Fire forming

Vern,
You think your necks are straighter?????
And you turn them after firing?

I have been turning them. Then shooting them in practice......
 
Zippy I dont have to think that they are straight. I have used my concentricity guage to see that they are straight with less than one thou run out.
I do turn them after fire forming.
 
Vern that was a question. I had to read it 10 times to get it.
I have been thinking about this. Since I saw that story from Jackie and JD Mock......
What is the best method???
Turn necks for 6mm or turn for .224?
1. 6mm is expand with 2 cuts.
2. 6mm on a mill is expand with one cut.
Then blast em.
3. .224 would be 2 cuts. One before blasting, then expand, and then second cut.
If I did not have access to a Bridgeport. I guess, the .224 route would be the way to go.
I have been thinking about this for 3 yrs.......
What do ya think?
Just trying to toss out some ideas....
 
zippy06 said:
What is the best method???
Turn necks for 6mm or turn for .224?
1. 6mm is expand with 2 cuts.
2. 6mm on a mill is expand with one cut.
Then blast em.
3. .224 would be 2 cuts. One before blasting, then expand, and then second cut.
If I did not have access to a Bridgeport. I guess, the .224 route would be the way to go.
I have been thinking about this for 3 yrs.......
What do ya think?
Just trying to toss out some ideas....
Click to expand...

Can anyone explain why when using a mill you can cut the necks with one pass as stated above and otherwise you have to make two passes? Just wondering.:cool:

Later
Dave
 
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The reason that I expand and turn .220 Russian at .22 caliber is that straightness depends on how much expanding is being done by a mandrel, and with a .262 neck, the neck of the chamber will leave an unturned neck (after firing a .22 caliber bullet) small enough that significant expanding is required at 6MM, with the attendant neck cocking. By turning at .22 caliber before loading rifle powder and a .22 caliber bullet, the thinner neck results in an neck ID that is close enough to the expander's diameter so that the case is not made crooked by expanding it to 6mm for final turning. The reason that I started doing this is to make the straightest brass possible, after fire forming and turning to final thickness. It works. Can I prove that it matters? No, I can not.
 
Boyd I don't have the problem you describe in the final neck up after fire forming with a 22 bullet in a no turned neck. I use a Pumpkin carbide expander mandrel and it easily expands the case and the resulting neck is straight. After turning my cases (with a Pumpkin turner) I use his tenth indicator gauge to check neck runout and it almost unerringly is less than a tenth. Pretty darn good considering I turn my cases in one slow pass.

Jim
 
DaveT said:
I'm sure you all know what you are doing, but how long has people been doing this? Is there any danger involved? Seems to me the bullet has to go absolutely straight down the barrel. You can understand my amazement can't you?
Dave T
Click to expand...

Pretty sure your amazement is understandable...and no, we don't know what we're doing (exactly) but we do it anyway cause it works. If you don't mind my asking, why does the bullet have to go absolutely straight down the barrel?
 
Jim are you indicating variation in neck thickness? I was referring to how straight the case is, measured on a concentricity gauge.
 
I fire form mine with bullseye and wax as stated above.
I dont have to "expand or neck up" it happens when I pull the trigger.
I then use the expander so that the necks are exactly what they need to be for the turner.
Yes the necks and cases are concentric.
Since I am shooting a .269 neck I only make one pass.
And now I am done. AND my cases are turned to the exact junction or neck and shoulder.
No wasted money on bullets, no need to go to the range and so far as long as it is done exactly the way instructed no danger. The only danger is by those who "think" there is a danger or by someone who cant follow instructions, but then that exists for any part of any of this topic including .22 bullets down a 6mm barrel.
 
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Boyd yes I have measured my cases on a concentricity gauge before fire forming, after fireforming and after neck turning. Had to prove to myself that using 22 bullets to fire form cases would not denigrate my desired end results. I use two concentricity gauges, one large one to check case neck runout and the small Bruno's to check bullet runout.

Yes the bullet goes straight down the barrel...we're talking about a .223 bullet going down a .243 barrel...thats a .020" difference. It sure won't tumble or get lodged at the pressures we shoot!

Jim
 
I use a neck micrometer to check for uniformity of neck thickness, and my results have been good. As to the straightness of cases, measured near the ends of their necks, on an old Sinclair concentricity gauge, a survey of new, out of the box brass shows readings of about .002 TIR, and if cases are expanded with a mandrel, to 6mm, that figure increases (before they are turned) to at least .004, often more. This is the main reason that I started using a modified version of what James Mock does.
 
If you want to play a great joke on someone. I have a barrel I do the 22 trick to but it will still shoot 3/8-1/2" groups with normal turned and 6mm bullets. I had it out at a friends (make sure you have a very large...mountain or so...for a backstop). I had two fireforming loads, one with 22cal bullets and others with 6mm. I shot the 6mm fireforms and shot a nice 1/2" group. I asked a friend to sit down and shoot some of them and gave him the 22cal loads. Well...needless to say...he couldn't even hit paper...some friends were dogging him (they didn't know what I was doing) but could see rounds hit all around the target (and quite far away).

I then sat back down and shot another group...this went on for about two hours....I never did tell him what I was doing but I think it drove him to meds. Funny as He**

Hovis
 
HovisKM said:
If you want to play a great joke on someone. I have a barrel I do the 22 trick to but it will still shoot 3/8-1/2" groups with normal turned and 6mm bullets. I had it out at a friends (make sure you have a very large...mountain or so...for a backstop). I had two fireforming loads, one with 22cal bullets and others with 6mm. I shot the 6mm fireforms and shot a nice 1/2" group. I asked a friend to sit down and shoot some of them and gave him the 22cal loads. Well...needless to say...he couldn't even hit paper...some friends were dogging him (they didn't know what I was doing) but could see rounds hit all around the target (and quite far away).

I then sat back down and shot another group...this went on for about two hours....I never did tell him what I was doing but I think it drove him to meds. Funny as He**

Hovis
Click to expand...

Kevin. You don't have many friends, do you????
 
Dave. Might be because I was using a coolant. And everything was only getting warm.
Here's a couple of stories....
http://www.accurateshooter.com/technical-articles/neck-turning-with-lathe/

http://www.accurateshooter.com/technical-articles/neck-turning-tool-cutting-tips/

And I ran across this recently. I had made something similar. Last year. But, used a mill to do about 300 this winter.
http://www.youtube.com/watch?v=VHiyWZ0iplY
http://forum.accurateshooter.com/index.php/topic,3762964.0.html
http://benchrest.com/class/index.php?a=2&b=1776

Francis and Paul got something going on here. Looks real nice.
 
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