Adding a chunk of iron to the front of any rifle will change the vibration characteristics of the barrel, thus altering the Point of Impact.
When the Number 4 Lee-Enfield came out, it was equipped with that slow-to-use but lovely Mark 1 rear sight. Unfortunately, that rear sight turned out to be the bottleneck in rifle production, so a whole series of replacements was engineered. First among these was the little Mark 2 sight, which was a double-aperture flip type with apertures for 300 and 600 yards and, of course, nothing in between.
The big problem then became the fact that, although the rifle shot rather well at 300 and 600, the Germans, having absolutely NO sense of ha-ha, refused to stand up politely at those two ranges to be shot at. They INSISTED on creeping about at OTHER ranges, which really screwed up the PBI who were trying to shoot at them.
The SOLUTION lay in that silly little spike bayonet which was issued for the Number 4, so the School of Musketry worked out a system for shooting at INTERMEDIATE ranges by using the rifle sometimes with bayonet fixed, other times without the spike. There actually is a CHART (and I do hope somebody posts it; I am still photobucket-illiterate) which shows you how to shoot from 200 out through to 600 and beyond by alternately using/not using the bayonet with the rifle. The system WORKED and the Number 4 Rifle with the simple Mark 2 rear sight became a valued combat weapon rather than simply a curiosity..... so they cranked out a couple million more of them. AFTER the War, many of these Mark 2 sights were replaced by later models (including many Mark 1s) but that was only because production, by then, had finally caught up with demand.
Remember, the Russian Army, and then the Red Army, issued a bayonet with every rifle.... but they did not make or issue scabbards. The bayonet was to be carried ON the rifle.... and for more reasons than simply saving 30 kopecks apiece.
Hope this helps.
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