Cheers for the advice.
I've never actually thought of just running them with boltguns with special ammo i probs should spread out upgrades so i can have more bodies over one large group.
Remember, your basic Veterans are essentially Sternguard. Special Issue ammo is fantastic.
Dragonfire rounds are good at clearing people out of cover, as well as removing things that rely on Jink saves (even glancing AV10 flyers),
Hellfire will wound those 6+ Toughness targets normal bolter fire can't handle (and remember, you're probably rerolling ones!),
Kraken is relatively subtle - Only slight improvement to AP and range over normal bolter rounds, which still works great on most 4+ (such as Fire Warriors and their drones, or Skitarii)
Last but definitely not least, Vengeance rounds. Slightly lower range, but AP3. Downside is that they occasionally explode, but if you're using the right Mission Tactics? You reroll ones to hit. The Deathwatch can use weapons that Get Hot with FAR less risk.
In regards to doing the Shotgun/boltgun combo i did some research on that and turns out you aren't actually allowed to do DW Shotgun w/ Boltgun this was clarified in the Deathwatch Errata so that sucked.
Whoops. In my defense, I don't actually PLAY mine much. Sisters remain my primary army
The only real benefit with the Black spear formation is giving all troops the deepstrike rule and re-roll on the warlords table. Given i still won't be able to field many men in total cause DW are point heavy i'd rather avoid using deepstrike.
The main benefit in my eyes is the additional Mission Tactics switch, though the (near-obligatory) Warlord Trait reroll is also important. With a usual BS of 4, Rerolling 1s To Hit means you're rerolling half your misses (and helps avoid Gets Hot, as noted before). As for Deep Strike... that's what drop pods are for
Though yeah given the Watch master is a god at clobbering people to death it would probs be more effective to keep him out on his own, doing what he does best.
He's vulnerable on his own (esp. to S8 weaponry). Launch him from a Veteran squad or something similar
If you're not sure he can earn his points back, replace him. A Chaplain will (for DW only slightly, it must be said) boost a squad's melee with Zealot, or better yet toss in one or two Librarians (2 ML2 libs will get you 5-10 psyker dice a turn, and you have a wide selection of Disciplines to choose from).