I've four through mortises to chop. The tenon is a one shoulder tenon that is close to splitting the stretcher in half giving a 20mm wide tenon and mortise. That presents a small problem. My largest pigsticker is 1/2", I could use the 5/16" pigsticker and do two rows inside the mortise and then clean out the middle. Or drill out most of the wood and clean up the "Vs" and sides with a paring chisel. I do not like either of those options, the double mortise is too slow and too much work, The drill and pare is also slower than just going at it with a correct sized chisel.
Awhile ago I bought a set of Narex firmer chisels on a lark, mostly because it is hard to find new firmer chisels and they were cheap. The handle shape and size sucks as with most Narex chisels so after a quick sharpening I stuck them in a chisel rack and forgot about 'em until today.
As mentioned earlier I needed a 20mm chisel and guess what, the Narex set had a 20mm firmer chisel. Well they are cheap enough not to worry about ruining. I thought about using a "chisel" hammer for a couple of seconds to protect the handle but rejected that thought, again because they are cheap. Out comes my normal mortise mallet, "lumpy", and off to the races.
While I use a lump hammer as a mortise mallet I do not go all Conan on the chisel. I find light taps gives better control and is faster than whacking it hard. The lump hammer just takes less energy than other hammers.
Anyway, after a quick mortise chop I'm pretty happy with the Narex chisel and for grins I looked at the Narex web site to see what they said about the firmer chisels:
The firmer chisel is a "Special tool for rough work. Blade tapers in width and lengthwise from tip to shoulder for sidewall clearance. Forged blade is made of traditional Cr-Mn steel and heat treated to 59 HRc. Ergonomic handle from hard and hefty hornbeam wood is strong enough to withstand heavy blows with a mallet."
Hornbeam handle is good but I expect if I use the chisel again I'll take a spokeshave to it and put a couple of flats to help orientation much like a pigsticker has.
The first of four mortises is finished:
The iron held up well, after finishing the first side I looked at and felt the edge. There were no chip outs, just a couple of shiny spots. I took a couple or three strokes on the medium India and a quick strop and it was back to work.