The Parker Hale two band rifle has 1 in 48 twist, it has progressive depth ie deeper at the breech end shallower at the muzzle. They shoot better at longer ranges than the 3 band rifles with 1in 78 slower twist. Parker Hale reproductions were produced using the original gauges from the Tower of london. My only comment is they are not as well set up as original rifles, and do need the barrels to be bedded. To much wood was removed at the breech ends. David Minshalls great site. The Enfield Rifle Resource, explains how to get the best out of these fine rifles. If you have an opportunity to purchase any of the Parker Hale reproductions, do it you won't be disappointed.
The P53 patterns, jigs and gauges, in their secure storage box, were loaned to Parker-Hale by the Ministry of Defence Pattern Room, at that time - mid-70s - located at the Royal Small Arms Factory Enfield Lock, home of British military small arms since the 1840's. I wasn't there when they were loaned out, but I sure WAS there when they came back in the late 1990s, to the re-located MoD Pattern Room at Nottingham, at that time home of BAe Systems and the manufacturers of the British Armed Forces L85A1 bullpup service rifle - AKA SA80.
I personally assisted the curator, Herbie Woodend MBE, in checking the contents of the chest against the original loan card details, to make sure that everything was there. I was asked to do it as I was in no way connected with either the Pattern Room, or Parker-Hale, and would therefore be unbiased in my checking - these were, after all, small but nevertheless significant national treasures we are talking about here. Their return had been the subject of much acrimony over the previous many years, and although I was not privy to it, the not-happy-bunny feeling was distinctly lacking on the part of the MoD. Mr Woodend was of the opinion that had they not been returned at that time, they may well have ended up in Italy.
Adding to Heelerau's comment, Mr Minshall's excellent article particularly highlights the slightly raised ridge of material in the centre of the barrel channel, which prevents the barrel from snugging down correctly. This can easily be removed by means of a piece of fairly coarse sandpaper wrapped around piece of dowel of suitable diameter, and its removal makes an almost instant improvement.