Fire forming help

[TTE]

Forming 6.5 06AI from Lapua 06 brass.
Brass annealed, used 06fl, 280fl, 270fl and 6.5 neck dies. With previous advise, no expanders in dies. All cases had a false shoulder.
Before COW fire forming

After fire forming
Max case length is 2.494.
The majority of the cases are what I assume is trim to length (2.484) or shorter. Is this normal ? Which of these cases are no longer useable ? Am I doing something incorrectly ? Why are the cases so different in length ?
Would appreciate any help and adivse.
Thanks

 

[6bra1k]

first how did you determine trim to length? buy sinclair's tool and measure YOUR CHAMBER NECK LENGTH. then take .005\.010 off that number not some book number. my opinion is the cow is the issue.
i do not use cow, only fast pistol powder WITH NO BULLET.
once you have a known trim length, load with a solid load and fire once and see what happens to case length. in the end pick a length and go with it.

 

[TTE]

first how did you determine trim to length? buy sinclair's tool and measure YOUR CHAMBER NECK LENGTH. then take .005\.010 off that number not some book number. my opinion is the cow is the issue.
i do not use cow, only fast pistol powder WITH NO BULLET.
once you have a known trim length, load with a solid load and fire once and see what happens to case length. in the end pick a length and go with it.

I did not trim the cases. I reformed them with the dies mentioned above and tried the COW method (700X powder). I used 700X with the non COW method (no bullet) with the same results in length difference.

 

[22BRGUY]

I found the similar results when forming 260AI cases. I used cow with Unique
and then a moderate load with bullet jammed 20 thou usually twice to get them where they were right. As 6 bra mentioned, be very careful about length so that you don't have
the chamber neck squeeze down on the brass neck and bullet!
Either get a reamer print or do a chamber cast with Cerro Safe would be my
suggestion.

 

[TTE]

I found the similar results when forming 260AI cases. I used cow with Unique
and then a moderate load with bullet jammed 20 thou usually twice to get them where they were right. As 6 bra mentioned, be very careful about length so that you don't have
the chamber neck squeeze down on the brass neck and bullet!
Either get a reamer print or do a chamber cast with Cerro Safe would be my
suggestion.

Are you saying that after you fire formed your cases with bullets the cases got longer and closer to max length ?

 

[358WCF]

When the cases are blown out to fill the Ackley chamber the brass has to come from somewhere. That's why they get so much shorter. I've seen better than .040" shrinkage. As for all your different lengths, who really gives a rip? They probably need trimmed to square up the case mouths after the cases are more fully formed (which they likely aren't now). I've never had particularly good luck fireforming with anything besides a crush fit in the chamber, a bullet, & a warm charge of mid burn rate powder (3031 thru 4064) for the parent case. There will still be length differences, but maybe not such a spread as they should form the shoulders better. At least 2 firings, probably 3 until the shoulders fill out fully & sharpen. Your 2.501" length may or may not be a problem on the initial firing. Got a bore scope? Sinclair sells plugs to check chamber length as well.

If you're concerned about barrel wear, experiment enough to find a reasonably accurate load & go hunting. All the Ackley's in my safe shoot forming loads well enough to hunt with at a slightly lesser range than the full bore loads, or at least ring steel out to 300 yards. For example... my 338-06 Imp. shoots 200 Speer Sptz to 2750fps when fireforming & just touches 3000 with a full load. The best I can manage is around an inch with both @ 100yds. with a 5x scope & old eyes. With 53 Hornadys my 22-250 Imp does 3500fps into a tad over an inch for 20 shots before & just reaches 4000fps after forming with much smaller groups. Keep your locking lugs lubed when doing the crush fit thing.

Edit: Just looked more closely at the lengths in your chart. Were the 2.8xx" measurements a brain fart or for real?

 

[22BRGUY]

Are you saying that after you fire formed your cases with bullets the cases got longer and closer to max length ?

Yes for me it did, The brass is trying to form itself to the chamber but it takes more than just one firing sometimes depending on how much pressure is being produced
by what method. I wanted to be careful about too much pressure and listened to
other guys experiences. The brass has to thin out in that neck shoulder area to get longer.
Keep asking questions and don't rely on only my input but that is how mine worked.

 

[22BRGUY]

Keep in mind like 358 said, the brass has to come from somewhere. The case body is thicker brass than the neck and shoulder area so that thinner brass has to pull back
first but with more firings the body begins to lengthen out also.

 

[L.Sherm]

You need some rounds on the barrel anyway to get serious about load development. Just use some good neck tension jam into the lands with a bullet about 1.5-2.0 grains under max so you don't hurt the web or Primer pocket on first firing and shoot away.
I just did this on 100 Lapua 06 cases for a 6.5x06AI and they turned out great.

 

[22BRGUY]

Are you saying that after you fire formed your cases with bullets the cases got longer and closer to max length ?

One other tidbit I learned after believing the opposite for many years. I get better groups
when I trim Back to minimum length than when I trim close to max length. I have a theory why but for me it does what it does.
Good Shooting!!

 

[TTE]

Edit: Just looked more closely at the lengths in your chart. Were the 2.8xx" measurements a brain fart or for real?

All measured and lined up according to OAL case length

 

[L.Sherm]

All measured and lined up according to OAL case length

Look at your pic of your cases to the right 2.8

 

[TTE]

You need some rounds on the barrel anyway to get serious about load development. Just use some good neck tension jam into the lands with a bullet about 1.5-2.0 grains under max so you don't hurt the web or Primer pocket on first firing and shoot away.
I just did this on 100 Lapua 06 cases for a 6.5x06AI and they turned out great.

With the Norma brass I used previously, I max out at 55.2 grains of powder. Are you suggesting 52 or so grains to fire form ?

I have to neck turn before shooting bullets. If I have to adjust the turner tool for each case length, it will make for a
l o n g turning session for sure.

 

[TTE]

Look at your pic of your cases to the right 2.8

Oh I see .... my mistake Shortest in the pic is 2.480

I did not add 1 case in the pic that was 2.4790. I figured that one was way too short and was going to pitch it.

I do use a false shoulder with all the fire forming, as I don't have 6.5 06 AI dies yet ( I called yesterday, they should be here next week .... they took my CC info ! .... so am optomistic)

I hope I can use these cases, .... there is an investment in cash on the table.

edit: duh ..... 2.481 ... 2.480

 

[L.Sherm]

. Are you suggesting 52 or so grains to fire form ?

53.0 -53.5
Try a couple at 53.0 see how they turn out. I neck turn mine but I keep them about .0005 bigger than what I want for final turn then turn again after once fired.

 

[Spoonbill]

I know Lapua doesnt make 270 Win brass but save yourself some heartache and trouble and just use it. Trim brass to 2.510. Run it up a fl sizing die and leave about .020 false shoulder. I ALWAYS used a 129 grn Hornady Interbond and 44 grns of IMR 4064 to fireform. Cases will come out in between 2.500 and 2.490. BAM! Fireformed cases

 

[L.Sherm]

. Cases will come out in between 2.500

Thats exactly what my 06 Lapua case are after forming and trimmed to length

 

[TTE]

I know Lapua doesnt make 270 Win brass but save yourself some heartache and trouble and just use it. Trim brass to 2.510. Run it up a fl sizing die and leave about .020 false shoulder. I ALWAYS used a 129 grn Hornady Interbond and 44 grns of IMR 4064 to fireform. Cases will come out in between 2.500 and 2.490. BAM! Fireformed cases

I wanted to use 270 brass, but no Lapua brass in 270 as you mention.
I have some Starline brass in 270 (50) ..... and 270 Winnie brass Not sure how good that brass is however.

 

[TTE]

Thats exactly what my 06 Lapua case are after forming and trimmed to length

would like mine to measure the same, however, you see my results.

 

[358WCF]

would like mine to measure the same, however, you see my results.

Go slow, go far is what one of my older buddies used to tell me when I was young, dumb, & in a hurry. Close is for horseshoes & hand grenades, not handloading. Brain fart or not, 2.8xx" is a rather large difference from 2.4xx" in this situation.

Answers to all of your questions & non-existent problems are in the thread above. I might suggest that you slow down & re-read for comprehension. Read twice if you dont understand. Three or more times if needed. Internal ballistics kinda is rocket science, but case forming is boringly mechanical. Nothing magical about it. I might also suggest practicing with some cheaper brass before ruining some of your premium pieces.

All of your brass is likely fine as long as there's not a stretch ring started at the top of the web. At this point I'd be more concerned with varying headspace dimensions than case lengths. It all needs to be fired again to more fully form the cases. This takes pressure. Maybe someone with more engineering background will chime in with exactly how much, but wimpy loads wont do it.

If this is your first foray into wildcatting, there is a learning curve. Welcome to the world of non-standard cartridges. It aint for everybody.