9.3x57 sloppy chamber?

conor_90

conor_90

CGN Ultra frequent flyer
Rating - 100%
90   0   0
Location
NW BC
Hi guys, doing some hand loading with the 9.3 WSM ( Wagner short mooser)

Using lapua 9.3x57 brass, privi projectiles and 3031 and loading the cases to 3 inches length

I have attached some images of what is happening to the brass after it has been fired and comparing case oal and shoulder here: https://ibb.co/album/WkVv5Y

Am I right in thinking that I should just necksize the cases and keep living my life? I’m a bit concerned but the rifle functions well
 
Last edited:
You probably can continue to "live your life", but your fired brass is getting fire formed within your chamber - may or may not be an issue for headspace. You do NOT want to move that fire formed shoulder back any more than needed to re-chamber that brass. Ted Wagner has helped me to read other Internet posters who seemed to have it figured out - more than just opening an 8x57 case into 9.3x57 case - have to essentially make a "straight wall" case - like with a 41 magnum or so sizer - so neck is opened up like .400" or so - then use the 9.3x57 sizer and work that case back down to length that just so chambers in your rifle. Cases resized that way, and fired cases, look very, very similar, and you will know that there is NO incipient head separation about to occur. If you care about stuff like that...
 
That can be an issue - from other posts, seems to be a lot of "dimensions" floating about regarding 9.3x57 - in the end, need to size your brass to match your chamber - warts and all.

Is what "hand loading" might be about - some of us do similar with store bought 303 British brass - open up the neck larger than it was made, and re-form a new shoulder that matches to the chamber in our rifle. After 100 years, nothing really says that "new" stuff matches up to "old" stuff, any more...
 
Yes this is how I have reloaded 303 for Lee enfields in the past, in fact I’m selling my full length dies atm lol

I figured this was the same issue. It is clearly well enough in spec to load, fire and eject. I guess either neck size to fit my chamber or accept shorter brass life. At the price of this brass it will be necksizing
 
I am maybe not smart enough to figure that out - I do not own any neck sizing dies - but I do do "partial" full length sizing on many cartridges - gives me a smidgeon of squish on the brass body to be sure I am bottoming out on the shoulder of the case, when I try them in the rifle chamber, not on the swollen case body. So, most of my reloads can see the neck is sized to within a "bit" of the shoulder junction, if not fully FL sized - but some are not completely all the way. I am not a precision target shooter by any stretch - mostly a deer (coyote, jack-rabbit) hunter - so I need and want really slick easy re-chambering - not so much an issue when I pull off the first shot - but more when I don't - I really want that second one (or third one) to be available "slickly".
 
I found that my Lee 9mm Makarov F/L Die worked great for me as a neck sizer for 9.3X57 and 9.3X62, but it depends on the brass you use.

If you decide to make brass from 8X57, you could try what I do to make 9.3X62 from 30-06:

I ordered the 416 Rem Expander/Decapper through Higginsons. It's Part Number SE2935 and cost about $12 shipped. It was not in stock so I had to wait until the next shipment, which are multiple times/year. It has a long transition to 41 Cal, so gives you almost a straight-walled case and I have yet to split a neck. I installed it temporarily in a 45-70 Die Body, but any Lee Die Body greater in size than 30-06 will work. Lube the neck well, and you'll get an almost straight body which is what you need for correct shoulder placement. Next step, size it in a 9.3X57 die, and I always anneal at this point. On first firing it will fill out and from there you're good to go.​
 
Last edited:
I use the oversize expander method, have also used a soft cast bullet seated long to engage rifling and ensure the brass is all the way back against the bolt face. Doesn't work on rifles with long freebore.
 
dan belisle said:
I made my 9.3x57 and 9.3x60 brass from 30-06 brass for years. It let me fit the brass to the chambers handily. I have factory brass for the 9.3x57 now as well, it is noticeably smaller than what the chamber is. So, fireform and neck size afterwards. - dan
Click to expand...

Dan are you trimming to min length after neck sizing every time to make up for the long throat? Or do you trim to the length of your initial fire form?
 
Per my own experience, it is the shoulder of Husky rifle chambers that is often a little further forward, relative to new brass or 8x57 brass. I make brass for mine from 30-06 brass and my FL sizing die is about half a turn off the shell holder. I size it just enough to make it chamber
 
Last edited:
What's that shiny ring above the base on the fired case? Run a bent paperclip inside the case to see if there is a corresponding ring on the inside that could indicate stretching/thinning of the case sufficient to indicate case head separation may be imminent? Then again, it could be something else entirely I am seeing...
 
. I have sectioned a case and run the clip down and there is no seperation


BUT only some of the 1f cases are like this, the other are actually SHORTER than the factory brass

I’ll eat my crow on this one, I think my loads are too hot. I will toss the maimed cases (damn) and continue with lighter loads

https://ibb.co/kDHmPHv


I think I need a 9.3x62 or 338 wm again to meet my desire tbh
 
Last edited:
I have seen that - cases get shorter on firing - I do not know for sure, but my guess is the original brass case, before firing, is significantly "small" in the chamber - upon firing, the walls swell out, the shoulder might move forward, the neck part might get wider - only place that i can think that the material comes from to do that is for the case to end up shorter??

I do not recall ever seeing that on previously fired / fire formed brass - often they tend to "creep" a bit longer with each firing? As if they are a snugger fit in the chamber, to start, so breech pressure causes a bit of "brass flow" to occur? I really do not know - that is the best explanation that I can come up with to explain what I see and measure.
 
So look at the stretched cases here; I can tell which load started the stretching.
I’m considering full length resuzing and reusing these cases after trimming. Opinions?

As I said there’s no sign of any case head separation besides the shiny ring and growth of the case ( I guess we could call this a sign of case stretching?)


Thank you woodlot owner for your comment, it is greatly appreciated


I don’t usually hot rod my loads at all, this is a wake up call
 
conor_90 said:
. I have sectioned a case and run the clip down and there is no seperation


BUT only some of the 1f cases are like this, the other are actually SHORTER than the factory brass

I’ll eat my crow on this one, I think my loads are too hot. I will toss the maimed cases (damn) and continue with lighter loads

https://ibb.co/kDHmPHv


I think I need a 9.3x62 or 338 wm again to meet my desire tbh
Click to expand...
What is your load? Looking at your brass I'm not sure it's fireforming correctly. Or maybe just the pictures not showing it well. New factory 9.3x57 brass needs to be fireformed to the chamber on first firing using the expanded neck or long cast bullet.

Brass getting shorter happens because the headspace is long, brass is flowing BACK to create the new shoulder. If some brass is long and some is short then you maybe need to rethink your fire forming method to make it more consistent.
 
There will not be any case body stretching occurring, if the shoulder is within a thou or so of the chamber shoulder, and the case head hard on the bolt face - the idea of sizing new, never fired brass to make that "false shoulder" is so the case body fire forms to the chamber with no stretching going on. Once you have the case matched to the chamber, do not want to re-size it any more than needed to re-chamber - so do not want to push that case shoulder back again, regardless of how the die instructions say to do re-sizing. Can not "undo it" however - I have seen on multiple 303 British - factory fired cartridges - definite ring inside felt with wire. Nothing that you can do to "undo" that - was done on that first firing of a case that was not tight - case head to shoulder - in that chamber. (For rimmed case like 303 British, also requires some "slop" in the headspace dimension for that case rim)

Just inserting a factory cartridge in an over long chamber and fire it, may not be fire forming it without that "incipient case head separation" - under firing pressure, the case is going to expand in every direction to fill the chamber - I think starting by grabbing chamber walls first. If there was "slop", the firing pin moved the case forward in the chamber - hence the case head is going to get blown back tight to the bolt face - stretching that case wall area just in front of the case head, which creates that "ring" - if the distances involved exceed the "spring back" within the brass alloy. I think.
 
Last edited:
You must log in or register to reply here.
Back
Top Bottom