Why is this off?

[wooltie]

Any idea why the first shot from a cold, fouled bore would be off target 3-5", but the next 9-10 shots are moa or better?

I mean, aside from shooter error.

[bobcat]

No, that seems excessive, unless the bore had been oiled.

[Crunchy]

How tight is the rest of the group.  We talking 100 yards or further?

[wooltie]

1" and less at 100 yards, 9 shots. Half the shots are touching each other. I plan to shoot a few more times to see if the cold bore shot is just a fluke.

I'm new to reloading and finally found a load that groups well, this cold bore issue is just weird.

[Bob33]

1" and less at 100 yards, 9 shots. Half the shots are touching each other. I plan to shoot a few more times to see if the cold bore shot is just a fluke.

I'm new to reloading and finally found a load that groups well, this cold bore issue is just weird.

It's not at all uncommon for a cold bore to shoot to a slightly different point of impact, but a change of 3 inches is excessive.

[jasnt]

Ime it’s more often cold shooter than cold bore

[Hemlock]

What rifle are you shooting?

[RadSav]

Is it a wood stock?  I've had wood stock guns actually push the lug off the bedding with the expand and contract while they sit cold.  Takes a shot or two to get the lug seated again.  Usually an easy fix with some relief behind the tang and some good torque on the lug bolt.  Though I have never had one to the extreme you are talking.  3-5" is a bit crazy with a fouled barrel.

Will be following this in hopes to learn something new.

[fishngamereaper]

IS it 3 or 5.    3" is possible on some guns for cold bore. 5" is pretty extreme. How fouled is the barrel. Copper fouling can wreak havoc on accuracy. If you shoot 10-15 rounds and throw it in the safe for a month, that cold bore is guna be a wild card. AT least pull a bore snake through it after a day at the range.

Of course you could of jerked the heck out the trigger while flinching because of fear of felt recoil...

[Stein]

Did you clean it at all, even run a dry patch through?  In my experience, it has always been clean bore, not cold bore.  As long as every shot sees the same barrel, they hit the same place.  It was hard for me to leave guns "dirty" but after a ton of research and experiments, it's all I do with my hunting rifle.  I never touch it with anything.

I also agree with the above, often your first shot isn't your best in terms of technique.

[BigGoonTuna]

I had an m70 featherweight with a pencil barrel that would always put the first, and sometimes second shot exactly at the point of aim.  It was those subsequent shots that were an issue.  For a hunting rifle, not a huge issue, but was kind of frustrating.  The windage would not change, but it would string shots vertically up and down 2 inches or so.

[wooltie]

Shooting a m70 in 30-06, w/a benchmark barrel. It's seated in a b&c that's not lug bedded, but torqued to spec.

I leave the gun dirty and shoot every week or two.

I shot another load that groups moa, and the cold bore shot poi was where it was supposed to go. So, I think this other load must need some tweaking because the cold bore shot was off, again.

The cold shot was dead center, but 5" high. Next shot was center, 1.5" high. Third shot was moa.  I should have checked the velocity because these rounds had more felt recoil.

The finiky load is 165g ttsx, 49.4g 4064. Seems to take 2-4 shots to start grouping. The other load that groups well cold is 165g sgk.

I might dial down the powder on the ttsx to see if that helps. When I did a powder test, the ttsx and 4064 showed the same group size and location for 4 different, sequential charge weights, so I picked the highest charge.  I played with SD and watched three shot groups go from moa to touching, so I went with that load and have been 'proofing it's since,  but running into this cold bore issue. Kinda important when hunting.

Also shooting resized brass, same brand. Though I did the powder and seating test using resized brass, same brand.

[yakimanoob]

Did you clean it at all, even run a dry patch through?  In my experience, it has always been clean bore, not cold bore.  As long as every shot sees the same barrel, they hit the same place.  It was hard for me to leave guns "dirty" but after a ton of research and experiments, it's all I do with my hunting rifle.  I never touch it with anything.

I also agree with the above, often your first shot isn't your best in terms of technique.

Wait you don't clean your bore....  ever?  My standard process is to clean and oil for long-term storage, then fire a shot or two without caring much about POI, then sight in or confirm.  I try to do this no more than a day or two before opener, and then I don't touch the inside of the barrel for the rest of the season (unless it gets water in it and sits there for a day or two -- then the whole process starts over).  That's worked well enough for me, BUT I'm not a long range shooter so that process my change as my experience level and shooting distance increase. 


Now that that's out of the way....  Ditto to everything said.  Clean bore ≠ cold bore ≠ fouled bore ≠ warm bore.  And ditto to the idea that those differences should never sum to 5" error.  That's a bit crazy.  Do you have a sled to shoot from?

[jasnt]

Starting to sound like a bedding issue to me

[wooltie]

Starting to sound like a bedding issue to me

Could be. I haven't bedded the rifle, not even the lug. But the barrel is floated of course.

Yeah, this is three times now they the first few shots are way off impact.

I'm going to try again but reduce the charge to see if there are pressure issues causing the higher poi.

Other loads don't behave this way from a cold, fouled bore.