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.40 sizing problems with Lyman 10mm dies


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Hi guys, 


I've just started with reloading .40 for my SVI 2011. 


I have an assortment of range brass and most of them have 'glock bulges'. 


I am reloading with a Lyman 10mm die-set and here comes the problem.   The sizing die seems to be way too tight, pushing material down wards. 

Some cases are acceptable and will chamber check easily but most come out like below.... and then they hang up during chamber checking. 


Do I need to buy one of those Push Through dies to first get the cases back to 'normal' diameter before I size them with the Lyman die? 

Any other tips/ pointers?   

Thanks guys. 



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I was afraid it was going to be the Lyman die.... 

I use an RCBS Piggyback II progressive press (5-station)

I should probably just by another die-set from Dillon.....

But I'm wondering if buying a Redding GRX or Lee Bulge Buster might solve it as well...

Because the picture above is the worst case scenario....  cases that haven't been shot out of a Glock do not have this 'step' as in the picture above, at all!



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you also want the LEE U-Die for sizing, this is a must, the bulge buster is the last measure. your fail rate will be around 5%, if you are still loaded with glock shot brass,  or less once you run the U-Die in the sizing station...

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I still had an old Lee size-die lying around which had a damaged carbide ring, but still good enough to test if this one also creates this strange 'step' in the cases. 

I 'selected' a few cases with the worst 'Glock-bellies' and the Lee size-die had no issues with them at all. There was no extra bulge, no 'ring', no 'step' in the cases after sizing.  They even chamber-checked, but barely...

A fellow shooter had a Redding GRX push-through die which he no longer uses as he shoots production now, and he was nice enough to sell it to me for next to nothing. 


So like you said, Furrly, the 10mm Lyman die-set, even though it looks quality, is simply not usable. Too bad.


So hopefully, with a new sizing die from either Lee, RCBS or Dillon and the Redding GRX push-through die, I hope I'm good..... 

If not, then I will also have to get a Lee undersize die.....



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Got home during my lunch break, saw the Redding GRx push-thru laying on my table already! 


So tried about a 100 cases... man... some really needed some major pushing to get through the die!   But, after getting them through, they go through the Lyman 10mm sizing die without any issues and without leaving any marks!   And they all chamber-check easily with room to spare! 

So, problem solved. I'm a happy camper!

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One tip I learned along the way with the GRX push thru die is to gauge the ammo right off the press first. 


If I have a cartridge that won't gauge, run it through the GRX and that usually sorts it out and it will gauge just fine. Perfectly safe to run a completed cartridge through the GRX. I've found that means fewer rounds having to go through the GRX die, which can be a little tedious if you do it for every single case. 


The U die is great if you're having issues with sizing.

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I ran completed cartridges through a GRX before, and then one got stuck. A live round stuck in the die. I ended up detonating it into the ground with a hammer tied to string, a nail, and the die clamped to a piece of plywood as I was hiding behind a forklift. Was kinda scary, till it detonated and then was very anticlimactic.

Sent from my iPhone using Tapatalk

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