Barrel Contour vs Accuracy Potential

[rcoody]

This is a pretty interesting thread so far. I don't have the necessary experience to weigh in on it, but I have noticed that it seems like some folks have missed a few points made by the OP. I'm not trying to start a troll-battle, I just think that this thread has a lot of really knowledgable folks posting already . . . so there's a very high likelihood that us noobies stand a chance to learn some valuable stuff from it if we keep it on track.

1. He's stated that he demands better accuracy than most (with regards to hunting rifles) because he enjoys shooting and hitting steel at long distances. There's been a lot of debate about cold bore accuracy, 3-shot grous, 5-shot and even 10-shot groups. It seems like that's a very opinionated debate, but to answer the OP's questions, we need to go back and look at what he's trying to accomplish . . . he doesn't require accuracy/consistency for cold bore, 3-shot or 5-shot groups, he requires it for fun sessions of shooting steel, so multiple successive shots that likely won't allow the barrel to cool very much. With that in mind, this is going to be his main hunting rifle, so packing weight is a major consideration. What's the best compromise of lightest contour verses consistency and accuracy.

2. Some of the replies include folks asking "did you check this . . . " or "are you doing that . . . ?". The OP told us that he's experimented ad nauseum with multiple manufacturers in multiple light contours, I'd have to believe that he's a pretty experienced shooter and that we can skip all of "the usual diagnosis steps" that are engaged on noobies. With that, we'd also have to assume that he's put in the time to become a proficient shooter (form, equipment, environmental considerations all having been finely tuned and accounted for) . . . so we don't need to debate whether he's got the right stock or if he's shooting on bags, in a sled or over a log in the field. We need to be debating barrel contour, that's what he's after.

3. Not calling anyone out on this one, just a question to consider for folks that have already engaged in this thread. How many of you pros have shot lighter contour aftermarket barrels (not factory)? To take it further, can you provide us all with some control data that might help?

Countour
Brand
Finished Length
Caliber
Bullet Weight
relative accuracy (if you know it would do 5-shots in 3/4 MOA, or 10 shots in 1 MOA, or .....)

Thanks all, again, I'm not trying to call anyone out or start a flame session, I just want to see this thread continue in the direction as directed by the OP, I think a lot of us hunters are very interested in the topic.

I have chosen the #3 for my hunting rifles for a balance of accuracy and weight. I have a bartlein and a kraiger. those weigh in about #8 with the scope. Now I have never been one to shoot at game much further than 300 yrds. Where I live it just isn't necessary.

But I am in the process of building a brux #4 chambered in 6.5 saum for a long range hunting rifle. It will probably weigh #10. hope to hit some of those wide open spaces out west with this one.

I don't use my hunting guns for range guns. I have a selection for the range with bull barrels..223, 6mm turbo, 6mm BR, 6.5 creedmoor. They are all fun to shoot and don't go away when they get a little warm.

 

[Hondo64d]

Well, amidst all this discussion I didn't give up on trying to find a load that my 2b barrels REALLY like. I think I've succeeded with the .308 barrel (still have more work to do with the 6.5x47 and 22-250 barrels). 5 shots at 100 yards. Thrown charges. OAL includes Sinclair "hex nut" bullet comparator. I WILL stand by my experiences that a load that does this is MUCH more difficult to find for a light barrel that it ever was for any of my #5s.

John

 

[ohiohunter]

No doubt. Thin barrels have smaller nodes vs thicker. My theory is due to the resulting frequency of the barrel caused by the projectile.

 

[bigngreen]

Your convinced that your fighting barrel contour yet your throwing charges, you need to be more open minded and critical of a lot of factors before contour on a custom barrel needs to be evaluated. It also helps to get away from the hundred yard line for development, fine tune your loads at the ranges you want to shoot, I shoot a whole lot better at 300 than I do at 100 and paralax is less of an issue as well.
Thee hardest custom barrel I had to tune was a sendero contour, some of the easiest have been #3 and #4's and a freak of a 338 barrel that will post .8's at 300. My buddy who is a benchrest builder just ran a ladder on a 28 Nosler with a #4 that was 1.5 of vertical at 300 for a five grain ladder. It's way more the nut on the trigger or loading press than the contour!!

 

[Iron Worker]

I prefer 4 shot groups. That way out of 20rnds you get to experiment with 5 different loads and not waste to much stuff.

 

[blacktail 8541]

Your convinced that your fighting barrel contour yet your throwing charges, you need to be more open minded and critical of a lot of factors before contour on a custom barrel needs to be evaluated. It also helps to get away from the hundred yard line for development, fine tune your loads at the ranges you want to shoot, I shoot a whole lot better at 300 than I do at 100 and paralax is less of an issue as well.
Thee hardest custom barrel I had to tune was a sendero contour, some of the easiest have been #3 and #4's and a freak of a 338 barrel that will post .8's at 300. My buddy who is a benchrest builder just ran a ladder on a 28 Nosler with a #4 that was 1.5 of vertical at 300 for a five grain ladder. It's way more the nut on the trigger or loading press than the contour!!

There is a whole lot of truth in this statementlightbulb

 

[Iron Worker]

On my Weatherby Vanguard I have a 8"twist 26" Brux #4 contour BBL chambered in 22/250 (Smith trued up the action ) . Its bedded in a B&C medalist stock(Free Floated forearm ) . What size groups should I be satisfied with at 100 yds ?

 

[ohiohunter]

On my Weatherby Vanguard I have a 8"twist 26" Brux #4 contour BBL chambered in 22/250 (Smith trued up the action ) . Its bedded in a B&C medalist stock(Free Floated forearm ) . What size groups should I be satisfied with at 100 yds ?

1'

You shouldn't have any problems getting that to 1/2"... but I would expect better.

 

[engineer40]

On my Weatherby Vanguard I have a 8"twist 26" Brux #4 contour BBL chambered in 22/250 (Smith trued up the action ) . Its bedded in a B&C medalist stock(Free Floated forearm ) . What size groups should I be satisfied with at 100 yds ?

If you reload, under a half inch for sure. What are you getting?

 

[Iron Worker]

I've gotten a few half inch ,but a few flyers also . I understand there can be a multitude of reasons for that. Does better with 3-4 shot groups than 5. Been reading this thread I think I'll give up on the 5 shot groups.

 

[ohiohunter]

I've gotten a few half inch ,but a few flyers also . I understand there can be a multitude of reasons for that. Does better with 3-4 shot groups than 5. Been reading this thread I think I'll give up on the 5 shot groups.

What bullet and powder?

 

[rcoody]

On my Weatherby Vanguard I have a 8"twist 26" Brux #4 contour BBL chambered in 22/250 (Smith trued up the action ) . Its bedded in a B&C medalist stock(Free Floated forearm ) . What size groups should I be satisfied with at 100 yds ?

I always wonder when I see a rebarreled weatherby if it is still a weatherby or not. nothing wrong with a more common freebore but it won't be a weatherby.

With that setup and quality reloads I would be extremely disappointed with 5 shot groups greater than half inch at 100 yrds.

Is it you or the ammo?

 

[Timber338]

My personal experience is that any barrel contour can make for a very accurate rifle. The light rifles are obviously more challenging to shoot because of shooter error, but that is not the rifles fault.

I have owned some very light rifles with light barrel contours, the most aggressive being a 338WSM wildcat with a Pac-Nor ultralight contour. The rifle shot 1/2 MOA all day long and twice on sunday. That's not going to win any gold medals, but it's going to kill animals to that rifles lethal limit any day.

I have come to like #3 and #4 contours on hunting rifles. They have enough weight to shoot accurately, but not so much weight that they become too heavy to carry in the field.

Of course any light barrel contour is going to heat up much quicker so I limit groups to 3 shots. I have never found any reason to shoot more than 3 to prove out the accuracy of a hunting load, and once I know the load is accurate I test out the rifle at longer ranges with either the single cold bore shot or 2-shot groups. For hunting the first 1 or 2 shots are really all that matter anyways.

 

[Iron Worker]

What bullet and powder?

55gr Nosler 60gr V-Max Varget 69gr Sierra MK Superformance and W-W760