Accuracy Loss

[Susquatch]

In my experience, that kind of dramatic change is almost always mechanical. My first guess would be action screws and scope bases. But you say you checked them and they are ok.

My second bet is that your scope went wonky. Try another one. Easy to do with a rail. Even a low mag scope will work. With that kind of deterioration, 2 or 3 shots will tell you all you need to know.

My third bet would be dirt in the stock or something wrong/broken with the bedding or stock.

A really long shot - did the barrel come loose?

Did something on your gun rest setup go wonky? Maybe a stop touching the barrel?

Above all else, don't let yourself be tricked into thinking its gotta be some sophisticated detail - like carbon ring. Such things are extremely unlikely to cause that big a deterioration so fast. Focusing in on minutia will blind you to the obvious. You don't have time for that. I vote for obvious.

Since you brought it up, I doubt it's a fouling issue. Nonetheless, I do swear by BoreTech solvents. I don't like to use JB unless I absolutely have to. But BoreTech C4 is a carbon solvent. It doesn't work well for copper. Try some BoreTech Cu too. It's awesome stuff.

Good luck!

 

[wmadams2]

I had a very similar problem recently. Couldn't find anything wrong until I picked the gun up by the barrel and it spun in my hand.

 

[jimmybrost]

You said you're shooting handloads. I'd double check my dies and OAL, just to be sure. I've had dies get loose before. Also, I'd buy a box of quality factory rounds and try them. Good luck. Waiting to bear how it turns out.

 

[Swinehunt74]

Make sure the scope base isn't cracked. Had new build with Bartlien barrel in 260 when break-in shooting would throw 2 touching then flyer 1-2 inches off. Thought it might be harmonics, cut inch off to fix, no bueno. upon reassembly after 2 cuts, (wanted 24in, ended with 22 in). Saw slight gap in EGW base (new). Replaced base and now have my fav hunting rifle. One of the most accurate rifles i have.

 

[aghunter]

Well guys shooting was a bit of a let down. 1st group was a bit larger than 1" but was expected after cleaning. Next group three shots in 1 hole. Starting to get excited. Next 4 groups still hovered right over 1". I'm stumped. Now I'm really thinking something is loose but can figure out what it could be....

 

[ButterBean]

Well guys shooting was a bit of a let down. 1st group was a bit larger than 1" but was expected after cleaning. Next group three shots in 1 hole. Starting to get excited. Next 4 groups still hovered right over 1". I'm stumped. Now I'm really thinking something is loose but can figure out what it could be....

Don't clean it and Shoot it some more

 

[Susquatch]

Well guys shooting was a bit of a let down. 1st group was a bit larger than 1" but was expected after cleaning. Next group three shots in 1 hole. Starting to get excited. Next 4 groups still hovered right over 1". I'm stumped. Now I'm really thinking something is loose but can figure out what it could be....

That's a heck of a lot different than your first note. Your first note said it went from 1/2 MOA to 2 MOA. Now it's more like 1 MOA. Thats a much smaller difference that could be anything from cleaning and shooter and shooting rest technique to loads and reloading or even just warm vs cold barrel or clean VS fouled, or ambient temperature.

It's probably unlikely that you will get that figured out before your hunting trip. I'd focus on how to best use what you have rather than trying to fix something like that with no time to do it right. Lots and lots of hunters are thrilled with 1 inch. I'm not and neither are you. But I wouldn't let it spoil your trip.

 

[JAYgs8163]

Make sure you are letting the barrel cool substantially before second and third shots. Remember your first shot when hunting hopefully is the only one you will make. Accuracy with a cold bore is imperative and will give you a great read of your rigs hunting shooting capabilities. Also, have someone else shoot it also when you go out next time. Repeatability in your technique is imperative also. Many times we start to get fatigued after sitting at the bench and we lose the repeatability in our technique. I sometimes wait as much as 10-15 minutes before sending another round down range when I'm dialing in my hunting rigs.

 

[Orange Dust]

There is one other thing I didn't notice someone saying; Whenever you have a sudden change or accuracy, as several have said, something is different, and it is usually mechanical. However, it could be your ammo. How long has it been loaded? With so many people cleaning brass the liquid method and getting it spotless, cold weld of the bullet to the neck is much more common than it used to be. You could simply have increased bullet pull and raised velocity just enough for an accuracy loss. Chrono your loads. Even if they are fresh, make sure they are going the correct speed. Take that out of the puzzle.

 

[Susquatch]

........ Chrono your loads. Even if they are fresh, make sure they are going the correct speed. Take that out of the puzzle.

This is a great suggestion. No idea why I didn't mention it.

Just like the simplicity of trying another scope, the chrono will instantly tell you if you likely have a load / bore problem or a mechanical / optics / shooter problem. If you don't have a chrono yet, you are lucky cuz you can go get a LabRadar without spending money on something else first.

I also vote for the idea of getting a known good shooter to try your system out. I don't care how good you are or how confident. We can all benefit and learn from what someone else can do with our rig.

Lastly, it looks like you favour 3 shot groups. While that is ok for some, I prefer 5 shots and sometimes 10 or more even for thin barrelled sporters. 3 shots are too prone to luck. A 10 or 15 shot aggregate tells you much more about what is really happening. In other words I have zero confidence that your first small group is any indication of what your rifle and you can do. It could be luck or just a random spread. If I take your targets and put all those holes onto one target, they don't suggest that you have a 1/2 MOA rifle at all. The small group just fades into the random nature of most rifles with the rest of your shots. There is no clustering. Just a random group with a weighted mean someplace around an inch. I'm NOT saying I don't shoot 3 shot groups. I do. But I would never rely on what they tell me about my accuracy. There is nothing wrong with waiting for the barrel to cool down between shots. As others have said. It's almost always the first shot that counts anyway. The rest just let your hunting buddies know that you missed. So I like to think that all the groups I shoot are all about knowing where that first shot of mine will go.

 

[ButterBean]

This is a great suggestion. No idea why I didn't mention it.

Just like the simplicity of trying another scope, the chrono will instantly tell you if you likely have a load / bore problem or a mechanical / optics / shooter problem. If you don't have a chrono yet, you are lucky cuz you can go get a LabRadar without spending money on something else first.

I also vote for the idea of getting a known good shooter to try your system out. I don't care how good you are or how confident. We can all benefit and learn from what someone else can do with our rig.

Lastly, it looks like you favour 3 shot groups. While that is ok for some, I prefer 5 shots and sometimes 10 or more even for thin barrelled sporters. 3 shots are too prone to luck. A 10 or 15 shot aggregate tells you much more about what is really happening. In other words I have zero confidence that your first small group is any indication of what your rifle and you can do. It could be luck or just a random spread. If I take your targets and put all those holes onto one target, they don't suggest that you have a 1/4 MOA rifle at all. The small group just fades into the random nature of most rifles with the rest of your shots. There is no clustering. Just a random group with a weighted mean someplace around an inch. I'm NOT saying I don't shoot 3 shot groups. I do. But I would never rely on what they tell me about my accuracy. There is nothing wrong with waiting for the barrel to cool down between shots. As others have said. It's almost always the first shot that counts anyway. The rest just let your hunting buddies know that you missed. So I like to think that all the groups I shoot are all about knowing exactly where my first shot will go.

I'm with you on your last 2 posts but I wouldn't be scared to take it on a hunt anywhere, I'm still betting if he keeps sending rounds down range it will tighten up a bit

 

[capona]

Maybe you just had a bad day shooting.
Big difference between .5 and 2 moa.
At 1 moa, your getting in the ballpark .

 

[Susquatch]

I'm with you on your last 2 posts but I wouldn't be scared to take it on a hunt anywhere, I'm still betting if he keeps sending rounds down range it will tighten up a bit

I agree totally. In fact, I wouldn't be afraid to take it hunting as is. I don't know about you, but it's not very often when I get to setup a concrete shooting table and cast iron rest before I make the kill. More often than not it's take the shot God gives me - or pass. And I pass a lot!

I'm just trying to sort out in my minds eye where our friend is at here and where he really came from. The odd half inch 3 shot group or a number of half inch groups in different places, or a half dozen half inch 3 shot groups all in the same place. The difference between these three scenarios might totally explain his frustration. I think we have all been there at one point or another in our shooting lives.

 

[ButterBean]

I agree totally. In fact, I wouldn't be afraid to take it hunting as is. I don't know about you, but it's not very often when I get to setup a concrete shooting table and cast iron rest before I make the kill. More often than not it's take the shot God gives me - or pass. And I pass a lot!

I'm just trying to sort out in my minds eye where our friend is at here and where he really came from. The odd half inch 3 shot group or a number of half inch groups in different places, or a half dozen half inch 3 shot groups all in the same place. The difference between these three scenarios might totally explain his frustration. I think we have all been there at one point or another in our shooting lives.

I concur and I really feel like its something simple