Which barrel contour?

[hogpatrol]

I've had great accuracy with the small varmint cartridges and 18" featherweight barrels. As Ggmac posted, cut 'em short.

 

[AckleymanII]

Tuners could really help out, in spades. I have had some remarkable success with factory sporter barrels with the rubber doughnut on the barrel, nothing short of amazing.

 

[CTK]

Tuners could really help out, in spades. I have had some remarkable success with factory sporter barrels with the rubber doughnut on the barrel, nothing short of amazing.

I briefly tried this as well. Will try again. Got the idea one day when several different loads with different bullets stacked up at the same poi when using a Magnetospeed. Poi was low and right of general area that rifle was grouping with other loads. Have a picture of the group somewhere.

 

[CTK]

exactly

These groups were all shot with a 23” Bartlein2b in 6.5x47 hunting rifle. This may be a “hummer” light barrel. It shoots loads that it likes in the .25” range at 100y. No great cooling regimen was followed. I am not a skilled shooter like most here. Sometimes you get a combo of a skilled gunsmith and the luck of the draw. I do not anticipate this accuracy to be repeatable in my new 280ai build on a 2b. The caliber vs outside diameter likely matters for stiffness.

 

[Bryan Z.]

I’ve shot a lot of contours and I shoot short range bench rest for agg and score, 600 yard prone F, and PRS/NRL matches. I would say that the medium Palma or similar contour is where the accuracy gains start to become dramatic relative to smaller contours. With good factory ammo, you should be .5 MOA or below; with well-tuned reloads, you should be .3 or below all day. For hunting, that should be more than good. Moving up in the weight of the contour from there isn’t going to get you any additional benefit within the context of hunting.

 

[CTK]

I’ve shot a lot of contours and I shoot short range bench rest for agg and score, 600 yard prone F, and PRS/NRL matches. I would say that the medium Palma or similar contour is where the accuracy gains start to become dramatic relative to smaller contours. With good factory ammo, you should be .5 MOA or below; with well-tuned reloads, you should be .3 or below all day. For hunting, that should be more than good. Moving up in the weight of the contour from there isn’t going to get you any additional benefit within the context of hunting.

I would be thrilled with a sporter barrel that shot in the .3’s.

 

[epc308]

I have spent literally years and $thousands 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 one MOA 5-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.

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 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. 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.

What say you?

John

Have you tried a light weight contour with some forend pressure? I have a 25+ year old Remington Mountain Rifle in 7mm-08 with the pencil thin contour. The original wood stock had a fair amount of upward pressure. Fast forward to putting it in a synthetic stock. I bedded the action and chamber area, free floating the barrel, because that's what the experts said, right? It went from 5/8"-3/4" 5 shot groups to plate size. I full length bedded the barrel, the groups dropped to about 3-4". I started shoving shim stock between the barrel and forend tip, kept shooting, and watched the groups shrink back to the original 5/8-3/4". The rifle has always shot way better than anyone expected. Score one for big green the day that one was built.