Helping someone zero their savage 110 in 7mm mag.
He was using some kind of federal. ( I will see the box again
tomorrow) I shot 7 rounds. He didn't have any empty brass so I kept the brass to reload for him. Upon examination of the brass - the primers were fairly well flattened back to the edge of the firing pin and at the outer edges. This gave the impression of a max load. One of the primers showed a further artifact. the brass in the primer had showed plastic flow--- and the material at the outer edge of the primer has flowed out formed a little flap of "foil". It was standing outward like a burr when I first noticed it. I expect it was pushing out between the case head and the bolt face. The perimeter of the primer beside this extrusion showed a lumpy raised area like it just starting to flow.
This is factory ammunition. Now I am asking --- why ?
Two things come to mind. First is---- maybe the ogive is in the lands
when the round is chambered. If it is all ready a max load of powder---
that could give the pressure a kick upwards--- right ? So I will try an unfired round-- measure OAL before and after chambering-- see if it sets back. and I will also ink the ogive and see if I can see rifling marks in the ink. Those two should tell me if the round it loaded too long.
the other issue i am wondering is if the barrel could have lead build up from the previous owner. I took a bright flashlight and shined it in at near right angle to the muzzle and I could see some white looking
residue in the grooves. It didn't look like copper-- as much as it did lead according to the color. I don't understand who would or could shoot lead bullets out of a 7 mm. anyway I cleaned the whole gun and scrubbed the bore for about 20 min with Iosso abrasive bore cleaner. Then did hoppies. It looked somewhat better after. But its very hard to get the light angle right to see in there very far. maybe I need to get it bore scoped. (mine is too big to fit inside) Didn't have any sweets copper cleaner.
I am thinking if the bore is slightly fowled somehow-- that would drive up pressures. I am considering putting a stopper in the muzzle and filling it up with something like CLR to attack the fowling. I have never had to get that "tough" with a bore before---- if I use that how long is a safe time to let it sit ?
This gun was bought used-- so there is that chance it had a hidden problem and that was kept hidden and just sold to the next guy.
My intention was to load him some reduced (like starting loads) using 139 grains at about 2600 to make it easier on his shoulder. But if these things are giving high pressure-- the bad recoil may be another sign of
a problem.
Opinions ?
He was using some kind of federal. ( I will see the box again
tomorrow) I shot 7 rounds. He didn't have any empty brass so I kept the brass to reload for him. Upon examination of the brass - the primers were fairly well flattened back to the edge of the firing pin and at the outer edges. This gave the impression of a max load. One of the primers showed a further artifact. the brass in the primer had showed plastic flow--- and the material at the outer edge of the primer has flowed out formed a little flap of "foil". It was standing outward like a burr when I first noticed it. I expect it was pushing out between the case head and the bolt face. The perimeter of the primer beside this extrusion showed a lumpy raised area like it just starting to flow.
This is factory ammunition. Now I am asking --- why ?
Two things come to mind. First is---- maybe the ogive is in the lands
when the round is chambered. If it is all ready a max load of powder---
that could give the pressure a kick upwards--- right ? So I will try an unfired round-- measure OAL before and after chambering-- see if it sets back. and I will also ink the ogive and see if I can see rifling marks in the ink. Those two should tell me if the round it loaded too long.
the other issue i am wondering is if the barrel could have lead build up from the previous owner. I took a bright flashlight and shined it in at near right angle to the muzzle and I could see some white looking
residue in the grooves. It didn't look like copper-- as much as it did lead according to the color. I don't understand who would or could shoot lead bullets out of a 7 mm. anyway I cleaned the whole gun and scrubbed the bore for about 20 min with Iosso abrasive bore cleaner. Then did hoppies. It looked somewhat better after. But its very hard to get the light angle right to see in there very far. maybe I need to get it bore scoped. (mine is too big to fit inside) Didn't have any sweets copper cleaner.
I am thinking if the bore is slightly fowled somehow-- that would drive up pressures. I am considering putting a stopper in the muzzle and filling it up with something like CLR to attack the fowling. I have never had to get that "tough" with a bore before---- if I use that how long is a safe time to let it sit ?
This gun was bought used-- so there is that chance it had a hidden problem and that was kept hidden and just sold to the next guy.
My intention was to load him some reduced (like starting loads) using 139 grains at about 2600 to make it easier on his shoulder. But if these things are giving high pressure-- the bad recoil may be another sign of
a problem.
Opinions ?
