Off and on over the years  I have been working a Trapdoor Springfield "carbine".   It may actually be a cut down rifle. Some who have seen it seem to thinks a Bannerman parts gun.  Barrel was smooth bore and had no sights, but it did have screw hole for rear sight.  The barrel seemed to conform to carbine dimensions

I had  the barrel lined and front and rear sights installed.  I think John  Taylor did that for me. Might have been some one else but not likely.  The front sight blade is a blank and has not been cut down.

I have been meaning shoot the gun and cut the sight down for a while.   

The other day a friend and were I talking about something to do with Trapdoors and I drug out my old copy of Wolfs book Loading  Cartridges for the Original .45-70 Springfield rifle and carbine.   

I was reading Wolf's section on sights and in particular the information on the two different height sights.  Wolf says the front sight with the M1879 rear sight is approximately .10 above the front sight stud.  For the M1884  rear sight the the blade should be .14 above the stud.

Now when I started writing this,   it was to ask those here if they might know what the Trapdoor Front sight stud is?  is it just the front sight base? 

But referring to Wolf and writing this post I realized I don't know the difference between an M1879 and M1884 sight.   

Then Wolf says there are differences when the M1888 cartridges are used with the M1879 sight and differences when the M1873 rifle cartridges  are used with N1884 sights.

I was getting more confused as I typed and decided to just shoot the gun, do the math and file the sights in to center.   

And, leave this post up to increase my post count.

I don't know about the height but an 84 front blade is thinner and a carbine blade is taller than a rifle blade.

And if you ever need a higher sight blade for an 84, one from a US Krag will slip right in and pin.