Cutting out Donuts???

[Scott Harris]

The quick fix, if you don't foresee having .284 Brass available for the life of the barrel would be the Ream the Barrel Deeper past where the Donut would form. You would have to fire-form your brass as you would any "Improved" Cartridge. The drawback would be slightly shorter Necks. I'm no expert, but according the Diagram the shoulder on the 6.5 is .024" shorter than the .284. if this is correct, which is not a good thing for case life or case separation.

Super

say what??? Donuts can extend .030 or more above the neck should junction, are you proposing running the reamer .030"+ past GO? The drawback would be instant case head separations.

 

[RustyPin]

say what??? Donuts can extend .030 or more above the neck should junction, are you proposing running the reamer .030"+ past GO? The drawback would be instant case head separations.

My Limited Experience with Donuts is they form at the original Junction of the Neck & Shoulder. The objective would be to move this Junction into the Shoulder. I am not going to attempt to explain how to form Improved Cases, as I cannot be responsible for that. It appears someone here has exposed the Flaw with using the 6.5-284 Case, I am merely proposing the "Possibility" of using an improved version, the same as any "Improved" such as an Ackley Improved or RCBS Improved. As I stated you would have to follow procedures for Fire Forming Improved Cases, many of which are successful well beyond .030 inches.

I would also like to add I did a simple search and found .284 Brass by Norma is still very available. (at the time of this posting..)

Super

 

[Steve Ladino]

Quick question guys. My friend and son in law both are shooting Lapua brass in the 284s formed from 6.5x284 and both have donuts in the necks. My question is, "If I cut the donut out with my reamer will they return once they start shooting them again"??? I don't know if this will solve the problem or if the brass will need to be neck turned to stop it. Thanks Guys!!!

I have rotated the donut by hand on the flute of a close fitting drill bit held horizontally in a vise to remove donuts, left hand thumb nail on the neck at the donut and turning with my right hand.

 

[F Class John]

I just turn my gage pins over so the squared off end is down. I carefully guide it in to any case with a donut and with one clean stroke I shear the donut off. Quick, clean and easy. Simply dump the donut out afterwards and move on.

 

[distantfoe]

The best method I've found has been to neck up new brass to the next caliber, neck turn at 1 caliber up, then neck back down to desired caliber. Never had doughnut issues after doing this with virgin brass.

 

[MrMajestic]

If you chew up the inside of the neck maybe you shouldn't be trusted with anything mechanical.

Dave, I see you read "How to win friends and influence people" by F. Guffey

 

[TikkaSporter]

Inside reaming can be tricky. Size the case. The trick is to expand the inside of the case neck with a Vermont pin gage (from Amazon Prime $5.00) .002 larger than the cutter tool diameter and stop when the pin touches the donut. Do not push pin past donut as that will push some of the donut to the outside. Now turn the case on the cutting tool IN REVERSE until you reach the donut. Now turn in the cutting direction or normally clockwise and cut through donut. Turn case back off the cutter again in reverse. By turning case in reverse to and from the donut will stop any damage to the inside of the case neck. May sound complicated at first but it is very simple after a few tries.
Roger Gower

Minus the pin gauge, that is how I ream donuts out (reverse the cutter unless actually removing the donut, cutter sized properly to only cut the donut, not the neck). In my case I send several pieces of fired brass (with donuts) to Wilson and have them send a custom inside reamer. Then use said reamer with their neck trimmer lathe/tool.

 

[Tod Hendricks]

You can can remove donuts in fired cases with these reamers, it’s so easy a cave man can do it without scratching or scarring or even touching the inside of the neck. I pre test fired cases with a 284 pin gauge, then chuck the reamer in a cordless drill and cut out the donut in the cases that need it.

My bullets are seated well above the donut, but I like to use a expander mandrel before loading, it seems better to have the donuts removed prior to this operation.

I start with a .283 reamer then finish with a .284 reamer.

https://www.mcmaster.com/8803A539

 

[ChrisNZ]

.. the better approach might be to expand the neck and turn at the bulge and prevent the need to fool with the ID.

Gerald

Yeh, it "makes sense" but there is still the issue of springback where the donut area isn't fully eliminated by the mandrel.

I do agree having adequate freebore to stay out of the trouble zone helps