Hydro forming 6-dasher vs blow length

[Northridge]

What type of blow lengths are people seeing with 6 dasher brass after hydro forming & after first firing in chamber? Has any body tried wiping a little silecon spray on case Pryor to hydro forming to get a slightly longer and more crisp shoulder Pryor to first firing in actual chamber?

Shawn Williams

 

[ShootDots]

I have had DJ's Brass Service do 200 pieces of 6mmBR brass into 6 Dasher brass. The returned brass I received was about 1.540-1.545... After 2 firings, I was at 1.550.. The returned brass was above 90pct of a 2nd firing would appear to be and was just as accurate as any "completely" fireformed brass..

 

[DJSBRS]

Putting lubricant on a case to fire it is only putting pressure on bolt thrust against the lugs with a heavy bolt lift. Hydro-forming should be done to fit your chamber. Fact is, the brass will expand and become shorter after the first firing.

Use the correct reamer for OAL and one will not have to worry about how long they are. In my opinion, a 1.560 reamer should be your OAL for a Dasher or BRX. Too many reamers out there with 1.570 OAL. Guaranteed first place the carbon starts to form a carbon ring.

My .02¢ worth.

DJ

 

[DJSBRS]

I have had DJ's Brass Service do 200 pieces of 6mmBR brass into 6 Dasher brass. The returned brass I received was about 1.540-1.545... After 2 firings, I was at 1.550.. The returned brass was above 90pct of a 2nd firing would appear to be and was just as accurate as any "completely" fireformed brass..

That is typically what I have seen as well. I think if you fire form it, you will see around 1.545 if you don't hit too hard with PSI.

DJ

 

[Alex Wheeler]

Shawn,
Mine come out around 1.540". I shoot them once, trim them all the same and forget about the length. I have never had a carbon ring and wouldnt care if they were 1.530". I like short, the reason being is that tells me they are forming right. The neck is pulled down into the shoulder. The guys getting long cases are yeilding the case in the body/ shoulder somewhere to get it. That is inconsistent IMO.

 

[johara1]

I'm doing some right now, fire forming and breaking in the barrel at the same time. The short ones are 1.549 and long is 1.551 had one go 1.547 and i don't know why. I mark them and it most likely won't grow. Lube, polished chamber and heat make them shorter……… jim

 

[Dusty Stevens]

Jim, you're getting hydro form to come out near 1.550?

Tom

I think he was fireforming and breaking in the barrel if thats the post you were referring to.

 

[Dusty Stevens]

Like most threads i think it took a turn tom. Have you tried much hydroforming?

 

[Dusty Stevens]

I definitely like the idea. Which hydro die do you have?

 

[dmoran]

Tom -

How was the dispersion while fire-forming.... where they all in one hole in the dirt?
Great picture.... so you even prepare in cold & snow as well. I call that commitment !.!.!
D

 

[Dusty Stevens]

Thats handy!

 

[johara1]

Yeah, it's Fire Forming…………. To a acceptable length. Random length sure don't lend it's self to accuracy. Hydo formed need shot again anyway, the first firing breaking in barrels is a freebe. The rest are through a fire form barrel. All is done in the winter out the basement door. all cases are around 1.550 and with in .003 or they will be tossed….. jim

 

[Alex Wheeler]

Yes, its a hornady die. I form them a few thousandths long so you can bump them in you die to fit your chamber. I feel its the most consistent way and also the correct way to form dasher cases. I want the neck to pull down into the shoulder, I dont care how short they are.

 

[Alex Wheeler]

Thats handy!

For him it is. Hydro forming is about as fun as sorting bullets.

 

[johara1]

Yes, its a hornady die. I form them a few thousandths long so you can bump them in you die to fit your chamber. I feel its the most consistent way and also the correct way to form dasher cases. I want the neck to pull down into the shoulder, I dont care how short they are.

Alex, what do you do shoot the short ones all together and then the longer ones by them selves? or is it mix and match? I think the correct way is all the same length. With a 1.570 chamber you will never need to trim, unless you are over working the brass…… jim

 

[Alex Wheeler]

Jim, they all come out within a thou or two. Its a very consistent way to form, you dont have long and short ones. After the first firing I just trim them enough to equal them out, then never again.

 

[Northridge]

Yes Tom, very informative as always we bounce from one side of the tracks to the other and back again with our discussions but very happy with responses from every one. Just trying to figure out how to incorporate that rat tail file into my setup to reduce my time in the shop, I'll pm Alex for details I need all the help I can get Lol!!!

 

[Dusty Stevens]

I use those rubber bullets impregnated with lapping compound to break in my barrels. A few hundred rounds and my brass is formed and my customers have a very broken in barrel