Home Forums Reloading Big Game Rifles Bumping shoulders back

I switched to Lee neck collet does a couple years back and have been quite pleased with the results. Today was shooting and noticed a couple cases were chambering with a little more effort. I don’t own a Redding body die and was wondering if I could take the expander ball out of a full length die to just bump the shoulders back? Then neck size with the collet as I have been. Or would I be better served to full length size, then anneal, then neck size? Cartridge in question is 30-06.

Craig

I just use my fl die with the expander and measure with my hornady case gauges until the shoulder is pushed back about .002. It's basically a partial resize and the neck gets done at the same time.

Continue to use your collet die until the issue happens again.

You need a body die.

The full length die will size the neck down to where the mandrel of the collet die won't fit into the neck.

This.

+ 2. Redding body dies are what I use

Not saying a body die wont work, but there would be other ways not requiring a die change.
Rather than take the word of people like me, why not talk with a tech at a place like Sinclair’s?
You might find they suggest you have a set of what they refer to as (competition shell holders).
They will also work with other cartridges of the same head size.
There will be 5 shell holders in the set, and you simply change the shell holder until the bolt closes on the case.
It’s a common issue, and easily solved.

Yeah, thats what i do. Why people try to overcomplicate this schidt is beyond me. No one here has ever proven to me that they load more concentric or more accurate ammo by using all the fluff they do. KISS for fu cks sake.

Take the expander ball out and hone the neck until it won't size the neck down. Anneal before you bump the shoulder back you get a much more consistent bump that way


Trystan

Sheeit, I forgot all about that Sunnen machine sitting out in the garage.

Think I have to agree with bsa...I’m over thinking it. I’ll just FL size next time and then go back to the collet.

Craig

Yup, do that and leave the expander ball in the FL sizer. Just try not to bump the shoulder back more than necessary. 1/8 turn of the die is the difference between not enough and too much, so some of us prefer to measure shoulder bump to get it right.

If you like to tinker with stuff you can make a pretty good bump die from a Lee FL sizer. Just drill or polish out the neck and then take a case and chuck it on a drill and cover with valve grinding compound and polish the die with very light or no pressure on the shoulder portion. You will need to start with a FL sized case and the graduate to an un-sized or partially sized case. A faster way would be to use a chamber reamer on the die and then polish.

I think Dirt Farmer posted instructions for this.

But the FL size is all you really need every 3rd or 4th loading or anytime you anneal.

Redding will polish their dies for a better fit at a minimal fee and this is worth it to keep from over working the brass especially if you only load for one rifle.

A Redding body die is only $36

Expander ball dies suck but if it doesn't bother you to shoot a batch of [bleep] crooked ammo go for it with the expander ball die

I know Forster does this, but I didn't know about Redding.

I'm basically a rookie in this department,

so if some one could explain the above quote I'd really appreciate it.

Seems like something I should have knowledge of.

An old post of mine:

Lee collet neck sizers + Redding body dies..........easy as it gets.

How often are you guys setting the shoulder back?

For some applications it's every time, but not very far.

The reason I ask is I use the Lee Collet dies for almost all of My loading and have never seen the need to set the shoulders back.

After a few firings with full power loads do the bolts on any of your rifles need a bit more pressure to close?

No they don't seem to I just did 40 rounds of 270 Win last night that are on their 8th loading all they have been sized is with a collet die no problem chambering them in several 270s that i have. These were Rws Factory loads and it seems to be very hard brass but do the same thing with Win. or Federal brass with no problems.

Depends on how hot the load is, case design and brass hardness. A case with a lot of taper like the 220 Swift may need it every time especially if it is in a maximum sized chamber. A cartridge like the 280 AI could get close to ten rounds before needing it.

I do it every 4th loading for consistency and before it needs it. This is also when I anneal so it gives the cases a new lease on life.

I've been using that die combo for my 7mag, 6.5CM, and 7-08 and set back shoulders only when round becomes "tight" when chambering, every 3-5 loadings for my rifles. I neck size only as long as I can.

This is what I do. Anneal before FL size, for more consistent results. But I don't have to set shoulders back very often. After about 10-12 firings. The only time I seem to use the FL sizer anymore is on once-fired stuff I acquire.

I anneal every 3-4 loadings, keep pressure below 65K PSI, and will only do a full-length size on a batch if several require noticeable force to close the bolt.

I have run some cases through over 25 loadings, and have only lost a couple using this method. The annealing seems to be the key. Gotta quit buying that crappy Winchester brass.

I don’t have the tools to measure, so I just mark up the shoulder with a dry erase marker, and then adjust the die so that it just kisses the shoulder and removes some of the marker. On my RCBS dies, that’s just a slight 1/16 more turn.
Sound about right?

A true 1/16 turn is about right, equivalent to .004" more shoulder bump, although it can be pretty hard to really judge 1/16 turn accurately.

If you have a digital or dial caliper and a piece of fired 40 S&W or 10mm brass though, you have the tools to measure shoulder bump. Really any piece of round tubing that fits approximately in the middle of the case shoulder works for measuring shoulder bump. Zero the caliper on fired brass from your chamber, and compare the same reading on your sized brass.

This pic is with a piece of .357 Mag brass, same idea. This piece of 6.5 Creedmoor brass has the shoulder bumped back .003".

Good stuff Yondering. Thanks for the pic and great idea.

It works. I've been doing it and recommending it with a 40 S&W case for a long time now.

Great idea! I love redneck engineering!

I use a 9mm case for most of my rifle reloading.

Yup.
Just as a note of explanation - the 357 case was used in that example because the round had a bullet loaded, so a .40 or 10mm case is too short. An even longer case would be needed for a longer bullet though; 35 Rem, 35 Whelen, etc would work, or maybe 41 Mag. (A bud was trying to determine headspace of loaded ammo to his rifle.)

I normally use a piece I machined that attaches to the caliper jaw, a lot like the Hornady tools; that's more convenient but a round piece of fired brass works too.

.32 ACP case works pretty well for .223.

I have a .25 saved back my future .204.

Rather than fiddling around adjusting dies for shoulder bumping/partial resizing or buying expensive specialty dies, just get a set of Skip’s spacers. Set up your sizing die for FL sizing then experiment with the spacers underneath the die’s lock ring. Start with a spacer thickness that won’t allow your bolt to close then gradually go down to a thickness that allows the bolt to close with a barely noticeable resistance. You can use the spacers singularity or in combination to achieve the desired thickness. This way, your never have to re-adjust your die for FL sizing when necessary and you’ve probably saved yourself a bundle of dough.
Works for me.😊

Sounds like a whole lot of fiddling around to avoid 5 minutes of setting up the die correctly to start with. I don't know why some guys have trouble with this concept: correct shoulder bump of a few thousandths IS full length sizing.

Actually the “fiddling around” is only when the proper shim is initially determined. After that there’s no more “fiddling” to be done. Just grab the pre-selected shim, drop it on the die and get to work.

Why bother to use a shim at all? Just set the die up right the first time.

For partial sizing the die IS set up right when you use the shim. For FL sizing it IS set up right when you don’t use the shim. No die adjustment necessary. Sorry if I didn’t make that clear.

What's apparently not clear to you is that bumping the shoulders back a couple thousandths IS full length sizing. It is not partial sizing. If you want to use a shim for partial sizing that works, but it's a different topic and not what we're discussing here.

Correct shoulder bump is NOT partial sizing. Partial sizing is when part of the neck is left unsized, and the shoulders are not bumped back at all.

I’m quite aware of the difference between bumping the shoulders and partial sizing. However, since people seem to have a lot of difficulty achieving the proper bump I thought I’d offer the Skip’s shims suggestion. The shims make it a lot easier to achieve a perfect fit.
I also realize that partial sizing some less tapered cases (IE: .243 win. and probably some of the newer short magnums) has been declared impossible by many as the partial sizing tends to push brass forward into the shoulder. That being said, I have used shims successfully in partial sizing .243, .308 and .284 Win. brass - although there might have a bit of shoulder bump. If that’s the case, it demonstrates that the shims can be used for bumping as well as partial sizing.

IME, what you’re calling ‘partial’ is generally called neck sizing. Partial FL sizing is typically considered to be bumping the shoulder, but not all the way back to SAAMI dimensions, while FL sizing usually means restoring body dimensions and headspace to SAAMI spec while also sizing the neck.

That’s a diplomatic way of clearing the air.😊 However, with partial sizing the die does come in some contact with the case body but stops a couple of thou short of touching the shoulder hence, it’s neither pure neck sizing nor shoulder bumping. Case lube is required whereas, with pure neck sizing it isn’t - other than using a (preferably) dry lube such as graphite on the inside of the case necks. If I choose to shoulder bump, a shim about .002 thinner than my pre-determined partial sizing shim Will generally do the trick.

With all of that said, if you're using an off the shelf FL die you're most likely sizing the neck section of the brass more than necessary.

You’re probably correct there mathman. Nonetheless, I still get nicely accurate and dependable ammo with the partial sizing. Also, excellent case longevity - although I don’t load to “burn, blind & deafen” levels and I anneal after every 3rd firing, which I’m sure helps with longevity.

That's mitigating the effect of cold working the neck.

No, that's never been the meaning of partial sizing as I've ever understood it or seen it used. Perhaps that's what some guys call it, but that's incorrect and misleading IMO. Sizing the shoulder to fit your chamber IS full length sizing - neck, shoulder, and body all get sized full length. Anything more is just excessive sizing (i.e. bumping the shoulder back too much causing excess headspace) and poor die adjustment, most guys just don't realize it. Just because your die is capable of being run down to the shell holder doesn't mean that is correct "FL sizing".

Neck sizing is a different thing from partial sizing the neck with a FL die. Partial sizing still reduces body diameter to fit the chamber easily while leaving an unsized ring of the neck to center the cartridge. The neck is only partially sized, hence the term.

Regardless, bobber257's idea of "less fiddling" is actually a lot more fiddling than just measuring and adjusting the die correctly.

I get what you're saying but I've always heard people use the term "partial neck sizing" to refer to, well, only partially sizing the neck leaving some of it unsized.

Whereas "partial FL sizing" refers to what that the others are saying, setting the FL die to just bump the shoulder.

Four terms to describe four basic ways to size, "neck sizing", "partial neck sizing", "full length sizing", "partial FL sizing".

I agree about setting up the die correctly in the first place, but this is the first time I've seen someone describe FL sizing that way. Pragmatically, the purpose of partial FL sizing has always been to tailor the case dimensions with a specific chamber in a non-interference relationship. The reason some people FL size (meaning to SAAMI spec) has always been to use the ammunition in various chambers that may vary somewhere between SAAMI min and max specs.

Your description of "partial" sizing also leave me a little confused, since IME when the FL die sizes the entire neck and approaches the shoulder, it begins sizing the body enough to stretch it so that you have negative headspace. Doing it that way, you'd likely be approaching a fine line between partial neck sizing and negative headspace. Personally, I prefer to do my partial neck sizing with a neck die, and then size the body and bump the shoulder with purpose every few firings.

Sounds like you've never done it that way. That method has been around a long time, I certainly didn't invent it. When the die is backed off 1/8" or so to leave part of the neck unsized, the shoulder isn't pushed forward to any perceptible amount. Pretty easy to measure if you don't believe me. With most cases the shoulder doesn't move forward until the die is pretty close to bumping (maybe half turn of the die, give or take). Obviously it's not a techique to use in semi-autos but it works well in bolt actions.

I’ve done it that way with a FL die before, but I call it partial neck sizing, and these days I prefer to do it with a neck die. I see what you mean about minimally sizing the body, but don’t see much benefit in it. IMO if the body needs to be compressed, I want to bump the shoulder as well.

IMO partial neck sizing indicates using a neck sizing die to partially size the neck. Partial FL sizing is doing the same thing with a FL die. Partial sizing with a FL die holds the neck centered as it's sized, while a neck die does not.

Seems to me the definitions some of you guys are going by are pretty arbitrary. Is bumping the shoulders for a tight chamber still "partial" sizing? What about when it's tighter than SAAMI specs, is that still partial sizing if it's set to match the chamber? Or, if we have to set the brass back to SAAMI spec to consider it FL sized, how many of you actually measure that, vs just screwing the die down to the shellholder? I think this whole discussion is based on a common flawed perception of what FL sizing really is and how to do it correctly.
There is nothing "partial" about FL sizing cases to correctly fit your chamber, whether that's one rifle or several, or whether that happens to be at standard specs or a few thousandths on either side. The arbitrary distinction of calling a correct die adjustment "partial" and screwed to the shell holder "full length" is a bit absurd in my opinion.

Quote: “Regardless, bobber257’s idea of “less fiddling” is a lot more fiddling than just measuring and adjusting the die properly”.

Well, if Yondering (in his infinite wisdom) thinks that quickly and easily using the shim method for various tasks is more fiddling than re-adjusting your die for each task (IE: shoulder bumping, full length sizing to origional specs, or partial sizing (partial neck, partial body or whatever semantics you choose) then, so be it. The system has worked for me for years and will continue to work. (with minimal fiddling😁)

I can see where you’re coming from, but the definitions being used are due to common convention. A SAAMI adopted case starts off at SAAMI dimensions. Sizing it only partially back to its original spec, but more than the neck (differentiating it from neck sizing), is typically called PFLR. This includes your example of sizing down further than SAAMI as well, IMO, since FL sizing implies SAAMI spec, which means that it can be used safely in any SAAMI chamber. Don’t make the mistake of thinking you’re the only guy on planet Earth who measures things. I’m sure not everyone does, but SAAMI means SAAMI.

Commonly used arbitrary definitions are no more absurd than your arbitrary definitions. Being common practice means that most people understand each other when using the prevailing terminology.

In any case (pun be intended), you know what they say about opinions...

What you're saying would be correct if the common definition of full length sizing meant bumping shoulders back to SAAMI spec, but it's not. That would require measuring shoulders at a specific diameter and comparing to specs for that cartridge, which most people don't do and is definitely not the "common convention". Instead, the common interpretation of full length sizing is just screwing the die down to the shell holder, which in most cases is NOT bringing cases back to spec but something less, often .010" or even .020" below spec. I'm sure most people think that brings their brass back to correct spec, but it does not in most cases. Of course most people using that method don't measure it, and don't realize the dies are setting shoulders back a lot more than needed. Factory ammo and new brass is usually sized somewhat below spec as well.

Bumping case shoulders back to fit a chamber in most rifles is very close to SAAMI spec, usually within a few thousandths; it's usually closer in my experience than what you get with the die down the shell holder. That is where our interpretations differ. What you're insisting is "partial sizing" is actually correct adjustment for full length sizing (whether that is adjusted for SAAMI spec or to fit a specific chamber, very similar either way), rather than excessive sizing. Obviously there are exceptions that go either direction; I've had some setups where setting the die to cam over on the shell holder was correct, and others where a loose chamber needed the die backed off more than spec, but those are exceptions.