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Fire forming brass

Jcalder

Jcalder

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Recently got in some new brass. Measuring new brass vs old brass and the shoulders on new brass are pushed back .014". Should I find some cheap bullets and fire form the brass before I get serious about loading this up and looking for a load. I plan on using a Lee collet neck die if it matters. Hate to waste components if I should fireform first, and don't wanna burn my barrel up either
 
Some people use cheap bullets to fire form before shooting for accuracy and some start shooting right off with what they intend to shoot with and then just tune with the fire formed brass if needed. I've got to the point where I load what I'm going to shoot with new brass(after sizing) and test for group then load up and fine tune if needed from that point.
 
MUP said:
Some people use cheap bullets to fire form before shooting for accuracy and some start shooting right off with what they intend to shoot with and then just tune with the fire formed brass if needed. I've got to the point where I load what I'm going to shoot with new brass(after sizing) and test for group then load up and fine tune if needed from that point.
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I'm planning on using some eldx I finally found. Problem is I don't wanna spend the whole box chasing my tail lol. If you feel the .014 in the shoulders won't matter than I'll start development, after deer season now. Just looking for consistency and thoughts on the matter.
 
MUP said:
A hot load will help push the shoulder out quicker and with fewer shots too. I think you had a pretty hot load IIRC in that WinMag so I'd check the shoulder after first firing to see how much movement you get.
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I wasn't planning on using those bullets tho lol. But I could. And yes. The load is warm.
 
Jcalder said:
300wm and purpose is both target shooting and hunting. I'll bump shoulders when they get tight, I figure after 3-4 loads.
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Talk to some of the very best in the benchrest game and they will tell you that they either shoot virgin brass all the time, or wish they could. I'd use it like normal and not look back.
 
I always, always conduct load development with fire formed brass. You will find that most of the time, your final load with formed brass will be different than with Virgin brass.

However, I never waste the forming process. Use those rounds to determine a potential node with your bullet/primer/powder of choice. By the time you are through forming 50-100 pieces of brass, you should have a very good idea where your node is and can hone in on it pretty quickly with the formed brass.

This is how I've always conducted load development for long range shooting. Hasn't failed me yet.
 
Wiley said:
I slip my new brass into a case gauge and if it's right I load it. I also do this with my fired cases after I de-prime.
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I let my gun be the case gauge. I know some people really love a case gauge, but it's not for me. If I had multiple guns in the same caliber that I was loading for I might have one. Pistol ammo would be the exception.


In this application, the brass capacity is smaller than what a fired case would be since the shoulder is .014 shorter than what a fired case will be. I'm not smart enough to figure out that much difference means a lot, or is something to be overlooked.
 
Case volume will increase sightly after fire forming, but as markwondi said you'll have to shoot the same load you settle on when shooting virgin cases to see how much, if any, difference it'll make. Also fire formed cases that have been neck sized just fit tighter into your chamber and that in itself takes some movement out of the equation for a more controlled test group. Every little variable that I can remove and/or refine to help offset my poor shooting ability is what I'm trying to accomplish. ;)
 
MUP said:
Case volume will increase sightly after fire forming, but as markwondi said you'll have to shoot the same load you settle on when shooting virgin cases to see how much, if any, difference it'll make. Also fire formed cases that have been neck sized just fit tighter into your chamber and that in itself takes some movement out of the equation for a more controlled test group.
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And one of the reasons I'm using a neck die. I got both so I figure until my brass gets tight I'll neck size and bump shoulders back .002.
 
I full length size all my cases, and have not really seen a huge difference between virgin brass and once/many fired cases. But I load for hunting purposes, so just covering three rounds with a quarter at 100 yds is good enough for me.
 
I haven't noticed enough difference in virgin vs fire formed brass in my .308 to separate the 2. My gun shoots about 3/4" I do trim and FL size new brass before using.
 
Tenntrapper said:
Can you use cream of wheat?
Ive never tried it, but I have heard about people using it. Also heard it makes a mess.
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I used it before when forming cases. Would start with 12 grains of Unique then fill up most of the case with cream of wheat then stuff a piece of tissue paper in the neck to seal. Point the gun to the sky and fire.
However………. My conclusion is this is good for forming cases. But the pressure is not high enough to fire form. Shoulders would not be well defined. To fire form to the chamber you need a fairly stiff load.
 

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