A bulging case is definitely not a sign of improper headspace on a rimmed cartridge.  It indicates only one thing:  A cartridge that does not fit the chamber.   

The reasons for this may be (1) Improper brass for the chamber as cut.  (2)  Ringed or bulged chamber due to barrel damage (3) Improperly annealed brass that isn't fire forming to the chamber combined with improper oversizing of the brass during reloading.

Earlier when you were seeking advice on this gun, you indicated that you had chamber cast it.  Carefully compare all measurments from the chamber cast to the fired brass.  This should tell you where the problem lies.  I suspect that the brass is too small, since if you had a bulged chamber you wouldn't have been able to get the chamber cast out.  I doubt that it is improperly annealed brass, since it shouldn't be annealed within an inch of the head anyway, and the brass as produced should fit properly in that area unless you've sized it with improper dies.

I know that this isn't the advice you want to hear, as you've indicated already on previous threads, but I would give up on this rifle, or take it to a competent gunsmith that can definitively measure the chamber and indicate with what brass and under what conditions it can be safely shot. That answer may be that it cannot be safely shot at all.

If you don't have access to a competent gunsmith, post what make and caliber brass you are using, the dimensions of that brass, the dimensions from the chamber cast, and a careful description of any anomolies seen on the chamber cast and we can try to help you further here.  At this point, I wouldn't shoot the rifle any more at all, until I find out what's bulging the brass and correct it.   

The rolling block does not handle split cases and leaking gas well at all.  An accident of this type with this rifle has a very good chance of resulting in the loss of your eyesight.  I would interpret a bulging case as one that just luckily didn't split.   

dave

The .348 brass is way too small for making the reformado.  .030 at the base is too much clearance, and will also contribute to making the accuracy even worse than it would be otherwise, as the shell will fit in the chamber crooked, misaligning the bullet with the bore.  When I spec a reamer, I use zero clearance at the base, and .003 or .004 at the mouth of the cartridge to give bullet release room.  On a straight taper cartridge, the rest of the cartridge has proportional clearance somewhere between the two extremes.   

The mismatch brass is the cause of the bulge.  The .348 brass is quite strong, and "probably" won't rupture.  That's my uninformed opinion, it's your eyes and your choice.   

I had a chamber that was slightly too big for .348 brass once, and I used cases that bulged for a while, even used a wrap of scotch tape around the base to keep them centered while they fireformed a bulge out to fit the chamber.  Then, I swaged some bigger by using a punch in the interior and an arbor press to expand the web, recut the primer pocket and turned the case to fit.  That kind of worked.   

Finally I gave up and re-barreled as numerous people had advised me.  I've been a lot happier since.  It was fun trying to get that old rifle to shoot, but it would have been a lot more fun it I had started out with a shootable barrel.  It might just be me, but I have very little fun with a rifle that won't hit the backer board, much less the target.

You can get custom cases made that will fit what you have by going to Rocky Mountain Cartridge.  Cost will be about $3 per case as I recall.  I don't have the address, but do a search on the web and you will find them.  They will fit the brass to your chamber cast.

Good Luck,
dave

Fellows,

The Buffalo Arms 43 Spanish, 43 Spanish Reformado and the 43 Spanish basic ( a longer case ) are ALL made from the 348 basic brass. I guess  a good question is " why doesn't the Spanish Remington brass or the basic brass fireform to the Reformado " It is my understanding that the Span. Rem. and the Reformado are essentially the same cartridge except the Reformado is not bottle necked and therfore takes a larger bullet ( .454 jacketed ). 

Chuck

Chuck,

 I'm going to have to go at this in a roundabout way since I don't have any info on the Reformado.

 If, as you say, the Reformado is just a straight sided Spanish Remington case then there are some basic differences between it and the .43 Spanish. I am assuming you shot .43 Spanish in your rifle thinking that was the caliber until the cases came out straight.

 What I have are the dimensions for the .43 Spanish & the .43 Spanish Remington. Here they are......

                             .43 Span.                .43 Rem.
----------------------------------------------------
Rim Diam.                     .629                       .641
Rim Thickness               .085                       .090
Head Diam.                   .521                       .525
(just in frt, of Rim)
Length to Shoulder       1.525                     1.545
Diam. at Shoulder           .512                      .510
Length top of Shoulder  1.755                     1.760
OAL                           2.255                      2.279

 As you can see there are some changes all down the line between the two cartridges, so if your firing .43 Span. cases in a Reformado...... which you claim to be the same as the .43 Rem., except for being a straight case..... you can see by these figures this MIGHT be where your problem is.


  You are probably correct in that BA uses the .348 case as the basis to make these cases. But, and that's a big but, BA uses many methods to get the case they advertise. This can involve spinning and swaging, plus some machining as you can see by the case dim.'s of the .348.

Rim Diam.                           .610
Rim Thickness                     .070
Head Diam.                         .553
Length to Shoulder             1.6499
Diam. at Shoulder                .4851
Length to Top of Shoulder    1.8041
OAL                                  2.255

 Also, don't forget that most if not all the old BP chambers were cut oversize so as to help in extraction, which in the case of the Rem. RB is pretty weak.

  So when firing an undersized case in the wrong chamber, plus probably an oversize chamber, the case is gonna bulge somewhere ahead of the web area, and depending on how the case was annealed after forming, this could take on some pretty weird shapes.

 So, I would suggest you either get ahold of BA and get the proper cases, or contact RMC and see if they'll make cases from your chamber cast.

 After that I would fireform the cases and only use a neck sizing die, keeping in mind the over sized chambers I mentioned above.

PETE

Chuck,

   You mentioned that you thought your gun was a .43 Spanish, and fired .43 Spanish cases in it, only to find out it wasn't a .43 Spanish, but what you THINK is a .43 Reformado. I don't think we've really established that fact for certain yet. So I was trying to show, that firing a bottle-necked case in a straight chamber can cause all sorts of problems.

  Apparently you ordered .43 Spanish cases before taking a chamber cast, or you didn't read your cast right. I see you have finally got it figured out...... maybe..... we all hope!

PETE