Proof barrel issue

Couple of details might help. Barrel twist and length, bullets tried, what powder, what primers, what brass. I am assuming you have a good smith.

Is it Carbon Fiber or SS?

I experienced the same thing with my Proof CF. It’s a hunting rifle so the 1.5@100 was somewhat acceptable but not ideal. Low and behold, after about 150 rounds the thing settled in and now she’ll shoot 1/2 moa with factory Nosler hunting ammo. None of my other cut barrels did this, but now this one is good and I expect a lifetime of shooting out of it. Go figure.

I have owned 4 proof barrels - 3 being prefits proof cut. They shoot phenomenal. I only buy the prefits now because it’s a lot cheaper and I’ve had a gunsmith who cut one that would not shoot and my very expensive barrel is trash.

What bullet are you shooting?

My local smith had said, in his experience, proof barrels need a lot of shots fired to break in, vs bartlein ... which is local for us. Maybe true maybe not for your case?

Adam B said:

Berger 180, 184, 190
Hornady 162
Hammer 177
Cayuga 170
None will shoot
I think the throat is too long, here is a pic of one touching the lands and one that is mag length

Click to expand...

Sounds like you have some good bullets you have tried. How close to the lands have you tried shooting them? Or have you stuck with mag length?

Run a Teslong bore scope down it and a tight fitting patch feeling for any loose spots. LRO Forum some guys had some barrels out of spec. Think it is uncommon, but easy to check. I have 1 proof barrel in 6 creedmoor. Could be more smooth. Would buy another but think they should take a few more passes lapping them.
Longest break in of any aftermarket barrel vs Brux, Bartlein, Muller, Schneider, Shilen, Hart, or Wilson. More along the long of the lines of a factory remington stainless barrel.

BTW,
My Proof CF barrels (4) are all very good. Going with a new one now on a LPA Ti action.

That long of a throat will not help accuracy issues, but I would think you could get it to group better than 1 MOA still. You could see if they can cut a little off of your barrel and rechamber it with a shorter throat before you buy another barrel.

Assuming you measured to the lands correctly, that throat is way too long. Doesn’t look like you have anything left in the neck of that case.

Adam B said:

Berger 180, 184, 190
Hornady 162
Hammer 177
Cayuga 170
None will shoot
I think the throat is too long, here is a pic of one touching the lands and one that is mag length
View attachment 7495522

Click to expand...

What reamer? It would help to know the freebore spec, that seems pretty long for s custom barrel, but i have had plenty of factory barrels that shot fine with freebore like that. Have you talked to proof, I would hate to have to burn 200 rounds to get top quality cut rifled barrel to shoot. They would know if that is common. i am guessing it is not.

I had a Kreiger that wouldn't shoot. i sent it back to LRI, and they hashed it out with the maker and rebarreled the rifle. Pretty good customer service IMO. I sent them the blank too, so it wasn't even their baby. I imagine their word the barrel wouldn't shoot, is better than mine when calling barrel makers.

7 twist in a 7mm? Jesus man! This is not helping your cause either. The first thing I would suggest is do a seating depth ladder. You should be able to get it to shoot if the chamber was cut straight. It looks like your throat was cut to run heavies in a long action. Be careful pushing too fast, you’ll start to blow up bullets. I have that issue in my saum with 180 eldm’s at 2990 with an 8 twist proof steel.

My small sample of proof barrels shoot immediately, prefits and smith chambered.

That is a whole lot of jump. Wow.

7 twist? Did you mean 8? Didn't think Proof made anything less than 8 in 7mm.

I know recently of one barrel of a friend that shot like yours. He could load one bullet really slow, but it lost too much velocity. Hard for me to believe it is the barrel, but it could be. I would believe it is other factors before the barrel though. Reminds me of the recent thread where IIRC, it took two top smiths to figure out it was actually the action...

I would start with the chambering, see if something is messed up there. Check the stock, trigger, all sorts of other stuff before you tomato stake a proof.

Definitely sucks...

Adam B said:

It is a 7 twist based on what I was told by the original owner (who won’t stand behind the barrel now). 1:7 will easily stabilize all of those bullets based on the Berger bullet stabilizer calculator

Click to expand...

Sounds like the original owner knew the throat was too long and wanted rid of it. see if you can finds someone to borescope and rechamber it , the rest of the barrel is likely fine.

Adam B said:

It is a 7 twist based on what I was told by the original owner (who won’t stand behind the barrel now). 1:7 will easily stabilize all of those bullets based on the Berger bullet stabilizer calculator
View attachment 7495594

Click to expand...

Stabilization isn’t the issue, more like over rotation of the projectile. Theres been a bunch of differing opinions over the issue, makes for some interesting reading. One opinion is with standard cup & core bullets, spinning them too fast will lead to bullet failure inflight. I’ve experienced this with hornady’s in my 8, the Berger’s are fine, could be more of a QC issue with Hornady. With your barrel/throat combo, I wonder if it was set up for solids in a long action? Solids would be awesome though expensive. Or it could be as simple as whoever cut your chamber ended up cutting it a bit too long.

Another option is sending it to one of the smiths here. A shop like LRI or equivalent will tell you exactly what’s going on. Definitely a shitty situation to be in

BJames said:

Stabilization isn’t the issue, more like over rotation of the projectile. Theres been a bunch of differing opinions over the issue, makes for some interesting reading. One opinion is with standard cup & core bullets, spinning them too fast will lead to bullet failure inflight. I’ve experienced this with hornady’s in my 8

Click to expand...

I have not seen this in my long action 7 WSM 8 twist, 28" Bartlein barrel. I have pushed well north of 3000 fps with this combo, never seen a 180 eldm go poof. I might be lucky or you unlucky, but this is the first I have heard of this problem at those speeds. Either way, I agree with the rest of your post.

Rounds 4 thru 9 on a spankin new proof carbon, in one grain increments. No published data for this combo. They act like other high quality barrels in my experience.

Contact proof, they’ll likely stand behind it.

Shouldn’t hurt anything, although if asked proof will say don’t saw any shank off prior to chambering.

You tried putting that barrel on with torque vs the bind screws only?

Adam B said:

one other thing that made me curious is why is the shank so short on my barrel when this the shank of an unchambered barrel
View attachment 7495661View attachment 7495662

Click to expand...

many take 1' off of the muzzle end as the bore swells a little at each end, but they shouldn't need to take much off of the chamber end as the reamer removes all of this material. Once again sounds like someone's screw up

Sounds like your smith is treating you right. Do you know if the barrel was originally intended for a long action? Or did the previous own request a custom throat? If the smith is offering to replace it, they might be able to give some information about the history of it.

2.95 with what bullet, and what is your mag length?

how did it shoot for previous owner?

Supersubes said:

Contact proof, they’ll likely stand behind it.

Click to expand...

I have a proof in 308 that shoots OK. Getting better over time also. My Criterion 30-06 is more accurate out of the gate though.

Damn that sucks! I can guess the smith just by the engraving and if I’m right, they have cut me 3 Proof barrels for my vector. Zero issues and they will take care of you.

I have two carbo fiber proof barrels on chambered by proof and the other by Dave Tooley on a Tikka. Both shoot extremely well right off the bat. The one that Proof chambered is a little ugly looking at it with a bore scope but it shoots.

I would just let the smith get you a new barrel and chamber it. Sucks to wait but at least they are willing to stand behind their stuff.

This kind of stands out for me, however, i am not a gunsmith and can almost safely sharpen a pencil . It also looks that the set screws aren't fully on that strip??

Adam B said:

good catch, none the less they still have to fix it

Click to expand...

This one of the Zeus barrels i bought from you....in comparison

I had a proof barrel not to long ago that was shooting pretty poor compared to all my previous proof barrels. It took 60-80 rounds and then tightened up. My previous barrels shot excellent from round 1

Adam, I hate to ask but will b/c I haven’t seen it mentioned yet. Have you eliminated the optic and mount and checked the bedding? Just to be on the safe side...