Have a .50 cal. Rayl that is a real tack driver, 5 holes almost touching at 25 yards. I have a .40 Rayl that will not shoot consistently, but I think that is my fault. Didn't pay attention to what I was doing, & the bottom of the barrel, with the Rayl stamp, ended up on the same side as the lock. Big no-no. I just did a 20 ga. smoothbore flintlock with a Rayl barrel, but the only time I got to shoot it I couldn't get a group as the muzzle is well below the line of sight over the tang. May have to put a front sight on just to tell where the muzzle is. Plus it was about 20 degrees out there in 3 feet of snow, so may have had a bit of shiver in my sight picture. One problem I had with the smoothbore barrel was that I could not get the breech plug out. It is really in there, so inletting took some time. Which reminds me, I think his plugs have a slight taper. On one of the rifled barrels, which I had to shorten on the breech end to match correct architure, I stripped the plug threads after I tried to fit it. Had to retap & get a new plug. The other barrel went together OK.