A friend of mine in San Diego built a 257 Banshee. We all got a bug under our saddle to build some 25 Caliber hot rods. A fellow gunsmith of ours wanted to play. He had an old Mauser action, ordered a ss Douglas Barrel, el dirt cheapo Brown Precision stock (company had only been around for a year or two then) and a 257 Weatherby reamer with zero freebore. We all shot at the range together.
The friend with the 257 Banshee had a goal of shooting the 100's at 4000. He got his powder charge up to 96+g of some kind of powder thinking it was cool as heck. My gunsmith buddy, started off at 69.0g of R#22 with a fed 215 and got 3800 on the first shot. Working his way up to 71.5, he was shooting tiny groups at 3875-3900 out of the 26" barrel. Later on, another friend put a 30 inch, 1-12 Hart using my 257 Roy reamer and he is getting 4000+ shooting tiny, tiny groups with the Sierra 100's.
My friend with the 257 Banshee was mad as heck. He had ordered special German brass, 30" Kreiger barrel and the old 257 Roy was stomping his butt.
Well, we were all chomping at the bit to go hunting with the new 257 Roy with zero freebore. Off to Az. we go. First stand I have the rifle and a dog comes running in so fast that my buddy misses him with a shot gun. The dog, turns and runs straight away. I could hear my buddy swearing trying to get that pump to be an automatic. I gave the yote the old Texas heart shot, jeez! You could not believe the hair fly'en! That yote blew up just like shooing a paint ball on a brick wall!
As we passed the rifle around shooting yotes and crows...crows were really out that day, hanging up on the tops of the cactus at 300-350, All you had to do is aim at the crow's head and watch the feather's fly!
I had a serious talk with the gunsmith on the reamer design on the drive back home. He suggested that I neck down 7 Mag brass, send it to Pacific Precision with the instructions that Dave Kiff grind the reamer with zero freebore, .2575 throat, and add .003 to the bottom dimension of the neck on the 7 mag brass after it was necked down. I got her done, and 4 rifles later, it is one of the very finest long range blow'em up rifles that I have ever put together
100's at 3800-3850 with R#22 is normal with a 26" SS barrel and the 85's at 3100-3130 are typical with AA3100.
Only the 7 STW with zero freebore shooting the 120's at 3850-3900 will equal the flat shooting trajectory along with the BLOW UP factor that these fine cartridges give.
I gots to have the blow up factor.
It took less than 30 rounds to develop extremely accurate loads with both of these hot rods where groups were in the 1/3" area and below using Nosler BT's. When shooting these custom guns, two shot groups are all is needed, either the shots are in the same hole or you "ain't there yet" in your load development. Sighted in 1/2" high at 200, you have to really concentrate to not shoot over the top of something at 400 yards.
I kept in touch with my gunsmtith buddy in S.Deigo, he had a cult following of guys that had their guns chambered with that zero freebore 257 Weatherby reamer.
Good luck on your 25 Hot rod, they are sure fun in the field!