257 Roberts issues

[PondPopper]

It sounds like you are describing vertical stringing. Check the barrel channel and make sure it's free floating with plenty of clearance for barrel harmonics, I prefer to use an index card instead of a dollar bill. Try that and check torque on all screws....top to bottom, action, bases, rings etc.

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M77 barrels are not floating.
My M77 .243 is a tack driver. If it wasn't I would be floating the barrel on it as my next move.

[NF HUNTER]

If you haven't checked barrel float you probably need to check it. I had a couple of new guns that shot every where on the target. Until I floated the barrel on them, now they are tack drivers.

[PondPopper]

If you haven't checked barrel float you probably need to check it. I had a couple of new guns that shot every where on the target. Until I floated the barrel on them, now they are tack drivers.

I have a old, but like new, Weatherby 7mag that shot like that.. All over the place.. 4-6 inch groups at 100.. I removed the "factory" pressure point at the fore end of the stock and relieved the barrel channle and walla, It's a sub MOA gun now..

[Low Fence]

I have a old, but like new, Weatherby 7mag that shot like that.. All over the place.. 4-6 inch groups at 100.. I removed the "factory" pressure point at the fore end of the stock and relieved the barrel channle and walla, It's a sub MOA gun now..

I had a m77 that was a 4" at 100 and removed factory pressure point and floated and it became a 7" gun....

[locolobo]

My Savage 111 has never been a "shooter". Cold barrel is always spot on. Second moves a little toward 10:30. 3rd a little more and so on and on. I have narrowed it down to the plastic stock which is free floated according to a dollar bill but the bluing worn off at the end of the stock tells a different story. Stock is so weak and vibrates enough to throw the shots off and gets worse as the barrel heats up. Getting a new stock soon so tune in to the coming thread where I will be asking for input.

[Cottonfish]

We have an older tang-safety M77 in the family that initially refused to shoot anything over 87gr accurately, until it was full-length bedded. Now it handles the shorter 100gr bullets OK, but still will not group anything heavier. It likes Sierra Pro-Hunters, Hornady Spire Points, and tolerates Ballistic Tips in 100gr, all around 2900fps using IMR4350. I would figure the OP's MKII has a better barrel on it, and would respond to handloading with careful attention to seating depth.

Stu