Shrink group size...some advice or help.

[Orange Dust]

I am going to go out on a limb and say play with the seating depth on the 98gr load with the 215's. You are close. I know it isn't the bullet you want to shoot, but every rifle is different. My new 28 has a node that is so narrow I can't believe it. .2gr either way and it opens up. It just does not like heavy bullets and I've had to force it to like at least one load. Spent a lot of money on it too, and it has been challenging to say the least. I think it has broken me of Proof barrels.

 

[L.Sherm]

I think it has broken me of Proof barre

Why do you say that?

 

[entoptics]

You've proven you can shoot with the other rifle, so I think it's the rifle or scope.

If you were getting 1.25 MOA groups, chasing 3/4, sure it might be powder/seating/bullet/bipod, but you've posted some 2-3 MOA groups from a variety of recipes with pretty consistent fliers and/or dramatic vertical stringing.

Just swap the scope before you burn any more barrel up.

 

[Orange Dust]

Why do you say that?

For a whole list of reasons, if I ever do another one it will be in a small cartridge like a 6.5x47. When the one on my 28 is toast its getting a Hart.

 

[L.Sherm]

Carbon or steel?

 

[Tensilon]

Shooters.... after reading through most of this thread, with all of your troubles, I was going to drop you a line with a suggestion a couple of days ago. Now I see that others have to some degree also addressed just what I thought might serve to isolate an issue more effectively. You are certainly chasing your tail with this one. First thing to do is check the barrel with a dial indicator while tightening and loosening the front action screw. If the barrel moves up or down that would show up on the indicator. Any movement of the barrel indicates that it is under stress and this could be the cause of vertical stringing. If it does move up or down this would mean the bedding is probably causing the stress and it would need to be reworked. If the barrel stays where it should be the next thing that might isolate any issues further would be to dump the bipod, not forever just take it off for now. Get sandbags for both the front and the back. I know you said you have a back bag but get one under the front also...any big bag will do. Pick your best load to date. If you have been shooting off of a bench then do that again. Hold very solid forearm when you shoot and see if it tightens up for you. I have seen many shooters that had problems with using a bipod for whatever reason, become amazed after they tried their problem child over the bags. If your groups do not substantially get any different, I would probably make the assumption that the barrel itself is bad. I don't have the correct set of machinist's equipment and or tools to check all of the things that could be wrong with a barrel so I would be most likely try and get a replacement from wherever I got it. As others have pretty clearly stated... using a bipod can in and of itself be a problem that can degrade consistency. No disrespect or anything like that meant at all... I just believe that reducing the rifle to it's bare self can give a more accurate assessment of consistency (accuracy) issues.
Good luck with this rifle. I hope it comes together for you.
Tens

 

[Orange Dust]

Carbon or steel?

The one I have now is my first carbon. Will replace with Hart SS

 

[palerider3]

Reading through this thread a number of things have struck me. First, I see you loading groups of different powders and charges all over the place. If it were me I'd start by picking a powder and the bullet you want and shooting a ladder through a chronograph to find the node. Load 1 round at each charge weight .3 grains apart and shoot them one every 2 or 3 minutes till you see the first sign of pressure. Then look over the results and pick a charge weight in the middle of the node. Then load 4 rounds each .020", .035" and .050" off the lands and shoot for groups with those. If that doesn't get me the results I want, something is wrong. I had a Schneider barrel that a sponsor spun up for me on my PRS rifle that did the same thing. Nothing would shoot well. After checking everything else I finally measured the fired brass and if was the same diameter as a loaded case. I called the Smith and had him measure the reamer and found the reamer was mis marked. I had .0005 neck clearance and the bullet wasn't releasing freely and it caused all kinds of issues. Unfortunately we didn't have time to get another reamer and I ended up neck turning a whole pile of brass. Shot great after that. Might be something for you to check. Have you contacted your gunsmith? Most reputable Smith's would want to know of a gun shooting this badly and would probably want to check out the gun. As frustrating as this may be, I definitely wouldn't write off proof barrels forever over this either as there's a lot more variables than the barrel and you'd be more likely to find a gunsmithing issue than a actual bad barrel. Hope you figure it out.

 

[Shane Lindsey]

As suggested, stick to one powder and one bullet.
Different manufacturers have different specs/alloy contents in their jackets that act differently when shot over each other. If anything, it will be very hard to duplicate.

I have seen this when shooting different bullet/ powder manufacturers. Several shots to get it to group with any consistency. Very similar to a clean barrel that needs to be fouled.

 

[Mram10us]

I'm definitely looking forward to you shooting again. I really think you are close to an answer. My initial guess is barrel heat, but it might be premature. If you were in Idaho I'd head out to the range with ya.

 

[L.Sherm]

The one I have now is my first carbon. Will replace with Hart SS

I've loaded and shot 3 Carbons and 4 or 5 of Proof's Steel barrels and all shot extremely well. None seemed to be any different than other good barrels ive loaded for.

 

[Mram10us]

I've loaded and shot 3 Carbons and 4 or 5 of Proof's Steel barrels and all shot extremely well. None seemed to be any different than other good barrels ive loaded for.

You're lucky. I've built 4 in the last year and 2 didn't like stringing more than a couple shots together. Bedding was stress free and barrel was floated

 

[Orange Dust]

I dont like the way they hold heat in overbore cartridges, and the one i have is very hard to tune. Pretty soured on them right now. They cost twice as much as a good steel barrel. Look cool, but not worth the extra money IMO.

 

[Mram10us]

Mine were 300rum, 7-300wm, 28 nosler and 6.5-284. 7-300 was amazing for two (see pics) but not for three. Rum was a bit finicky but ended up loving 225 elds. 6.5 was a 6.5. 28 nosler shot great out of the gate. When I shot one every 2 minutes or 2 then let cool, they all shot fine.