Re: 2011 Wasington State bull/ 450 Ultra Magnum
It all started with several .375 Ultra Magnums I had, 1911 fan recalls at least one of them.
I was shooting one of them one day and thought I want something bigger but I want a cartridge that is a big bore but will fit on a Rem700 Action and feed from a mag box and the Ultra mag case would be the best choice and of course about as large a case head I could go on a Rem700.
So I called Dave Kiff at PTG (Pacific Tool and Gauge) and had him build me a 450 Ultra Magnum reamer and Go Gauge. I took delivery of the reamer back in July of 2010 and it just sat and sat. This year I drew and branched antler permit for Elk here in Washington state and thought a Elk would be the perfect test media for my 450 Ultra project. So I called Lilja and had them do a 26", 14 twist, 6 groove, stainless fluted .458 barrel in the lightest contour they would do with flutes. It turned out to be a #7 contour. I boxed all the parts up and sent it to Benchmark Barrels to have it put together. My only major concern was it HAD TO FEED RELIABLY FROM THE MAG BOX!
Action was trued
Sako extractor
PTG Pinned recoil lug
Harrells brake installed with a thread protector/ Now it has a 4 port Muscle brake.
Feed rails machined out and a Wyatts extended center feed mag box fitted and installed.
GreyBull stock
Shilen trigger
I got the rifle and the load development started... I started from a base charge of 82gr of Win748 and worked my way up to a accuracy load of 96 grains for a 350gr bullet. I used cheap Hornady Interlocks for my load development and fire forming. There really isn't much fire forming, the first firing sharpens the shoulder up. 1/2 MOA was the norm out to 300 if I did my part, I even ran 500gr Hornadys on top of 105 gr of Win748. If your not awake before you slap the trigger on this load, you will be!
After several days at the range a bloody shoulder a few PM's from experienced big bore shooters I came to the conclusion the Harrels brake was not compatible with this bore/ cartridge combo. It just wasn't reducing the recoil, the rifle was hitting me harder on the bench with a brake than my .375 Ultra in a sporter weight without a brake
A quick call to Benchmark and they hooked me up, I sent the rifle in and had a 4 port Muscle brake installed along with a extra port cut in the top and a custom set screw machined in.
The rifle after the Muscle brake was installed.
Removed feed rails and Wyatts extended center feed mag box.
Pictured along with a loaded 450 Ultra Magnum cartridge, CEB BBW#13 Non Conventional Hollow Point 370gr with Hi BC Polymer insert tip.
My original brake along with my shoulder after my first bench session with it.
After some basic load development and fire forming. I basically got a feel for the rifle. I switched to the hotrod CEB BBW 13# 370gr Non Conventional Hollow Points with the Hi BC polymer inserts and the rifle really started to shine. I still have a ways to go with this bullet. I am currently out and need to get more. I have pushed them at close to 3000fps.
Left- 450 Ultra Magnum W, CEB 370gr BBW#13 Non con.
Right- 500 Jeffery
And YES, with the tip and all they feed from the mag box!
Even while fire forming and ladder testing, still cleaning between every shot during barrel break in, it was showing some promise.
Once I ran out of the CEB's I said screw it and got a bunch of Speer 350gr HotCore bullets because I knew they would hold together better at the 450 Ultra Mags velocities way better than the Hornady's. They shot very well at 300 yards also. when I left to go after my bull I pulled a zero that was.
+5" 100 yards
+4" 200 yards
-5 1/2" 300 yards
I knew the area I was going to hunt and the heavy timber basins I would be hiking would very rarely offer a 300 yard plus shot. Besides I had other hardware along to cover the off the road ridge to ridge shot. I wanted to take my Elk with the 450.
The rifle feeds from the mag box like glass, this was a rush project to get it ready for elk. Now that thats done with. I can really do some serious bench work with it.
Im going to be testing a bunch of Hawk custom spire points in assorted weights. Then test them on Groundhog media in the spring.
