.257 Weatherby - Poor groups

you are in business.

put the bs'r on it and note the location on the grid.

take a shot and the use the bs'r again.

if the grid location hasn't moved you can rule out the scope.

if it has, time for a new scope.

*make sure you take the bs'r out before the shot! I know I likely didn't need to say it, but I recall seeing a picture where a fella forgot
 
BrotherRockeye said:
My old school grid type bore sighter makes it easy to rule out the scope.
Bore sight, shoot, check with bs'r.If the cross hairs have moved on the grid, the scope is jiggled.
I usually smack the scope a few times for good measure when bore sighting initially to see if the reticule moves on the grid.
Do you have or know anyone that has one?

it works great to see if the x ring or ao moves poi too
Click to expand...

I doubt you could see a movement that equates to a 4" change of impact at 100 yards.
 
Well, I think I may have figured it out.

I checked the scope, rings, and base. All tight. Checked torque settings. Pushed, pulled, and twisted the scope. Solid. All good.

Installed the boresighter and took a look through the scope. DEAD center on the boresighter. Exactly where it was when I installed the scope, approx. 50 rounds ago.

Hmm...

Took the gun apart and reinstalled everything as per the manual. Checked stock to receiver torque settings. All good.

Took another look through the scope. No change.....no wait....was that reticle movement I saw on the boresighter grid?

Yes it was. Looks like putting pressure on the bipod is flexing the forend of the stock and putting/relieving pressure on the barrel. The barrel is tight against the stock normally.

How much movement? If I lean into the bipod when prone (I tend to prefer to "load up" the bipod a bit) the reticle moves about 1 grid line.....that equates to 4" at 100 yards. I can even induce a small amount of windage error if I put lateral pressure on the stock.

Is there any way to correct this? Other than shooting off a bag/rest or replacing the stock?
 
10 shot groups????? only shoot 3 shot groups. Mine likes 110 gr accubonds, 70 grains of IMR7828 and fed 215 primers. I would use a front sand bag rest over the bipod to eliminate the possibility of tip pressure changing.
 
Not sure how I could free float the barrel in this case.

I did try it without the bipod attached and there is far less movement of the reticle.

I can't believe there is that much flexibility in the barrel!
 
Of course you can free float it. Unless you meant "I don't want to, because I don't like the way it looks", in which case then learn to accept poor accuracy.

Otherwise, wrap some sandpaper around a socket and hog the barrel channel out. And dab bed the lug while you have it apart.
 
No one has mentioned it yet but 1/4 bores are finicky about bullets and loads, my 257 was disappointing at first but came together with 110 ABs and RL 25 powder, my Bob was the same and only came together with 110 ABs as well, didn't like any other bullets, not even match bullets. After 30 years of playing with the 257 Wby and other 1/4 bores I have learned to expect this initially, but don't give up after 50 rounds there will be a load your rifle likes. I highly recommend you throw away the rest of your Hornady bullets and try the 110 ABs, 115 Parts and 115 BTs.
If you intend to hunt using your bipod then you must fix the forend pressure problem, bedding in a 1/4" steel rod or small alum channel or pipe will take most of the flex out of the stock and then float the barrel. This can be done without changing the appearance if you want to take the time and care to do it.
 
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1899 said:
I doubt you could see a movement that equates to a 4" change of impact at 100 yards.
Click to expand...

Then I doubt you know what I am talking about. Any change is obvious on the grid.

consider a piece of graph paper with cross hairs on it. Would you be able to tell if the cross hairs moved at all?

That is essentially what I'm talking about...each square = 4 inch(according to the bs'r) pretty sure you'd see that.

edit: I see upon further reading that the op discovered his problem...using his bs'r.

I guess HE could see it... :p
 
BrotherRockeye said:
Then I doubt you know what I am talking about. Any change is obvious on the grid.

consider a piece of graph paper with cross hairs on it. Would you be able to tell if the cross hairs moved at all?

That is essentially what I'm talking about...each square = 4 inch(according to the bs'r) pretty sure you'd see that.

edit: I see upon further reading that the op discovered his problem...using his bs'r.

I guess HE could see it... :p
Click to expand...

Yup I guess I was wrong. I figured a 4" change is +/-2" at 100 yards which would be too small of a change.
 
hawk-i said:
Doesn't weatherby guarantee 1 MOA or less on the S2....maybe its time to sent it back for repairs.
Click to expand...
With Premium ammo.
Some would argue that hand loads are not Premium loads.
There might be something more than the a simple loose screw ...
I have never had issues with any of the four Vanguards.
Three S1's and my current S2.
Then again my current fav is the 100grn SP by Wby.
Hope the Groups tighten up for you.
Rob
 
Tikkam65 said:
Just watch how many weatherby have bad groups it's common
Click to expand...

You must be sunray's kid or something.
Vanguards are Howa's and both are very well known for being accurate. Not quite an uber long range 6.5x55 elk slayer, but even when they are chambered for the cauterizing 7mm Rem Mag they shoot very well.
Please stop giving advice to people......
 
A pal of mine had a Weatherby Ultralight in .25/06 that had an incorrectly cut chamber. Groups from that rifle, like yours would exceed 4" at 100 yards, and he was at a loss to explain why, until we examined the fired brass. Turns out the chamber was the problem, and Dave Jennings who was Weatherby's warranty guy at the time, said that Weatherby chamber problems weren't unheard of. If you've looked at everything else, sights, bedding, human error etc, start taking some brass measurements, they will mirror the dimensions of your chamber.

By the way guys, a rifle that shoots 4"+ groups won't suddenly start shooting MOA by tweaking the load. Provided that is, the bullets aren't too long for the rate of twist, or have damaged or poorly formed bases, that will certainly produce flyers, and switching to an appropriate bullet will then fix the problem. Anyone who has ever tried to get bulk military .224 FMJs to shoot, knows all about that. These days a new rifle with good ammo should produce 1.5 MOA at 100 without too much trouble, regardless of the jump to the lands or the consistency of powder charges.
 
The suggestions that I would make is to replace the rifle with a better quality scope (or have it checked) and to use a proper front rest instead of the bipod. Also, when I conduct load development I use only one bullet and six different types of powder with various powder loads. If that doesn't work then I would use a lighter/shorter bullet (100 grain). If that doesn't work it could possibly be the rifle.......a lemon. Good Luck!
 
Something is wrong somewhere...

I suggest making sure you have cleaned all the copper fouling out of the barrel and try a box of factory. Shoot 3 shot groups... also shoot another known accurate rifle to compare conditions.


Every Vanguard Series 2 is guaranteed to shoot SUB-MOA (.99" or less at 100 yards) right out of the box.
 
I'm pretty sure the problem is with the bipod mounting, as I described earlier. Definitely can see a shift on the boresighter when pressure is applied to the bipod - which is in turn flexing the barrel.

I removed the bipod and looked through the boresighter with the rifle resting on a bag closer to the receiver. NO shifting seen on the grid.

Searching online showed the bipod issue as not uncommon, with many upgrading to an aftermarket stock with a better (i.e. stiffer) bedding system such as a B&C or Boyds. There is a fair amount of leverage applied to the forend if you put any forward/rearward pressure on the bipod.

Next time at the range I will test without the bipod. My guess is that the groups improve.
 
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