Proof barrel issue

[Adam B]

I have a proof barrel chambered in 7 SAUM. I have not been able to get it to shoot any better than 1-1.5 moa at 100 yards. I called the smith who chambered it and he is telling me that I need to do load development in order to get it to shoot. I have tried 6 different types of bullets with various charges and seating lengths and nothing shoots. I was also told by him that at 200 rounds it should just start to shoot. Now I have never owned a proof barrel in a centerfire before but that just sounds crazy. All of the other cut rifles barrels I have ever used have shot great out of the box. Am I missing something here?

 

[kyzim311]

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.

 

[RTH1800]

Is it Carbon Fiber or SS?

 

[uncle_smokey]

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.

 

[Maurygold]

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.

 

[Adam B]

It is a carbon fiber barrel, 1:7 twist, I am not going to name the smith right now since he is willing to stand behind it but he is well known.

 

[Shoots 700's]

What bullet are you shooting?

 

[Adam B]

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

 

[bb505]

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?

 

[kyzim311]

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

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?

 

[Adam B]

I am only loading them to mag length because the barrel has a useless otherwise

 

[6AYoteHunter]

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.

 

[RTH1800]

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

 

[Adam B]

So based on what I am seeing, I need to plan on spending $200+ in ammo just to get a $1000 custom chambered barrel to shoot

 

[kyzim311]

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.

 

[Greg0326]

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.

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

 

[Adam B]

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.

Exactly what I thought

 

[supercorndogs]

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.

 

[BJames]

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.

 

[hereinaz]

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]

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.

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

 

[kyzim311]

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

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.

 

[BJames]

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

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

 

[kyzim311]

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

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.

 

[Supersubes]

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.

 

[Adam B]

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.
View attachment 7495631

These are the results I expected, I have no idea why the smith would tell me 200 rounds for break in.

 

[Supersubes]

Contact proof, they’ll likely stand behind it.

 

[Adam B]

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

 

[Supersubes]

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]

yes did both and it didnt change a thing

 

[kyzim311]

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

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

 

[Adam B]

I am really hoping this isn't the case, I bought the barrel from a member that has been registered on here since 2013 and the smith is well know. The smith offered to take it back and give me a new barrel and rechamber it but I have to wait for a new barrel from Proof.

 

[kyzim311]

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.

 

[Adam B]

It was chambered for a short action Curtis Vector and was supposed to be for a 2.95 OAL

 

[kyzim311]

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

 

[Adam B]

just a little over 2.95

 

[Heretoimproveforhunting]

how did it shoot for previous owner?

 

[Sanwizard]

Contact proof, they’ll likely stand behind it.

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.

 

[Adam B]

how did it shoot for previous owner?

It was unfired by him

 

[Adam B]

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.

That is depressing to hear

 

[Lunchbox27]

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.

 

[Jrb572]

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.

 

[Adam B]

Dave is on a whole different level as far as I am concerned. He is one of the best!

 

[bb505]

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]

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

 

[bb505]

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

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

 

[Adam B]

This one of the Zeus barrels i bought from you....in comparison
View attachment 7495737

Well that was done by a smith I trust and I know does great work!

 

[Btillr]

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

 

[jbell]

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...

 

[Adam B]

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...

yes, I have used 2 different scopes and mounts