Fireforming

[scpaul]

I was doing alot (100+) fireforming cases. Small amount of rifle powder, 1/4 sheet of single layer tp, about 1/3 case of dry cornmeal another 1/4 sheet tp. Each time packed down with a wooden dowel. After 50 or so fireformings the barrel clogged with tp and cornmeal. I had 1 heck of a time, hours to get it cleared. Has anyone ever experienced anything like this? The cornmeal had been kept in a refrigerator to keep it dry. The powder was sufficient that I had to use a wooden box stuffed with paper and cloth to keep from box from damage. I tried cardboard but it blew through quickly. I was getting good shoulders from this forming.

 

[Mike D Texas]

I always used pistol powder. With a light charge of rifle powder you may not be building enough pressure.

 

[scpaul]

It's been a while ago. I don't remember which powder I was using. It was strong enough that I had to go to a wooden bird feeder packed with paper and cloth tostop it from ricocheting ba k at me from 5 ft.
Thinking about it, it may have/probably was pistol powder. Like I said it's been a while.

 

[lancetkenyon]

I use a bullet, backed by a moderate load for the parent case, and work up a load like any other. Then go shoot steel, break in the barrel, hunt, etc. Practice while fire forming.

Win, win, win.

 

[scpaul]

Good idea. I'd already done my break-in and was at the point where I was punching paper at 100 and my next step was 300 then 500. I never got that far.i was fireforming for the longer ranges because I hadn't formed enough incase there was some problem.

 

[nksmfamjp]

COW Fireforming recipe

I thought I posted this somewhere else, but I did not. First: The formal instructions https://bulletin.accurateshooter.com/2017/02/how-to-fire-form-brass-without-bullets/ Found this reference for starting charge weight...

www.longrangehunting.com

i won't ever use a bullet again, I believe.

 

[QuietTexan]

After 50 or so fireformings the barrel clogged with tp and cornmeal.

You need to clean out the barrel every 5-10 rounds when fireforming with non-bullet media or you get exactly what you got.

 

[scpaul]

I think that I've got that part figured out. It was a tough lesson and one I won't soon forget.

 

[APDDSN0864]

I have never used TP or any other barrier between the powder and the cornmeal or Cream of Wheat. Just charge the case with the appropriate amount of pistol powder (Unique is my favorite), pour in the cornmeal/C.O.W. to the case mouth, make a small ball of TP and press it into the case mouth or press a wax wad over the mouth to seal it, and shoot.

I have fireformed many hundreds of cases with this method.

Ed

 

[Zen Archery]

Stop Wasting Components Fire Forming • Standard -vs- A.I. Load Development

 

[Barehandlineman11]

I use to use air compressor every 2-3 rounds blow it out. Now i just hydro form. Then fire form. Barrel break in plus fully forming. The cornmeal works but i think more peta then hydro.

 

[scpaul]

I'll definitely give it a shot. My biggest concern is that I'm blowing out a much larger case,300Wm, minimizing the case taper the max amount , forming a much flatter shoulder (37*) and changing from 30 cal. to 284. The loads that I'd worked up to were close to 100% density with the formed cases. Like I said, I'll definitely try it because it is a powder hog, but xxxx it shoots good for no more than I've tested it. I will say thatat 300 yards+- with the 139 7mm Accubond it tears a deer up bad enough that lf I can't head or neck shoot I'm going to let it walk.

 

[scpaul]

Barehandlineman11, what all is involved with hydroforming? Would I have to buy a bunch of equipment. With the cost and availability of supplies buying what I need to hydroform may be the cheepest way to go. Let me know please.
Paul

 

[lancetkenyon]

Good idea. I'd already done my break-in and was at the point where I was punching paper at 100 and my next step was 300 then 500. I never got that far.i was fireforming for the longer ranges because I hadn't formed enough incase there was some problem.