I need some help in the loading room

[Matt_3479]

^^^ this - can be remedied by using an expander to set the ID and neck turning for removal (usually appears as a raised band at the neck-shoulder Junction).

Yes, especially if the brass isn't closely fitted to the chamber. As suggested above, measure it! You should have a ball mic; if you don't, get one.

Okay thank you. I forgot I have 1 piece of brass that is fire formed and 2-3 firings (Lapua sent 101) and it fits fine. So tomorrow I’ll measure both loaded outside diameters, I’ve emailed my smith for reamer dimensions on the neck, and I have a buddy with a ball mic that I’ve called as well.

So If it turns out to be the neck thickness that is now an issue, you’re saying to first expand the neck/neck arbor to make ID perfect and then turn down the neck. How much should I be turning down. .001-.002 thou?

 

[ronemus]

Okay thank you. I forgot I have 1 piece of brass that is fire formed and 2-3 firings (Lapua sent 101) and it fits fine. So tomorrow I’ll measure both loaded outside diameters, I’ve emailed my smith for reamer dimensions on the neck, and I have a buddy with a ball mic that I’ve called as well.

So If it turns out to be the neck thickness that is now an issue, you’re saying to first expand the neck/neck arbor to make ID perfect and then turn down the neck. How much should I be turning down. .001-.002 thou?

Enough to get the clearance you want, which depends on the diameter of the chamber neck. The general consensus seems to be 0.003-4" but clearance as small as 0.001" works for some and much larger clearances for others. I usually have my turner set from when I originally turned the necks, so I turn again with no adjustment; often only the band at the base of the neck is turned.

 

[Matt_3479]

Enough to get the clearance you want, which depends on the diameter of the chamber neck. The general consensus seems to be 0.003-4" but clearance as small as 0.001" works for some and much larger clearances for others. I usually have my turner set from when I originally turned the necks, so I turn again with no adjustment; often only the band at the base of the neck is turned.

Okay so if I can get my chamber specs from my smith or fire that 1 extra piece of brass and take measurements. Let’s say the fired piece measures OD at .269 so that’s my chamber neck dimension. I’d want to expand my ID to .243 and turn the necks down to .266 at the point?

 

[ronemus]

Okay so if I can get my chamber specs from my smith or fire that 1 extra piece of brass and take measurements. Let’s say the fired piece measures OD at .269 so that’s my chamber neck dimension. I’d want to expand my ID to .243 and turn the necks down to .266 at the point?

Fired brass will usually be 0.001-2" smaller than the neck diameter, especially if you haven't been annealing. You've got the general idea.

 

[PeteB]

I know that but I’m wondering if brass flow can instead of growing neck length wise, grow them in thickness making my no neck turn chamber into a now neck turn chamber due to brass neck thickness growth. There’s no crimping on the bullet pushing the shoulder out. I pull the bullet and check with my shoulder bump gauges and the brass doesn’t move. But it still won’t chamber. The more I eliminate the more it’s leading me to believe it’s the neck

Gday Matt, just had a read through your problem mate and i have an opinion. I guess you have a no turn neck chamber around .272 to be safe, this will give you .0035 to .0045" clearance on a lapua case depending on batch which is what i suggest to aim for, tighter than this and you need to be very observant on neck brass flow.
depending on freebore length and projectiles being used if you are seating close to or below the neck shoulder junction, if you are close or below this area i would be fairly sure you have some brass flow into this area. A quick way to check this critical area would be to use steel wool to polish a sized case with a seated projectile (as used), chamber, close bolt extract and examine the area for any change in the polished area.
you will most likely notice some longitudinal marks in the vicinity of the junction.
IMO you may need to neck turn to suit your neck dimension and back into the shoulder slightly.
I had a similar problem using Lapua 22-250 fireformed in a 6XC after several firings, and it was not a neck turn chamber.
Good luck, and dont fire if its hard to close, you'll do damage to your cases mainly primer pocket expansion, and maybe firearm damage.
Pete

 

[1shot]

If you turn your necks to .002 clearance per side (.004total) I'm thinking your problem will go away. As others have said, get a ball mic, or some call it a tubing mic.
I hope this helps,

Lloyd

 

[wildcat3d]

I don’t believe I understand what you’re trying to say then? I’m unsure how the case neck is crooked when after sizing it’s 100% fine. The second I seat a bullet its off?

Just a thought but have you checked the bullet Dia. And are they 6mm or maybe 6.5 got mixed up,

 

[22BRGUY]

Take a magic marker and color the entire round from bullet tip to case head and then
chamber or try to chamber it. Then examine where the magic marker is rubbed off to
know exactly where the problem is.
Good Luck

 

[archerforkids]

Small base die. Get a 308 small base die. Run it through that. If it fixes it you’ll be good for another few cycles, reuse as needed.

This remedied me having identical problems that your having with my 6BR.
I bought a Wilson small base 6BR die and problems went away.
Mr. BoydAllen suggested I size my cases in a normal fashion (only a couple of rounds). Chamber a bullet with no primer or powder. Measure OD of cases. Assuming you meet the same chambering problem by testing, then chuck the entire cartridge by the neck in a cordless drill and spin this entire cartridge while sanding the case down with fine emery cloth. After reducing the case in very small increments, I would chamber said round until the bolt closed with a soft touch. If this fixxed it( it did for me) then the small base die is your answer.
Thanks again BoydAllen for the council on this.

 

[Matt_3479]

Just a thought but have you checked the bullet Dia. And are they 6mm or maybe 6.5 got mixed up,

I did check actually! Lol I thought I was going nuts and measured them like 3 times, left the room frusterated started cooking dinner and was like oh SH**! I should check the bullet diameter and checked again lol

 

[J.d. Popkes]

This remedied me having identical problems that your having with my 6BR.
I bought a Wilson small base 6BR die and problems went away.
Mr. BoydAllen suggested I size my cases in a normal fashion (only a couple of rounds). Chamber a bullet with no primer or powder. Measure OD of cases. Assuming you meet the same chambering problem by testing, then chuck the entire cartridge by the neck in a cordless drill and spin this entire cartridge while sanding the case down with fine emery cloth. After reducing the case in very small increments, I would chamber said round until the bolt closed with a soft touch. If this fixxed it( it did for me) then the small base die is your answer.
Thanks again BoydAllen for the council on this.

That sounds like an awful lot of work and a long way to get there

 

[Ringostar]

As brass flows, the necks can get thicker. I’ve had to turn again after about 5 firings. As someone else mentioned, about .002 clearance per side so you have .004 total. Color the neck and shoulder of a loaded round with a marker right now. It should leave rub marks where it’s tight when attempting to chamber.

 

[Matt_3479]

Okay thank you everyone. I will start with the marker and try closing the chamber and see what it says.

 

[Matt_3479]

This remedied me having identical problems that your having with my 6BR.
I bought a Wilson small base 6BR die and problems went away.
Mr. BoydAllen suggested I size my cases in a normal fashion (only a couple of rounds). Chamber a bullet with no primer or powder. Measure OD of cases. Assuming you meet the same chambering problem by testing, then chuck the entire cartridge by the neck in a cordless drill and spin this entire cartridge while sanding the case down with fine emery cloth. After reducing the case in very small increments, I would chamber said round until the bolt closed with a soft touch. If this fixxed it( it did for me) then the small base die is your answer.
Thanks again BoydAllen for the council on this.

But here’s the thing I don’t understand. If a sized case clothes perfectly fine how would a small base die solve the neck issue. After sizing it’s flawless, the second I seat a bullet it won’t close at all. There is very little resistance on seating and no notable changes. The only dimension that should be changing significantly when seating at that point should be the neck. How would a small base die clean this up?

 

[DocDoc]

It would not. Waiting for the report on the case and bullet you colored with a felt tip then attempted to load. That will show you where it is binding.

 

[eschafer]

you mentioned "chamfer" but no mention of "deburring" the outside of the case mouth... just a tiny burr and a seated bullet can make chambering difficult and sometimes impossible... if it's been mentioned in this thread, I apologize... I tend to skim read...

 

[J.d. Popkes]

It would not. Waiting for the report on the case and bullet you colored with a felt tip then attempted to load. That will show you where it is binding.

I hadn’t gotten a full dose of coffee on board when I said small base die. I read again and saw that fl sized brass chambers. My bad.

 

[Matt_3479]

you mentioned "chamfer" but no message of "deburring" the outside of the case mouth... just a tiny burr and a seated bullet can make chambering difficult and sometimes impossible... if it's been mentioned in this thread, I apologize... I tend to skim read...

Sorry it’s chamfered and deburred

 

[Rick300]

Sorry it’s chamfered and deburred

I had a very similar issue and even though I chamfered and deburred in and out, there was a small "ring" at the case mouth that was larger in diameter than the the rest of the neck. I ended up having to run them through a neck turner again just enough to remove that "ring" without turning the entire neck. Worked like a charm.

 

[Matt_3479]

Okay well I’ll be getting my reamer specs soon, my buddies neck turning took this weekend if needed. If this isn’t the case and it happens to be the body and need a small base die, will any 308 base die work for a bra to fix the body?