Float Pilot
Member
I have been playing around with some handloads for the CZ safari I picked up a while back in a trade, 375 H&H. I have owned a few 375s over the years, but this one actually has the potential to be a good shooter.
The former owner devalued it, because it was super in-accurate. I discovered that was because somebody had lost the bushing inserts for the thru-stock action screws. So I made a couple of bushings and she works just fine.
The only current problem is that since it has a mid-barrel support bolt, it changes zero when the barrel gets hot.
So it will put the first two shots in the same hole or touching (at 100 yards) , but then the third round is 3/4 of an inch away and any follow up shots wander out further.
CZ made the barrel lug look like a rail and the attaching thru-forestock bolt is connected in such a way that it slides on the rail. So it may benefit from glass bedding the action or maybe the entire barrel channel. As it is right now, it will ragged hole the first two shots at 100 yards with a dirty barrel, and that is just fine for a dangerous game rifle that could also take huntable game out to 200-250 yards.
I like how the action holds 5 rounds. Actually 6, but the first round sometimes hangs if you load six.
The 1.25 to 4 power Leupold 30mm scope I have on there now is nice for a dangerous game rifle, BUT I have noticed that the cross hairs are too thick and thus obscure the smaller targets I am using for hand-load development.
For some reason the CZ barrel does not like the lighter 375 bullets. The 235s and even the 260 grain Nosler accubonds shoot much slower than they should. The old 270 grain Hornadys and Speers shoot at the advertized velocities in various loading books. The 270 grain Speers at super accurate, BUT they tend to come apart when hitting bone during hunting.
The really weird part is that the old 300 grain Barnes or the 300 grain Hornady interlocks with the flat base shoot over 100 fps faster than they should.
For example:
The Hodgon book lists a load for a 300 grain sierra boat-tail using 81.5 grains of H-4350. They used a fed 215m primer and WW brass to push the Sierra BT to 2645 fps and 49,500 CUP of pressure.
I used Hornady virgin brass, a fed 215M primer and the 300 grain Hornady interlock flat base with the following charges of H-4350 ( my barrel is one inch longer at 25 inches. )
With three shot groups
81.5 grains = 2,748 fps and a 1.5 inch group. ( FIRST TWO SHOTS TOUCHING)
81.0 grains = 2,720 fps and a 1.25 inch group ( first two 3/4 inch apart)
80.5 grains = 2,713 fps and a 0,75 inch group ( first two in same hole )Nice Load. ...
80.0 grains = 2,706 fps and a 4.0 inch group ( first two 1.5 inches apart) What the heck???
Apparently this rifle is very velocity and pressure node sensitive as it it currently set up. The brass does not show and signs of super high pressure, just the slightly flat primer and slight crater edge around the primer strike dent that you would expect from a top end load with a heavy bullet. Since the Sierra boat tail used by Hodgon would stick way down into the powder, you would think that their load would have more pressure and velocity than mine.
Anyway I thought it was interesting. Considering that the lighter boat tails are 100 to 200 fps slower than they should be...
The former owner devalued it, because it was super in-accurate. I discovered that was because somebody had lost the bushing inserts for the thru-stock action screws. So I made a couple of bushings and she works just fine.
The only current problem is that since it has a mid-barrel support bolt, it changes zero when the barrel gets hot.
So it will put the first two shots in the same hole or touching (at 100 yards) , but then the third round is 3/4 of an inch away and any follow up shots wander out further.
CZ made the barrel lug look like a rail and the attaching thru-forestock bolt is connected in such a way that it slides on the rail. So it may benefit from glass bedding the action or maybe the entire barrel channel. As it is right now, it will ragged hole the first two shots at 100 yards with a dirty barrel, and that is just fine for a dangerous game rifle that could also take huntable game out to 200-250 yards.
I like how the action holds 5 rounds. Actually 6, but the first round sometimes hangs if you load six.
The 1.25 to 4 power Leupold 30mm scope I have on there now is nice for a dangerous game rifle, BUT I have noticed that the cross hairs are too thick and thus obscure the smaller targets I am using for hand-load development.
For some reason the CZ barrel does not like the lighter 375 bullets. The 235s and even the 260 grain Nosler accubonds shoot much slower than they should. The old 270 grain Hornadys and Speers shoot at the advertized velocities in various loading books. The 270 grain Speers at super accurate, BUT they tend to come apart when hitting bone during hunting.
The really weird part is that the old 300 grain Barnes or the 300 grain Hornady interlocks with the flat base shoot over 100 fps faster than they should.
For example:
The Hodgon book lists a load for a 300 grain sierra boat-tail using 81.5 grains of H-4350. They used a fed 215m primer and WW brass to push the Sierra BT to 2645 fps and 49,500 CUP of pressure.
I used Hornady virgin brass, a fed 215M primer and the 300 grain Hornady interlock flat base with the following charges of H-4350 ( my barrel is one inch longer at 25 inches. )
With three shot groups
81.5 grains = 2,748 fps and a 1.5 inch group. ( FIRST TWO SHOTS TOUCHING)
81.0 grains = 2,720 fps and a 1.25 inch group ( first two 3/4 inch apart)
80.5 grains = 2,713 fps and a 0,75 inch group ( first two in same hole )Nice Load. ...
80.0 grains = 2,706 fps and a 4.0 inch group ( first two 1.5 inches apart) What the heck???
Apparently this rifle is very velocity and pressure node sensitive as it it currently set up. The brass does not show and signs of super high pressure, just the slightly flat primer and slight crater edge around the primer strike dent that you would expect from a top end load with a heavy bullet. Since the Sierra boat tail used by Hodgon would stick way down into the powder, you would think that their load would have more pressure and velocity than mine.
Anyway I thought it was interesting. Considering that the lighter boat tails are 100 to 200 fps slower than they should be...