Fireforming faux pa???.......

[762willdo]

I was at the range today sighting in my deer rifle and I noticed a guy a couple benches down doing something I considered very strange he was removing his bolt after every shot and clipping a new round in under the extractor before putting the bolt and round into the gun and firing, my curiosity got the better of me so I Wander down and asked him what he was doing he told me he was fire forming cases I asked him why he was putting the round into the bolt and he said that the round wouldnt fire unless he did he was firing 6br brass into something else either dasher or some other round ........

 

[Sheldon N]

Too much headspace? Should seat the bullet long into the lands to hold it against the bolt, I would think.

 

[nosualc]

Should seat the bullet long into the lands to hold it against the bolt, I would think.

+1

 

[Brians356]

It's not a faux pas if the cases come out properly formed, and the rifle is still intact.

 

[lpreddick]

Seating the bullet long into lands will result in increased pressure as opposed to his technique. May not be a problem if fireforming load not max. The increased pressure can probably produce a more completely formed case.

 

[1shot]

Was he using the COW method, or did he have a bullet to top off the case?
Lloyd

 

[762willdo]

Bullet

 

[swd]

It may or may not have been safe. Without him giving you more information there is no way to know for sure. If the bullets were jammed but seated with lighter neck tension he may have just wanted to give the best chance he could.

 

[scott_at_vortex]

The problem I think he will run into is premature case head separation. I have found that if you dont have a SUPER hard jam or use a false shoulder that you get some case stretch instead of just blowing the shoulder forward. I have found that a false shoulder is the most reliable way to fireform IF you are going to shoot bullets.

When fireforming that involves blowing a shoulder forward you can see a line where the old shoulder was. The false shoulder method visibly leaves that line lower on the case than the hardest Jam I have been able to achieve with a 6mm.

For example- The distance between that line(previous shoulder) and the new shoulder might be .100" when using a false shoulder. When just jamming that distance can vary and is generally .080"-.050". So if that distance is .100" when using the false shoulder I am getting little to no case stretch. If any other method allows that distance to be less than .100" where am I loosing distance? I am loosing in the case body. In other words, If the actual shoulder has the potential to physically move .100" and it doesnt but the case still completely forms to the chamber then case stretch is providing the length that the shoulder didnt blow forward.

You can see this very easy just by firing a jammed round and a false shoulder rd and looking at the distance between the old shoulder and the new shoulder.

Again this has just been my experience,but unless the guy at the range has a super tight fit between his extractor and case rim(Im not aware of any extractors that do this) that really hugs that case rim I think he will run into issues after a few reloads(depending how hot the loads are).


Hope I explained that well,lol

 

[Brians356]

The problem I think he will run into is premature case head separation. I have found that if you dont have a SUPER hard jam or use a false shoulder that you get some case stretch instead of just blowing the shoulder forward.

Exactly. My 250 AI was not cut short for a crush fit at the neck/shoulder junction. I was getting a pronounced stretch ring in the head. and shoulders not pointed. Rather than fight it using bullets jammed or false shoulder, I switched to 22-250 brass and went bulletless with Bullseye, and lightly lubed cases.

 

[fguffey]

767willdo, it is possible his reloads would not feed. There are control feed rifles, there are push feed rifles. It would help if you knew what design/receiver he was using.

It's not a faux pas if the cases come out properly formed, and the rifle is still intact.

I have to agree with Brian. He could have been using a late Model 70 Winchester receiver.

Then there is that old saying about the firing pin driving the case, powder and bullet to the shoulder of the chamber before the firing pin crushes the primer, I have fired cases that were .127" shorter from the shoulder to the case head than the chamber from the shoulder to the bolt face. When ejected, the fired cases came out perfectly formed.

F. Guffey