Twice fired brass chambering with a bit of effort

[coolbox]

My 308win twice fired brass takes a bit of effort chambering, some more than others. The chambering marks are near the case head. Body sizing with shoulder bump (no neck sizing) solves the problem.
Factory brass 1.622"
Once fired 1.624-1.625"
Twice fired 1.626-1.627"

After body sizing, I get 1.625".

I was thinking of using the twice fired as is, and maybe keep applying the bit of extra effort required to chamber.

My OCD tells me this would give better accuracy as brass dimensions are close to chamber dimensions (maybe too close).

Need advise. Should I go with my OCD? Or should I body size and rely on brass consistency to get better accuracy?

Brass is Lapua, redding dies.

For once fired brass, I hardly face this issue, and can almost ignore it.

 

[HTSmith]

I’d say forget your OCD and go with consistency.

 

[RustyInBend]

Anneal, FL Size, and Shoulder Bump ... are the best ways to extend the life of your brass, and ensure consistency and accuracy. Using "extra force" to fit into a chamber ... is not going to give you better accuracy, and in the long run, will likely decrease the life of both brass and barrel. I suppose you could always do a test ... load up 10 rounds with sizing, and 10 without, and go shoot for groups and velocity.

 

[fkimble@charter.net]

Be sure you keep your bolt lugs greased with that extra force having to be applied! What are you using the 308 for? I would full length size every time but keep it to the minimum. How much are you bumping the shoulders back when full length sizing? Folks having to fireform their cases often report excellent accuracy during the fireforming.

Frank

 

[JFrank]

Length is only one dimension that requires measuring . We also measure at the case shoulder junction as well as the .200 line to monitor growth and sizing reduction.

 

[drop_point]

Can you repeat this every time? Probably not. Do it the repeatable way.

 

[Texas10]

Your twice fired brass is now fully fire formed. Take one the the cases that chamber with a stiff bolt and measure the base to shoulder. That is your chamber dimension. Set your dies to bump the shoulder back just a thou or two and you'll keep your brass growth to a minimum. The less you work the brass, the longer it'll last. Annealing also extends brass life.

Don't forget to trim your brass when it grows past maximum length! Having a borescope camera allows you to actually look into the chamber and see when the brass is so long it jams against the end of the chamber, a dangerous situation you want to avoid. Know that dimension and set your trimmer accordingly.

Happy shooting!

 

[AccelR8]

For what it's worth, I did my own study over a summer some years ago. This was a factory Remington 700 in 223. My conclusion was I got measurably, consistently better accuracy with full length sized brass over neck sized only brass. The difference was not great but it was definitely there.

 

[243winxb]

Have the shell holder make full contact with the bottom of the full length die, with cam over, at top of stroke. The cam over may produce an extra .001" to .002" more shoulder bump. Shoulder bump is over rated. Most upsets will produce .005" maximum head clearance. Not an issue for case life or separations.

 

[D-4297]

Punch the primer out . Measure to datum point on the twice fired . Write that number down .
Clean
Aneal
Deburr neck , inside and out
Lube
Size - I use a F/L Bushing Die -Redding Type S
Check "Bump" for .001 - .002
Clean Lube off
Prime
Load
The short form version of the standard F Class shooters process . I said "Short Form".
Use correct size Bushing so as to not over-work neck diameter . Less is more .

 

[Doom]

I have neck sized for the 11 to 12 years that I have been reloading. This past year I decided to try bumping the shoulder back with a FLS die. While I have no definitive test to prove it, I seem to have fewer unexplained flyers with bumping. That’s now the process I use.

 

[243winxb]

If primer pockets become loose in 5 firing or less, pressure is to high.
Fired brass should extract easly & go back into the chamber with no sizing.

Fl dies dont size some areas of the brass.

 

[coolbox]

Thank you all.
Rifle is for FTR 32" Bartlein. I shoot 200 hybrids @ 2660 fps, and 185 juggs at 2750 fps.