Full length vs shoulder bump sizing

[dbaird]

What do you professionals suggest? I have read that some people use hand dies (wilson) for neck sizing then a shoulder bump die when round gets hard to chamber-others say you need to full length resize after each firing- that the shoulder bump die is no good. Any suggestions? This is for single shot varmint rifles so feeding from a magazine is of no concern.

 

[necchi]

There's arguments to both sides,
First you have to consider what your rifle is,, Custom or Off the shelf,(?)

Personally I used to be concerned about fireforming and spending time fitting my brass to each rifles chamber.

Then I read here several times that many of the winning shooters of long distance matches FL size all their brass,, every time.

My rifles are off the shelf, with chambers that are accordingly large,, they need some body sizing and a shoulder bump to fit back in the chamber.
I can accomplish all this by simply spending time to adjust my FL die properly.

As an aside;
I've found that getting control of case neck runout and assuring proper neck/bullet concentricity with the guns chamber leade and bore to be vastly more important to accuracy.

 

[broncman]

For my 308 FTR I use a redding full length body die with the redding shellholders. The shellholders are in .002" increments to making bumping easy and consistent.

Then neck size with Lee collet die.

 

[Erik Cortina]

You should F/L size every time. Just get a redding F/L neck bushing die and adjust it to where when you chamber a round the bolt handle with no firing pin mechanism in bolt will close about 60-80% down on is own.

 

[bigedp51]

I'm with necchi above also, and it depends on the type rifle and chamber, and on standard factory rifles a Lee Collet die works wonders.

 

[Erik Cortina]

I'm with necchi above also, and it depends on the type rifle and chamber, and on standard factory rifles a Lee Collet die works wonders.

Why does it depend on the rifle and chamber?

The reason for the bushing die is so that you can properly size for a custom or factory chamber. Other than that, the case has to be full length sized every time regardless of chamber dimensions.

 

[broncman]

Erik, what does the bushing have to do with anything chamber related? Does it not have to do with brass neck thickness and achieving the neck tension you desire?

Custom or factory has nothing to with bushing selection??? Am I missing something..

I can see brass dictating chamber dimensions etc.

Ken

 

[mikecr]

I use several cartridges that have many reloads on the cases, and have NEVER been FL sized.
All I do is bump shoulders & partial NS.

So I know better than " the case has to be full length sized every time regardless of chamber dimensions "
Nothing about this is true..

 

[LHSmith]

I use several cartridges that have many reloads on the cases, and have NEVER been FL sized.
All I do is bump shoulders & partial NS.

So I know better than " the case has to be full length sized every time regardless of chamber dimensions "
Nothing about this is true..

I have found the exact opposite to be true.......if I run loads in most chamberings that are anywhere near the max as listed in load manuals....I will get a click and/or hard bolt lift. It's just easier to FLS every time and eliminates the possibility of galling the bolt lugs.

 

[Erik Cortina]

Erik, what does the bushing have to do with anything chamber related? Does it not have to do with brass neck thickness and achieving the neck tension you desire?

Custom or factory has nothing to with bushing selection??? Am I missing something..

I can see brass dictating chamber dimensions etc.

Ken

The neck is part of the chamber. Factory chambers have bigger necks, therefore unturned brass is used in the gun and the appropriate bushing is used to size brass to provide about .002" Neck tension.

Now, if you have a tight neck chamber, brass is neck turned to provide proper neck clearance and the SAME die is used but with a smaller bushing to provide the same neck tension as the unturned brass.

 

[Old Navy]

If your bolt closes and opens with very little effort by all means neck size with a bushing die and bump the shoulder down as needed. I shoot a 6BRX BR rifle. My chamber is a little tight down near the base. My bolt has the infamous clack at the top of the stroke and was hard to open with just neck sizing. This was a problem after only two firings. I was using a body die, bump die and neck die to do what a FL die would do. Finally found someone that had a Redding FL bushing die. The idea is to do the least amount of resizing to make the case fit your chamber. Do what ever you can get by with. Later! Frank

 

[mikecr]

I agree Frank, the idea is to do the least amount of sizing -as needed.
With some cartridges, chambers, and loads more/less & different sizing is needed. Not all need FL sizing (as though this were actually a standard).

Nor is it good advice to just FL size everything, every time, because it's easy, or best, or because so & so does it..
For some folks this just isn't true. Same with annealing.
About the only thing about sizing dies that can be generalized across the board is that custom dies are preferred.

 

[Leaddog]

Full length sizing and annealing ( everytime ) works best for me.

 

[necchi]

About the only thing about sizing dies that can be generalized across the board is that custom dies are preferred.

And there in lies my info from my first post, I said;
"First you have to consider what your rifle is,, Custom or Off the shelf,(?)"

I kinda figured this topic would take this turn sooner than it did. This is after all, a premier site for Bench Rest shooting, and many prefer to seek out all the minute detail that's needed for superior long distance shooting.
Of course Custom Dies will or should answer many sizing difficulties, but at the same time using expensive custom dies with any off the shelf rifle will gain the shooter little. Granted there are many fine rifles available at many fine gunshops, but SAMMI specs are just a guideline for factory rifles that allow Factory SAMMI ammo to be used in all of those rifles.
A blueprinted rifle and chamber are a little different aren't they?

And Yes, the best is to work the brass as little as possible for extended brass life. This is something every loader should be keeping record of and constantly checking also, that's how old, how many shot's, is the case stretch happening to your brass and at what rate.

Not to argue with mikecr at all but he brings up the point saying;
"Not all need FL sizing (as though this were actually a standard)."

Well it actually is Mike, FL sizing is advocated in just about every manual and "how too" book available out there until you get into custom rifles and advanced loading.

Let's not get lost in all the available styles of dies, Just two posts above Frank tels us that he was using 3 different dies and preforming 3 different functions.

It's not carved in stone that FL dies need be setup for a hard or full cam-over sizing, or that the button stem needs to be used to size the neck, as that's where most of the stretch is coming from right?

Why use a body die and a bump die? When with a little set up care both can be accomplished with just an FL die for a large factory rifle chamber?

 

[BoydAllen]

The answer to the question depends on one's goals and budget. If you want to wring all of the available performance out of a cartridge then your loads will probably dictate FL sizing. (I am speaking bolt rifle here.) If not, perhaps not, depending on the pressure of your loads.

In all of these discussions, one important thing generally gets overlooked, which is how much the die will size the brass. Many of the objections that some have to FL sizing, unless absolutely necessary, come from long experience with dies that are a really bad match to the chamber that they are used with. Leading to the conclusion that FL sizing is bad. Wrong...I have a die that is such a close match to the chamber my 6PPC reamer cuts that does not measurably reduce the shoulder diameter, and reduces the back of the case by about .0005. The shoulder bump is usually set to .001 or slightly less, while the amount that the neck is sized is determined by bushing selection. When I chamber a round that has the bullet seated to jump to the rifling, there is no noticeable resistance. Sizing with this die, for this chamber, bears absolutely not resemblance to what I used to do with a factory FL die to brass from a factory chamber...apples and oranges.

 

[mikecr]

When I said "as though this were actually a standard", I meant that FL sizing dies are not standardized.
10 different, off the shelf brand/type 'FL dies', would create a pretty significant range of actual sizing.
So unless your using a custom die, you shouldn't just grab any ole FL die & go at it -because it's a popular thing to do.
You might find that it was the very worst thing you could have done.

The declarations that FL sizing is a must(for everyone) holds no real basis. What we do is our choice.
You chose a cartridge & chamber & load & path to FL sizing? That's fine, sounds like a plan to me.
But anyone can chose another path & do well with it. No reason to deny it.

 

[BoydAllen]

I should have probably mentioned that the die that I mentioned is a semi-custom, and that the only real way to be sure of a proper die to chamber relationship is to match the chamber to the die, by ordering a reamer based on brass sized by the die, or to order a custom die, based on brass from the chamber. If you are already planning a rebarrel, or new rifle, a custom chamber reamer is the best option. (IMO)