Sudden loss in Groups

[6.5 forever]

I can't recall ever switching to a new lot of powder and not having to make some tweaks on the powder - as velocity can vary 50 fps+. On a good load, that 50 fps won't usually open a group up that much - so I'm with many of the others in looking at the bullets primarily. A chrono will tell you a lot.

I'm dealing with a big swing in powder lot speeds right now. And I agree. That should not cause that big of a drop off in accuracy. Must be something with bullet and it is a Berger. Might be a easy solve with seating depth change.

 

[Park ranger]

As Hornady would say, your groups are too small.

 

[fkimble@charter.net]

new box of bullets and new tin of powder

This is where I would start. After rechecking all the screws and bolts.

Frank

 

[moe africa]

To reply to all in this post
The load was 43gr of N150 with 168 ELDM
I shot 15 x 5 shot groups running different depths and charges could not get rid of the errant shots

I tested some 175gr lapua scenars today and got better results but nothing amazing, there is 1 consistent shot out of the group
I will look at getting the rifle bedded
Below is the 175gr scenars from 42.5 to 44.5gr
(Pic with Key )
The rest are the ELDM
There is one group of 168gr berger vlds for confirmation

 

[Big Mc]

Good Day All
I recently got a new bbl on my tikka 308 and it shot amazing
I had 3 shots groups over 1gr which were all on average 0.3"

My hornady ELD Match load shot about 0.4" for 5 shots
This last week I took the rifle out to zero and loaded from a new box of bullets and new tin of powder
And my groups opened up to 1 moa
I've checked all torque settings
Rifle is not bedded, yet it shot well before bedding as well
Any suggestions?

Clean it Tommy Mc

 

[Kazman1960]

Good Day All
I recently got a new bbl on my tikka 308 and it shot amazing
I had 3 shots groups over 1gr which were all on average 0.3"

My hornady ELD Match load shot about 0.4" for 5 shots
This last week I took the rifle out to zero and loaded from a new box of bullets and new tin of powder
And my groups opened up to 1 moa
I've checked all torque settings
Rifle is not bedded, yet it shot well before bedding as well
Any suggestions?

Just a question . Which model Tikka is it and what barrel did you swap to ? Just asking as i have an original T3 Tactical , big heavy barrel with factory brake . I,ve had it for approx 12 years and must have put over 2,000 rnds through it . It shoots amazing with the load and bullet selection i use . I do however notice impact shift when i go to a new tub of powder . Groups are still ok but just a shift in poi.

 

[L.Sherm]

will look at getting the rifle bedded

Untill all mechanical are taken care of no since in wasting time, powder, bullets, primers etc.