I love Portsmouths, spent 6 months convinced i could hit a 560, how are you shooting, i am guessing you use POA, i found that to really get up there your poa and where it is makes a huge difference, so i tailored the arrow for the job, i like my poa on the edge of the paper on the right hand side (this helps if you get a right hand face at a shoot, as if your poa is off the face you are concentrating at a bit of netting behind or a dodgy bit of straw on the edge of the boss).
with your 50 Lb bow i would say that your poa must be pretty low with the fast-ish arrow, even though it is long (whats your draw length?- if you are drawing almost 30 inch then you may need to slow it down considerably), anyway i used only a 40LB for portsmouth but it was blindingly fast (for a
longbow- i got about 20 of the blighters), i used a matched set, which took me a while to put together as to match 8 shafts i had to go through several hundred.
they are a little stiff to bring me right and long and heavy to get the height where i wanted it, at the blue/red 6 o'clock and a line drawn from there to the rh edge
I put on 125gr points and 5 3/4 fletches cut from single feathers cut in the Pope and young style- make a sweet noise as they lazily whoop down the range, i left them full length as yours are so as to gain even more height for my poa. I like to use Boyton pine heavier than POC, but Chris makes superb shafts Total weight 480grn
when you get into the 500's with a
longbow your form has to be very good, to get from there to the 525+ your form must be excellent 550 requires almost flawless form
matching you arrows will be a start and is simple if you know what you want.
Form is another thing and again if its a high portsmouth score you are after then you may need to change a few things, i say may as every archer has his own technique and if it works it must be right- for you .
I would come middle finger to a point half way between the front of my lower lip and the corner of my mouth, i find that bit quite sensitive and it shortens my draw by a half inch, good when you don't want the extra power and it can be found consistently, what i also did was to standardise as much as possible my shooting routine, stand straight as it is easier to replicate a straight posture than one at an odd angle, i held the bow straight up and down with no cant or angle and then i shot.. and shot making sure i was not practicing my bad shots but only good ones, i was fortunate to have some exceptional
recurve and
compound shooter to give advice on stance and shooting posture cos if you are shooting for score and it really is score you are after then you have to go with what is going to get that score- if you follow.
This may sound bizzare but even if your arrows are matched to the Nth, with wood there will always be a variation, no matter what you do and eventually you will have 3 poa's, one for each arrow (which of course by this stage will not only be numbered but named too!!), i hate to admit it but i even shot whole portsmouths with one arrow to identify exactly where that poa was for that arrow, so the long and short is that my pb was 551, which i hit on 3 occasions, i stopped fairly shortly after that as the fun went out of it for me, chasing a score is great whilst you are improving but when you reach a plateau it gets boring and wanting that 560 was making me crazy!!,
mind you having said all that if you are shooting instinctive pretty much ignore everything i've just said cos that is another story....