6.5 PRC headspace?????????

[bluedog69]

So this is a new factory rifle that I had another thread on. Best 4 shot group 1.25" at roughly 140 yards. The ONLY group that small. Letting barrel cool about 5 - 10 minutes between the shots. ALL the other groups have been 3" to 7".(let's just say BAD) 4 or five different bullets. 2 factory loads. 3 powders. 4 different seating depths. Glass bedded the stock.

So this is my last ditch check before I get a new barrel. See picture. These were taken with a lathe made headspace gauge. Hole is about .4215 instead of .420 but oh well.
Hand loads on left. Factory loads for comparison using my gauge on right.
Thoughts?????

 

[bluedog69]

So is .005 to .008 to .010 a heck of a stretch?

My main question is is there any chance that I can tighten the barrel up.(less headspace) and get it to tighten groups up?

Second question is why does there seem to be such variance in headspace on resized cartridges? Do I need to lube case necks? Is the expander ball pulling some back out longer?(see left column)

 

[Dmagna]

So your fired brass was 1.646 and you resized it to 1.639? That's a huge resize, set your dies to the specific brass and only resize .002. You are resizing past pre fired brass. I am not trying to be rude but I think you are doing things very wrong, and potentially dangerous

 

[QuietTexan]

Once-fired brass shouldn't be resized to the point the shoulder moves pretty much ever, definately not -0.008".

But that said none of those brass measurements have a thing to do with shooting 7" at 140 yards. You have a major problem, send it back to the manufacturer. Another round of Factory Barrel Roulette that landed on 00 and went to the house.

 

[bluedog69]

So your fired brass was 1.646 and you resized it to 1.639? That's a huge resize, set your dies to the specific brass and only resize .002. You are resizing past pre fired brass. I am not trying to be rude but I think you are doing things very wrong, and potentially dangerous

So my question is this…. Is the factory headspace way off? Is my Redding die way off?
Probably 99.99% of reloaders have never measured headspace and resize according to die instructions.

 

[bluedog69]

Once-fired brass shouldn't be resized to the point the shoulder moves pretty much ever, definately not -0.008".

But that said none of those brass measurements have a thing to do with shooting 7" at 140 yards. You have a major problem, send it back to the manufacturer. Another round of Factory Barrel Roulette that landed on 00 and went to the house.

So I have never ordered a custom barrel.
I do know that I will pay shipping to the manufacturer they will pay it back.
What are my chances that a new custom select match Shilen prefit will not shoot under MOA?
I have several other factory rifles of this brand and all of them shoot well under MOA.

 

[bluedog69]

Once-fired brass shouldn't be resized to the point the shoulder moves pretty much ever, definately not -0.008.

Do you suppose that my Redding die is that far off? I set it to spring over on the handle a little. (Yes I have experimented with just neck sizing before)
Just seems weird that a die would be made to where it would size it that far past factory. Die Roulette?

 

[QuietTexan]

Very common for FL dies to be able to oversize brass. Set the die to size ~3/4 of the neck until the case doesn't rechamber without resistence, then throw the instructions that came with the die away and set it up correctly:


At 7" there's no telling what's wrong it could be so many things. IMO don't sink your own money into the rifle until the factory fixes whatever the root issue is and gets it down to about an inch. It might not be just the barrel that's causing problems, that's a God-awful level of hot garbage precision there.

Shilen makes good barrels, but you run the risk of putting a good tube on a buggered action until the manufacturer get's it to less horrible.

 

[bluedog69]

Very common for FL dies to be able to oversize brass. Set the die to size ~3/4 of the neck until the case doesn't rechamber without resistence, then throw the instructions that came with the die away and set it up correctly:


At 7" there's no telling what's wrong it could be so many things. IMO don't sink your own money into the rifle until the factory fixes whatever the root issue is and gets it down to about an inch. It might not be just the barrel that's causing problems, that's a God-awful level of hot garbage precision there.

Shilen makes good barrels, but you run the risk of putting a good tube on a buggered action until the manufacturer get's it to less horrible.

Thanks for the info. I probably will call them and see what they say.
That was my main concern. Buying a barrel and still having problems.
BTW I have neck sized many of my guns before. This being a brand new gun I was just trying to break it in and see what was up before I started messing with just neck sizing.
Another one just like this purchased at the same time is shooting .5-.6 MOA at 300.
Guess I finally got a bad one.

 

[Varmint Hunter]

Sounds more like a bedding or optics issue to me, but that's just a wild guess.

Before you return the rifle, you should eliminate the possibility that it's being caused by the scope, rings or mounts.

 

[cajun]

Do you suppose that my Redding die is that far off? I set it to spring over on the handle a little. (Yes I have experimented with just neck sizing before)
Just seems weird that a die would be made to where it would size it that far past factory. Die Roulette?

This is why you should buy the Hornady headspace tool and set your die to bump shoulders .002. At least you didn't have a case head separation due to over sizing. It happens. There are tolerances in chambers, tolerances in dies. Sometimes you get all that working against you. Also, die manufacturers want their dies to resize brass fired in a minimum chamber. If your chamber is on the max end you will be over sizing. But that being said I don't think that is your accuracy problem.

 

[bluedog69]

Sounds more like a bedding or optics issue to me, but that's just a wild guess.

Before you return the rifle, you should eliminate the possibility that it's being caused by the scope, rings or mounts.

Yep. We have tried two different scopes. Re mounted blue Locktite everything. And I bedded the stock.

 

[Varmint Hunter]

Yep. We have tried two different scopes. Re mounted blue Locktite everything. And I bedded the stock.

Then I guess the next step would be to contact the manufacturer. Good luck.

 

[bluedog69]

Then I guess the next step would be to contact the manufacturer. Good luck.

Yep. I have about exhausted every possible thing so far.