Proof barrel way out?

[Nealm66]

My 300 prc shot like crap with factory. Shoots 1 big hole at 200 with 245 Berger’s and 250 Atip hand loads. 245’s with n570 is 2940fps. Mild load for target with the 250’s.

 

[Nealm66]

Definitely not a roast but recommend not to judge by Hornady factory ammo

 

[jelenko]

Two, three shot groups is not enough data. Try repeating both at least 3 times.
The three shots at 100 could easily exceed the group at 200 with a couple more shots and the group at three hundred might not grow.

 

[Nealm66]

You can easily tighten them with an ats tuner to get through season but I’d really consider rolling your own

 

[PigButtons]

Not really in my wheel house, but I fully understand your concern, it's a dream build and you want it "RIGHT". It would be like buying a new car and having a shadow in the paint on the driver's door. It might get the best gas milage ever, never break down, but every time you climb in you are gonna see that shadow.

 

[jelenko]

Great analogies. For me it would be more like building a rig to use on racetracks and one of the tires has a blem. If the blem didn't affect the handling, I'd use those tires until they needed replacement.

A barrel is just a consumable.

 

[jackieschmidt]

I will put in my .01 Cents worth.

Barrel ID runout does not manifest its self in the fashion of a curve. If you look through most any barrel’s ID as it turns in the lathe, you will see spots that a running out at a specific area, and spots that run in just about the opposite direction in another area of the barrel.

Sometimes these areas of runnot are pretty close to one end. When you use the “Gordy” range rod method to true a barrel for chambering, and that particular barrel exhibits one of these spots where you are indicating, it will greatly influence the runout at the muzzle end.

I do not use this method of indicating a barrel, but I have had barrels that exhibited a fair amount of runout from the rest of the ID exactly where I want the throat to form. I don’t like this, but it is simply a product of the deep hole drilling process in the initial manufacturing stage of the barrel.

A while back, I took a unlimited barrel and scribed a straight line down the OD as a reference. I then cut the barrel in 2 inch long pieces an put each piece between centers to see the OD runout in relation to the scribed line.

It showed that the runout was random, almost in opposite directions just 4 or five inches from another spot.

I made a detailed account of this on BENCHREST Central and here.

Nobody really paid any attention. Most would rather just keep believing that barrels are “bent” in a curve rather than plagued with various spots that exhibit runnout in a seemingly random pattern.

 

[Alex Wheeler]

Jackie, I think what your saying is relatively well known. I do not think how the barrel is curved matters. But depending on how its indicated you can have the bullet entering bore thats concentric to the chamber or not. Once the bullets fully engraved its on a trip that can no longer be controlled. How it enters and how it exits, we can control. No doubt this is a debate that never will end, but I respect both trains of thought.

 

[jackieschmidt]

Jackie, I think what your saying is relatively well known. I do not think how the barrel is curved matters. But depending on how its indicated you can have the bullet entering bore thats concentric to the chamber or not. Once the bullets fully engraved its on a trip that can no longer be controlled. How it enters and how it exits, we can control. No doubt this is a debate that never will end, but I respect both trains of thought.

Exactly

 

[spitfire_er]

Thanks Alex and Jackie for chiming in, much appreciated. I understand that a barrel maybe a snake inside as was easily seen on this barrel. I could see the shift in bore "wobble spots" when I switched from zeroing for throat runout to zeroing both ends just as a check. It moved from muzzle end to the center as would be expected. I can't say if deflection was proportional in any direction or not. I haven't done as many barrels as you two, but I am always wanting to create the best product possible and always willing to listen and learn.

 

[HillbillyLongRifle]

All of this stuff gets lost in the mix if the barrel has a concentric throat and shoots lights out!

 

[jackieschmidt]

All of this stuff gets lost in the mix if the barrel has a concentric throat and shoots lights out!

^^^^^^^!!!!

 

[Hal]

Jackie if your worried about large rifle primers you could always bush a set of cases to small rifle and see if it makes a difference.

Hal

 

[kendog]

. ....Do I want a nice straight barrel... Sure I do. Does it really matter? ...

Mostly only at the keyboard.

 

[DR_2297]

The ratio between right and left side of the wire is so great that a metric ton of movement at the muzzle translates to very small movement at the breech. I would have dialed it in between pins sticking out each end to be coaxial at those two points and then evaluated the bore in the range of interest. Also need to make sure that you aren’t over tightening that copper and flattening it which will result in some bending of the barrel when trying to move it around with the spider. YMMV, just some of my BTDT observations.

 

[spitfire_er]

I still have the barrel. I'm going to put it back on and do some testing this summer. I'm fairly certain at this point in time that it'll shoot. Everything was concentric after I machined it so I am curious to see how it will do with some load development. I will report back when I have time to work with it.

 

[Delfuego]

One of my gunsmiths and a good buddy said he was done with Proof. He threw in the towel over a year ago and won't chamber them anymore. Too many issues, too inconsistent (both Carbon and Steel).