Barrel Contour vs Accuracy Potential

[Hondo64d]

I have spent literally years and thousands of $ trying to make light barreled hunting rigs shoot to my satisfaction, but to no avail. I am, at this point, pretty much done with the attempt and am now going to go with heavier tubes.

I have had several rifles chambered by top name 'smiths with #2 tubes from Douglas and Hart and most recently three Bartlein 2Bs. My experience with these light contours is that 1 MOA five-shot groups is what they are consistently capable of, even if being very careful to not let the barrel get hot. Very often I will have 4 shots in .5 MOA or so and one out about .5 to 1 inch. I may not be the best shot, but I KNOW if my crosshairs were .5 to 1 inch out at the trigger break or if I have had a significant wind shift. I have also used a #4 Brux that was somewhat more consistent than my #2 and 3 contours and I have used two #5 contours that were significantly better than any of the lighter tubes, including the #4.

Anyway, all of this leads to this question:

At what contour have you guys observed that barrels become significantly more consistent than the #2 and 3 contours?

I have asked this question of a couple of well known 'smiths. One of them said Light Palma is where things become noticeably better and the other said a #5.

Also, at what point in barrel contours will the increase in accuracy potential be REALLY difficult to measure? That might help me decide how heavy I am willing to go.

What say you?

John

 

[ohiohunter]

I have spent literally years and thousands of $ trying to make light barreled hunting rigs shoot to my satisfaction, but to no avail. I am, at this point, pretty much done with the attempt and am now going to go with heavier tubes.

I have had several rifles chambered by top name 'smiths with #2 tubes from Douglas and Hart and most recently three Bartlein 2Bs. My experience with these light contours is that 1 MOA five-shot groups is what they are consistently capable of, even if being very careful to not let the barrel get hot. Very often I will have 4 shots in .5 MOA or so and one out about .5 to 1 inch. I may not be the best shot, but I KNOW if my crosshairs were .5 to 1 inch out at the trigger break or if I have had a significant wind shift. I have also used a #4 Brux that was somewhat more consistent than my #2 and 3 contours and I have used two #5 contours that were significantly better than any of the lighter tubes, including the #4.

Anyway, all of this leads to this question:

At what contour have you guys observed that barrels become significantly more consistent than the #2 and 3 contours?

I have asked this question of a couple of well known 'smiths. One of them said Light Palma is where things become noticeably better and the other said a #5.

Also, at what point in barrel contours will the increase in accuracy potential be REALLY difficult to measure? That might help me decide how heavy I am willing to go.

What say you?

John

IMHO you already have exactly what you want out of a hunting rifle, but you are expecting bench gun precision. For hunting purposes I see no reason to shoot more than 3 shot groups, for a bench rig I wouldn't consider groups less than 5. I bet your 3shot groups are sub 0.5".... which would make the majority of this site happy.

If you are in fact letting your barrel cool when you attempt your 5shot groups the conditions can change enough to make a difference, esp where I live, even at 100yds.

The heavier you go the more shots you're gonna pack into a group, so the real question is how heavy are you willing to go?

 

[Hondo64d]

IMHO you already have exactly what you want out of a hunting rifle, but you are expecting bench gun precision. For hunting purposes I see no reason to shoot more than 3 shot groups, for a bench rig I wouldn't consider groups less than 5. I bet your 3shot groups are sub 0.5".... which would make the majority of this site happy.

If you are in fact letting your barrel cool when you attempt your 5shot groups the conditions can change enough to make a difference, esp where I live, even at 100yds.

The heavier you go the more shots you're gonna pack into a group, so the real question is how heavy are you willing to go?

Have you ever shot multiple three shot groups at the same POA? I have done it countless times and found that three shot groups by themselves are not a very good indicator of where the next shot is going to go. I have often shot tiny three shot groups only to have the next one be MUCH bigger. If I shoot multiple three shot groups at the same POA, I get a much clearer picture of how the gun is going to shoot. And, by letting the barrel cool between those groups, I cannot blame any inconsistency on barrel heat. When doing this, I have seen, that more often than not, what might normally be thought of as a flyer really isn't, but is actually an indicator of how well that load is going to shoot. For me, three shot groups have been able to tell me that a load may not be that great, but virtually never tells me that a load IS a good one.

Anyway, I have come to the conclusion that a light barrel is just not going to give me the consistency I am looking for and was hoping the collective wealth of knowledge on this and other forums might be able to answer these questions:

At what contour have you guys observed that barrels become significantly more consistent than the #2 and 3 contours?

Also, at what point in barrel contours will the increase in accuracy potential be REALLY difficult to measure? That might help me decide how heavy I am willing to go.

John

 

[mobenzowner]

How many times in a hunting situation are you going to get off more than 3 shots. I know it can and does happen, but if I can put 3 shots where I want them and don't have game down, the animal is either out of my range ability wise, or not presenting a type of shot I should be taking. I would worry much more about the accuracy of the cold bore first shot on a hunting rifle compared to where shots 4 and 5 are going. But that's just me. Good luck on your quest.

 

[ohiohunter]

I am able to put 5rnds in <0.5" with my light palma. The gun fully outfitted comes in at 12lbs. I could knock off another pound with a lighter stock. It's a 300wm pushing 215's with 25" Bart tube.

IIWY I'd look at my 500yd+ groups with said barrels.

 

[roninflag]

my Krieger sendero contour barrels are great.

 

[Hondo64d]

How many times in a hunting situation are you going to get off more than 3 shots. I know it can and does happen, but if I can put 3 shots where I want them and don't have game down, the animal is either out of my range ability wise, or not presenting a type of shot I should be taking. I would worry much more about the accuracy of the cold bore first shot on a hunting rifle compared to where shots 4 and 5 are going. But that's just me. Good luck on your quest.

Once again, three shots is statistically not a reliable predictor of where the next shot is going to land. If you don't believe this, shoot a three shot group, let the barrel cool, and shoot another three shot group at the same POA. I PROMISE you the six total shots will be noticeably bigger than the original three. If you want to blame this on changing conditions, then do it at an indoor range. The results will be nearly the same.

Anyway, I want more accuracy because I enjoy having it. I shoot a lot, and only a small percentage of rounds fired are on game. I enjoy long range steel and it is very gratifying to have a high level of confidence that my bullet is going where I aim. I had hoped that with all the experience on this board someone would have chambered/shot enough different contours to be able to share some trends they have observed in regard to contour vs accuracy potential.

Thanks,

John

 

[rcoody]

fior me on my hunting rifle it is that first cold bore shot that matters. With hunting season approaching I will sight in or more likely check to make sure it is still sighted in. Then every time I go to the range till hunting season I shoot one time with my hunting rifle. Where is that cold bore POI? usually right where I want it.

My hunting rig has a McMillian edge stock, trued 700 action and a bartlien #3 contour barrel. Weighs a little under 7# without the scope. Nice lightweight packing rifle.

I am about to build another one. Use the McMillian A3 sportster with edge technology, a #4 brux chambered in 6.5 saum. Best I can calculate this one will weigh between 9 and 10 pounds with the scope. more of a long range gun for sitting and and glassing.

 

[ohiohunter]

There are a lot of factors to consider and to single out the barrel especially a quality barrel seems a little absurd to me. Not to mention several barrels of different build per the ops claims

 

[shortgrass]

Hunting rifles , light packing rifles in particular, only need to be 'tested' with 3 shot groups. I completely agree with the fist cold bore shot as mentioned by others in previous posts. If I need more than two (2) shots I need to practice more. And if you need more than that for that charging grizzley bear a 1/2" or an inch ain't gonna matter!

 

[Plinker147]

I think the Sendero (#6ish depending on barrel maker) Contour is about when you start seeing better accuracy in larger calibers say bigger than .264. Smaller the caliber the more meat on the barrel even in lighter contours so it doesn't seem to be the same. I have sporter #3 type contour in 25-06 and it shoots the same for 5 shot groups. I have lighter barrel on a 8mm Mag and it starts to spread after the 2nd shot. If your shooting 20 rounds in a row like F class then you will notice a difference between #6 and full heavy barrels. But for hunting I like the #5-6 contours seems to be a happy medium from accuracy and carry weight

 

[bigngreen]

I don't think raw accuracy potential is hardly different between a 3#-4 to a sendero, if the barrel is good it's going to shoot small, the difference is how shootable a heavy gun is vs a light gun, much easier to run a heavy gun that lays there and tracks and rides the bipod better. Flutes make a difference in this also, a light barrel is more likely to suffer bore growth from fluting vs a heavy weight but that is not a taper issue but a fluting. Heavy is easier to shoot, tracks better on the bipod or bags but that's not the barrel, light guns take some careful shooting and perfection every shot or it really stomps you! Lighter barrels are more effected by heat but that's not really an accuracy issue it's a sustained fire issue.

I completely disagree with the cold bore being the only one that counts idea, if my cold bore is so much different than the next couple then the issue needs addressed, if you can't shoot at least a three shot group with sustainable accuracy then you don't have good enough form or rifle to be taking a cold bore with certainty either. I've seen guys only shoot cold bore, they blame a miss on every thing but a second and third shot would reveal the need for more shooting and learning. The cold bore is critical and what we strive for but if you can't follow it up with an equally quality shot then your just getting lucky on the cold bore!!

 

[rcoody]

I don't think raw accuracy potential is hardly different between a 3#-4 to a sendero, if the barrel is good it's going to shoot small, the difference is how shootable a heavy gun is vs a light gun, much easier to run a heavy gun that lays there and tracks and rides the bipod better. Flutes make a difference in this also, a light barrel is more likely to suffer bore growth from fluting vs a heavy weight but that is not a taper issue but a fluting. Heavy is easier to shoot, tracks better on the bipod or bags but that's not the barrel, light guns take some careful shooting and perfection every shot or it really stomps you! Lighter barrels are more effected by heat but that's not really an accuracy issue it's a sustained fire issue.

I completely disagree with the cold bore being the only one that counts idea, if my cold bore is so much different than the next couple then the issue needs addressed, if you can't shoot at least a three shot group with sustainable accuracy then you don't have good enough form or rifle to be taking a cold bore with certainty either. I've seen guys only shoot cold bore, they blame a miss on every thing but a second and third shot would reveal the need for more shooting and learning. The cold bore is critical and what we strive for but if you can't follow it up with an equally quality shot then your just getting lucky on the cold bore!!

Opinions vary

well I can't remember the last time I shot more than once to put the meat on the ground.

I know my rifle and its limitations. Don't take chances on wounding game.

I am happy with this. I have plenty of range guns that shoot better but I sure wouldn't want to pack them in.

the target below is when I was dialing in my berger hunting vld jump. found my jump 0.095 off the lands then fine tuned it below. Each group is seated 0.010 deeper. started 0.010 high. as you can see it was out of the seating node.I found my jump 0.105. off the lands. That seems to be the middle of the node.

 

[gusd]

I wish I had enough experience with barrels to answer your question, but I do not and it does not seem that you are getting the answers you are looking for. So I would suggest calling the barrel makers and asking them I know the guys at Bartlien Barrels and know they have a ton of experience shooting all barrel types and am sure they would be more than willing to talk with you, and answer your question.