Since this concerns reloads in a double decided to post this here instead of the reloading section.
Rifle is a Chapuis in 9,3x74R shooting a "middle" load of 56 grains of RL 15 and the Speer 270 grain bullet to be used for off hand practice.
I didnt keep good records but think this brass was reloaded 4-6 times and it was purchased new. Yesterday two cases separated at the base so I tossed the remainder of box (RWS brass). The brass is not FL resized. Bascially the resizing die is about the thickness of a nickel above the shell holder. I am going to try some Hornady brass and keep better records but am certain never had a case seperate untill it has been reloaded at least 4 times. This also happened one other time 2 years ago but it was with used Norma brass that was purchased from someone else. Brass does not seem to be stretching as trimming isnt required between loadings, maybe every two firings.

Should I be concerned about anything?

Snowwolfe,
I have shot RL 15 out of my Chapuis,my load was 61 grs with the 270 speers,it shot very well,I did not have any problems with my brass either,I would think it's the brass in your case,Tony 450 # 2 had some problems such as you describe with the earlier Norma brass,he was also getting case separation,when we compared the earlier brass to the brass that I was shooting,it turned out to be heavier in weight,so we felt that Norma had added a bit of weight and strengthened the brass somewhat eliminating the problem,my loads were clocking in at approx 2350 fps,keep in mind though that RL 15 is notorious for variations from lot to lot,maybe Tony will pipe in & give us his opinion as well.

I only get 2 firings from the lots of Norma Brass I have used. Most split on the third firing..

I have not tried any of the newer thicker norma Brass I have yet.

If you are getting 6 firings that seems about right to me...

Funny thing is in my 450 No2 I have some Bertram cases that have been fired at least 25 to 30 times, I have not had a case failure yet.

My load is 65 gr of IMR 4831 with 286gr Woodleigh Soft and Solid, Nosler Partitions, and 285 gr Hawk .035jkt.

Bal, how many loadings are you getting from the newer heavier Norma Cases?

Thanks guys. Makes me feel better it isnt my rifle.
I am going to order some of the Hornady brass and cut a case apart and compare it to the RWS brass.

Randy, If you're in a time bind I have a few fresh boxes of Hornady I'll 'loan out' til you get some in.Then we can swap out.

Mike,
Thanks but in no rush as I still have 5 boxes of RWS.
Will order some Hornady's next time I find a Cabelas coupon

BTY, just "won" another Sparta 30 06 on Gunbrokers. This one is an O/U. Good price, $471.

If it shoot as as well as the SXS it'll overcome the 'fugly' part! That one shoots great. Hopefully the triggers will be better with this one.
Drag it along next time.. Another girl for the orgy wouldn't hurt!

Tony,
I have been using that brass and some newer stuff,have'nt really kept a count,but even the earliest stuff has just never failed!!

That's pretty normal. 9.3x74 has a short life span before seperation. I've seen alot come out in almost two pieces.

Many of the older double rifle cartriges specify an undersized case in an oversized chamber. 9,3x74R and .375FL are two of these.

If case is at CIP maximum size and chamber at CIP minimum, you still have 8 thou of rattling space just in front of the case head. If you get minimum spec brass and have a maximum spec chamber...you have a rattling good fit!

Also becuase of the nature of double rifles the cases seldom bulge or stretch evenly. I always mark my practice brass with a line...that always points up when I load. (some folk take it to extremes and mark rounds for left and right). This has doubled the number of reloads I get out of my .375FL

On some of the old brit doubles of 'second grade' makes , yes, you should probably mark cases L & R as well and neck size only.

Remember, these rounds and the dimentions were drawn up over a century ago when tollerances are not what they are today, and were designed for maximum reliability with factory ammo. Nobody in Europe of the British empire relaoded once smokless came in, until well after WWII

There is a system that reduces the brass death in double rifles, and break top single shots. I have an old Cape gun chambered for 8X57JR and for a very long time Norma brass was all that was available in the USA for that chambering. I had problems with brass head separation, and brass was hard to come by. I tried several things to solve this problem. What I finally came up with was to fire form the new brass in my chambers with nothing in the case but cream of wheat,(NO BULLET)a small amount of pistol powder,and afterwards only neck sized the brass. I now get sometimes ten or twelve loads from the Norma brass in the 8X57JR. The same thing will work with the 9.3X74R brass and the 375 Flanged as well.

Tony's Bertram brass for the 450NE #2 lasting well in no surprise! The 450NE #2, and the 475NE #2 are the two strongest brass cases in the NE cartridge world. I have to use the 475NE #2 brass to make cases for my Westley Richards 500/450#1 express double, and that brass is so tough that I broke the top of my loading bench's 4 inch butcher block from the pressure of forming the brass in an RCBS BIG-MAX press. That stuff never needs anything but neck sizing! Making brass for the 500/450#1 express is a pain in the butt! That is why I shoot that rifle so little!