How much do you backup from your max. load?

[Jayjay1]

Hey guys,
I´m just wondering.

Creating a load ladder for a new bullet and test-shoot them.
How much do you backup for a regular load from your first sight of pressure marks?

Let´s say you test a ladder for the 6.5 CM and with a 140gr. bullet you realize your first pressure marks with 45gr. of the tested powder.

How much would you now backup from this load for safety / ease up reasons?


Would be happy to hear your opinions.

 

[spife7980]

I back up to where the accuracy is... be it 3 grains or .3 grains.

Just be aware that if you are .3 under a winter max then you could be well over max during summer temps so pay attention to it.

 

[Steel head]

More with powders that go nuclear in the heat

 

[Deleted member 113831]

I have noticed a trend of sweet spots showing up around 2% from where you see pressure.

2% will keep you out of trouble in the summer time.

 

[Jayjay1]

Hey guys,
thanks a lot for your response.

Well, the temperature thingy summer/winter is a good point!
(I just want to admit, that I experienced this with one pistol powder (Lovex D032)exactly the other way.
The speed dropped with higher temperatures, partly down to 97%.)

@Skookum:
2% is a number someone can deal with, thank you for your experience.

If there is any more advice to this subject, I would appreciate it.

Cheers,
Jay

 

[Deleted member 10043]

I know a few old timers whose entire load development is in the lands until they find max then back off .5 grains.

 

[Sig Marine]

The temperatures where I live are not too extreme so I typically back off 0.5 - 0.7 grains on loads using between 30 and 50 grains of powder and use this as my max charge weight when doing my OCW. I’ve found my best accuracy at charge weights at the mid and lower ends of my test parameters. While the higher end is faster, I take accuracy over speed.

 

[Jayjay1]

@Culpeper:
Fact that they got old, proofs somehow they´re doing not to bad.


@Sig Marine:
Well, depends on what you understand by saying "mid and lower end", depends too, what you want to do with that bullet.

I want a load, which makes me reach out as far as possible, as accurate as possible.
Without speed this won´t work.

Cheers!

 

[Deleted member 113831]

The temperatures where I live are not too extreme so I typically back off 0.5 - 0.7 grains on loads using between 30 and 50 grains of powder and use this as my max charge weight when doing my OCW. I’ve found my best accuracy at charge weights at the mid and lower ends of my test parameters. While the higher end is faster, I take accuracy over speed.

30 x .98 (2% off) = 29.4 which is only 0.1 different than your 0.5
50 x .98 (2% off) = 49 which is very close to your .7 off

 

[Huskydriver]

I know a few old timers whose entire load development is in the lands until they find max then back off .5 grains.

Exactly what I do.