sudden accuracy Problems

[Bernedti]

Hey Guys

In austria are no more guys left to help me, so maybe you can help me

So i buid a rifle early this year, based on a Tikka T3 Supervarmint in 7mm-08rem

I rebarreld it with a 26 Inch .260rem 1-8 twist (barrel blank from Lothar walther)

So the first groups were pretty bad at all but i thought it would possibly be a bad load (groupsize ~2 Inches at 100meters), but it functions so i gave it to the, in austria, recommended check of the I say department of Weapon and Arms (don't know how to translate this better)

So when i get it back i saw that the forend of the original stock touches the barrel a litte bit, so i grinded some material of to freefloat the barrel

Next Time i went shoot the groups were perfect, ~1/5 Inch at 100m and at 1000m i shot a 8 Inch group

the Gun functions perfect but i really wasn't satisfied of the stock at all, so i screwed the Action out of the stock to measure und draw a alloy Stock for it

Needed some time for this bit after one month i scewed it back into the original stock, because my buddy isn't in the shop yet to mill the alloy stock

So this weekend i went shoot with it again to test out 139 grain Lapua Scenars, but the Gun shoots like crap

I tested 4 different powders, with each powder 4 loads but i wasn't able to shoot groups under 2 inches

Even the old Load shoots horribly

Some times 2 or 3 shots in one hole and the rest an inch away

I tighten down the action screws correctly, the mount screws were tight, the barrel was clean, i switched from Kahles to Steiner scope

So i exclude quiet every error i could find
It cant be:
The camber
barrel
trigger
muzzle break
optics
mounting
load

So my last thought is: could it be that these crappy goups are a result of the wobbly foreend of the Stock?

I mean the since i Grinded some of the forend isn't really stiff any more

But if it is so the first groups must be pure luck?!

I'm at the end of my knowledge yet, and i really have not the desire to waste more of my Lapua bullets

 

[Hopkins]

In my limited experience, a flexible forearm in combination with a bipod mounted on it is a compounded accuracy killer.

 

[wwbrown]

Is the action bedded, I ask because of the extreme difference in accuracy when you took it out of the stock and put it back in even if torqued the same. Then there is also the potential issue of changes in temperature and humidity causing the stock to shift, this could be worse if the action is not bedded.

Hope This Helps!

 

[Terry_M]

Are your action screws binding on the stock and allowing the action to move even though torqued down? Have you looked at the action out of the stock since firing to see if there are ant different marks on it, that were not there when you took it out to measure it for the stock you're building?

 

[ebb]

Sounds like a bedding problem to me. Put dial indicator on action, loosen action bolts one at a time if indicator shows movement, bedding is at fault,

 

[Dusty Stevens]

Only common denominator is the stock removal.

 

[Tozguy]

My take is your Tikka synthetic stock is just too flexible in the fore end for a bipod. After putting a Robertson JTR stock on my super varmint I got much better groups. This is shooting from a rest, not bipod.

 

[GunnerJacky]

My friend owned Tikka and he was troubling with inaccuracy problems. There's always logical reason why a rifle shoots poorly. Once that is identified, you can enjoy your gun shooting. My friend adjusted the torque scope and rings with the proper torque settings and he found significant improvement with the accuracy.

 

[hogpatrol]

Carbon ring problem maybe? If you can get access to a borescope, see if that may be it. May just need a good thorough cleaning.