Fire forming Brass Cases

[bladeracer]

K&M...

BTW... I was always the skinny kid that got bullied all my school life... However, the shoe was on the other foot when it came to life in the real world...

You mean you grew up to be a bully yourself...

[Apollo]

Yes, to stir you up to make a stupid reply.

But more so to get my mate into gear and get going comparing notes on a rifle we both own....

Maybe I'll just keep our thoughts confined to phone calls and leave you out.....!!

[bladeracer]

Yes, to stir you up to make a stupid reply.

But more so to get my mate into gear and get going comparing notes on a rifle we both own....

Maybe I'll just keep our thoughts confined to phone calls and leave you out.....!!

Unless you have something to offer to the thread I think that would be a good policy.

[Stix]

Att case prep experts...

So...these new cases are ready to size...

But they differ in size (shoulder dimension) quite a bit...at least a good 7 thou...

The majority (ive only measured 20 or so) appear to be just short of the chamber, but the shortest ones are atleast 5 thou shorter than chamber...

So...should i FL size them ALL...or just the ones that are too long...

On one hand id like to keep everything consistant, so if i size one case, id rather do them all, but on the other hand, It seems silly to me to FL size cases that are nearly to chamber length , only to blow them tight out again...

So, only FL size the ones that are too long, & neck size the others...?
Or crank them all through the FL sizer to the shortest length & fire them back out again...

[marksman]

"& another 15 or 16 out on the coffee table that have bent necks & cant get the flash hole uniformer in..."
this troubles me Stix, l recon it may be that the flash hole itself is very tight or the burr is over where the end of the de-burr tool needs to go
anyway
you know it may take a couple of firings for the cases to be 100% formed to your chamber and it wont be till then that you will 100% see a difference
what l would be doing myself is to find your longest cases and fls them to just fit the chamber - 2 thou and wait till the others catch up

if you are going to have the bullet jammed fls to the smallest case, no worries, that does work and quite a few comp shooters l have spoken to do exactly that
but only if you are jamming into the lands, the bullet will find centre
l dont think thats what you want though so my recommendation would be to fls to your chamber lenth - 2 thou and go shooting

[Madang185]

Done two.
Std 243 Winchester to 243 AI. 20 gns of W296 or AR 2205 topped with polenta with a wad of tissue on top. Rounded shoulders squared up with first powder load . No problems.

7mm RM Cases to 257 Weatherby Magnum. Bertram cases. Leaves necks short, no issue

25gns AR2205 etc + polenta same result

All straighforward

[marksman]

Done two.
Std 243 Winchester to 243 AI. 20 gns of W296 or AR 2205 topped with polenta with a wad of tissue on top. Rounded shoulders squared up with first powder load . No problems.

7mm RM Cases to 257 Weatherby Magnum. Bertram cases. Leaves necks short, no issue

25gns AR2205 etc + polenta same result

All straighforward

l use a similar method for foming to non standard cases myself Madang
but l use a cork of soap in the neck to hold the powder in instead of tissue
l still need a shot or 2 to get the perfect fit

[Stix]

Well ive got around 60 left to FLS...

Something must be wrong with my press...still gett upt to .004" difference in shoulder after they've been through the die...
So they are all 2-4 thou shorter than chamber...

Im not holding out much hope for this brass--its all over the place in size length & weight...

Hopefully ill get it all done tonight...

[marksman]

it may be that the case heads are not square Stix another can of worms mate very sorry

its something that not many people worry about or know about
https://www.longrangehunting.com/thread ... ring.9866/
https://www.shootersforum.com/handloadi ... heads.html

l do square the case heads of my cases that the action has been worked, the bolt has been squared to the chamber ect...

now to explain my theory
when squaring the case heads you see that on most of these case's there is not a lot of the case head actually touching the bolt face
usually l find its only a ring around the primer hole raised up like a mound or the case head is lopsided ect..
but there are only a few out of say 100 that will contact more than 75% going by the cut on the case head,
expensive cases are affected no different to the cheaper cases
so when you are measuring headspace you may be measuring the high part off the case head that does not get touched when sizing because there is a hole in the shell holder you may be able to check this by holding different cases up to a light to see if you can see light through a gap when measuring, some say this is corrected by shooting your cases so they fireform to your chamber at the casehead as well as the body, its also said that an action that is not trued with the bolt face true to the bore wont make any difference, l dunno

but if it is true that when you fireform your cases the case head is flattening out on the bolt face it isn't really a problem after you fireform
these cases were fireformed before the case heads were trimmed and l only took off the humps around the primer pocket,
you can see they are not lopsided like some are
l'm only saying this may be the cause of inconsistent readings not that its another step everyone should do
hows that for OCD micro (anal) makes me happy

[Stix]

lol...
Bloody hell marksman...!!

I did that once to a batch of brass & have managed to not do it again since...you are not helping...

But youre right...i doubt these are flat--can tell by the marks left from primer pocket tool...

If going to do that, is it better to do before or after first firing...?



PS...& i agree...ive tried it after firing the cases & same result as you--still not an even case head after having been fired in the chamber...

[marksman]

lol...
Bloody hell marksman...!!

I did that once to a batch of brass & have managed to not do it again since...you are not helping...

But youre right...i doubt these are flat--can tell by the marks left from primer pocket tool...

If going to do that, is it better to do before or after first firing...?



PS...& i agree...ive tried it after firing the cases & same result as you--still not an even case head after having been fired in the chamber...

with these cases in the photo l blew them out from br to dasher first but it is up to what you think,
maybe try and see if they are out of shape after the first fire, l dont think it will hurt but remember headspace issues can arise
after the first fire the cases should fit the chamber better so less headspace issues in theory
l dont know if this is going to give any increase in precision at all, it just makes sence to me to have all surfaces mating properly and true
the reason comp actions are trued in the first place

[Stix]

Well hows this for a pissah..

Really pushed myself tonight...instead of loading other stuff to test & mounting a scope, i FL sized the last 70-80 cases, trimmed 280, then chamfered & deburred the 250...

My hands were black & well lubed...

Went to grab the wet tumbler and...bloody hell...the rubber ring on the lid is busted... ...ffs...!!!

Cant clean the cases, so wont be shooting the new rifle...again...



Big effort on these cases this week to shoot the rifle this wekend......very deflating...!!!...

So anyone know where to get rubber rings from...?...(the o ring for the lid)...

Its for a machine like this...https://www.ebay.com.au/itm/3KG-45W-Rot ... 0677.m4598