Crooked chambers/ uneven lands

[DLT]

How many have had factory built guns that shot great and upon inspection later with a newly acquired bore scope noticed the chamber / lands cocked ? Several moons ago I bought one of the first savage 6mm creedmoors from a big box store, shot it very few rounds and sold it off. Well it’s found a way back home and now I have a bore scope and it’s pretty ugly lol. I know it’s happened to more than just me

 

[AccelR8]

How many have had factory built guns that shot great and upon inspection later with a newly acquired bore scope noticed the chamber / lands cocked ? Several moons ago I bought one of the first savage 6mm creedmoors from a big box store, shot it very few rounds and sold it off. Well it’s found a way back home and now I have a bore scope and it’s pretty ugly lol. I know it’s happened to more than just me

Me.

 

[paperpuncher]

Yep borescope is a tool not a crystal ball

 

[Bill K]

Just about every make and model of rifle will show up sometimes with bore, etc. looking ugly. BUT often they shoot so well, it does not matter how they look.
It is how they shoot and group that counts.

 

[SKWERLZ]

How many have had factory built guns that shot great and upon inspection later with a newly acquired bore scope noticed the chamber / lands cocked ? Several moons ago I bought one of the first savage 6mm creedmoors from a big box store, shot it very few rounds and sold it off. Well it’s found a way back home and now I have a bore scope and it’s pretty ugly lol. I know it’s happened to more than just me

I had a Shilen savage prefit in 260 that was a really good shooter and had a pretty wonky chamber with rings that lightly marked brass and a very cattywampus throat

 

[Murray Brook]

Purchased a varmint barreled 22/250 last year off of Gunpost here in Canada. Got the rifle and was very pleased with the outside. Got out the bore scope and started down the chamber. Looked great till I got to appx the 10" mark. From there to appx the 18" mark it looked very bad. Got in touch with who I purchased it from and sent him a video of the bore. He told me to shoot it ( develop a load) and then we would talk. Rifle shot in the low 4's. Told him no way was I sending it back. Barrels can be a tricky item.

 

[ChrisNZ]

I've seen a borescope video of a Rem700 .308 with the bore 40 thou eccentric to the throat. Surprisingly, it didn't shoot well..

 

[urbanrifleman]

Yep borescope is a tool not a crystal ball

Well said.

 

[DShortt]

I've yet to personally see a barrel with a non-concentric throat that shot well. If I ever do I'll change my mind. Meanwhile I want my throats and chambers concentric to the bore.

 

[Ray Gross]

I had one some years ago, shot fine. But I never sent another barrel to that gunsmith

 

[Dimner]

Does anyone have a picture of what this would look like? Any tell tale signs? Maybe I'm just lucky and have not had one.

 

[SKWERLZ]

Does anyone have a picture of what this would look like? Any tell tale signs? Maybe I'm just lucky and have not had one.

You can easily see in equal land lengths in the throat as you rotate the bore scope when they are not concentric.

 

[JLDavid]

If you wanted to keep the barrel because it shot well would you set it back and rechamber it concentric to the bore? If so, how much would you set it back? 1/4"? 1/2"?

 

[Bronsin]

I have a M700 in .270 with a throat like that. Shot like hot garbage, so I had a new barrel put on.

 

[DaveTooley]

If you wanted to keep the barrel because it shot well would you set it back and rechamber it concentric to the bore? If so, how much would you set it back? 1/4"? 1/2"?

If it shot well why would you do anything.
It's impossible to straighten one without cutting most of the chamber off.
You have to straighten the hole with a boring bar.

 

[Ggmac]

listen to the target not the pictures of the barrel

 

[skeetlee]

I guess it all depends on what you consider shooting well? Yes lots of factory barrels have crooked chambers. They do because these big gun makers chambers these barrels off a live center. They don’t dial in a single thing I’ve seen myself this process at one of the more well known and trusted competition AR barrel makers shop. I was truly in shock. I’ve personally never seen a crooked chamber shoot better than 1/2” consistently. Ya maybe a wallet group here and there but never with any consistency. Stranger things can happen I guess.
Lee Gardner Precision

 

[338 Mollett]

I worked up a load for a buddy with a new rem 700 in 7 mag to deer hunt . The chamber was so crooked you could not see the angle of the throat on one side . It still put three in a half inch at 100 go figure .

 

[swd]

I had to do a setback on pre M70 about 15 years ago that had .008” run out at the back of the chamber. You just do the best you can at that point..

 

[DShortt]

If it doesn't look similar to this then what good do custom dies and checking runout do? You're bullet enters the barrel and is immediately thrust out of concentricity.