From what I can find on the net both are 1:9 twist rate. I can see no reason why 25grain will not work. Its going to be either a powder issue or a prep issue.
I changed from H110 as I could not get the speed I was looking for 20grain was around 3000fps, changing to n120 has raised it to 3485 fps.
I think Needle points are where you should explore further. I gave him my data and he did his magic on quickload. This was for both powders and the results are spot on for both. If I had more calibres I would get quickload as i have been so impressed.
Ditto - the Americans seem to be getting reasonable groups using 1:9 twist albeit using powders I cannot get my hands on.
We've ordered some H110 for now. We will try and achieve the accuracy we want, at which point we may look to speed up slightly. Off I go to measure H2O capcity etc.
Thanks again chaps, a true wealth of knowledge.
Regards
Rob