Anybody else experience the donut effect.......without the donut?

[VaniB]

There seems to be some kind of bottle neck squeeze or restriction at the neck-shoulder joint area of new or fired brass alike that suddenly stops the bullet from seating smoothly. While I've heard much discussion on the forums about the formation of donuts in reloaded brass, I don't ever recall of this phenomena occurring in new brass too. Perhaps the competition shooters here who reload quite a bit are very familiar with what I'm describing here and would be kind enough to explain just what it is and how to handle it.

Essentially, what I have experienced is that when I use a Wilson inline style seater, the bullet will slide down into the neck smoothly and evenly until it reaches down into the neck/shoulder joint area of the case. I then experience a lot of resistance on the arbor press, and as I keep exerting force, the bullet suddenly kind of pops down into that joint. Sometimes when this happens, the bullet then also often transforms from having had good snug tension at the start of the seating, to suddenly now being finger loose and practically falling into the case. Grabbing the bullet, and pulling the bullet back up a bit into the neck helps it to tighten up again in the neck. Naturally, this inconsistant neck seating tension is not conducive for shooting tight groups. I have experienced this phenomena with 223, 308 and 6.5 cal, and with Hornady brass, Lapua brass, and Remington brass alike. It happens with new brass and fired brass, and a donut cutter does nothing to alleviate the problem.

 

[BoydAllen]

It seems to me that what you have is a freebore length situation. None of my loads have bases of bullets, or fronts of BTs at or below the neck shoulder junction. Sometimes magazine length is factored in to chamber design with this result, which is why it is better to build rifles that are to be chambered for cartridges that had had this issue come up, on long actions.

 

[fguffey]

Perhaps the competition shooters here who reload quite a bit are very familiar with what I'm describing here and would be kind enough to explain just what it is and how to handle it

Do a search, competition shooters have been talking about 'the dreaded donut; for years.

I make donuts, I am a case former, when forming cases donuts are part of the process, I use neck reamers, the best and most expensive way is to use RCBS reamer dies. When forming some cases I never get 'the donut', other cases a donut is a guarantee.

Essentially, what I have experienced is that when I use a Wilson inline style seater, the bullet will slide down into the neck smoothly and evenly until it reaches down into the neck/shoulder joint area of the case. I then experience a lot of resistance on the arbor press, and as I keep exerting force, the bullet suddenly kind of pops down into that joint. Sometimes when this happens, the bullet then also often transforms from having had good snug tension at the start of the seating, to suddenly now being finger loose and practically falling into the case

Then there is no end to the variety of dies available, I suggest standard dies for beginners, problems began when a reloader jumps into reloading in a dead run. It is possible to crush a case when seating and crimping. A problem can be created when the crimp[ case mouth is folded into the bullet while the bullet is being seated.

F. Guffey

 

[artbosco]

I guess it depends on what you're shooting. A lot of us who shoot the 6PPC, don't even worry about it. We push back shoulders, neck up, trim, turn, load, seat and shoot. I say that because we normally seat long. The donut never comes into play.

 

[Alex Wheeler]

You can't control neck tension at the shoulder/neck junction. You don't have to have a donut formed to have that problem. 2 ways out, one is get your freebore lengthened or use a bushing die so you dont size that part of the case.

 

[Lapua40X]

There seems to be some kind of bottle neck squeeze or restriction at the neck-shoulder joint area of new or fired brass alike that suddenly stops the bullet from seating smoothly.

If I read that correctly, you're describing a bell shaped neck that is larger at the opening than it is at the base; and you don't see any evidence of a "donut". Just for kicks, let's agree that a "donut" - which represents a reduction in case neck diameter near the bottom of the neck - may not be clearly apparent on visual inspection. It doesn't take much brass flow to tighten up the neck/shoulder junction. So you may indeed have an unrecognized "donut" issue. I might experiment by preparing a case for its load as usual, and them running a neck reamer down the neck's length and taking another look at how the bullet seats.
Are you using a neck expander die with appropriate mandrel as part of your case prep. routine?
http://www.accurateshooter.com/technical-articles/reloading/expander-mandrels-and-neck-tension/

 

[gotcha]

Your experience is being effected by a couple of variables. (1) the bullets pressure ring is swaging the neck slightly larger as it proceeds down the neck. (2) As the pressure ring meets the neck/shoulder junction the bullet meets stronger resistance since the bottom of the neck is also supported by the shoulder. Using a bushing die that only partially sizes the neck will allow the lower portion of the neck to be blown out on 1st firing which also promotes better cartridge alignment of the reload. The same thing can be accomplished using a LEE collet die with a .030" to .040", 1/2 inch washer atop the shell holder. However, a bushing bump die would be ideal since you can bump the shoulder, size the body and PARTIALLY size the neck all in one stroke....... A lot of people read your problem as a donut when that isn't actually the case.

 

[Dos XX]

The same thing can be accomplished using a LEE collet die with a .030" to .040", 1/2 inch washer atop the shell holder.

I'm not following you on this. Does the case set on the washer or does it go through the washer?

 

[Toolbreaker]

The same thing can be accomplished using a LEE collet die with a .030" to .040", 1/2 inch washer atop the shell holder.

I'm not following you on this. Does the case set on the washer or does it go through the washer?

The spacer (washer) goes over the case & sits on top of the shellholder. Since the collet die activates off of the top of the shellholder, this forces the collet to close on the case further up the neck by how much the thickness of the spacer is.

 

[dkhunt14]

I agree with Gotcha. When the pressure ring gets past the junction it has made the neck bigger like an expander. Now the shank of the bullet is smaller and there isn't much of a hold. What caliber, kind of brass and how many firings are on the brass? I don't like my pressure ring at or below the junction of neck and shoulder. I like to keep it about 1/8 inch in front minimum. By throating the gun out it might help and also helps relieve pressure by giving you more capacity. Matt

 

[fguffey]

Essentially, what I have experienced is that when

I use a Wilson inline style seater, the bullet will slide down into the neck smoothly and evenly until it reaches down into the neck/shoulder joint area of the case. I then experience a lot of resistance on the arbor press, and as I keep exerting force, the bullet suddenly kind of pops down into that joint.

Essentially, what you have experienced is a problem created with methods, techniques or bad habits. You have a problem with 'the dreaded do-nut' in cases you have not fired. Again, I am a case former, I form cases, I create do-nuts, I make donuts in cases that have never been fired, when forming some cases I expect donuts.

I would suggest you start reloading with standard sizing dies. a bad habit begins when a new reloader starts with collet sizing dies, by design the collet locks onto the neck of the case, then! the case is shoved up, the shoving up of the case with the neck locked down causes the case to shorten in the form of a wrinkle/donut.

I have turned cases into accordions and or bellows without case body support, with case body support the only direction the case can go is inside.

What caliber, kind of brass and how many firings are on the brass?

Matt, He is creating the problem in new and used cases before he starts to seat bullets.

I have experienced this phenomena with 223, 308 and 6.5 cal, and with Hornady brass, Lapua brass, and Remington brass alike. It happens with new brass and fired brass, and a donut cutter does nothing to alleviate the problem.

F. Guffey

 

[dkhunt14]

I don't agree with that. Some of the bullets coming through are really fat and especially on the pressure ring. If the pressure ring is a half thousandths or more bigger than the shank and the pressure ring is below the junction you don't have much or any grip on the bullet. I would mention the brand that I have seen this on but then they would lock the thread. I have some that vary over a thousandth from lot to lot. It is just bad to make the junction below the shoulder junction. This will happen even in brand new cases from Norma and Lapua which is quality brass without a donut. Anytime you get close to the junction the brass goes from being straight with nothing holding it and then the shoulder comes in at a angle and it braces the neck so it doesn't want to move as freely. I have fired my cases up to 20 times and never get a doughnut. They are tight necked guns with the brass turned slightly past the junction and my throats are out enough that the bullet sits in front of this. On a Dasher I turn them to within about a 1/16 of the junction and fireform them. When they are formed the neck goes half way down the shoulder. Matt

 

[bow shot]

VaniB... just curious: what are you using for a doughnut cutter?

Personally, I think fguffey nailed it. 'Had a similar situation a while back, the Lee collet die (which I use and prefer, BTW... this is not a bash) was shoving back my case neck/shoulders, and I didn't realize it. In that case I was not using it properely..