Home Forums Hunting & Shooting Gunsmithing I'm stumped, any suggestions????

Ryan here is what I would do.

Get another barrel doesn't need to be 1-8" twist unless you want to shoot the 195gr or 200gr wildcat bullets. A 1-9" will stabilize the 180 bergers fine.

Fit and chamber up a new barrel with your reamer, same action. Then see if the new barrel shoots heavies any better. If it does then it might just be the shilen barrel.

Also as Sherm said check your inside neck for donuts. If your getting donuts use an inside neck reamer or expander to turn them off. The donut might be giving you issues with a longer bullet if its seated past the neck shoulder junction.

Are you still using the double radius shoulder design on your wildcats?

I know your a talented smith so I wouldn't think it was in your work. Maybe something with the barrel.

Freebie 7mag barrel punched would provide a lot of info for little coin.

My guess is that you have donuts in your case, the longer (heavier) bullets are getting erratic release and causing the huge groups. I think the problem is in your ammo, not the rifle.

Just for the hell of it have you tried any groups at 300 yards or so with the heavy bullets?

It sure ain't the barrel if it shoots like the photo and lighter bullets.

I haven't shot any heavies past 120yds. I'm kinda in a time crunch as I'm going on a deer hunt. I did shoot the 120s and 140s btips at 300. They have the same point of impact and grouped well under Moa. While I was out doing final checks on my drops, an unsuspecting p dog was the sad loser to a 120 gr b tip at 1273yds yesterday afternoon on the 3rd shot. 1st and 2nd missed by no more then a couple inches so drops are on and the rifle is shooting well.

The only reason I want to shoot heavier bullets is the fact the elk is my primary game that I hunt. I don't really fill comfortable shooting such light bullets. I will work with it more. If it keeps shooting like it does, I will just work up a load with 150s and call it good.

Shoot the solid copper,if they are expanding bullets, for now on your hunt and figure it out later.

Trying to picture the donut problem. So this can happen if you only neck size without the sizing button? Any pictures would be appreciated.

Thanks Chris

No one can shed some light on the donut theory what it looks like and how it happens?

A 300 Win has a short neck to start with so if you neck it down to a smaller caliber, you will end up with a neck that is too short.

Fixing that requires setting the shoulder back to gain more neck length.

However, since the shoulder area of the case is generally thicker, the case wall at the bottom of the neck ends up being thicker than at the top...that's called a donut because it tends to happen near the base of the neck.

To fix it, you want to ream the entire neck to a uniform case wall thickness as part of the case forming operation.

If this isn't done, you will likely encounter the symptoms described here.

This sums it up pretty good. I usually chuck the offending brass up in a case holder in my 3-jaw and spin it about 100 RPM. I then use a smaller chucking reamer to skive the donut down. Takes about 2 seconds. I use thumb pressure against the neck/shoulder junction and hold the chucking reamer in my palm. For most cases I use a .250" reamer. If the base of the bullet gets bumped over that bulge where the thicker brass has been ironed to the inside by the die, it can deform it and/or cause erratic bullet pull- both will generally cause bad things to happen to the bullet flight.

Just an update

I made it back from my hunt. The 284 Diablo took 2 deer with 2 shots. One just shy of 600yds with a 120 nbt at 3500 fps the other at 325yds with a 110ttsx at 3880fps. It's amazing how hard those lightweight bullets hit.

As far as the doughnut suggestions, I can see anything in the neck to point that there is a doughnut. Neck have been turned and reamed. I will update as I play with it more.

Thanks for all the input

Speed up or slow down the heavier bullet until you find the load that works in your barrel.