Lapua brass case head extreme stretch after 1 firing

[jikkyo]

I bought 100 Lapua 6.5 Creedmoor LRP brass from another forum to reload. It came as 70 once fired/30 new.

When I went to resize the 70 once fired brass today, I had multiple pieces get stuck in the FL die around 70-80% inserted. When I went to measure the width of the body of the brass, I found that the section of the body near the case head were consistently .005 to .008 over the the book spec of .470. Which explains why I cant even get the brass through the FL die.

My question is what would cause this type of case stretch? Has anyone seen this before with brass fired in rifles with loose chambers for lack of a better word?

I measured my other cases with multiple firings and found them to be very consistent with .470. The new Lapua brass all measured correctly as well.

 

[huntnful]

Definitely could have been sloppy chamber job, or an intentionally way over sized reamer?

But it goes without saying now, I would never buy someone else’s fired brass for my chamber. There can be small differences that lead to big head scratching moments. I know because I’ve done it before lol. It’s not worth the small savings IMO

 

[can1010]

sloppy chamber or AR10 with high pressure loads either way lesson learned.
if you want to try and save them back your sizing die out 1.5 turns and size, tighten die 1/4 turn and size, keep lowering die and sizing in multiple steps it will help but not sure if having .005-.008 case head expansion was good for the primer pockets so trying to size could be useless if pockets are loose or don't hold primers for more than 1-2 more shots.

 

[TaperPin]

I bought 100 Lapua 6.5 Creedmoor LRP brass from another forum to reload. It came as 70 once fired/30 new.

When I went to resize the 70 once fired brass today, I had multiple pieces get stuck in the FL die around 70-80% inserted. When I went to measure the width of the body of the brass, I found that the section of the body near the case head were consistently .005 to .008 over the the book spec of .470. Which explains why I cant even get the brass through the FL die.

My question is what would cause this type of case stretch? Has anyone seen this before with brass fired in rifles with loose chambers for lack of a better word?

I measured my other cases with multiple firings and found them to be very consistent with .470. The new Lapua brass all measured correctly as well.

There are a number of reamers out there with more body taper than a SAAMI spec to help with sticky cases causing clickers. There are probably even more chambers opened with sandpaper and a drill by well meaning guys tinkering with their own guns. Some factory chambers are looser than SAAMI - the SAAMI spec is more of a recommendation and there are no policing or enforcement provisions to this voluntary standard. Even going back to the 1960s I have some factory Remington barrels that are half dozen thousandths over SAAMI max.

If you have a chance to measure a number of fl dies, some are loose and some are so tight they aren’t much different from small base dies. Heavy duty lube like normal roll on RCBS stuff works well for case forming, but there are limits to how much the case head can be worked with smallish base dies. Many light duty presses have been damaged trying to do heavy duty forming. Just buying one $50 set of loosey goosey fl dies kind of defeats the purpose of saving money on once fired brass.

 

[Lawnboi]

What are you using for lube?

 

[jikkyo]

What are you using for lube?

Lyman quick slick case lube.

In brass shot from my rifle, which are sig brass, the lube seems mediocre. I need to lube both the expander ball and inside case neck vigorously to avoid a hard pull through.

What do you suggest?

 

[Lawnboi]

I use imperial. If you can’t even get a case through the die I’m guessing it was way over pressure rather than a chamber being that far off.

The real risk of used brass is getting it wedged in your gun once you size it.

 

[jikkyo]

I do the head space comparison trick with the disassembled bolt and found that some of the Lapua brass that I managed to size fully in the die were still oversized and did not allow the bolt to fully close.

I’m just going to cut this up to a learning experience and a loss on my end. The seller is completely ignoring me now and won’t answer my questions lol.

 

[jikkyo]

I use imperial. If you can’t even get a case through the die I’m guessing it was way over pressure rather than a chamber being that far off.

The real risk of used brass is getting it wedged in your gun once you size it.

I’m likely going to upgrade my dies to a bushing FL die and use a mandrel die for neck tension. Also getting the imperial die wax for lube.

 

[TaperPin]

some of the Lapua brass that I managed to size fully in the die were still oversized and did not allow the bolt to fully close.

You’ll be able to sell the brass - someone with with small base dies will be able to get it down enough to chamber.