6XC coal

SmimL7

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Jan 22, 2012
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I purchased a used 6XC barrel for my AI which supposedly only had a few hundred rounds through it. After determining my seating depth with 115 VLDs right at the lands I’m getting a coal of 2.9100 Which seems to be long for this cartridge. If I shorten it up, I’m gonna be way off the lands. Am I missing something or did I get a barrel with a worn out throat?
 

spife7980

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Feb 10, 2017
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Are you also measuring the ogive with a comparator? I can offer some ancillary data based on those right now.

With my 6xc and 105 rdfs (different bullet I know) I get a measurement of 2.133 to the lands based on the ogive with my hornady 6mm comparator, your comparator can easily be slightly different but it should be close enough to tell if you are having a glaring issue. I shoot them .02 off at 2.113" Im not sure what the actual over all length comes to but if you have a comparator you can check and see where you are at relative.

My chamber was the normal ptg reamer that criterion uses that has a .105" throat. I set it with a ptg go guage and a piece of scotch tape so I should be no more than .002 over spec.

Ill measure my OAL when I get home tonight.

Capture.JPG

How did you find out your distance to the lands?
 
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Supersubes

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    My reamer is a .160 fb. A 115 dtac at a .020 jump(I think, not more than .030 for sure), is 2.73. Ive never used the berger 115, so no idea how short the bearing surface is or how long the nose is for a comparison.
     

    SmimL7

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    Thanks for the reply guys. I’m not using a comparator. I’ve partially seated the bullet into the case then close the bolt on the cartridge. This is where I’m getting the 2.9100 measurement.
     
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    spife7980

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    My rdfs being 2.113 on the ogive pretty much exactly give an oal of anywhere between 2.690-2.700 with an even distribution throughout that range.
    The bullet itself is 1.240-1.250” long. Base to ogive is .662

    Do you know where yours was chambered at that could could maybe ask for a reamer print? Because as you can see there’s a big difference between .105 and .160

    Did you strip the bolt like this? Or are you trying to guess through the ejector and firing pin? When you close it have you sharpied the bullet to see if you can see exactly where the land imprints disappear? It’s easier with a micrometer but even with out the coarse adjustment can give you a finer touch down to a hundredth maybe


     
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    SmimL7

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    I tried something else and found I was a little off but my coal is still long. I typically remove the ejector but the AI bolt head is epoxied to the body so I didn’t this time. I removed the barrel and started seating them .001 deeper at a time until the case would just fall out of the chamber. I’m at 2.8180 which still sounds excessive. The barrel is marked Stuteville precision, so I try contacting them to see if they could tell me which reamer was used.