Impulse

Depends on the areas and the game modes, much like Worthing. You can make it work in the right circumstances, but there is a lot of rapid advancing and cover in small areas that makes either a DMR or a 1J no MED a better option. They do also tend to play a trench game in the afternoon which is also going to give very limited opportunities for a bolt gun. 

I tend to find running the MP5 works better at that site for me. By all means take a boltie, but maybe plan to be able to swap out if you find it's not working.

I've been to Dogtag loads of times and every time they've started with the same hold the line, attack and defend game. Defenders get one life and then have to retreat to the next point, with the attackers respawn being immediately behind the players furthest at the back. It's a good way to get warmed up, as on either team you don't have far to go after being hit. As mentioned, it is fast paced and target rich. I had a friend use his Boltie and he had a great laugh when he dug in and let the attackers advance past him, before picking them off with a pistol. The afternoon trench game is great fun, but again you'll likely want something which will allow you to burn through a few more BB's.

Dogtags my regular, bolt actions are good fun there. Back when I had one I never had an issue with any part we played, theres always engagements over 30m. (obviously their cqb village is a bit tricky but they only tend to use it at the end of the day). Definite worth bringing a boltie but as above, bring something you can fling bbs with too!