Rifle Changes Favorite Ammo

[the blur]

2 of my rifles, .243 & 7mm-08. Normally they like a specific ammo, 1" groups. at 200 yards.
Next trip to the range, it won't group at all. Same box of ammo, and no group.
Then I go back to the range, and it's grouping again.

Same sandbags, same range, Only thing that changes is the temperature, and wind. And possibly my rifles need to be cleaned more.

Any other possibilities ?

 

[lancetkenyon]

Shooter?
Rifle position?
You mentioned wind. Depending on which bullets, wind can have a big effect on bullet flight and POI, even at 200 yards.
You also mentioned temperature changes. Powder can be temp sensitive. Meaning velocity changes which could be pushing out of an accuracy node with barrel harmonics.
As for rifle.cleaning, if it shoots good one week, then poor the next, then back to good, I would not say it is barrel cleaning. Unless you cleaned in the middle. I don't clean until my groups start to open up. Anywhere from 60 to 600 rounds depending on the rifle/powder/bullet combo.

 

[Elkeater]

Not really sure on this one. Maybe someone else will have a better idea.

I have two guesses. One is your form. Everyone has good days and bad days. I'm generally a pretty decent shot but some days I'm just not feeling it and other days I fell like I can shoot anything.

The other guess and it would depend on what ammo you have is if you had powder that wasn't temp stable and had some big temp switch.

Anyways just a guess. Good luck maybe someone else has better ideas.

 

[the blur]

I should have stated, I use off the shelf ammo. Once I find what my gun likes, I'll buy 15 boxes.

 

[Rick Richard]

Based on the information provided, I would point at the ammo if everything else is the same.

 

[SMK1000plus]

I should have stated, I use off the shelf ammo. Once I find what my gun likes, I'll buy 15 boxes.

Are you matching the lot numbers on your factory ammunition? Not the Mfg. P/N, the actual lot number...

What factory ammunition and bullet specifically, are you using?

 

[the blur]

I try to match lot #'s, but it's not always easy.
The most consistent ammo I found is NOSLER.com. Accubonds. Hornaday ELD-x is also consistent.

 

[SMK1000plus]

I try to match lot #'s, but it's not always easy.
The most consistent ammo I found is NOSLER.com. Accubonds. Hornaday ELD-x is also consistent.

What bullet and weight in 243? Bullet and weight in 7mm-08? What are the twist rates of each of your rifles? What are the ambient temperatures and atmospheric/environmental variables on your good days? What are they on your bad days?

You may be right on the border of bullet stability, where range conditions may play an unusually huge role in accuracy...

 

[Greyfox]

Does this happen with both of your rifles the same in the same session?

 

[the blur]

I really need to take better notes at the range. My 243 Mossberg ATR, (Cheap rifle, that has been accurized to the gills.) which has been bedded & crowned normally shoots Hornaday 80gr, GMX ammo rather well. Last trip, all over the paper.

 

[Lynn Coleman]

I had one box of Federal premium that would not hit a bill board at 200 yds. Came in to 100 yds. Still couldn't hit target, was thinking ***, is it my rifle? Scope? Me? Did an impromptu bore sighting, looked good!! Went to another box of ammo. In the ring at 100 and 200. If you're not reloading, buying the same lot number helps.

 

[Samesaw]

2 of my rifles, .243 & 7mm-08. Normally they like a specific ammo, 1" groups. at 200 yards.
Next trip to the range, it won't group at all. Same box of ammo, and no group.
Then I go back to the range, and it's grouping again.

Same sandbags, same range, Only thing that changes is the temperature, and wind. And possibly my rifles need to be cleaned more.

Any other possibilities ?

Sounds

2 of my rifles, .243 & 7mm-08. Normally they like a specific ammo, 1" groups. at 200 yards.
Next trip to the range, it won't group at all. Same box of ammo, and no group.
Then I go back to the range, and it's grouping again.

Same sandbags, same range, Only thing that changes is the temperature, and wind. And possibly my rifles need to be cleaned more.

Any other possibilities ?

Try checking your scope base screws.
They all need to be tight, or even lock tighted down.

 

[arch408]

Two different rifles. Don't take this wrong. Only common denominator is the shooter. Check your form, rest, ect.

 

[DavidleeCole]

I had the same with my .300 Whby mag and it turned out after several frustrating hints and sight in trips I took off the scope and the back base was completely loose. Lock tight and all good. Shooting proper I went to reloading after that any ways for cheeper price