doublegunshop.com - home Forums General Discussion Double Rifles, Paradox Guns & Gauge Rifles @ doublegunshop.com Reloading question for 8x57jr pre-war Merkel

I have a pretty pre-war Merkel double rifle from 1931. Has .318" bores. Shoots S&B 8x57JR very well.

For reloading, I'm using a RCBS 8x57JR FL die with a .318 expander plug (RCBS #56366). Sized necks are correct, but unloaded brass won't allow the rifle to fully close. I'm using a shellholder that I had on hand for 44-40 work. RCBS package says use #26. Is there any chance the recommended shell holder for this rimmed cartridge is thinner, measured from the where the base of the cartridge sits to the top surface that contacts the die's bottom? I have the die turned 1/4 turn past where it bottoms out against the shell holder.

I have not yet smoked a case to see where the contact is, nor done a detailed measurement at different stages up the case to compare a factory round that fits to my resized cases that don't. I will, but wondered if I might be missing something else.

Anyone have thoughts on this?

Thanks,
Chris

This rifle was offered on Gunsinternational awhile back before being auctioned elsewhere. Pics are still up on GI: https://www.gunsinternational.com/g...ble-rifle-8-x-57-jr.cfm?gun_id=101787360

CJF,
I suggest you don't adjust your dies the way you do, even if the instructions say to do so. Once you fire a cartridge in the rifle, I suggest you smoke the case and adjust the sizing die to just 'kiss" the shoulder of the fired case. This way you are adjusting the headspace to fit the cases to the actual rifle (adjust it to a case fired in one barrel and verify with a case fired in the other barrel). This way you are headspacing on the shoulder, instead of on the rim, as you are now doing. By adjusting the die like you are now doing now it is likely you are pushing the shoulder back, and when it is fired, the case will elongate and likely result in head separation after only a few firings. It may be that the case elongates enough on the first firing that the end of the sized case strikes the ledge at the end of the chamber neck and beginning of the chamber throat. Or it may be that setting the shoulder back as much as you are likely doing may create a bulge at the shoulder. Either of these conditions might result in the problem you have. If you measure the head diameter of both an 8x57JR and 44-40 case and if they are the same, or very close the shell holder is not the problem. While you are checking this all out, it will be worth your while to check whether a .321-.322" or .323" bullet will easily fit into the neck of a fired but not resized case. If a bullet other than .318" will fit easily, it can be used to load ammunition. You will need to smoke a case to find what is causing the failure to close. You might not have a problem, unless it takes significant force to close the rifle. Good luck.
Mike

Ford:

Do you tighten the set screws on the dies for each calibre for each rifle in that you have a specific die for each chambering for each rifle? Or do you just adjust a single die each time to the requirements for the rifle of choice @ the time?

Serbus,

Raimey
rse

This is my only rimmed 8x57 and my first time attempting to size and reload any cases I've fired. So the dies are not set for each rifle. Typically I'll do that once I get a load working well.

For rimmed cartridges, I usually don't do the extra quarter turn when setting the sizing die, but for rimless, that seems necessary.

I'll smoke cases tomorrow. I used a universal decapper so some of the S&B rounds I fired should still be in their original dimensions...I'll confirm they chamber well now. I know unfired factory ammo with .318 bullets chambers. The loaded round I'd made had a .318 bullet, but one shaped differently than the factory ammo. Might the shape of the bullet, but these are seated pretty deeply compared to the S&B. Need a good night sleep before I mess with this more.

Thank you for the help Mike & Raimey. Always appreciated.

Chris

Raimey,
Unless I intend to load a significant quantity of the same cartridges, I don't usually tighten the set screw. If I only have one rifle with a particular setting, I will tighten the set screw. I use the same set of 8mm Mauser dies to load 8x57 I-IS, IR-IRS, R/360, 8.25x57R Hagen, and 8x72R, so I have to set them for each rifle. On the other hand, the 5.6x61R vom Hofe Super Express stay set the same.

Cris,
The universal decapper doesn't do anything to harm the cases and a factory round fired in a particular chamber can't be larger in diameter than that chamber but will likely be larger and/or different shape than the factory rounds. This is why I set the dies like I do, to make the reloaded cases the same as the chamber rather than a factory round. Custom/ commercial hand loaders need to make cases the same as factory rounds, so they fit everybody's rifle (unless they have the rifle or cases fired in it to set the dies by). If a case fired in a chamber won't go back into the chamber (absent excessive pressure) something has happened during the reloading process to change one or more of the dimensions. When you smoke the cases, you should be able to see what changed. The case length should be measured and the cases trimmed to the "trim to" length (usually a little shorter than new case length). Bulges in the shoulder area are often caused by seating a bullet w/o cannelure in a too long case or crimping too much on a solid area of the bullet. I believe you will quickly "figure" the problem out when you smoke a case. Good luck.
Mike

Thanks Mike. Apologies, I haven't smoked a case yet. Weather finally turned here, so I'll go to the range Monday to move a few projects forward. I'll also pre-measure some of the S&B ammo I have and then fire that so it can be measured again to see what's changed. The Merkel shoots so well with the S&B factory ammo, if worse comes to worst, I'll just stock up on that (one of my favorite online ammo retailers has 6 boxes in stock at $23/box.)

Cris,
There is no need to apologize, we all delay projects in bad weather.
Mike

So I think I have this sorted out.

First off, I was making things harder than they needed to be, by simultaneously working with once-fired S&B brass that had been shot in my rifle, and a mix of loaded (by someone else) once-fired and new Norma brass and another handful of fired RWS brass that I had purchased.

By measuring the factory ammo before and after firing in my rifle I could see where cases had 'grown' during firing. There weren't appreciable differences between left and right barrel fired cases. Basically the body of the cases expanded in diameter, most appreciably by .002-.005" measured 0.75" up from the rim. And the shoulders moved forward in firing, by .0065". Cases expanded elsewhere, particularly the neck, right above the shoulder. The biggest increase as a percentage was how the neck immediately past the shoulder increased during firing (+1% in diameter.) Brass fired in my rifle still chambered in my rifle (no surprise).

But the handloads I had purchased and pulled down for the brass sometimes chambered but often would not. I couldn't tell why until I dumped the powder.

I pulled down the handloads I had bought because the bullets were 0.323" and my rifle is 0.318" What I found with those was a mix of previously fired brass, which wouldn't chamber, and new Norma cases with pristine case interiors (vs dark, obviously used cases). These new Norma cases would chamber without running thru my .318 sizing die, assuming I'd already pulled the bullets. (For what it's worth, the load appears to have been 170gr JSP over 43gr of 4895, which seems to be on the safe end of 8x57 loads, which start at 40.0 and work up to a max of 48.0grs of IMR-4895 for 170gr bullets (per loaddata.com)

Anyway, once I focused this previously fired empty brass that I knew wouldn't chamber I tried setting the Hornady dies have again. Initially I turned the sizing die, with the decapper/expander removed, into the press till it bottomed out on the shell holder. Resized cases still wouldn't chamber. Then I turned the dies a further 1/3 turn into the press and locked them down and resized...now these cases chamber correctly. (Not all the previously fired cases will chamber, but at the least those I had purchased loaded. I've got enough brass that works that I'll put the remaining problem cases aside for now.)

So I wasn't setting the shoulder back enough to match my gun's chambers.

The only other point to share is that my used 0.318" 8x57 dies came with a bullet sizer. I've been using that, and Imperial Case Lube, to size the 0.323" jacketed soft points down to the 0.318" diameter I need. Takes some force, but all the bullets resized without visible damage. (I also love the collet bullet puller from Hornady. So much easier to use than the Franklin kinetic puller!)

Now to reload some rounds with my own stash of powder and see how these compare to the factory S&B ammo, which is super accurate but seems a little hot for my rifle (primers look fine but rifle is slightly hard to open. Garmin has those at 2,400fps.)

Thank you all for your advice as I worked thru this.

Regards,
Chris

Cris,
Once you have the different cases chambering, I suggest you trim them to the "trim to" length and reset the FL die to avoid setting the shoulders back to avoid head separation. You might try a .323"bullet in fired cases. If it easily slips in, you can use .323 bullets, but only in cases that accepts the bullet. This may or may not increase accuracy.
Mike

Hey Mike -

A 0.323" bullet will not slip into a fired case from my rifle, but a .318" bullet will.

My new (unfired) Norma brass, sized down from 8x57JRS, is 2.2315" or 56.7mm in length. Brass from S&B factory ammo, fired once in my rifle, has an overall case length of 2.244" or exactly 57mm. I'll keep an eye on how that grows.

Once I'm back from my next range trip (hopefully tomorrow), I'll try sizing those cases without any extra turn on the dies after bottoming out on the shell holder. Further, I'll back off from that contact and resize and check the brass again in the chambers and with a 0.318" bullet...if I feel I can seat those bullets without resizing and moving the shoulder, and still get the rounds to chamber, I will.

Regards,
Chris