Expander mandrel and doughnuts

[Sandstorm]

I just dont seat them past the donut...No worries..they shoot great.

 

[riffraff]

Great thread, thanks for resurrecting it.... I am requesting opinions on the safety of my load in relation to the donuts that form in my cases after four firings. I have only been reloading for three years, so not an expert by any means. I do PRS style shooting with .260 Rem (not optimum, but it works). So I am limited by magazine length. I use Lapua brass and Lapua 139gr Scenar bullets.... good groups, and SDs around 6 with extreme spread around 16 with a 20-shot sample. Redding Type-S FL Bushing Die. The bullets seat beyond the neck-shoulder junction to conform with magazine length. After about four firings I get a donut, causing hard bolt closures. With my current batch of brass I have been using an LE Wilson case trimmer body with a .264 LE Wilson neck reamer. It eliminates the donut and allows smooth bolt closure... and accuracy remains excellent. Some of the rounds have been reamed twice (eight firings). I anneal after every firing with an AMP annealer. The brass 'grows' about .004 each firing and I trim every firing. I got 15+ firings out of the last batch of brass, but didn't figure the donut issue out until late, so they had only been reamed once near the end of the brass life. I plan to ream the necks every four firings with this batch. Is this a safe operation? Response #2 of this thread mentions the possibility of broken necks, but the Redding article only mentions that reaming is less uniform or concentric... it does not mention safety as an issue, or multiple reamings. I will call Redding on Monday, but thought some of you might have some insight on this issue.... thanks in advance

 

[whatsupdoc]

@Rat Rifle as previously posted if the case neck separated there would be telltale evidence and if the
jacket separated and got stuck in the barrel, that shot would never have hit the paper.

So if there is no case with a missing neck and the shot before the catastrophic failure hit the target
it is something else.

 

[Sandstorm]

Is this a safe operation?

riffraff I could see you having isues with your reaming as mentioned in the earlier posts.
Im no expert with altering the necks by reaming.
I do not magazine load in F-Class and have ample freebore to seat beyond the donut.

 

[Rat Rifle]

whatsupdoc, I don’t know if anyone ever thought to examine the target. The event caused considerable excitement. The RSO caught a piece of shrapnel in the chest and had to be taken to the hospital. He returned ok the next day, told it was best to leave the little piece of metal where it was hence forth and forever more. Marines are tough The shooter and others on the line received very minor injuries. ALWAYS WEAR SAFETY GLASSES!

As far as I know, the whole event is still a big scary mystery.

 

[dskogman]

I use my Uni-throater to ream the inside of a neck. The pilot on the end guides the case on and keeps it straight. Much easier than the reaming tools. You can even use a hand drill. A lot more expensive if you don’t have one though.

 

[FNSafari]

I have ran into some doughnuts on some necked down 270 WSM brass to 6.5 WSM brass. I use Redding bushing dies. Would using a .002-.003 smaller bushing than i am already using, then "push" the doughnut to the outside with an expander mandrel work? I already tried purchasing a Foster trimmer and inside neck reaming tool. Issue is that the tight neck chamber doesn't allow the neck to open up enough to only cut the doughnut. Looking for a way to figure this out for future projects....

If you must get rid of it, try the K&M neck turner with the turning mandrel that has a cutter on its tip to remove donuts.

 

[Rat Rifle]

I have removed the donut from a retired case with a drill bit, just to see what would happen. Of course, the inside of that case neck was so scratched up it was no longer suitable for competition, which it wasn’t anyway.

I am currently searching for a 6mm chambering, suitable for 1,000yds, THAT DOES NOT NEED CASE FORMING. The ones that I feel are good candidates, are apparently not being used because Laupa cases are not available.

Case forming is a HUGE WASTE. With 2021 technology, We should be able to avoid it.

JMAO

 

[FNSafari]

I have removed the donut from a retired case with a drill bit, just to see what would happen. Of course, the inside of that case neck was so scratched up it was no longer suitable for competition, which it wasn’t anyway.

I am currently searching for a 6mm chambering, suitable for 1,000yds, THAT DOES NOT NEED CASE FORMING. The ones that I feel are good candidates, are apparently not being used because Laupa cases are not available.

Case forming is a HUGE WASTE. With 2021 technology, We should be able to avoid it.

JMAO

The old 6mm Remington with suitable twist barrel depending on the bullet length? Only possible issue is brass availability and quality. Longer neck, steeper shoulder angle than the 243 and runs rings around it in the velocity department affecting both drop and wind deflection at longer ranges. Just a thought.

 

[Rat Rifle]

Yes. The 6mm Rem is a candidate, as is the 6.5x55. But both can be loaded beyond the 243, which is considered a barrel burner. So certainly they would be also. In My opinion, the 6.5x47 uses too much powder and is reportedly difficult to tune.

Something using a good factory case that is available, that burns a little more powder than the 6Dasher, is needed.

To Me, this would be a good way to avoid donuts.