As we all know the remarcable taper bore guns were only used for a short period given the lack of tungsten. In the scenario they could be used basically unlimited what changes would that make in tank warfare on the eastern front ? If i remember correctly the 75/55 weapon with its remarcable performance could be mounted in the pzkw III. (at least it was tried) Many greetings, Aglooka.
Barrel wear was also higher and the barrel would require replacement after a limited number of shots. Allied intelligence thought barrel replacement could be required after only 400-500 rounds. Ammunition for German 42-mm Antitank Gun
The 75/55 had a quick change barrel liner i believe. But indeed tanks would be much less powerful using HE, which was the most used ammo anyway. Aglooka
I've heard that there was an effort to build an Allied version of the taper bore gun, based on the 57mm anti-tank weapon. This involved a removable barrel liner which produced the taper. Unfortunately, I haven't yet been able to find a reference on the Web.
There was also the Littlejohn adaptor which operated along similar lines. Theoretically I suppose there's no reason why that couldn't have been scaled to other calibers, and it did mean that barrels could be made using existing techniques/machinery, and also allowed full-bore ammo to be used (after some poor schmoe was volunteered to clamber out and unscrew the thing).
There's a distinction to be drawn here between Taper Bore & Squeeze Bore. I think they're too often presented as exactly the same thing. Gerlich's 'Taper Bore' system is where the entire bore of the gun is tapered, it's primary difficulty is in making the actual tapered tube (Germany's problem with the Tungsten ammunition is related, but perhaps more one of requiring such heavy shot for the small bore guns they attempted full Taper on? ). The sPzB 41 & variants are full taper bore weapons'. Once the barrel inevitably suffered from the high wear associated with the system then that was it for such guns. 'Squeeze bore', while following the same philosophy, is where most of the tube is parallel, but tapers for the final section. The PaK41 was the only major piece to use the principal successfully in the war, the conventional rifled barrel of c.10ft had an unrifled squeeze section c.3ft long attached, it apparently worked quite well as the wear problems associated with Tapers only affected the easily replaced final section. The Littlejohn is also a squeeze bore device. I know the 2pdr could fire quite happily with the littlejohn removed, and I believe the PaK41 could also function without the squeeze section? ~A
At least the 42mm gun saw some limited service into 1944. I have seen pictures of it in action in Rome as late as that year with both Fallschimjäger units and SS units in Italy.
What would have changed, the Germans could have kept alot of their older, smaller caliber guns in service longer since the russian main battle tank through the whole war was the t-34 and any gun that could penetrate it would be useful.