i remember getting some plastic ones , male/ female which were a lot easier to pull apart, mine come out of my bullet ones often, maybe because i just tighten up with pliers because i have no crimper pliers. to connect securelly.
ive seen some crimping pliers on ebay for as little as £190 + free postage.
wilkinsons £4.90 with some bullet crimps.
ive just connected mine up to those double connectors . wilkinsons around £1 for around 10