I used a 10x44 mtc viper & a mtc mamba lite 4-16x44 when I first started HFT in the midlands. but now I use a delta optical titanium 4.5-14x44 ao ffp hft ret scope as its image is very clear, & I think it was the best thing I have done \ brought shooting wise apart from selling my DS rifles & getting a steyr
you can use most scopes but look through a lot if you can & see what suits you.
best to go a club \ range & see what folks are using & have a chat along with maybe looking through there scopes if you can do
Rich I like the idea of 55 yards hft targets ! or do I as I bet my HFT scores would drop off a bit..... ha-ha
I have gone the greyhound a few times & shot there longer range FT targets a few times when plinking about there.
There is a couple of 40mm or 50mm knockdowns & a couple of 20 or 30 mm spinners at 55 yards at furnace mills zero range what is fun but in a comp at 55 yards I guess it would trip up a few folks.