Fire Formin and Seating Depth Test.

[JCardenas]

I am going to fire form some brass and I was hoping to get a bit more out of it than just forming by testing seating depth at the same time. For those that have tried it and found a seating depth that worked...did it remain so as you worked up in powder. I am going from a 6br to a dasher and going to be shooting a 105 hvld with Varget. Thanks for your input
Jaime

 

[Ggmac]

I am going to fire form some brass and I was hoping to get a bit more out of it than just forming by testing seating depth at the same time. For those that have tried it and found a seating depth that worked...did it remain so as you worked up in powder. I am going from a 6br to a dasher and going to be shooting a 105 hvld with Varget. Thanks for your input
Jaime

I doubt any fireform info will hold . The case volume changes , it gets shorter in length , all these will change pressure and accuracy . You can try but when I fireform , I'm usually using non target bullets ( seconds , older hunting bullets , etc ) , no sense in wasting good bullets or primers or powder . I use whatever bullets on hand or cheap seconds , whatever leftover primers and a non premium or hard to obtain powder .

 

[dkhunt14]

The difference in loads will be 3 to 4 grains after formed. I believe that is too much difference to get any valuable info. I woukd find so embody with a fireform gun and form them so you save rounds through your barrel. Matt

 

[JCardenas]

Thanks, I will use cheap bullets and left over powder then. I was hoping I could get ahead of the game just a bit

 

[dkhunt14]

I like a powder like Varget or slightly faster. It seems to form them better. I also like long bullets seated into the lands. The longer bullet gives you more hold in the neck. This also helps form them better. Matt

 

[JCardenas]

Thanks Matt, just went it any they seem to of formed pretty good

 

[jr600yd]

Well, I do it a little different. I shoot a BRX so it's pretty close. I use the false shoulder method and 30 grs of Varget pushing a 105-108 gr bullet. Take these to a F class mid-range match and shoot. "FIREFORMED"

Now for working up a load with X powder and Y bullet I don't until at least the second firing. Do a search you'll find some good loads that perform well in most rifles for the second firing.

 

[Sheldon N]

My 0.02... if you are fireforming you should jam the bullet, even with the false shoulder method. If you want to tweak your fireforming load for accuracy maybe try a bit of variation in powder charge to see what shoots best and still gives good formed brass. I just used my fireforming loads for positional shooting practice.

 

[dmoran]

With fire-forming 6Dasher's, the most important aspect I am after is volume consistency. I find the virgin Lapua brass to hold very good volume consistency, from which is my objective to retain that consistency when fire-forming them from there virgin 6BR state to 6Dasher. The amount of case shove from the firing pin and sustained pressure of the load, need to remain equal to retain volume consistency in my experience, and is why I strongly suggest to refrain from testing seating depths while fire-forming.
Donovan

 

[Mulligan]

Well, I do it a little different. I shoot a BRX so it's pretty close. I use the false shoulder method and 30 grs of Varget pushing a 105-108 gr bullet. Take these to a F class mid-range match and shoot. "FIREFORMED"

Now for working up a load with X powder and Y bullet I don't until at least the second firing. Do a search you'll find some good loads that perform well in most rifles for the second firing.

Exactly!
CW

 

[500Stroker]

With fire-forming 6Dasher's, the most important aspect I am after is volume consistency. I find the virgin Lapua brass to hold very good volume consistency, from which is my objective to retain that consistency when fire-forming them from there virgin 6BR state to 6Dasher. The amount of case shove from the firing pin and sustained pressure of the load, need to remain equal to retain volume consistency in my experience, and is why I strongly suggest to refrain from testing seating depths while fire-forming.
Donovan

Listen to Donovan
I have fire formed several hundred Dasher and would never try to test for seating depth during fire forming. I always jam bullets during fire forming so the head space is zero, this provides the same chamber space for the brass to blow into for every round, produces a nice clean crisp shoulder.