.308 hand load workup input/advice wanted

[datguy]

Loading up more rounds to take to the range later today. I load eight of each charge weight. My rifle's magazine holds four. I'm going to load up 41.5, 43.0, 43.5, 44.0, 44.5, 45.0, 45.5 and 46.0.

 

[Blitzkrieg]

If you don't have one a bullet puller is a must for working up loads.. the too hot or inaccurate ones can be salvaged for components

 

[datguy]

I have a RCBS collet bullet puller with collets in the sizes I load. I have already had to disassemble a fair share of loaded rounds. Good advice.

I have the rounds made up. Headed to the range now. Excited to see the results.

 

[Blitzkrieg]

With the cost of Jacketed rifle bullets they pay for themselves fast

 

[datguy]

Target from today's outing.



I tried 41.5 to ensure that I hadn't started to high in my previous outing. I fired four rounds at each charge weight except 44.5. Eight 44.5s. The center of the target shots that are high were me adjusting the scope. The group is four Federal GMM 168 SMK factory loads.

I'm not sure where to focus my efforts now. 43.0 and 43.5 both had a tight group of 3 rounds. Then 45.5 and 46.0 had tight grouping as well.

I ran out of daylight or I would have shot the other set of each charge weight.

 

[Blitzkrieg]

Assume nothing until the hot weather comes and you lay a few of your chosenite loads out in the sun to bake for a while. The pressure difference can be quite extreme and can make them unsafe

 

[datguy]

Assume nothing until the hot weather comes and you lay a few of your chosenite loads out in the sun to bake for a while. The pressure difference can be quite extreme and can make them unsafe

Hmm.. Am I wasting time working on load development now then? Or do I need to "re-check" charges in hot weather to ensure I'm not too high on pressure?

 

[Blitzkrieg]

Hmm.. Am I wasting time working on load development now then? Or do I need to "re-check" charges in hot weather to ensure I'm not too high on pressure?

Yes, hot weather can make your loads VERY unsafe

 

[deadshot2]

Hmm.. Am I wasting time working on load development now then? Or do I need to "re-check" charges in hot weather to ensure I'm not too high on pressure?

I wouldn't loose a lot of sleep over it unless the loads in question were right at the MAX when you tested them in cold weather. One thing to consider, the Action/Chamber of a rifle has a moderating effect on the round. In cold weather, it warms up the cartridge. In hot weather, the difference may not be all that much.

Definitely use caution if your loads were max. What will more likely the case is that a load that was accurate as all get out at 30 degrees outside temp will have the groups open up somewhat when the weather warms up. It's ALWAYS a good practice to check your cases for overpressure signs regardless. That's how impending case failures can be spotted.

 

[Silver Hand]

I have been a long range shooter for a wile now. I am primarily a hunter that shot targets in grade school, Dad was a Koren vet - Two purple - One Sliver.
I love accurate weapons. I also like to push my bolt action rounds in my more modern firearms.
By that I don't mean you need a lead hammer or a stick to open the bolt as one my friends a - WW- 2 vets insists on doing.
To the point. I do not think a flat primer at reasonable velocity and pressure is going to be a problem on a hot day. I would consider a primer to large to be normal looking? A primer that has a tit, or has some how dented itself in reverse and wants to blow out your eye ball next, a problem!
Hot weather - Dash board rounds - I would be reluctant if rounds that were Hot to begin with, and temperatures 100+ degrees in direct sun light for long periods. You bet.
I do not condone pushing the limits of reloading. Although I am guilty of doing it myself.
What you do is what you decide to do, it is part of the science after all.
Read on pressure signs including incipient case failure. Primers can tell you a lot about what is going on.
Never get to a point extraction is abnormal and ignore it. Afterward if the gun is in one piece the maximum CUP has usually has been surpassed. A gift from the manufacturing and engineering department.
There is a small hole to release gas pressure at the side of the bolt in most modern weapons. It can save an eye on a good day.
Make your decisions based on your understanding and goals.
I like shooting a deer @ 300 yards with the cross hairs between his eyes and hitting him in the tear duct, knowing exactly ahead of time what the papers said.