6.5 grendel to 6mm arc

[herman lesley]

I necked down 6.5 grendel to 6mm arc. Will I need to fireform them before running a ladder test?

[BG Shooter]

Firing forming is not required for the 6ARC. Trim, size, load, and shoot. Been loading mine for a year now and never firefirmed any of it.

[alwie]

I necked down 6.5 grendel to 6mm arc. Will I need to fireform them before running a ladder test?

Depends on how precise you want to be. Firing them and then measuring the headspace would allow you on the resize step to bump back the should the minimum amount leading to better precision and longer lasting brass(IMHO).

[GRH]

Too late I know...

If you're re-forming Starline brass it may be wise to anneal beforehand.

IDK about anyone else, but the prior batch of new Starline I re-formed got very hard at the shoulder and did not fireform well, or resize what I would consider "normally". They were squeaky tight and I had to use more Imperial than is normally necessary but still managed to get one case stuck in the die.

I have no idea if they anneal or not, but just got another 200 6.5G Starline cases and the first thing I did was anneal them concentrating the heat on the shoulder. By the time it was hot enough, the necks were done also.

Since no one else seems to be really concerned with making Grendel cases never mind 6ARC, I really do appreciate that Starline is doing so pretty regularly. However I did notice a unusual amount of "iffy" looking cases with this batch.
Rough, uneven case mouths, lots of indentations from dirty forming rolls/dies, dented necks, shoulders and mouths. I don't see any that will need tossing, just something unusual I noticed. Fortunately after processing and trimming all should be fine

I think QC may have slipped a little to fulfill demand.

[CZ527 Guy]

Boy my experience with recently purchased Starline brass seems to have been considerably better. Order was for 250 cases & i think I received 2 extra. weight variation was within 1.5 grains. never annealed prior to first firing. Used what may be considered a premium forming die. (mighty armory) with lanolin based spray on lube. Brass forms considerably easier than I have experienced in the past.

BTW past experience has been quite easy any way. I have been a huge fan of imperial sizing wax in the past. Though with this Mighty armory die the PEG 75 (lanolin based lube) worked amazingly smooth. inadvertianly I did run a few with my tried & true Whidden form die. Don't get me wrong. The Whidden die is a top of the line die. Mighty armory is just that much better IMHO.

With either of my dies I have never come remotely close to sticking a case. Ill atribute this to this success to good lube adiquitly applied. Good smooth dies with a 5 micro or better polished ID docent hurt either. I have had very good luck with both Starline & Lapua 6.5 Grendel brass. Though to be fair I have quite a bit of history re-forming brass to alternate calibers. So I went through my learning curve on 17 fireball & 17 Hornady Hornet.

[GRH]

Boy my experience with recently purchased Starline brass seems to have been considerably better. Order was for 250 cases & i think I received 2 extra. weight variation was within 1.5 grains. never annealed prior to first firing. Used what may be considered a premium forming die. (mighty armory) with lanolin based spray on lube. Brass forms considerably easier than I have experienced in the past.

BTW past experience has been quite easy any way. I have been a huge fan of imperial sizing wax in the past. Though with this Mighty armory die the PEG 75 (lanolin based lube) worked amazingly smooth. inadvertianly I did run a few with my tried & true Whidden form die. Don't get me wrong. The Whidden die is a top of the line die. Mighty armory is just that much better IMHO.

With either of my dies I have never come remotely close to sticking a case. Ill atribute this to this success to good lube adiquitly applied. Good smooth dies with a 5 micro or better polished ID docent hurt either. I have had very good luck with both Starline & Lapua 6.5 Grendel brass. Though to be fair I have quite a bit of history re-forming brass to alternate calibers.  So I went through my learning curve on 17 fireball & 17 Hornady Hornet.

=========================================================

I agree, and use many different Starline cases, maybe just luck of the draw. I took a bath on them from Midway because I was desperate. I should have kept a closer eye on the Starline website and put in a backorder when it opened up.

I have the Hornady Custom grade dies, took the expander/decap completely out and use a 21st Century mandrel die to neck size. Next up is probably a Wilson busing die but I'm doing ok for now and give my wallet a rest.

[StoneHendge]

OP, you are going to need to tweak your load when you move to fired brass since the case volume of virgin brass will be lower than that of your fired and then resized brass. When I switched from a Hornady die to the RCBS Small Base die (which will have the dimensions of virgin brass), I think I ended up using 0.3 gr less powder and ended up with slightly lower velocity. The internal ballistics do change a bit.

You can see/feel the difference with your virgin converted brass. Since the brass flows down the shoulder towards the body when you neck down, there is a slight bulge at the base of the shoulder where it meets the case body. Whatever slight bulge there is will be the difference between the dimension of the virgin case body and what it will be after you fire and resize it.

I used to subscribe to fireforming virgin brass, but no longer do with component costs and availability. When I had to buy new 6.5CM brass and switched brands, I developed a load, shot 2 PRS matches with virgin brass and then tweaked it a few tenths. In addition to component costs, it didn't seem prudent to use 20% of a $500 barrel's life (300 of 2500) for fireforming either.