Thread: 6.5x55 barrel length

I've done a bit of a search but can only find relevance to target shooting.
I've got a DPT can to stick on my T3, I would ideally like to keep the same OAL of the rifle but that would mean a chop to around 18.5".
95" of my shooting is done at less than 150m and would hardly see a shot over 200, Max 300m. I reload my own 140gn Amax rounds @ 2670fps in the current setup.
Am I going to lose much going down to 18.5? Is 18.5 too short for the 6.5?
Any other thoughts?