Finding the lands troubles


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rb85cj7
August 29, 2011, 06:16 PM
A buddy built a 260 on a long action and gave a model bullet to the smith. there was a misunderstanding somewhere along the way as the smith built it to SAAMI min specs. there for to shoot the berger 140's there was barely any bullet sticking out of the case and really defeated the point of having it on a long action. however, it shot awesome. Since then he took it back to the smith to have it re-throated like he originally wanted and it has never shot near what it originally. We had been using the old trick of loose neck to find the lands and it seemed to work, but I finally bought a Hornady COAL gauge and have some questions. it feels as though I can still feel the original lands. I can push through them to get to the actual lands but it leaves marks on the bullets. when I compare this to my factory 308 it is night and day. 308 is smooth and very easy to find compared to the 260.

My question is, is this normal on custom guns or do we need to go back to the smith again. (or a different builder)

Shilen 6.5 barrel
BC stock
Remington 700 LA
new lands are 2.363 using the COAL tool zeroed out with bergers and 2.368 using AMAXs.

first sign of resistance is 2.200 with COAL gauge zero'd

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noylj
August 29, 2011, 11:38 PM
Personal opinion--you don't mess with an accurate rifle.
You need to inspect the chamber and be sure it is clean. Your 'smith may have a bore scope any you can all inspect the chamber and decided what needs to be done, if anything.

243winxb
August 30, 2011, 11:25 AM
it feels as though I can still feel the original lands. The new longer throat is now rough & tight is my guess. SAAMI measurements here> http://www.saami.org/specifications_and_information/index.cfm?page=CC 260 rem. drawing> http://www.saami.org/PubResources/CC_Drawings/Rifle/260%20Remington.pdf

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