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Chamber cast shows rifling is "off"

joshb

joshb

Gold $$ Contributor
I got a new to me used gun. I did a chamber cast today to check dimensions and noticed something off. On on side of the casting, the rifling is approximately .18 from the edge of the neck. Roll the cast almost 180* and the rifling is app. .10 from the edge of the neck. Is this showing me that my chamber is off center of my bore? If so, how bad is it? Thanks for any thoughts, Josh.
 
joshb said:
I got a new to me used gun. I did a chamber cast today to check dimensions and noticed something off. On on side of the casting, the rifling is approximately .18 from the edge of the neck. Roll the cast almost 180* and the rifling is app. .10 from the edge of the neck. Is this showing me that my chamber is off center of my bore? If so, how bad is it? Thanks for any thoughts, Josh.
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Only then target will tell. Larry
 
I ran into this once, rifle shot great but I saw pressure problems early. A throater fixed the pressure problems and rifle continued to shoot well. It could be a reamer pilot issue, however, as Larry has already mentioned, only the target will tell if it is a problem.

What caused you to get a chamber cast?

-Mac
 
it's common for rifling to wear more on one side than another, it tends to become more exaggerated as the wear increases, starting out with a slightly off center throat doesn't help
 
mac86951 said:
I ran into this once, rifle shot great but I saw pressure problems early. A throater fixed the pressure problems and rifle continued to shoot well. It could be a reamer pilot issue, however, as Larry has already mentioned, only the target will tell if it is a problem.

What caused you to get a chamber cast?

-Mac
Click to expand...
I cast the chamber to find the neck dimension. I just bought this gun from a guy who bought it from a friend that built it. It was the sellers first bench gun and inferred that it was"over his head". He couldn't give any specs except caliber. I got it for the sum of it's parts. The barrel was not marked. I thought it would be quicker than trying to get the specs "thru the grapevine" and more accurate if I just cast it myself. Call it "peace of mind". It'll be my face behind the gun.
 
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I cast 100% of my chambers. I find it a good practice because I have actually had a riflesmith use the wrong reamer on my barrel - same cartridge as my reamer, just not *my* reamer.

Yes, it was corrected immediately upon discovery. That is also the best shooting barrel I've ever had - in any caliber!
 
joshb said:
I cast the chamber to find the neck dimension. I just bought this gun from a guy who bought it from a friend that built it. It was the sellers first bench gun and inferred that it was"over his head". He couldn't give any specs except caliber. I got it for the sum of it's parts. The barrel was not marked. I thought it would be quicker than trying to get the specs "thru the grapevine" and more accurate if I just cast it myself. Call it "peace of mind". It'll be my face behind the gun.
Click to expand...


Understood, Given the information provided I had to assume it could have been a new to you used R700, or other factory rifle which you might be accurizing due to poor performance.

So, you aren't chamber casting due to some other problem which is prevalent. Certainly the best way to know for sure what chamber is cut and what neck dia. to turn

You'd be surprised how many times we get a question on this forum, where we have many specific and well planned activities to solve the problem to find out that there was a bigger more glaring root-cause.

I'd recommend evaluating its performance baseline then.
In my case, I created a chamber cast as a friend and I ordered two barrels, and when working up loads we found that my barrel reached pressure signs far before his barrel did. Both were accurate, but I found that curiosity got the best of me and researched further.

-Mac
 
Sorry. There I go, not giving enough info. It's a Krieger on a Bat MB action. I don't know who did the chamber.
 
Obviously this is not a desirable situation. How does it shoot? It would be interesting to set the barrel up in a lathe on the CL of the bore (which would be a bit tricky given how far in you would have to indicate) and check the tenon, shoulder, and back of chamber for runout.
 
BoydAllen said:
Obviously this is not a desirable situation. How does it shoot? It would be interesting to set the barrel up in a lathe on the CL of the bore (which would be a bit tricky given how far in you would have to indicate) and check the tenon, shoulder, and back of chamber for runout.
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It is .018 off half of that would .009 be the shoulder has nothing to do with bore being off center. Larry
 
BoydAllen said:
Obviously this is not a desirable situation. How does it shoot? It would be interesting to set the barrel up in a lathe on the CL of the bore (which would be a bit tricky given how far in you would have to indicate) and check the tenon, shoulder, and back of chamber for runout.
Click to expand...

This is nothing new..... seen that much chamber runout and worse in factory barrels a few times over the years.
Had a Savage through the shop that basically had 100% run out to one side. And a 700 Remington once that was similar.

On a whole, of rifles made the last few years, Sako & Tikka have the best appearing chambers and barrels that I see.
 
dmoran said:
This is nothing new..... seen that much chamber runout and worse in factory barrels often over the years.
Had a Savage through the shop that basically had 100% run out to one side. And a 700 Remington once that was similar.
Click to expand...
Year ago it was very common. The reamer's didn't have bushings. Larry
 
Larry
I see it more in the ladder years then older rifles.
And wonder how many factories would use bushing reamers any how..... betting few do (carbide solids)
 
Fellows, you must have overlooked this additional information. "Sorry. There I go, not giving enough info. It's a Krieger on a Bat MB action. I don't know who did the chamber."
 
^^^^ Yep.... missed that....

Sad to hear a smith chambered that much runout, and didn't check and/or rechamber his own work.
There are no doubt some "want-to-be's" out there.....
 
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Assuming that it does not shoot up to expectations, I think that the tenon could be cut off and a new chamber cut, starting with drilling and boring so that the old one would not push the new one off center. A friend has done a little experimenting cutting most of the chamber pushing the reamer with a center and then switching to a floating holder for the last bit. His particular lathe has very good vertical tailstock alignment. The backs of the chambers that he has cut that way are as tight as the reamer, and very well aligned.
 
I just rebarreled a 700 sendero for a client since it would not shoot groups and since he bought it used Remington would not make it right but the chamber was .009 TIR and the back of the chamber. So he opted for the krieger and is now shooting very well.
 
I'm confused the first post says it's off .180 on one side and.100 on the other. later post are talking about .018 which is it?
 
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