I found an easy cheap substitute for the plunger guide tube in the blasterparts kits.
It also make converting a retaliator into a recon much easier. And all you have to do is cut down a peice of nerf barrel.
The back caps tend to be just under 2" so thats the length of nerf barrel you want. Then its just wrapping it in tape till it fits snuggly into the cap. Its simple its easy and its standing up to an 7kg retaliator spring and a stock recon spring just fine.

It also make converting a retaliator into a recon much easier. And all you have to do is cut down a peice of nerf barrel.

The back caps tend to be just under 2" so thats the length of nerf barrel you want. Then its just wrapping it in tape till it fits snuggly into the cap. Its simple its easy and its standing up to an 7kg retaliator spring and a stock recon spring just fine.