It will work fine.

I have one of those adaptors, but mine is .32 ACP in .30-06. A Lee 93 grain cast bullet sized to .311 pushed by 1.7 grains of 231 gives around 800 feet per second.......and makes less noise than many pellet guns.

The 26" barrel of the 1917 Enfield helps.

I tried a .311 FMJ bullet for .32 ACP with the same load and found that the long barrel caused enough friction to keep the bullet from exiting. A little tap with a cleaning rod fixed it, but it is simpler to stick with the cast (slick) bullet for this particular application.

It is surprising how fun this little setup is.