Thanks.With the .312 bullets wouldn't the pressures go up if you used the same charge as the .311 bullets?Wouldn't you want to use less with the .312s to keep your pressures the same as the .311s?
.303 Brit and .45-70 Govt
- Thread starter skokie
- Start date
The only thing i can think of is the burn rates change with temp.
How i found this out was living and hunting in PG,FSJ,and yes GP area mostly my m88 win i like to use CCIs 250 mag primers in my 308s and 303s so i found again my m88 mostly would start giving me a hard punch in say -20 to -30 weather so i started putting my rounds in my pocket and it would get liter not that real hard punch i was getting i noted this in hot weather also.[a light went on d oh]
How i found this out was living and hunting in PG,FSJ,and yes GP area mostly my m88 win i like to use CCIs 250 mag primers in my 308s and 303s so i found again my m88 mostly would start giving me a hard punch in say -20 to -30 weather so i started putting my rounds in my pocket and it would get liter not that real hard punch i was getting i noted this in hot weather also.[a light went on d oh]
Maxinumarmor:
Have you ever Chronyed the loads on either side of the temperature you worked your loads up?
I would bet that the low temps are going to chrony slower, and hotter, faster.
The chrony will tell you the story.
There is something else going on.
Maybe ignition problems with your primers? Have you ever noticed a very slight delay of ignition? This could create erratic pressures.
Have you experienced this with other guns you have loaded with this batch of primers?
What charges of what kind of powder?
Have you ever Chronyed the loads on either side of the temperature you worked your loads up?
I would bet that the low temps are going to chrony slower, and hotter, faster.
The chrony will tell you the story.
There is something else going on.
Maybe ignition problems with your primers? Have you ever noticed a very slight delay of ignition? This could create erratic pressures.
Have you experienced this with other guns you have loaded with this batch of primers?
What charges of what kind of powder?
maxinumarmor,
You are smart to be cautious. However, the pressure difference in loads will be insignificant with just one one-thousandths of an inch difference in bullet diameter.
There will be a more significant difference as a result of bullet construction, bearing surface, etc, than there will be from diameter. In fact, there are some .312 bullets that give less pressure than .311 bullets.
Ted
