New Lapua brass vs fire formed and seating consistency

[Tesoro]

This is the second time, second blue box, where this has happened to me. I am using 105VLD in 6Br. I take new brass, run through body die to check and then set neck with my LCD and then chamfer for vld. All the brass is a tad undersize with healthy shoulder setback as usual. However when I seat the bullets with my Wilson arbor I can get erratic BTO's with up to 4 tho variance.

BUT if I do the identical process as above (less chamfer obviously) with 5-10x cases then I can seat the same bullets all dead nuts with at most a thousandth variance, excluding a rare and occasional cull.

So my conclusion is the new cases or bases have a little warp to them and need a firing to get flattened out and squared up. Makes sense to me, but what does not is how many times I have read of people shooting noteworthy scores in matches with new brass. Would this be attributed to them using a conventional press with a shell holder that indexes off the top of the rim base? Or using a different case brand or what am I missing? ( not enough lube when seating in the new clean necks or too much nt?)

 

[Bc'z]

Couple quick questions....
Any lube inside necks on the new brass?
After chamfer, did you brush inside of neck to remove debris?

I'm helping a buddy get ready for a African trip where we're using all virgin brass.
My process is to lube all cases with 1shot "all 4 sides of tray" @45° angle this gets in the necks.
Mandrel 1st to true necks
Size neck with Redding bushing die.
Bullet seating is smooth and consistent.

 

[Tesoro]

I lube with imperial wax - fingertips roll bullets
Yes on neck brushing.
The only thing I did differently on last batch of new brass was 4 neck crimps- turns instead of usual two. But it crimps onto a mandrel which is 2 tho undersize. But I can feel the diff on 4 vs 2 when seating as 4 has more friction and gives me straighter ammo. SO I dunno. Only thing to do is try 2 crimps on the new stuff to compare.

Heck If I was going to Africa I would fire form and test my brass! Unless it is some huge big bore which I dont know anything about.

 

[mikecr]

Varying seating force.
That new cases can produce better results, that's all for a different reason, and fleeting.

 

[Bc'z]

I lube with imperial wax - fingertips roll bullets
Yes on neck brushing.
The only thing I did differently on last batch of new brass was 4 neck crimps- turns instead of usual two. But it crimps onto a mandrel which is 2 tho undersize. But I can feel the diff on 4 vs 2 when seating as 4 has more friction and gives me straighter ammo. SO I dunno. Only thing to do is try 2 crimps on the new stuff to compare.

Heck If I was going to Africa I would fire form and test my brass! Unless it is some huge big bore which I dont know anything about.

The LCD makes lil Itty bitty pleats in brass necks, the 4 squeeze vs 2 may very well be the issue.

The 6.5bleedmoor is tuned, CDS dial is tracking true.
Seating test is done on 06' now to step on the gas.
He was supposed to be here this morning, but got called out on a wildfire.

 

[Tesoro]

True but the pleats are on the outside and the inside is as smooth and round as the mandrel. Yes I think now it is the 4 squeeze issue creating less spring back by hardening/over compressing the brass or? I just remembered that with the new brass I was getting some small click sounds on extraction, which means the collets weren't releasing smoothly and messing up something. My collet and cup are polished and lubed. This has to be the source of problem. I never get the clicks with fired brass and an extra turn. Back to the bench!

 

[JEFFPPC]

This is the second time, second blue box, where this has happened to me. I am using 105VLD in 6Br. I take new brass, run through body die to check and then set neck with my LCD and then chamfer for vld. All the brass is a tad undersize with healthy shoulder setback as usual. However when I seat the bullets with my Wilson arbor I can get erratic BTO's with up to 4 tho variance.

BUT if I do the identical process as above (less chamfer obviously) with 5-10x cases then I can seat the same bullets all dead nuts with at most a thousandth variance, excluding a rare and occasional cull.

So my conclusion is the new cases or bases have a little warp to them and need a firing to get flattened out and squared up. Makes sense to me, but what does not is how many times I have read of people shooting noteworthy scores in matches with new brass. Would this be attributed to them using a conventional press with a shell holder that indexes off the top of the rim base? Or using a different case brand or what am I missing? ( not enough lube when seating in the new clean necks or too much nt?)

It would have to do with their shooting skills.

 

[Kracken McGraw]

What is LCD?

 

[Bill Norris]

What is LCD?

Lee Collet Die

 

[Kracken McGraw]

Lee Collet Die

Gotcha, should have caught that one!
To the OP, I would make it simple and run the virgin brass through a Forster FL die with the ball expander.

 

[Tesoro]

Gotcha, should have caught that one!
To the OP, I would make it simple and run the virgin brass through a Forster FL die with the ball expander.

Why? i have a wilson body die and a mandrel on the lee neck die. that is simple! and i only work the neck brass once to size, instead of twice the way you suggested. i have a 21c mandrel die if i need to fix damaged necks or align them.

 

[Tesoro]

It would have to do with their shooting skills.

I would say more like reloading skills..to make consistent ammo!!

 

[Kracken McGraw]

Why? i have a wilson body die and a mandrel on the lee neck die. that is simple! and i only work the neck brass once to size, instead of twice the way you suggested. i have a 21c mandrel die if i need to fix damaged necks or align them.

I’m not sure it would help, but just thought it might be another option that might square up the virgin brass as you had mentioned earlier.

 

[Tesoro]

I’m not sure it would help, but just thought it might be another option that might square up the virgin brass as you had mentioned earlier.

Thanks..I dont think the prob was squaring up but creating too much neck grab by over 'clamping' with the lcd and it was hanging on to bullets during extraction. Helps to talk this stuff out.

 

[JEFFPPC]

I would say more like reloading skills..to make consistent ammo!!

Both are needed. You can be the smartest ballistics expert on the planet and know all the big words, but with no skill set on the range you will just be another donor. Making consistent ammo is about a certain amount of knowledge. More than that it's about being willing to do the work, not justifying shortcuts but investing the time to not skip steps that you have tested and proven, or dissproven. Thats ok, we need donors.

 

[prone.life]

i've experienced the exact same in my 6BR with Lapua Scenar-L 105s (.223 and .264 as well). i solved the issue using a larger mandrel (.243) on new brass and then .2425 after 3 or so firings and then usually settle on .242 after 5 reloads. that process results in very consistent seating depths for me at exactly desired bto or +.001" longer than desired. i chamfer new brass as well as with each subsequent reload. occasionally i'll dip the post-chamfering brush in moly.

i've also seen where increased seating depth can cause me fits with consistent cbto.

i chalk it up to new brass having more spring back?

fwiw i only shoot blue box brass.

ymmv.

 

[NorCalMikie]

New brass? Will it chamber with no issues? If so, prime it, dump your powder, seat your bullet and go shooting.
NOW work in sizing. Forget trimming till it NEEDS IT!!(?)

 

[Straightshooter1]

i've experienced the exact same in my 6BR with Lapua Scenar-L 105s (.223 and .264 as well). i solved the issue using a larger mandrel (.264) on new brass and then .2635 after 3 or so firings and then usually settle on .263 after 5 reloads. that process results in very consistent seating depths for me at exactly desired bto or +.001" longer than desired. i chamfer new brass as well as with each subsequent reload. occasionally i'll dip the post-chamfering brush in moly.

i've also seen where increased seating depth can cause me fits with consistent cbto.

i chalk it up to new brass having more spring back?

fwiw i only shoot blue box brass.

ymmv.

I've also had similar experiences with my .308 blue boxes. I've tried running a mandrel through them and got a slight improvement, mostly making sure there's no dents on the mouth. But what worked best for me was simply using my Lee collet die, which squeezes the necks tight against a mandrel and that apparently gets rid of whatever is going on inside of the case necks as seating became way more consistent.

 

[Ned Ludd]

The two critical contact points when measuring CBTO are the base of the case and the point on the bullet ogive where the caliper insert seats. Within reason, slight length/dimensional differences in either the bullets or the cases that lie between those two critical contact points will not affect the CBTO measurement generated by the reloading press/die. Bullet nose length variance between the points where the caliper insert seats on the ogive and where the seating die stem contacts and "pushes" on the bullet nose out near the meplat can easily cause CBTO variance. Likewise, varying friction in the neck during the bullet seating process that leads to incomplete/differential seating of bullets can also easily give rise to CBTO variance. I would therefore suggest checking for consistent neck tension (interference fit) and sorting bullets by OAL (not BTO), or using a tool such as Bob Green's Comparator. It is not uncommon when encountering issues like this that all potential contributing/causative factors have to be tested and eliminated one by one before the real underlying cause can be isolated and corrected.

Some time ago, I perceived that processing virgin brass using a bushing die as the sole sizing step left a lot to be desired. In my hands, the neck tension/interference fit of virgin Lapua brass can vary substantially straight out of the box. A bushing can make it better, but there can still be significant variance. I determined that using a bushing die first with a bushing that was approximately .001" smaller than I would have previously used as the sole sizing step, followed by expansion using a mandrel provided noticeably more consistent results. In fact, I use this approach now with all of my brass, whether it be virgin or fire-formed. The improvement in neck tension/interference fit consistency can easily be felt when seating bullets (i.e. seating force), as the number of outliers has markedly diminished. I do not actually measure seating force but I have no doubt the numbers would verify my anecdotal observation; the improvement is pretty obvious.

 

[JFrank]

Why? i have a wilson body die and a mandrel on the lee neck die. that is simple! and i only work the neck brass once to size, instead of twice the way you suggested. i have a 21c mandrel die if i need to fix damaged necks or align them.

I own and use a Wilson Fl bushing type sizing die but I didn’t realize they offered a body die. I do use a .002 under mandrel but only on virgin brass.