.270 Win with Magnum Primers
- Thread starter Bitumen
- Start date
Yes it works but take a look at Lyman reloading manual and you'll find that a magnum primer can increase pressure by up to 5000 PSI.
Just make sure that you're using a mild load not a maximum load.
I've used magnum primer in 243 Win precision loads and I'm still getting excellent accuracy!
Alex
Just make sure that you're using a mild load not a maximum load.
I've used magnum primer in 243 Win precision loads and I'm still getting excellent accuracy!
Alex
I use mag primers in everything I load. Including pistol. It lights a hotter fire Which is better in my mind.
I as always work up to max slowly. I have yet to see a difference with the amount of powder and using a mag vs a standard primer. It all comes down to what your gun likes.
I as always work up to max slowly. I have yet to see a difference with the amount of powder and using a mag vs a standard primer. It all comes down to what your gun likes.
- Location
- Somewhere on the Hudson Bay Coast
When I lived down south my rule of thumb was to use magnum primers when:
the powder charge exceeded 50 grs
when using ball powder
when the temperature dropped below 0 F.
Now I just use magnum primers for everything other than match ammo. Usually the .270 is charged with heavy charges of slow burning powder which compliments the use of magnum primers anyway.
the powder charge exceeded 50 grs
when using ball powder
when the temperature dropped below 0 F.
Now I just use magnum primers for everything other than match ammo. Usually the .270 is charged with heavy charges of slow burning powder which compliments the use of magnum primers anyway.
Example for Barnes 130gr TSX H4350
This is taken from Hodgdon online load data for 270 Win Barnes 130gr TSX
Hodgdon reference loads
Barnes 130 GR. TSX .277" CAOL 3.230"
H4350 51.0 gr 2905 fps 52,500 PSI
H4350 55.5 gr 3111 fps 63,500 PSI
Since a magnum primer can increase pressure by up to 5,000 PSI, your maximum load should have a 58,500 PSI ( + 5,000 PSI = 63,500 PSI).
This interpolates to roughly (51.0 gr + 55.5 gr) / 2 = 53.3 gr is the corrected maximum load.
Reduce 2.2gr (55.5 gr - 53.3 gr) from the starting load to get 48.8 gr the corrected starting load.
Nothing complicated just back off a bit to allow a margin of error for the extra pressure from a more powerful magnum primer.
Alex
This is taken from Hodgdon online load data for 270 Win Barnes 130gr TSX
Hodgdon reference loads
Barnes 130 GR. TSX .277" CAOL 3.230"
H4350 51.0 gr 2905 fps 52,500 PSI
H4350 55.5 gr 3111 fps 63,500 PSI
Since a magnum primer can increase pressure by up to 5,000 PSI, your maximum load should have a 58,500 PSI ( + 5,000 PSI = 63,500 PSI).
This interpolates to roughly (51.0 gr + 55.5 gr) / 2 = 53.3 gr is the corrected maximum load.
Reduce 2.2gr (55.5 gr - 53.3 gr) from the starting load to get 48.8 gr the corrected starting load.
Nothing complicated just back off a bit to allow a margin of error for the extra pressure from a more powerful magnum primer.
Alex
