Yes. You can plug a CO2 tank directly into the gun, but often the pressure is too much for the valve/spring combo so you get low velocity. The LPR is made to handle high pressure (up to 1000psi often) and the ram and 4-way is downstream of the LPR so they only get a little over 100psi so there is no danger of blowing out the hoses or ram.
"There's nary a beast that can outrun a greased-up scotsman!" - Willie
"What makes a VM so charming is that you can chop down small trees with it" - Jaan