Please school me, I am in need of advise. Poor grouping.

156821

156821

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Last fall I went ahead and bought the rifle I have always wanted. It is a Weatherby Mark V deluxe in 7mm Weatherby and I have not been able to get consistent groups out of it from day 1. The picture above is typical of what it does at 100 yards. I have been through 3 kinds of powder with various weights of IMR 7977, H4831, and Reloader 22, and about 5 different bullet makes and weights including 140gr, 150, 160, 162 and 175grn. I have also moved the seating depth in and out without much of a difference. After all this I even changed the scope out with no results. My other rifles will shoot 1" and don't seem to suffer from whatever is causing this. All the screws are tight and I am about out of ideas as to what to do next. Any help or ideas you have would be great. Thanks in advance.
 
flinching

flinching.jpg
 
Give us your load data, starting points , bullet brand and type, velocities if possible.Rifle info, barrel length , trigger , bedding, flaoted etc.

I have found that going with a normally good shooting bullet in these cases helps a great deal, a Sierra Game King is a very good choice.

A known consistent powder H1000 maybe H4350.

But, sometimes the combo eludes us , or there is a poor part of the rifle.

Are you doing group tests , ladder or OCW ?

What increments do you increase in? I have seen groups where one charge is beautiful and .3 of a grain on either side is all crap.Sometimes these rifles are finicky.
 
I would two things.

First chuck the bucks for a box of Weatherby factory ammo (It's all loaded by Norma in Norma cases so it's good stuff).

Second "clamp the rifle" at the range so that you take out any/all operator error and see what the rifle is capable of.

If, in the clamp, shooting factory ammo if the results are as you posted, and the rifle was bought new, then contact Weatherby.

If the results change, you know that the "rifle" isn't the issue which leaves the shooter OR the loads you have been trying.
 
I bought it used. I will look into copper in the barrel, I never thought of that. I don't know if it came bedded from the factory, It has a small amount of green epoxy material of some sort in the bottom of the stock. I take it that would probably be the bedding?
 
Well for example I used Hornady 162 gr SST, IMR7977 starting at 69 gr and went up to 76gr in 1 grn incraments. I dont have a chrono but the best groups seem to be at 70gr. I will try adjusting up and down by .3 and see in there is any difference. I will also clamp it down and see if there is a difference with factory ammo. Thanks for your help I appreciate it.
 
156821 said:
Last fall I went ahead and bought the rifle I have always wanted. It is a Weatherby Mark V deluxe in 7mm Weatherby and I have not been able to get consistent groups out of it from day 1. The picture above is typical of what it does at 100 yards. I have been through 3 kinds of powder with various weights of IMR 7977, H4831, and Reloader 22, and about 5 different bullet makes and weights including 140gr, 150, 160, 162 and 175grn. I have also moved the seating depth in and out without much of a difference. After all this I even changed the scope out with no results. My other rifles will shoot 1" and don't seem to suffer from whatever is causing this. All the screws are tight and I am about out of ideas as to what to do next. Any help or ideas you have would be great. Thanks in advance.
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Sell the Weatherby and buy a Sako... Kidding !

A Weatherby Mark V is a really good/beautifull rifle, it should group much better than this, these are sub-moa rifles.

Copper fouling sure don't help accuracy but I doubt its the only problem here.
Results are really bad, to the point any Vanguard S2 with factory ammo will humiliate this Mark V.

Do you know the rounds count ? Weatherby's calibers are barrel burners.

At this point, I would do what Galamb told you : clean the barrel and find a box of factory ammo to test the rifle with a nice steady setup on a solid shooting table.
 
I dont know the round count for sure as I bought it used but I was told it only had a box or two through it. I have put about 200 through it myself since. I will be back with an update once I can get something to clamp her down.
 
156821 said:
I dont know the round count for sure as I bought it used but I was told it only had a box or two through it. I have put about 200 through it myself since. I will be back with an update once I can get something to clamp her down.
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2-300 rounds is not enough to burn a barrel whatever is the caliber.
 


Well I finally manged to get out to the range this morning. I took a box of 175gr factory ammo out and wouldnt you know it, things smartened up pretty good. I also torqued the bolts holding the action to the stock to what was specified on Weatherbys site as they were done up about 15lbs tighter than what they were supposed to be, and cleaned the hell outta that barrel with a copper solvent.
So now I know things are on par with the rifle Im going to spend some time going over my reloading processes and try to figure out if I am dropping the ball somewhere along the way. At least I have something to compare to now. Thank you to those of you with constructive input, I appreciate the help.
 
Maybe shed some light on your reloading process and what equipment you're using. The more detail you provide the easier it'll be to trouble shoot.
 
Check the obvious first. Are base screws, ring screws and mounting screw tight and torqued to spec. Is scope functional. Since it is a used rifle, take nothing for granted. Do all the checks that you would do with a new rifle. Once that is done, as was suggested, see how it shoots factory after cleaning. Some rifles just don't shoot reloads well. (I have a Ruger 7/08 that shoots factory like a champ but reloads-not so much)
 
haffordite2 said:
Check the obvious first. Are base screws, ring screws and mounting screw tight and torqued to spec. Is scope functional. Since it is a used rifle, take nothing for granted. Do all the checks that you would do with a new rifle. Once that is done, as was suggested, see how it shoots factory after cleaning. Some rifles just don't shoot reloads well. (I have a Ruger 7/08 that shoots factory like a champ but reloads-not so much)
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If that is the case, then there is something wrong with your reloading process. Properly loaded hand loads will always shoot better than factory.
 
If you're in PG there should be some good guys around you might be able to get help from in person...Todbartel, 1899, H4831, and Eagleeye are all in that neck of the woods I think.

Second it looks a bit like double grouping, which I have been told is bedding(based on the pic of factory stuff).

Third even with big case capacity 1gr increments might miss a sweet load. I've settled on Mystic Precision's version of the Audette/OCW type ladder, you can read about it on his website. It does save me bullets(may include pulling) and I know I haven't missed an accuracy node. He recommends 0.5gr increments for magnums.

Sometimes we do forget something simple or even critical in the process when loading for a different cartridge.

Persistence will pay off,

Willy
 
I have had success loading the 7mm mag for many years and the go to load with 140 gr Nosler BT and accubonds

IMR 4350 max load from Nosler web site
good luck
 
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