first.
Jim

[gendoc]

You stated (I have noticed where the barrell meets the firing pin or stock it feels like it has a little play in it but not much.) If you feel movenent when the action is locked you need to check this first.
Jim

roger-that !!! major problem !!!

my 280-AI is finiky after the 2nd shot... barrel heats up quickly.
setup your scope with a cool barrel.  give time for it to cool down between shots
infared scan proved that 60 degrees above my second shot throwed me off 4"
from my third to fourth shot.
 
others here will prolly have a better idea of your problem i'm just guessing