Quick question, root cause of 2 + 1 groups?

[azsugarbear]

Could probably be a scope issue. Make, model and mount type? Even with great scopes, I have had one now and then that seems to move back and forth ever so slightly between the recoil of the rifle firing. When problems like this come up, swapping scopes is one of the first things I will try. One time, it was definitely the scope (a nice Leupold) and another it was the mounts. No way I would have discovered the mount issue if I had not removed the scope.

 

[billflangjr813]

I'm with you on that one Darryle!

That's exactly why I use SS lightweights or Carbons for hunting and the heavy SS for long range competition.
I never worry about longer shot strings for hunting rifles because they WILL drift with heat.
3 shot groups is good enough for me in a hunting rifle.

I'm not a professional but I'm sure someone can back this up.

I got your Back !!

 

[L.Sherm]

The variability in factory loaded ammunition would be my guess

My money is on this.

 

[baldhunter]

Shooter error.I have the same problem.Just go hunting,kill stuff and don't worry about it.If you can maintain the same shooting consistency in the field your not going to miss.If the third shot was out more than an inch or more you might have an issue to work on but you don't.

 

[L.Sherm]

Proof the problem,

You mean Barrel?

 

[Darryle]

Since it's a hunting rig I'd move on and not worry about it.

I am not overly concerned with this rifle, I think it's perfect for my intended usage. The first 2 will go where I intend them to out to about 320yds, I have a confirmed head shot at 306yds on a doe and the other was behind her slightly and it to was a head shot.

I was using this rifle to illustrate the issue and discuss possible theories and or solutions. Maybe I wasn't initially clear on the intent of this post, for that I apologize.

You can see from the above screenshot, it's an issue with numerous rifles, I am wondering what is the common denominator.

***I have seen the "It's a Proof CF" comment more than once, is it a "Proof" issue or a Carbon Fiber Wrapped issue? I have read that some prefer Hells Canyon Armory or Benchmark CF barrels because of the process they use to wrap their barrels.

I am a hunter, no intentions of being anything but, but I am intrigued by these issues, simply to educate myself and maybe others.

 

[L.Sherm]

Folks get hung up on shooting BR groups out of a hunting rig. I get it as we all strive for "itty bitty" groups, nothing wrong with that. But in the field we don't have the rock solid bench and squeeze bags and the advantage of slowed heart and breathing rates.

Thats why my load development is off a bipod and minute of deer isn't good enough for LR hunting.

 

[Philward]

Probably heat related. But what if it's the second shot that is the flyer? Could be many things, variances in case shape or thickness, bullet imperfections, heat, eye alignment to scope, variation of shooter input into rifle when fired, trigger pull...

How far off should the flyer be to become a rifle problem and not a shooter issue? We are not robots after all.

 

[25WSM]

Most likely a heat issue. I say this because its always the third shot. If it was a random shot from the group then maybe it could be a mechanical issue. Is your base bedded to the action? Had a custom I built and the customer put his own base and rings on. Brought it back to me with the 2 and one problem. Actually it was a 3 and 2 problem. 3 touching and 2 touching an inch away. After much fiddling and rechecking everything found the issue. The base didn't fit the receiver properly. Bedded it and it was a 1/4 moa rifle after that. Your rifle is shooting excellent for factory ammo. First 2 shots are 1/4 moa or under. When hunting how often do you need a third shot. And even if you do 1/2 inch moa will kill as far as you can aim accurately. When chasing extreme accuracy every tiny detail makes all the difference. Perfect groups require perfect rifle, ammo, scope, shooter, bag setup and mother nature. Ive built a bunch of rifles on Proof barrels and have no issues with them. My personal hunting rifle shoots in the 1s with a proof barrel. 6.5saum.
Botton line is since its always the third shot it's probably heat. But it shoots excellent. I would hunt with it anytime.
Shep

 

[Roughrice]

My theory:
I think it's the nature of the beast.
Regardless of whose method of carbon wrapping may be better…I think that once a blank has been turned down to a very light contour then wrapped in carbon, heat stresses cause the "bending " effect and the two materials have different heating and cooling tolerances and perhaps work against each other somewhat which may cause that unpredictable flyer once barrel temperature begins to change.

Hence, the reason long range precision shooters use heavy stainless or CM rather than Carbon Fiber wrapped barrels.

I have a friend that has a Savage Ultralight with Proof barrel in 6.5 Creedmoor and a Christensen Arms MPR with Carbon barrel in 6.5 PRC.
Both shoot very small 3 shot groups but open up considerably when trying longer shot strings.
I have a couple of carbons and they get 3 shot groups. Never shot more than 3.

My 2 cents.

 

[Mike Matteson]

I always like to see where my cold bore, and clean barrel places the first shot. Just to note what it's doing. After that I am very interested in what my cold bore rifle does after the barrel has been fouled. Because that's what's going to happen when you place your shot at the animal. The other is that animal isn't going to stand around and let you cool your barrel for a second or how many shots it takes. The group looks great to me. If you are hunting. Can you play with it yes.
The other is I came across this and copied it down.
Flyers:
Possible to use Lock Ease. Try using Lock ease when you stop cleaning every inch of the inside of your barrel you remove helpful buffers that work for the better. Especial in a purged barrel's. A very wise PRC Shooter started using "Lock-Ease Graphite Fluid reduce to protect against cold bore flyers" He started using this compound by placing it on a cleaning patch and liberally applying a generous amount then letting it dry before sighting and noticed less flyers from the first bore test shots.
I haven't tried it so I don't know it it's works or not. I am not sure if I am going to try this either.

 

[JamesWilson5]

I have a rifle that consistently does this, regardless of who's shooting it.

I get 2 essentially in the same hole then one right on the edge.

280 Ackley Sammi 26" proof barrel, this was with the EC Tuner brake, but it will do it with a standard brake or thread protector.

140gr Nosler Accubond factory

50ish rds thru the barrel

View attachment 397669

Sounds like it getting warm

 

[emp1953]

Barrel expansion from warming up.

A good way to test is to let 10 minutes sit between each shot.

That said, I wouldn't do anything less then a 10 shot average. I never got the point of a 3 shot group. Thinner profile barrels you'll notice more of this shift.

This is all assuming you're at 100y. Further than that, and it introduces more variables.

Yes, let it set 10 minutes with the bolt open.

 

[jlee91w]

I asked Mike Larue this same question. I have an ar15 upper from them that does this. Also, a Tikka 300wm with the fluted skinny barrel. I asked Larue because he is always posting 3 rd pictures and has posted a bunch of this exact issue. His unsatisfactory answer was, (I'm paraphrasing) ammo inconsistency. I don't think it has anything to do with ammo, but it is an interesting phenomenon. In other words, I'm just as stumped as you.

I do think the 5 rd group has merit, I read an article somewhere that talked about barrel grouping and how if you shot 50 separate rds they would all be in the same round area if it was an accurate rifle. Still doesn't answer this question, but I'm with you, I would like to know "the why" as well.
Jared