Rounds not chambering 6.5x47 Lapua

[Chaotik]

I am shooting a 6.5x47 Lapua rifle. Brass has 4-5 firings. At the range today, in over half of my reloads I was unable to close the bolt without using a lot of force (which I did not do).
My finished rounds neck diameter typically are .2905. The ones that would not chamber had a diameter of 0.2925 -.2930, which I think may be the problem. I have never turned necks for this rifle, but I am wondering if that is something I need to consider. Need help from the experts here. Thanks!

Process:
chamber neck .293 (my reamer)
neck thickness (micrometer) .0135 average
Deprime
clean wet tumble with SS media
anneal
body size (shoulder bump 0.002-.004)
neck size .288 bushing
trim
chamfer & deburr
primer pockets
expander mandrel .263 (using graphite lube in the necks)
powder
seat

 

[Webster]

I am shooting a 6.5x47 Lapua rifle. Brass has 4-5 firings. At the range today, in over half of my reloads I was unable to close the bolt without using a lot of force (which I did not do).
My finished rounds neck diameter typically are .2905. The ones that would not chamber had a diameter of 0.2925 -.2930, which I think may be the problem. I have never turned necks for this rifle, but I am wondering if that is something I need to consider. Need help from the experts here. Thanks!

Process:
chamber neck .293 (my reamer)
neck thickness (micrometer) .0135 average
Deprime
clean wet tumble with SS media
anneal
body size (shoulder bump 0.002-.004)
neck size .288 bushing
trim
chamfer & deburr
primer pockets
expander mandrel .263 (using graphite lube in the necks)
powder
seat

Sounds like you answered the problem. Chamber reamer .293, loaded round o.d. .2925-.293. 0.000 -.0005 clearance on the ones that don't fit. I would turn all the necks to get maybe 0.0125" wall thickness and see if it solves the problem. Some of the case may not have brass removed everywhere and some may get 100% cleanup.

 

[mikecr]

What do your fired necks measure for diameter?
Have you been FL sizing heavily?

 

[tmwinds]

As you size and fire a cartridge brass will flow into the neck. If your clearance was marginal to start with then it’s possible that some are to thick and need turning. The brass also grows longer and may need trimming.

 

[Chaotik]

What do your fired necks measure for diameter?
Have you been FL sizing heavily?

Fired necks are .292 before any sizing.

Yes, I was FL sizing with both a 6.5x47 body die, and this was followed with a .308 small base body die. (If I did not follow up size with the small base .308 body die, the base of the cartridge around the .200 datum line would be too big and it would result in difficult extraction.)

 

[Doom]

Check your headspace after using the 308 dies. You may be increasing the headspace as you decrease the base OD.

 

[HTSmith]

Well I am not an expert but I had an experience that may be germane. My first 6br had a .271 neck diameter (called no-turn at the time) and my batch of brass showed a measurement of .268 with bullets seated. Good to go. At about my 6th firing on the brass I was getting some rounds that measured a hair over .270. They had thickened and were too close for comfort. I got dragged kicking and screaming into neck turning. A lot of the unexplained flyers went away after I turned the brass. Just my experience.

 

[boltfluter]

First thing that comes to mind is using your dies in the wrong order. Use the small base die first, and then full length die. If you squeeze the diameter down in the back, the case will get longer. Good luck!

Paul

 

[Chaotik]

First thing that comes to mind is using your dies in the wrong order. Use the small base die first, and then full length die. If you squeeze the diameter down in the back, the case will get longer. Good luck!

Paul

Interesting. So if I am understanding correctly, once I have body sized and bumped the shoulder in the body die, I may lengthen the case when it is sized in the small base .308 die.....which could affect overall length and reduce any shoulder bump from the body die?

 

[boltfluter]

Interesting. So if I am understanding correctly, once I have body sized and bumped the shoulder in the body die, I may lengthen the case when it is sized in the small base .308 die.....which could affect overall length and reduce any shoulder bump from the body die?

Correct, been there and done that!! Good luck!
Paul

 

[rwj]

Interesting. So if I am understanding correctly, once I have body sized and bumped the shoulder in the body die, I may lengthen the case when it is sized in the small base .308 die.....which could affect overall length and reduce any shoulder bump from the body die?

Easy to verify, try chambering empty cases after the small base diameter die is used. Alternately, use a shoulder comparator to measure length before/after.

 

[Bill K]

I would use the small base die only and then neck turn/trim the necks, either before or after sizing and anneal prior to resizing. Lapua is noted for thick necks.

 

[MGYSGT]

Trim to length.