I have a Blaser r93 with .243 and .308 barrels, I have one jet-z mod in 30cal that is proofed for both barrels, it is shooting very well with the .243, but am unable to adjust my cross hairs enough to get a zero with the 308, with out the mod the 308 shoots fine and I can easily get a zero. The bullets are 150g SP, when I scale down to 120g BT I have just enough movement on the cross hairs to get a zero. Would welcome any advise as I want to shoot bullets at around the 150g, and I do not want to buy another scope and mounts due to cost, currently have a Swazoski 8x56. Hope some one can help.
Help! 308 will not zero with mod.
- Thread starter jon15
- Start date
csl
Administrator
24", that does seem a lot. 
To put it into perspective, my .30-06 moves about two inches right, two inches up.
Presumably you don't get the same shift with the .243 barrel?
If it was the mod interfering with the bullet then it wouldn't group at all, so whatever is happening is happening semi-consistently and only with one barrel
Could it be the weight of the mod is causing contact between the .308 barrel and the stock? Is the outer barrel profile different between the two barrels? Either that, or the threading/moderator to barrel interface like Bobt says?
Not really my area of expertise to be honest!
Alex
To put it into perspective, my .30-06 moves about two inches right, two inches up.
Presumably you don't get the same shift with the .243 barrel?
If it was the mod interfering with the bullet then it wouldn't group at all, so whatever is happening is happening semi-consistently and only with one barrel
Could it be the weight of the mod is causing contact between the .308 barrel and the stock? Is the outer barrel profile different between the two barrels? Either that, or the threading/moderator to barrel interface like Bobt says?
Not really my area of expertise to be honest!
Alex
2 ft at hundred yards! wow. I would say, do not fire another shot with the mod on your 308 barrel.
Get it checked out that there is no mechanical fault.
2ft is more than a stock touching and more than a mod should or possibly can do because of its weight.
Sounds more like a crooked mounted mod or a loose barrel. If it is not scope mount related.
edi
Get it checked out that there is no mechanical fault.
2ft is more than a stock touching and more than a mod should or possibly can do because of its weight.
Sounds more like a crooked mounted mod or a loose barrel. If it is not scope mount related.
edi
Its either an issue with the mount to that specific barrel or the screwcut, the mounts have 12MOA elevation as standard (a litttle known fact) but that still doesnt equal your drop and it would be high instead of low!!!!!
I would say there is clipping due to the screwcut being not alligned or poor machining of the mount recesses.
Two questions: is the .308 barrel factory threaded & you say 120gn BT, im unaware of anybody that makes a 120gn BT in 30Cal?
Either way do not use it any more untill investigated by a riflesmith.
I would say there is clipping due to the screwcut being not alligned or poor machining of the mount recesses.
Two questions: is the .308 barrel factory threaded & you say 120gn BT, im unaware of anybody that makes a 120gn BT in 30Cal?
Either way do not use it any more untill investigated by a riflesmith.
hunter gatherer
Member
Hello,
Swarovski had a problem with some reticals on moderated rifles due to the different recoil harmonics and they changed the glass retical to a different material but I doubt that you would maintain a group and don't know which scopes were affected.
Check action screws.
How tight are you fitting the moderator but 24in is serious cause for concern.
AL
Swarovski had a problem with some reticals on moderated rifles due to the different recoil harmonics and they changed the glass retical to a different material but I doubt that you would maintain a group and don't know which scopes were affected.
Check action screws.
How tight are you fitting the moderator but 24in is serious cause for concern.
AL
Offroad Gary
Well-Known Member
i think more than 4" impact change is highly irregular and totally unacceptable, jackson rifles may be able to advise what is acceptable/normal. cant offer any more than that, but a good riflesmith may!
i run 2 fully assembled blasers and i have another barrell, scope, mount and mod awaiting collection, i would definately advise another scope and mounts for your 2 calibres(its ok to share mod if its working ok), you have one of the most accurate and consistent hunting rifles available - why frustrate yourself by ****ing around changing the scope between barrells and re-zeroing every time. the blaser saddle mount will go off and on its zeroed barrell without loosing zero, but i'm sure they never intended people to swap scopes between calibres - its just a ballache that you dont need - and even high end scopes cannot be trusted not to miss a click. a friend has 3 barrells and 2 scopes/mounts and his intention was to keep 1 setup and swap the other scope between 2 calibres - there are 50 clicks difference between the two, its just too much of a difference.
in my humble opinion of course!
i run 2 fully assembled blasers and i have another barrell, scope, mount and mod awaiting collection, i would definately advise another scope and mounts for your 2 calibres(its ok to share mod if its working ok), you have one of the most accurate and consistent hunting rifles available - why frustrate yourself by ****ing around changing the scope between barrells and re-zeroing every time. the blaser saddle mount will go off and on its zeroed barrell without loosing zero, but i'm sure they never intended people to swap scopes between calibres - its just a ballache that you dont need - and even high end scopes cannot be trusted not to miss a click. a friend has 3 barrells and 2 scopes/mounts and his intention was to keep 1 setup and swap the other scope between 2 calibres - there are 50 clicks difference between the two, its just too much of a difference.
in my humble opinion of course!
Many thanks for all of your views, it was screw cut for me by a reputable rifle man, i have not gone back to him yet as i thought it might be me or something very simple, it is cut 1:14. The two barrels are different styles, the 243 is a standard type the 308 is a fluted barrel. The rifle has been proofed, would they not have picked up a bullet catching the moderator in the proof house?
Moonraker68
Well-Known Member
I had a similar problem recently, which was down to bad screw cutting and wasn't picked up at the Proof House. Several members on here recommended Steve Kershaw as the man to sort the problem out, which he did in less than 48 hours...including collection and delivery.
Moonraker68
Well-Known Member
Have a word with Steve Kershaw (www.stevekershawfirearms.co.uk) and he'll be able to give you an idea. I'd also ask him to call you with a diagnosis once he's seen the gun, so that you can try and get your dealer to pick up the bill if it is down to poor workmanship.
Take your gear in to a professional rifle smith and take your cheque book too. Good luck.
I've seen this before, it is probably not the threading not cut right, but probably the shoulder of the screw cutting uneaven, even if it is out by a couple of thou' of an inch, but the time the bullet passes to the mod muzzle, it will be enough to clip something. Like they have said - a bright spot on the mod muzzle will indicate a bullet touching.
One thing that will indicate this is when you zero with the mod - the groups will be all over - not consistant - you should never have to shim a mounting system on a Blazer.
If you can group with the mod off with comfortable clicks either way, you problem is from the screw-cut shoulder onwards. Another point to make too, is that recently i helped shoot-in some Heym SR21's, 3-4 shot sub-zero groups with the 150g Feds, but one would not group at all (in fact it just wouldn't shoot a group mod on or off - just as a matter of course, we put some 180gr Geco things through it and it zero'd sub inch. - lesson learnt - even when you told a rifle has a 1:10 twist, now and again they will get it wrong and putting light bullets through (i cant remember which) either a too tighter twist or too open will spit light/heavy bullets all over (5" groups is bad in this case)
Tom
One thing that will indicate this is when you zero with the mod - the groups will be all over - not consistant - you should never have to shim a mounting system on a Blazer.
If you can group with the mod off with comfortable clicks either way, you problem is from the screw-cut shoulder onwards. Another point to make too, is that recently i helped shoot-in some Heym SR21's, 3-4 shot sub-zero groups with the 150g Feds, but one would not group at all (in fact it just wouldn't shoot a group mod on or off - just as a matter of course, we put some 180gr Geco things through it and it zero'd sub inch. - lesson learnt - even when you told a rifle has a 1:10 twist, now and again they will get it wrong and putting light bullets through (i cant remember which) either a too tighter twist or too open will spit light/heavy bullets all over (5" groups is bad in this case)
Tom
Similar threads
