Mike Venturnio's book Buffalo Rifles has pic. I have fooled with rollers many years and have to say any failures I've seen, were caused by some jack leg who had altered them or loaded with wrong smokeless. If the rollers are shot with black powder or equal pressure smokeless they are as safe as any rifle from their era. When I shoot smokeless I use accurate arms powder usually 2495 or 5744 which usually pretty much fills the dash cart cases that I shoot. Doesn't mean they can't fail, but not likely if used as intended. Jerry

Somewhere in storage I have the hammer from a failure. The block sheared the  front part of the hammer off.  This was the only damaged part. Storage being some where in Maryland and I am in South Africa.

This came off a Spanish Remington Rolling block that had been rebarreled to 45-70 and had been shoot with smokeless powder. The barrel was one of those kit barrels from  Numrich that was DIY installed.   

When I installed the new hammer I found when dropped the hammer cam surface would not contact the bottom of the block just as it struck the firing pin and lock the block. The block was pitched forward.  I set the barrel back so the block was perpendicular and everything locked up just fine.   

Asked the guy if he had been having problems with primers backing out and he said no, not at all.  But then they all say that.

Spoke to a former NORMA employee.
He sad the rehardened 8mmx58RD Swedish RB´s were kind of dangerous since they had no flex or deformation, the just break like glas when they go... no warning signs...     
He used to do this at his work to show pepole of the potential danger..
I have a picture of a broken one, on another computer, will try to get it up here soon.

Johan/ from Sweden

Swede wrote on Sep 20^th, 2007 at 7:25am:


Johan,

That raises all sorts of questions.   Did they determine whether it was the choice of alloys involved or the original case hardening process?  If it was the original case hardening process that was flawed that can be corrected.  If it the choice of alloy, well not much can be done.   There are a lot of these 8mm being sold here at moment.  It would be good to know.

Pete

Ziggy wrote on Sep 20^th, 2007 at 12:46am:


In the fired position the back edge of the breech block should be at or near in contact with the adjoining surface of the hammer.

Hera comes the promised pictures.
It was laying in the scrapbox at the gunsmiths, I took some quick pictures with my cellphone...

The RB is a m/1867 swede modified 1889 to 8x58RD, as you can see the hole for the sliding extractor has been plugged, you can also see the new hole for the c-shaped new extractor.

This one have been rebarreled and chambered for .458"x1,5"

The steel is hardened straight through, and brittle...

I know nothing about the load used in this one, just want to show what can happen, and according to the NORMA guy, there will be no warningsigns before it goes into pieces...

Cant se how this would happen with blackpowder??
Take care and load with common sense!

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At first glance, this would appear to be a straight tensile failure due to excessive load, but the rusty mark on the lower part of the block is interesting. This could be indicative of a heat treatment quench crack. In the light of the statement that these RBs were through-hardened, I would look closely at this.
Fred.