I have a M1888 unconverted black powder Mannlicher M1888. It suffered externally from being buried in an Austro Hungarian filthy dungeon for over 120 years ending up on the floor after the shelves above rotted and collapsed. Internally it is fine, good bore (barely used) and everything functions well after very, very extensive cleaning.
I am loading with 53 grains of 3f which leaves room for a tallow/wax wad with card disks front and rear. I can squeeze in up to 62 grains with great care but there only just room to seat a bullet and lubrication is all with black powder in a tight twist 8mm barrel.
The bullet I am using is the Lee 329-205 and a casting of the bore mouth shows that it seals on the rear bands into the groove and the front rides on the lands. This is supposed to be a suitable bullet. The dimensions of the bore are as per new production. This rifle was only in a soldiers hands for 2 years at the very most. Probably I have already fired more rounds through it than the Austro Hungarian Army.
However. Whilst the bullet holes on the target show no signs of tumbling (all perfectly circular) at 50 metres it has trouble finding a 200 metre target. I have experimented with a full 62 grains and that made no difference and it fouled up fast with no lubrication. I have tried hard and soft lead. I have even tried paper patching to ensure that the bullet engages the rifling and help scour the grooves. The patches fall a metre or two in front of the barrel in long strips where the rifling has cut into them.
The rear sights are raised 3 notches to compensate for the lesser charge which at least sprinkles the impacts evenly around the 200 metre target. That is the whole paper, not the black.
The barrel is perfect. The cartridges match all the advice (ex 7.92 cut down and formed). The sights are in good order. I am no great shot but better than this. Charges from 50 to 62 grains have been tried in 1.5 grain increments with no discernable effect.
Unless someone has some insight beyond mine then the finger points to the bullet. The original was a copper covered round nose of 244 grains. My Lee cast bullet is 205 grains which gives the same weight to powder ratio in my 53 grain load.
Now I am aware that the original black powder round of 1888 to 1890 was a solid pellet with an annular gap around the outside for flame propagation. Like the Lee Metford I assume that the purpose of the solid pellet was to control the combustion rate in a cartridge intended for future smokeless powder. Especially as it is possible to force the full service charge in using 3f powder so capacity was not the reason for the solid pellet which followed the Swiss army research. Equally like the Lee Metford, it was designed as a smokeless powder rifle but had to be introduced as a black powder rifle pending indigenous smokeless powder production.
The question is, can anyone recommend an alternative cast bullet that may better suit this rifle? The first of the straight pull military magazine rifles. How hard should the lead be? Given that it is a BP rifle is paper patching a suitable technique as an alternative to the copper jacket of the original?
I would try a smokeless powder as well but I cannot find reliable loads for these wedge lock rifles, Published loads tend to be for the later rotating lug M1890 and M1895 which are stronger. Somewhat like the Schmidt Rubin 1889 rifles which use the weaker GP90 round and are unsuitable for the later GP11 round which is the one in normal supply. By preference Vectan Tubal Tu3000.