Forming Brass Question...

[in2anity]

I'm new to brass forming world. Using brass that I have formed, it's tight when locking up. I believe headspacing is extremely tight, being particularly bad on some brands of brass such as Lapua. QUESTION: will the headspace correct/decrease after the first fire-forming?

[Sergeant Hartman]

Not sure i understand.

You first form a case by firing it in your chamber, so it takes the same dimensions. So it shouldn't be hard to chamber For the first time Around. Eventually it may grow a little after multiple firings and if you are only neck sizing ie grow by 1 or 2 or 3 thousandth of an inch. And may start to get harder to chamber. That's when people will FLS or bump the shoulder back

The headspace of the rifle doesn't normally change

[sungazer]

What brass are you starting with and what are you trying to form it into? I have bought 308 Lapua brass and had to resize it slightly pushing the shoulder back a few thou increasing headspace so that it would fit my chamber without any tightness to close the bolt.

[in2anity]

Not sure i understand.

You first form a case by firing it in your chamber, so it takes the same dimensions. So it shouldn't be hard to chamber For the first time Around. Eventually it may grow a little after multiple firings and if you are only neck sizing ie grow by 1 or 2 or 3 thousandth of an inch. And may start to get harder to chamber. That's when people will FLS or bump the shoulder back

The headspace of the rifle doesn't normally change

I’m referring to forming new brass - 223 down to 300aac. The brass is still virgin.

[in2anity]

What brass are you starting with and what are you trying to form it into? I have bought 308 Lapua brass and had to resize it slightly pushing the shoulder back a few thou increasing headspace so that it would fit my chamber without any tightness to close the bolt.

How does one go about “bumping the shoulder back” when the die is already in contact with the shell-holder?

[in2anity]

I think I have my answer- i’ll grind a layer off the shell holder - I have a few spare #4s. Key search term "shoulder bumping" opened the door for me - thanks sungazer

[sungazer]

You should not have to grind a shell holder back they normally over size. The Redding competition shell holders are a set of 5 shell holders that start at +2 thou thicker than a standard shell holder and they go up in increments of 2 thou the largest being +10 thou thicker than the standard shell holder.

I would be double checking everything before going down that route as it is most likely something else. It is only going to be needed if something else like your chamber is actually a bit small. In that case the use of the go no gauges would show that. If the barrel is just newly chambered go back and have a chat to the gunsmith.

[marksman]

I'm new to brass forming world. Using brass that I have formed, it's tight when locking up. I believe headspacing is extremely tight, being particularly bad on some brands of brass such as Lapua. QUESTION: will the headspace correct/decrease after the first fire-forming?

you will find that different brands have different thickness eg lapua, the reason why it isn't recommended for some wildcats eg.. 6mm slr
but to answer your question:"will the headspace correct/decrease after the first fire-forming"
you will find that the cases should fit easier after fireforming them, just be sure you have enough neck clearance, I am sure you would have turned the necks

a mate who makes these cases recons you should use the thinner brass brands eg.. win because he said that they are more consistent in wall thickness
he doesn't turn his necks but isn't to worried about it being a one holer as it is used for short distance

[in2anity]

You should not have to grind a shell holder back they normally over size. The Redding competition shell holders are a set of 5 shell holders that start at +2 thou thicker than a standard shell holder and they go up in increments of 2 thou the largest being +10 thou thicker than the standard shell holder.

I would be double checking everything before going down that route as it is most likely something else. It is only going to be needed if something else like your chamber is actually a bit small. In that case the use of the go no gauges would show that. If the barrel is just newly chambered go back and have a chat to the gunsmith.

So I ground down one of my #4s only to realize this is irrelevant - the die never reached the holder anyway so I figured OSA must be thicker than ADI because the ADI brass locks up better after a FL resize. I figured I could polish the inside of my spare lee FL die to make the ram drop a little lower (and in theory bump the shoulder just a tad more), but now it doesn't lock up at all. Think I've royally screwed my lee die

[in2anity]

I'm new to brass forming world. Using brass that I have formed, it's tight when locking up. I believe headspacing is extremely tight, being particularly bad on some brands of brass such as Lapua. QUESTION: will the headspace correct/decrease after the first fire-forming?

you will find that different brands have different thickness eg lapua, the reason why it isn't recommended for some wildcats eg.. 6mm slr
but to answer your question:"will the headspace correct/decrease after the first fire-forming"
you will find that the cases should fit easier after fireforming them, just be sure you have enough neck clearance, I am sure you would have turned the necks

a mate who makes these cases recons you should use the thinner brass brands eg.. win because he said that they are more consistent in wall thickness
he doesn't turn his necks but isn't to worried about it being a one holer as it is used for short distance

Yeah I'm not turning them, nor am I really interested in that sort of commitment. This is more an experiment than anything anyway - I have a heap of jagemann brass that seems to be surviving remarkably well; the blackout through a bolt gun seems very gentle on brass.

And yeah, it's far from a one holer; it won't shoot better than 1" on the best of days.

[sungazer]

At least the Lee dies arent that expensive. You arent the only one that has fked something up in the quest. Just put it down to educational expenses. Back to Youtube to find the guy that has the right information on converting the brass. Sorry I cant help with the blackout process. I did watch a Utube vid once on it myself and thats it.

[in2anity]

I tell you what - without neck turning, there's no chance of locking up tikka or sako brass, must be thick stuff

[in2anity]

Actually disregard what I said about the shell holder reduction being irrelevant - going back to a pristine #4 shell holder really does see the holder as the limiting factor - on the contrary the one I ground down by 15thou is enabling me to bump the shoulder on ADI, OSA brass, and with a squeeze even Lapua. My trim tool had crept out which was confusing the situation.

Tikka and Sako brass on the other hand - no chance. Need to turn those (which I won't be doing ).