I like the idea of short mags but am not a real magnum fan. Ill take a good old 30/06 over a 300 win mag any day. So when Winchester came out with the super short action line I thought to myself if the 300 WSM is like a 300 win mag and a 25 WSSM is like a 25/06 then a 300 WSSM should be like a 30/06. So I went out and bought myself two modle 70 rifles in 25 WSSM. By this time Winchester had the 325 WSM out and I decided to go with that as the basis for my wildcat. Im a believer in slow heavy and hard hitting vs. fast light.
I bought a shiline match grade 8mm barrel in the white and a set of redding 325 WSM dies, and some 223 WSSM brass from midway I gave the new barrel, the Winchester barreled action, and the dies to a machinist at work, who is also a certified gunsmith. He removed the 25 WSSM barrel so I could sell it on Ebay, and threaded and cut the new barrel down to 18 inches. He also cut the die set down the appropriate distance (about a ½ inch) for the new round. He used a 25 WSSM case and a shell holder to use as a gage so that the case shoulder just hit the die when inserted. He gave me back the dies so I could neck up the 223 WSSM brass. I used a 7mm, a .300, and then the 8mm neck expander to push the case neck out. To chamber the barrel I rented an 8mm-300WSM reamer from 4D rentals. This is basicly a 325 WSM with a tight neck. Once again we used the empty 25 WSSM case as a gage. The barrel was reamed until the action just closed on the empty case. I gutted the plastic stock to fit the larger diameter barrel and bedded the action in.
Like I said earlier I like heavy bullets so I started with Hornady 170 gr round nose. These shot ok using H4350 powder over std win primers. I was grouping about and inch at 100 yards at about 2300 ft/sec if I pushed them faster the group would open up (2500 ft/sec). I didnt have any primer set back or sticky cases until I ran them up to 2700 ft/sec. This was a little to fast and Im probably lucky to still have all my fingers.
Next I bought some Remington 185 gr bulk spire points. Using 45 grs of H4350 and win primers I can push them at around 2300 ft/sec and they group less than an inch. I shot 7 bullets in one ragged hole that measured just over .8 inches center to center. I have some sings of the primers starting to move, but nothing like what you see on factory WSSM ammo, also the cases drop right out. All my cases have had the necks reamed and annealed. Once all the brass has been run thru the sizing die pull out the expander plug. Reinsert the brass and ream out the neck thru the hole in the top of the die with an 8mm reamer. This will give you about .008 inches of compression on the bullet when seating.
I have on order Speer 200 gr spire points to try next. This will probably be as heavy as I will go. Will let you know how they work. So far ballistics is about on par with a 308 Win, keeping in mind that Im using an 18 inch barrel and powder manufacturers use 24 inch for there load work up. I was told you lose about 100 ft/sec and inch of barrel so if Im 6 inches shorter than Im doing quite well.
