OAL shrinkage??

[bama110]

I shoot a 6.5X284 and load to .005 of the lands which is 2.964" with a 140 grain Sierra MK. If fired the rifle 200 round and loaded more. I noticed the new rounds would not chamber. After triple checking length. I decided the rifle must be dirty. I cleaned and cleaned let soak overnight and cleaned and my new OAL is 2.910 and the bolt will barly close.

Do I need to get a throat reamer and rework the throat. I am at a lose???

 

[ANDY5]

Is your primer seated all the way in?

 

[Preacher]

It may just be long cases causing the problem, and not OAL.
Seems strange that cleaning would cause you to loose .054
of OAL, but maybe you changed it.
Will a fired case go back into the chamber with no resistance ??
If it won't, size em a little at a time till they will...........

 

[bama110]

I check the head space it has not moved. I full lentgh sized my brass and checked length and trimmed where needed. A empty case will chamnber without resistance. That is what has me puzzeled? I do not have a bore scope but I have trouble believing it is not clean. I have used Hoppe 9 BR and let set over night. I have used Barnes copper foul out. I have scrubber with nylon brush, patches, and single passes the bronze brush. I appretitate all Ideas.

Thank you

 

[sjk]

+++ to all of the above, but check this also. Place the fired case into the chamber, if it does not fit knock it out and put it in again but this time at a different position and so forth and so on. I'm not saying that you have an eccentric or out of round/bulged,it does happen) chamber, but it's a fast way to check if it has. If it is the problem, then you do have a problem, but one that can be easily fixed by a knowledgeable person, not a garage gunsmith.

 

[treeman]

I would suggest takeing one of the loaded rounds[out side to check fit] then seat the bullet deeper in the case a little at a time and see if that helps. also check loaded round neck size compared to chamber neck size. you can get a fairly acc. measurement of neck size by driving a pure lead ball into the neck portion of your chamber with a wood dowel then push it back out with a cleaning rod with a jag on it and measure the neck portion with a mic. hope this helps good luck. ______treeman

 

[Dubya]

Hi Bama110,
You say you are full length sizing, but does that include bumping the shoulder back .002-.003 ?
What is the neck size after firing? And what is it after sizing?
Sierra load book suggests OAL for 140 SMK at 2.910, and you did not mention what tools you are using to get your OAL.
I am not questioning your methods, just making some suggestions you may have over looked.
Good Luck & Good Shooting.
Gary.