If you have a suitable twist (e.g. 1-in-12 to 1-in-14), the Sierra 155 gr 2155
HPBT bullets work well with Viht N140, and make for a versatile, cost effective and easy-to-tune target round that you can use back to 1000 yards.
"Only" €35-40 per hundred...
You should be able to get them much cheaper than this, for example here
at € 270/1000. I use them for Palma shooting from 300 to 1000 yards and for ISSF 300m shooting. The 2156 is popular with F/TR shooters, and is quite capable of being competitive at the highest level in Palma and F/TR. Viht N140 in 3.5 Kg tubs can be significantly more cost-effective than the standard 1 Kg, if you can find them.