It is normal for locked breech recoil operated handguns. The LCP is a locked breach firearm utilizing a cam/tilting barrel. This may help you understand a little better how this action works
Recoil operation - Wikipedia, the free encyclopedia
Most small handguns operate with a blowback design which is explained here
The locked-breech, tilting-barrel design is usually utilized by larger pistols. the LCP is an exception. With the little Ruger the barrel and slide are locked together when surfaces on the breechblock cam against the hardened takedown pin. As the slide and barrel move rearward after firing, the barrel unlocks from the slide and ejects the spent case as it tilts down to receive the next round from the magazine.
Return pressure from the dual-captive recoil springs force the barrel and slide back into the locked position, completing the firing cycle.
Blowback operated handgun usually have the barrel fixed to the frame. With the locked-breech, tilting-barrel design the barrel moves as described above.