I tried a handful of 300 MH Parker's in my Rem Ultimate and wasn't impressed with the groups. I went from 95 to 100 grains of BH 209 (weighed NOT volume) and was not getting what I wanted. As stated above, maybe the bullet is too long for Rem's 26 twist at the velocities that the Rem can generate.
Bod Parker (great guy) suggested the 275 Ballistic Extreme with the short black sabot that they come with. I have them in my hot little have, as of yesterday, and will be testing withing the next week or so depending on the heat and wind. I want to give them every chance to shoot tight little groups.... or I'll go back to the Accutip 250.
My buddy has the same bullet in the 300's and I'll be trying those too.
If I had an elk tag, I'd opt for the Parker 300 BE for a bit more penetration... but that's just me.
Zeke
PS: It's suggested, by everyone who I talk with, that the spin-loader and spin-starter should be used for the best accuracy. The same one that fits the Accutip should work fine on the Parker BE according to Bob but the MH is a totally different shape and may account for my poor results. We shall see.