Seriously, most of the 6.5s received in this neck of the woods were pretty good; only saw one or two that I wouldn't have paid the cash for if I had had it. My buddy owned several of these, actually sent one back because the bore was much as you describe: a piece of sewer-pipe with a small amount of 'threading' in parts. But most of them were quite nice, had lttle stickers on the fore-ends to show which big matches they had been shot in.
The aperture sights were very good if a little obtrusive. Usually, they didn't last too long around here; if my buddy liked the way the thing shot with irons, the irons came off, drilling and tapping was done and monumental amounts of money were expended on optics and then there would be a beat-up old German Mauser out at the range wearing its nice Danish barrel and its Kahles scope and making itty-bitty little holes.
My friend was fascinated by the long, long lists of casualties of the Boer War which he saw in the churches around Glasgow and Cumbernauld when he lived there, right after the war. He wanted to find out what the rifles of that period, and later, COULD be MADE to do. This generally involved a careful and lengthy evaluation of the rifle starting with surplus ammo and proceeding onward to handloads mimicking military loads, then to developing specific loads for each rifle. It took a long time and it was a lot of trouble, but I sure learned a lot. Generally, we would play around with a couple of rifles at a time and it sometimes took a couple of years of testing to get one shooting what he thought was its absolute best. One test series we ran took 4 years; that was with a Moisin-Nagant 91/30, 1943 date. First thing each day at the range, the MN was fired 3 rounds from the 325 line, summer, winter, spring, fall, light's up, light's down, rain or shine. The first group was well over a foot (with Soviet-era sniping ammo) but the last dozen didn't get outside a 3x5 card: not bad at all for a $139 rifle, complete with all equipment and bayonet.
Brazilian 1908 (the first rifle we tested) settled in about point-five MOA
Kar98k Norwegian .30-'06 just kept shooting 1 inch at 300, time after time
P.-'14s we generally could get down to half an inch if the bore was nice
P.-'17s were generally BSA conversions and can be made to shoot about 1/2 MOA reliably and repeatably.
We started with a 14-inch group from an Aussie 1918 SMLE and got that down to 7/16 at 100 yards. Gave up at that point and never did scope it. I have that one today.
My HMS Canada Ross, fed what it wants, could keep up with the Norski Mauser at 100 but I never tried it at the longer ranges because my eyes aren't good enough and we didn't want to scope that one. It shot 5/16 of an inch half a dozen times in a row.
We were shooting generally 2-shot 'called groups': you start with a cold barrel and fire your round, then a follow-up roughly a minute later. The idea was to simulate hunting or sniping conditions and determine just what the rifle COULD do. All shooting was off sandbags. If a rifle shot well enough, it often was loaned out for a shoot at Shilo or at the local matches out at Wolverine to see what it would do in competition against SSGs and AIs.... with ammo, of course.
The Danish Target Rifles in 6.5mm had to shoot well under an inch or he got rid of them. The 7.62 Danish rifle which we bought as a barreled action with bolt shot a lilttle over half an inch regularly, right in with the 6.5s.
And I am still on the lookout for one of those "English" barrels!