question about neck die for 300 win Mag - Lee Collet or Forster bushing bump

[Mudduck]

Im reloading a Winchester Model 70 bolt action 300 Win Mag for medium range hunting 500 - 700 yards
I like Forster dies so Im planning on purchasing the FL sizer and Bench rest seater die (always found I get the lowest runout with it)
My question is in regards to neck sizing a belted Magnum case - or is it better just to fullsize
Im considering the following neck sizing dies - a Lee Collet or a Forster Bushing bump neck die. I have used Lee Collet dies in the past with good success but never went with a bushing neck type die. thoughts and opinions? Is the extra $$ worth it when its for med range hunting?

 

[Dogleg]

For all the playing I've done with neck dies, neck bushing dies, FL bushing dies, collet dies and body dies I can't really swear that I got much other than hours of entertainment. I can routinely get less run out with a good FL die, and to be honest I'd have a ##### of a time proving that super low run out helps anything.

That may be heresy or blasphemy to some.

 

[bigedp51]

Mudduck

I full length resize all my cases because in off the shelf factory rifles I get better accuracy. When you full length resize and chamber a round the base of the case is supported by the bolt face and by the bullet in the throat. Meaning the body of the case never touches the chamber walls and has no effect on bullet alignment. This is "WHY" Dogleg said above that super low runout helps anything because full length resizing gives the case more "wiggle room" to let the bullet to be self aligning with the axis of the bore.

Below a full length resized case is supported by the bolt face in the rear and the bullet in the throat of the chamber and the neck and body of the case does not contact the chamber walls. (wiggle room)

When neck sizing only and if you do not have good quality brass with equal case wall thicknesses the case can become deformed and out of alignment with the axis of the bore. Meaning the thin side of the case expands more when fired and the case warps and becomes banana shaped.

Below is an example, this Remington .223 case has .004 variation in neck thickness that extends into the body of the case and it warped slightly and has over .005 neck runout that can't be fixed.

I have two AR15 rifles and a .223 bolt action with a 26 inch bull barrel, and the first thing I do before reloading a case is check neck thickness and sort the cases in two piles. The cases with excess variations will be shot as "blasting" ammo in my AR15 carbine. The cases with minimum variations will be used in my AR15 A2 HBAR and the .223 bolt action and the cases will be fully prepped, uniformed, neck turned, etc.

Do yourself a favor and go the link below, Mr. Salizar is a long range shooter and his website is a wealth of information.

The Rifleman's Journal
Index of Articles
http://riflemansjournal.########.com/p/articles-index.html

I read the following in one of Mr. Salizar's articles and it was said by the late Jim Hull of Sierra Bullets testing lab and competitive shooter.

"I get my best accuracy when the cartridge fits the chamber like a rat turd in a violin case" (full length resizing humor said to neck sizers)

Below Kevin Thomas of Team Lapua USA on resizing cases.

Bottom line adjust your full length die to let the case headspace on the shoulder and not the belt with .001 to .002 shoulder bump and you will be better off than neck sizing.

 

[bigedp51]

Mudduck

You can buy replacement Forster decapping units and they also fit RCBS dies. ($12.00 US)

Mudduck said (always found I get the lowest runout with it) meaning Forster dies.

NOTE: More inaccurate ammunition is reloaded with excessive neck runout for the simple reason the decapping spindle is locked down off center and pulls the neck off center on the down stroke of the ram.

The Forster dies have the expander button located high on the spindle and there is a thick rubber washer under the decapping spindle lock nut.

The rubber washer allows the spindle to float and self center in the neck of the case.

On top of this because the expander button is located high on the spindle the neck of the case is still inside the neck of the die when the expander button enters the neck of the case.

Right now I'm resizing .223/5.56 cases and getting under .001 runout on the neck of the case after resizing. And in 47 years of reloading I have never seen this until I bought my first Forster full length die.

Also if you notice I'm using Lee lock rings on my RCBS dies that have a rubber o-ring on the bottom and this also allows the die to float and self center in the press threads.

Bottom line, my decapping spindle wiggles, my die wiggles and most importantly my case can wiggle in the chamber. And all this helps the bullet self align with the axis of the bore and shoot straighter.

 

[Mudduck]

Mudduck

You can buy replacement Forster decapping units and they also fit RCBS dies. ($12.00 US)

Mudduck said (always found I get the lowest runout with it) meaning Forster dies.

NOTE: More inaccurate ammunition is reloaded with excessive neck runout for the simple reason the decapping spindle is locked down off center and pulls the neck off center on the down stroke of the ram.

The Forster dies have the expander button located high on the spindle and there is a thick rubber washer under the decapping spindle lock nut.

The rubber washer allows the spindle to float and self center in the neck of the case.

On top of this because the expander button is located high on the spindle the neck of the case is still inside the neck of the die when the expander button enters the neck of the case.

Right now I'm resizing .223/5.56 cases and getting under .001 runout on the neck of the case after resizing. And in 47 years of reloading I have never seen this until I bought my first Forster full length die.

Also if you notice I'm using Lee lock rings on my RCBS dies that have a rubber o-ring on the bottom and this also allows the die to float and self center in the press threads.

Bottom line, my decapping spindle wiggles, my die wiggles and most importantly my case can wiggle in the chamber. And all this helps the bullet self align with the axis of the bore and shoot straighter.

Thanks so much BigEDP51 for taking time to share all this valuable information, especially with sound reasoning for sticking with full length dies in factory rifles! now.. I wished I would have known about the RCBS die with Forster spindle trick - I could have saved myself some money. BTW My experience with the Forster dies and reduced runout is similar for my 223 ( I shoot 90 Berger VLDs) and in my 3006.

Dogleg thanks for your input as well - you confirmed what I was thinking as well. You are both voices that I have come to trust when I scan various threads and I appreciate all the wisdom and information you take time to share! Have a great weekend

 

[Hotwheels81]

....300 win mag headspace off the belt... Untill it's fire formed to the chamber then you can get away with using the shoulder if your careful BUT it's best to FL size any case used in hunting rifles IMHO... And when you have to be super careful building precisely sized cases for a cartridge that uses a belt one day you will take For granted how easy it has always been and when it comes time to close the bolt you find the case has swollen just above the belt to the point it won't let the bolt close....

I have a nice 300WM 3 die Redding set with FL/N/S die's, expensive but very nice and as always it's nice to have options...

 

[dero338]

If you use a bushing die, you have to first turn your necks to a uniform tickness.
If you want to avoid that,a lee collet die is your option