problem with the Gras MLE 1871.

[trenches]

I restored a Gras . I bought a barreled action from Century and then bought the rest of the parts. And made some along with the stock.
Today I finally got to the range with it.
The load was from cases I bought that had been formed from Starline 50-110 cases. 85gr FFg powder and a 330 gr. cast bullet.
First shot I had a case separation.
So when I got home I cleaned the rifle and got the front half out of the chamber. Compared side by side with a dummy round the shoulder of the front half about 1/8" farther forward then the one on the dummy round. Measured from the case mouth to the beginning of the shoulder the fired case was .554". The dummy was .682".
The cases were only neck sized.
Not sure what is going on with that chamber. I'll take a chamber cast. But from examining the cases it's obvious that something is out of whack with the chamber. Or the cases I bought are incorrectly formed.
Wish I had an original case to compare to the other cases.
I measured the rim thickness of a PPU Lebel round and the Gras round. Both were .063". The dummy round is on the left the 2 pieces of the fired case on the right.

[Larry Gibson]

Nonte suggests 25 gr SR4759 under a 385 cast bullet to fireform cases made from 348 cases. Also didn't the Gras cartridge have a "Mauser" type case head? If so it is considerably thicker than the rim on the 50-110 cases. If so then those formed cases are being shoved in the chamber to headspace before firing then the rear portion is pushed back against the bolt face causing the incipient case separation. I would lube the inside of the necks and run them over a 45-70 expander. Then size the neck back down creating a false shoulder for the case to headspace on with a crush fit when chambered. That would hold the case head back against the bolt face and prevent case stretch or at least minimize it.

[trenches]

From what I read the Lebel was formed from the 11mm case. So the rims should be the same. Both measured .063". The bolt face is only .060" deep. So that would indicate that the case rim is being held against the chamber at the breech.
The bolt does need a little force to close. I'm sure that the extractor has something to do with that.
Maybe I'll take some shim stock, make some discs and see what the bolt will close on.
I'll check the rim thickness again. But at almost a 1/8" difference in length leads me to believe that the rim isn't the cause.
Something crazy is going on with this.
I'll have to try your suggestion with the 45-70 . Too bad I think I sold my dies. Should get a set though as I bought an original demilled trapdoor barreled action at the last gun show. It has the old demilled type where there are 2 divots melted in the chamber at the breech end. It came with a complete bolt. I want to make a sporting rifle from it. In any case something has to be done about the Gras brass.
But I'm in the midst of making a barrel for the Spencer. So that will have to wait a while.
So much to do and so little time.

[BP Dave]

I'll take a stab at it. As a rimmed case, the Gras headspaces on the rim of the case. If headspace is good--meaning that the distance between the bolt face and the back of the rim of your chambered cartridge is in spec, and the surface of the chamber is good, the lengthened chamber should blow the shoulder forward--kind of like fireforming a .348 Win into 11mm Gras like everybody used to do before .348 got so expensive. Blowing out the shoulder of the case like that ordinarily should not cause a separation.

However, if your headspace is too great, when you pull the trigger the firing pin tends to push the cartridge forward in the chamber, and recoil from the ignited powder then drives the case back against the face of the bolt. This stretches the case, because the case neck and wall are pushed hard against the walls of the chamber so they kind of "stick," but the head of the case is unsupported and driven backwards. Remember, even in an old black powder cartridge we are talking tons of pressure. A rough chamber can make things worse--the case really tends to stick, while the head and the thicker portions of the base walls of your case are driven back. This stretching can lead to a separation, often just ahead of the thicker part of the case wall, but in the middle of the case is not unheard of.

I wasn’t quite sure from your post, but it sounds like the cases you are using are .50-110 Sharps and that you are planning to continue using the same case. I believe the rim thickness on that round is about .050. I don’t have one with me right now, but I think the rim on the Gras is about .060-0.65 or perhaps a little thicker.

The first thing I would check would be your headspace--especially since this sounds like a parted-up gun, and also because a Gras round would ordinarily have a rim thicker than what you’re using. The bolt should meet resistance if you put a couple pieces of cellophane tape on the back of a chambered dummy round or empty case and close the bolt. Don't rely on fired cases for this test, because once fired, your cases can headspace on the pushed-forward shoulder and hide the headspace problem.

If you have excessive headspace it would be kind of a pain to correct the gun, but you probably aren’t going to be shooting cheap surplus, so you could just make your cases fit. One method would be by using a case with a thicker rim (or thickening the rims of what you have—there are various methods). Or you could wildcat your cases and form them with the longer shoulder so they headspace on the shoulder instead of the rim.

Also, if your chamber is rough you could polish it a tiny bit.

If none of this makes sense to you, you should probably link up with someone who has a lot of case forming experience and talk it though with them.

Oh, and you're using black powder, right? If not, it's probably a good idea.

Good luck, have fun, be safe.

[Wilderness]

Trenches - for a Hillbilly headspace check, seat a (fired?) primer about half into the case then close the bolt on it it. Remaining protrusion should give you some idea of what is happening.

If you do discover excess headspace you can take it up with headspace circlips made of the appropriate gauge electrical copper wire or brass wire. Leave a gap in the circlip for the extractor. Fine tune oversize circlips by flattening them slightly. This works best if your cases have a machined groove around the rim.

A couple of shots with the circlips in place should get the shoulder forward to where it can take over headspacing duties. This is provided the Gras has pressure to resist the primer blowing the case forward again. Otherwise it will be circlips forever.

I use this method on a Savage 99 with excess HS and cases are 100% on the shoulder after two shots with full pressure, and very close after one. The first time I formed shoulder headspacing cases I expanded .30-30s to .375 (4 stages) and then sized them back down, but the novelty wore off and now I just use the circlip method.

[trenches]

Just measured the rim thickness of the Starline 50-110 case. According to a set of dial calipers it is .069" thick. I've ordered a set of 3 dummy rounds with the bullet in them. I want to compare them with the other cases.
Wilderness I will try that primer trick.
And yes, I'm using blackpowder.
I'm no stranger to black powder cartridge rifles. I loaded for a 577-450 MH. The MOD load using carded wool and beeswax discs. Also for a .577 Snider. Even used 24 gauge shotshells for that rifle. And Minie balls.
Also 2 50-70's. One a custom barreled RB and a trapdoor Springfield. And the 45-70 Sharps. Along with .45 Colt and .44 Colt pistol cartridges.
I'll get this rifle straightened out. But it is something out of the normal for me.
Once I get those dummy rounds then I might have clue.
It's like Sherlock Holmes said. When you eliminate the impossible whatever is left however improbable is the solution.
And it's within the realm of possibility that the chamber is not a 11mm Gras one.
I bought a Greek Mannlicher-Schoenaur rifle that was listed as 6.5 MS. When I got it I saw a 7x57 stamped on the barrel. Sure enough it was 7x57. Somewhere in it's past the original barrel had been rebored and rechambered to 7x57. And I know it's 7x57 for a fact as I shot the rifle the other day. However, I have 6.5 barrel blank and a chamber reamer which will take it back to the original caliber.
Sorry, I sometimes run on.
Nice puzzle isn't it. LOl.

[trenches]

Did the hillbilly trick. The primer sticks out about.030" according to the depth mike.
If I really wanted to go trough all the trouble I could pull the barrel and knock some material off the shoulder.
I'll try the clips.

[Larry Gibson]

The 11mm Gras cartridge does indeed have the "Mauser" type case head and rim. The Mauser type case rim is much thicker than the rims of the cartridges you have. The "hillbilly" trick you tried confirms your rifle is headspaced for that Mauser type rim. Clips may work well enough but in the future the creation of the false should prove the better option, it has for me. Also, once fire formed, be careful to not set the shoulder back when sizing as you'll need to headspace off the shoulder, not the rims.

[trenches]

Could I reform 11m Mauser brass?
I'm still exploring what I can do to correct the problem. I'm wondering if I could solder or loctite a "washer" to the chamber mouth to make up for the bad headspace.
First off though I have to get the cerrosafe out and do a chamber cast.

[Argentino]

Could I reform 11m Mauser brass?
I'm still exploring what I can do to correct the problem. I'm wondering if I could solder or loctite a "washer" to the chamber mouth to make up for the bad headspace.
First off though I have to get the cerrosafe out and do a chamber cast.

11mm. Mauser cases should work too.
Both Mauser and Gras cases have similar dimensions but the shoulder-to-rim distance is smaller in the 11mm. Mauser case so you might need to fireform or resize them. Just make sure you anneal them before.

IINM, 11mm. Gras/Mauser rim thickness is around 0.090". So, if the rim of your cases are thinner than that then the only place in which I would solder a washer would be at the case bases, but that´s just me.

Just out of curiosity: Do both (bolt and action) serial numbers match? Mismatched parts might be an explanation to excessive headspace, though.
Perhaps you might also want to check if the rear face of the bolt handle (which is also the only bolt lug) is in good condition.

Argie.

[TNsailorman]

I have a tme or two in the past found rifles that have a little too much head space. The way I take care of brass for that is to set a lead bullet a little too long so that it is drive into the rifling when seated into the rifle. That will hold the cartridge back against the bolt when the rifle is fired and the case will be fireformed to your chamber. Just make sure to adjust your die to not set the shoulder back again when you resize your fireformed brass. Worked for me as I was taught by some old timers. james

[trenches]

Lots of good advice. thanks. The bolt and receiver serial numbers don't match. I got the barreled action from Century and the bolt and bolt head from Numrich. Or did I get the bolt head from ebay. Sort of forget which.
All that will have to wait. I'm in the process of installing a barrel on a Spencer receiver. Chambered it the other day.
Turned square threads on a piece of AL round stock. Went well so the next step is doing the real barrel.
In case you're wondering it is chambered for a trimmed down .500 S&W mag case. I already have a .500 S&W Handi Rifle and this seemed an easy solution to a barrel. Easy conversion from a mag case. And black powder.
Bought an Accurate mold in the right diameter and 350 gr. 1/20 lead.