9.3X57

At the point of substantial land wear, the groove depth will make a difference more noticeably, with accuracy deteriorating quicker than if the groove depth was of bullet diameter.

This is about the only part I was not fully aware of. I understand the rest of what you are saying. In your previous post you spoke of Custom rifles. I was pointing out that to my mind Custom does not come into it as with modern technology there is no reason a company can not build to tighter tolerances than days of old. I used .313 as the largest commonly avaliable .303 projectile I know of is .312. Allow for machining tolerances and the bore still should not be overly tight for a .312 projectile.

I do agree that the grove depth should have minimal to nil effect however I am not aware of any definative study/experiments to prove this.

If the grove depth is greater than the projectile will fill- slug out to- then you will have gas cuting past the projectile in the gaps provided. If this happens and there is any inbalance of this gas or the crown is not spot on then accuraccy will suffer. I would venture that in most cases the projectile will slug out to fill the groves, solids and Barnes types will not.

I just found the - to me- oversize bore to be shoody workmanship in this day and age and Ruger have taken licednce with bore let alone grove depth befor. Yes I do know that you can slug any number of bores on any number of rifles in any given calibre and there will be differences as machining tolerances vary for a number of reasons.

I still think the main or only problem lies, as said, with other areas rather than the grove depth.

Yes the No1 can be finicky but a company still has a responsibility to ensure that a rifle will shoot to some degree. Now if Ruger are happy for their rifles to shoot bigger than 4 inch groups at 100mts off a rest with factory ammo then I feel that they should publis this. Off course they wont. Maybe explains why they do not provide targets shot with that rifle or make gaurantees like a few European makes. If a car staight from the factory will not steer straight it gets fixed.

I hope you are able to get the problems solved, and for your own peace of mind it would be nice if Ruger rebarreled the rifle for you, but will that solve the problems? Maybe, if the barrel is lame in some other way.

Thanks and I hope it gets fixed. I do not necassarily require the barrel to be replaced especialy if the problem lies elsewhere. The rifle may just need the barrel face and action face trued up a tad.

Cheers and thanks for your help and wishes.

Greg