I would measure the throats . If lock up is good and the throats all measure the same you should be all right.

Just bought 454 SRH 7.5in barrel...slightly used but as new in box for 800...went out and shot it...and it is accurate as blazes....as are my Bisleys....really do love the 454 Bisley, 44mag and 41 mag Bisleys...thse are the most accurate revolvers I have had from Ruger....really like the sights on this SRH...old eyes can easily see them...will ne 71 this year and have diabetic retinopathy...so if I can shoot you should find it amazing...

Not sure when they changed the front sight but I think it HAS to be a cost cutting measure. I have one of the older target grey RSRH in .480 Ruger. The easily interchangeable front sights are very nice. One of the reasons I bought this gun instead of a new stainless model was that change.

Thanks again everyone. The gun is still available but maybe the time is just not right. Of course, it could be that there is 454 Bisley available from the local pusher!