Fire forming brass

Do you fire form your NEW “quality” brass before beginning load development?

  • Total voters
    72
jseandsje said:
Not arguing either, just wanted to emphasize that a standard twist, albeit with less than maximum weight, is better than the 8 twisters will admit. And the crossover point for from long to extra long bullets
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If you want to take advantage of the longer heavy high BC bullet offerings, no, your 1:11" .270 WSM is not better than a 1:8" .270 WSM or faster. One of the reasons, as you noted ...
jseandsje said:
The factory 270 wsm rifle is dying, just because it isn't stamped 1:8 twist.
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You must have the right barrel twist to stabilize the bullet you are going to use, period, esp. in LRH/S.

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I've formed .338-06 brass from new PRV 30-06 brass, shot in the rifle at moderate pressure, then will use the brass accordingly with somewhat higher pressure. That's about the extent of my fire forming. I will pretty much do the same with .35 Whelen if new brass is not available.
 
FEENIX said:
If you want to take advantage of the longer heavy high BC bullet offerings, no, your 1:11" .270 WSM is not better than a 1:8" .270 WSM or faster. One of the reasons, as you noted ...

You must have the right barrel twist to stabilize the bullet you are going to use, period, esp. in LRH/S.

View attachment 767511

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I don't need a fast twist to shoot a 170 grain bullet. A 170 at 2950 doesn't catch up to a 150 at 3250 until you reach didtances that 95% of shooters NEVER reach. Yet everything said is you got to have fast twist.
That 270 wsm doesn't need it.
 
To get back on track, a lot of my chambers show a 20-30fps increase in velocity using the exact same powder charge between new and thrice fired, the bolt, as well as my Precision Mic, show the headspace increase is no larger than .004" at the minimum, and .006" at the very maximum of my loosest chamber. This indicates to me that expansion is still taking place beyond the initial firing, taking 3 firings to fill the chamber completely, then I knock the shoulder back .002" (.0015" with spring back) and call that done. I also hover on each piece when sizing with cam over for 5 seconds, as brass moves when the pressure is released.

Cheers.
 
MagnumManiac said:
To get back on track, a lot of my chambers show a 20-30fps increase in velocity using the exact same powder charge between new and thrice fired, the bolt, as well as my Precision Mic, show the headspace increase is no larger than .004" at the minimum, and .006" at the very maximum of my loosest chamber. This indicates to me that expansion is still taking place beyond the initial firing, taking 3 firings to fill the chamber completely, then I knock the shoulder back .002" (.0015" with spring back) and call that done. I also hover on each piece when sizing with cam over for 5 seconds, as brass moves when the pressure is released.

Cheers.
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Good stuff!!
 
Never - high or not so high qualty brass from same lots will be close, to very close, to same after fire forming and not needing minute changes from established loads using same brass. During and after initial fire forming, established loads will be used. New caliber & different brass would be an exception.

Also consider different lots of powder, bullets & primers.

Paralysis by analysis?
 
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MagnumManiac said:
To get back on track, a lot of my chambers show a 20-30fps increase in velocity using the exact same powder charge between new and thrice fired, the bolt, as well as my Precision Mic, show the headspace increase is no larger than .004" at the minimum, and .006" at the very maximum of my loosest chamber. This indicates to me that expansion is still taking place beyond the initial firing, taking 3 firings to fill the chamber completely, then I knock the shoulder back .002" (.0015" with spring back) and call that done. I also hover on each piece when sizing with cam over for 5 seconds, as brass moves when the pressure is released.

Cheers.
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I find your observations, and your ability to measure such things, to be amazing. Those of us who primarily shoot more "standard" weight rifles for hiking and hunting, and an occasional rifle match, can certainly learn from the experiences guys like you are sharing here. I have changed a few of my handloading processes (such as dwelling for a few seconds while the case is pressed in the sizing die) based on observations folks like you have made and shared. While some of the advice posted on this site is highly technical, and beyond the scope of most of us who train with hunting-weight guns, I still try to take it all in. Not every process or handloading technique discussed here is practical for everyone. Still, it's true that all the tiny tweaks and adjustments we learn can add up and make a difference in field accuracy.

I'll never have a gun (or the ability) to shoot 1/4 MOA groups. Once I've developed the best load I can for a particular rifle, my focus moves to shooting in field positions and trying to figure out the dang wind. Those things become my priorities, along with only shooting game animals within the ranges and conditions I know will result in a quick clean humane kill.

So please continue measuring things to the nearest molecule and keep posting your results. I may not ever get that deep in the weeds myself, but I appreciate your abilities, your intellect and that you're sharing what you've learned.

Happy hunting and Semper Fi
 

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