I'll start with some background as i am new here. My name is Mike and i am 38yrs old. I started reloading when i was 4 running a Lubrisizer for my grandfather. He was teaching me to reload and it gave us time together. I am a very good shot and i guess i made grandpas work shine at the Houghton Lake Sportsmans Club, MI. Well he tought me to reload about every pistol cartridge there was and how to mould my own bullets etc. I started to chase women and sports in high school and kinda put off shooting a little and never got the chance to learn about the rifle cartridges much as when i was 17 he passed away. My knowledge base is gone and i'm looking for some help which led me here. I have been shooting factory loads in my rifles for 20 years and i want better. I own a Sako 85 stainless synthetic in .308, two Sako 75's in 270 WIN and 300 win mag. I read and read about headspacing and i just don't understand. I have Remington once fired cases from my rifle, if i full length resize them, they get a few thousandth longer. I keep hearing people refer to (bumping the shoulder back)to adjust the headspace. How is this possible with a standard die? If i resize in my rcbs full length die, the case gets longer. Doesn't that in turn by the added length move the shoulder forward minimizing headspace? Sorry for the long post, i forgot my equipment, I own a RCBS Jr single stage, pacific 007 single stage, new rcbs case trimmer, rcbs partner digital scale, hornady beam scale, all the dies, lyman 55 powder measure, pacific deluxe powder measure and a dillon tumbler. whew

Not sure what the distance is from the bottom of a 308 case to the middle of the shoulder but lets say it is 2.000". Lets say your chamber dimension is 2.005". Lets say you fire your virgin brass and it grows from the pressure to 2.004. That empty casing still chambers like butter in your gun. Now you resize it and by "squeezing the case" in the sizing die it now grows to 2.006". All of a sudden that casing won't fit the chamber any more. You now have to keep turning the die down in tiny increments so that it bumps the shoulder back under 2.005" or you can't chamber it properly.
Ea full turn of a die is about .072" so just a small 1/32 turn is worth about .002" of bump.
I highly recomend you get yourself the hornady headspace measuring tool with bushings to fit almost all casings so that you can see how your brass grows.....how your sizing die is working....and how much headspace your chamber has. It's about $35 and really works nice.

Thank you, that was explained really quite well sir. I am working on getting the headspace equipment. Doesn't bumping the shoulder back produce a bulge or crease in the case or make a weak spot? It has to displace the brass somewhere i would think? When you read die instructions it just says run the die in till it touches the case holder when it's at the top of the stroke, then lower the handle and add 1/8 to 1/4 turn and tighten lockring. It doesn't say a word about adjusting the die to correct headspace or anything like that. You would think they would as that is one of the most important aspects of the process to prevent case separation.

quote:

Originally posted by icemanls2:
I have Remington once fired cases from my rifle, if i full length resize them, they get a few thousandth longer.

When you say "they get a few thousandth longer", do you mean the case as measured from the case head to case mouth?? If yes, that has nothing to do with "headspace" - or better "head to shoulder" - dimension.

To measure this dimension, you need to measure from case head to the "datum line" on the case shoulder -- a task most easily achieved by getting the Hornady Head Space Gauge Kraky recommended.

quote:

Doesn't that in turn by the added length move the shoulder forward minimizing headspace?

Yes, but then you turn in the die JUST enough for it to "kiss" the case shoulder and that compensates for the shoulder moving forward.


As you correctly surmise, the head to shoulder dimension of a fired case will also grow as you size the case, until you have turned the die far enough in to compensate for this lengthening effect. Exactly at what setting of the die you get the desired effect of a shoulder "bump" of .001" - .002" is best established with the Hornady Head Space Gauge as well.

There is a bit of a religious discussion on this site, whether the correct shoulder bump should be detemined with this gauge, or whether "feel" upon chambering a sized case is sufficient. Let me stay out of that discussion, but just say, I use a gauge to quantify my shoulder bump and feel safe and happy with this method.

- mike

Yes i mean the entire case gets lengthened from the case head to mouth. I didn't understand that you could screw the die in in small increments to bump the shoulder back to it's original position. It is becoming much clearer to me now. Alot of times people explain things in a fashion that they assume you should know all these little details that may not be so clear. I must say i can't beleive the promptness in which people reply on here. I am very impressed thus far. Thank you guys for your time. I will be experimenting very soon with my headspace guages when they get here. I am curious, is the headspace procedure the same for belted cartridges like the 300 WIN mag?

quote:

Originally posted by icemanls2:
Doesn't bumping the shoulder back produce a bulge or crease in the case or make a weak spot?

Nope, but the total length of the case (measured head to mouth) increases (as a result of the complete resizing operation, including shoulder bump).

quote:

When you read die instructions it just says run the die in till it touches the case holder when it's at the top of the stroke, then lower the handle and add 1/8 to 1/4 turn and tighten lockring.

That recommendation is general, in that it does not attempt to make your sized cases headspace on the shoulder - i.e. shoulder bump of .001-.002". The general die setting recommendation just assures the case will (normally) be able to rechamber.

As you have discovered, this is not the ultimate die setting - but to achieve that, you have to set the die according to the chamber in which you fired the brass (see above).

Note: once a sizing die is set up for minimal shoulder bump, you really need a die per chamber and also keep the brass separate for each chamber. That is, unless you are happy to re-adjust your die again every time you want to reload for another rifle in the same caliber.

The brass needs to be kept separate as there is no guarantee that brass sized for one chamber will fit in another, or (even worse) not have too short a head-shoulder dimension for the other chamber. Dangerous situation leading to head separations. I use brass headstamped differently for different chambers, makes it easier to keep brass separate.

- mike

quote:

Originally posted by icemanls2:
is the headspace procedure the same for belted cartridges like the 300 WIN mag?

Yes.

With belted brass in particular, ensuring that sized brass headspaces on the shoulder will increase your brass life. Chambers for belted cases are often on the large side, so headspacing on the shoulder ensures you have sized the case minimally.

- mike

That makes so much sense now. My wifes grandfather reloaded and he died in 1975 and his room was untouched till this year when her grandma passed. When i went in there he had probably 5 or 6 sets of .308 dies, 2 or 3 sets of 300 win mag, loads of 270 dies. i could not figure out why he had so many die sets for. I get it now, so he didn't have to readjust them for each rifle chamber like you said. He also had a boatload of i believe L.E. wilson headpace guages, the solid tube looking kind. Do those work to do what i need or should i just buy a full new set of hornady's?

Mike, I have never used the Wilson gauges, so we will let somebody else educate us on those.

It is indeed very likely that your wife's Grandpa had a set of dies for each rifle/chamber. I do too. I even splash out and get a seater for each rifle as well - just because I prefer not to have to readjust my dies more than necessary.

The only sizing die you can easily share between rifles (of identical caliber) is a neck sizing die - as long as you make sure the die setting for brass fired in rifle A does not push back the shoulders of brass fired in rifle B.

- mike

O.K. I had to make this simple for a bunch of paper pushers, so I did and they hated me more. Life? Yeh...
#1). Guns go bang? Right!
#2). Guns go bang when the firing pin strikes the primer? right?
#3). "HOW" the primer is supported against the blow of the firing pin is "headspace."

The rest is details. Obviously, .38 Special or .30/30 rifle --"rimmed cartridges", the rim of a "rimmed" cartridge stops the case into the chamber and supports it. While we are here, "belted", the H&H people anyway had trouble making rims feed from the magazine (and cases were made from brass, no longer the soft, pure copper of buffalo days) so they moved the headspace point to a rim ahead of the extractor groove--a belt. That was with the funnel shaped cartridges, .300 H&H etc. When they started putting shoulders on the belted rounds they headspaced on the shoulder (per Mr. Ackley).

Odd ones out... .45 ACP, .30 Carbine, headspace is on the mouth of the case. Case length is critical.

And, Mr. Mauser just discarded the rim concept altogether. He specified that the cartridge headspace on the junction between the body and the shoulder.

One exception here. Uncle Sam was trying to make a bolt action rifle (1903 Springfield) without paying royalties on Mauser patents. Yeh. SO the .30/'03 and the .30/'06 were designed to headspace on a point one half way between the junction of body and shoulder and the neck and shoulder... called "datum line." The .27/'06 (better known as the .270 Winchester) also uses this abberaation... Mauser sued. Uncle Sam lost and paid royalties to Mauser until WW I started... (ha, ha, ha).

You mention cases lengthening. O.K. SAAMI (Sporting Arms and Ammunition Manufacturers Institute) specifies that all factory ammo be slightly "less big" than all factory chambers. You fire a factory round and it "grows"/ expands to fill the slightly larger chamber. You shove it into a die to reduce the neck to a tightness that will hold the bullet and it gets a trifle longer. So trim the neck.

Bolt actions have leverage closing of about 15 to 1 by some sources. So you don't have to resize down to the factory "small" size. Gets you slightly more powder space and works the brass less-longer case life. "Neck sizing" called as a rule.

Lever actions, pumps and semi autos don't have this ability and you might need small base dies to be sure your ammo will feed.

Each gun is a law unto itself and you need to experiment to get the best from the gun you have, the main purpose of reloading. When you consider all the tools, it don't save no $$$.

Wouldn't hurt you at all to buy up 5 or 10 used reloading manuals at a gun show and read them all a couple times. One will "read easier" than the others and you might buy a brand new one of that brand for current powder data. (Or look online). This is not complicated but it is "life and death" in the extreme goof ups. Study until you get it.

The other "faux paux", often a shooter will use a different brand of shell holder with a different brand of dies. No big standards here. You might set the shoulder back too far... Might. And there are many stories of rifles with a little extra headspace and the reloader just didn't move the shoulder, only neck sized. Works but a bit risky. You life... LUCK.

Thanks for all the information, you guys are great! I actually have the Hornady handbook 3rd edition on my lap as i write this, i also have Handloaders digest sixth edition, Lyman pistol and revolver 2nd edition, and several loadbook USA individual caliber books. I'm looking for a good new manual. I hear the Speer 14th edition is good, anyone have knowledge of this new manual or recomendations on a good one? I have been loading pistol rounds for a long time as well as AA shotgun loads on my MEC Grabber. I pay great attention to detail and won't attempt this until i am confident i fully understand everything. This may help, i tried twice to go to the Navy to be a Seal. I fragmented my left knee ( broke into about 15 peices)when i was younger. I was turned away twice by recruiters because of the knee i never had another problem with. This was before Desert Storm. I was very disappointed as i trained for 4 years cause i knew what i wanted to do. Thanks again for the help.

Mike,

It is always nice to have more reloading manuals. But don't expect that buying more will enlighten you in the sense of explaining the setup of a die for minimal shoulder bump. Most (all?) manuals target an audience of the "average" reloader - in terms of sizing, a person who wants his sized cases to rechamber, and possibly even in multiple chambers, and be done with it. Nothing necessarily wrong with that, we all establish our own goals for shooting and reloading activities.

If you are looking for more "advanced" reloading techniques, you need to look for other sources. There are Internet forums such as this one - where I picked up a bunch of information when I changed my attitude to reloading.

Then there are books such as Glenn Zediker's "Handloading for Competition" - giving a very personal but also comprehensive overview of various reloading tools and techniques. That book is a bit wordy, but if you can live with Zediker's style, he sure offers a lot of information.

Fred (?) Sinclair and others once published a small book about reloading for accuracy, I think it was called something like "Precision Reloading & Shooting Handbook". I have a feeling it might be out of print, but maybe you can find a copy or your local library may be able to help. That was an excellent introduction to precision reloading techniques, and covers die adjustment for minimal shoulder bump.

Stay with rifle reloading, educate yourself via the sources available, gain experience, and in just a few years you will be the one offering advice for die adjustment to new reloaders here...

- mike

I always forget the "technicals." Gettin' old.

The maker/gunsmith uses two gauges, maybe three.

When first fitting the barrel he (she???) uses a "no-go" guage. When the "fit" is tight on the "no-go gauge" then switch to "go" gauge. This fit --not too tight on the "go" gauge-- will mean that the factory chamber will accept all factory loaded ammo. No secret, shooting/working the mechanism will loosen up the mechanism, "seat threads," etc. Take a "no-go" gauge to a used gun supply and test the rifles. [Same gauge works for .243, .308, 7/06, .260, .358 WCF etc.] Most well used factory rifles will take a "no-go" gauge. It is a "makers tool." Factory brass is designed to allow this amount of stretch in first firing. Returning it, the brass, to factory dimensions works the brass and hardens it and cuts, slightly, the powder capacity, thus "neck sizing."

Military uses another gauge, the "field gauge." It indicates a chamber "way" too long. In fact there is a chance the firing pin will not reach the primer and fire the gun. Bad news for the soldier boy with that rifle and someone shooting at him. The fact the case may fail and release hot gases is of lesser concern, soldiers are considered "expendable."

Bottom line, your modern rifles work at gas pressure of 55K CUP. That equals gas temperatures of 4,000 degrees. I forget if that is F or C. Don't care. Cutting torches work in the 2,000 degree range. Your "bacon" rides on the brass bottle/case containing this gas for long enough the bullet leaves, pressure drops and temperature drops too. Bottle leaks and the locking lugs of the rifle, mere steel, subjected to 4,000 degree temps... "hot knife thru butter."

This is why Springfield and other have a lame little "tit" of metal back opposite the bolt handle and closing into a groove locking the action tooooooo. However small, it is far enough back to probably not be subjected to the temps of hot gas and "give." PROBABLY. (LOUSY bet.)

Then there is the problem of bits of things, metal, brass, powder, etc. coming back... That is into your face... (Wear shooting glasses, please)... Yup, headspace is worth understanding.

I suggested buying multiple books because some authors are just easier to read for some readers. Or the layout. Find the one you like best and keep the others for reference/ cross reference. Cannot have too many. Once in a while there is an error. One book says 70 grains of a powder and two others stop at 59 grains... The extremely young and foolish assume the 59 grain loads are in error. Like that. Happy Trails. Luck.

Gauging Success - Minimum Headspace and Maximum COL Brownells

While all of the above is true and quite usefull, the problem here may be a little more simple. Every RCBS full length sizing die I have used stretches the brass because it is using a pull through ball expander that is knurled. They grip to the inside of the case neck when you are pulling the case out of the die. This is the reason I quit with their dies, added more work into my process.

Ammo Troop
You need to go back and examine your RCBS dies more. The knurling touches nothing.....
The knurling is smaller than the expander surface.

Like many "older" shooters I am cheap. That said I have recently learned alot by watching my reloads dimensional changes more closily. For headspace on the .308 family of cartridges I use a nice round spent .40 cal pistol case, and for .223's a .32 ACP works wonders. How you ask... By measuring the total of that case plus the .308's case when put mouth to mouth. Granted it is an arbitrary number, but the difference between a virgin case and a fired case, and a resized case will tell you how much you are moving the headspace back, or not.

Works for me.

quote:

Originally posted by SR4759:
Ammo Troop
You need to go back and examine your RCBS dies more. The knurling touches nothing.....
The knurling is smaller than the expander surface.

Can't do that as I am deployed at the moment but I'll take your word for it. Even if it does not touch, the expanding ball being pull back through the case neck will stretch the case. I first noticed on an -06 I had that seemed to grow quickly. Then when I bought a 22-250 I noticed it as well. Measured a fired case that was shorter than max length, ran it theough the die and it came out over the limit.

His original post read "I have Remington once fired cases from my rifle, if i full length resize them, they get a few thousandth longer. " The reality is, his problem has nothing to do with the rifle or any other guage. If his cases are growing during resizing then it is because the expander ball is stretching the case as it is being pulled back through the neck.

This looks like an option to me.
I've got one on order.
Digital headspacing gauge.
http://www.larrywillis.com/

quote:

Originally posted by icemanls2:
I hear the Speer 14th edition is good, anyone have knowledge of this new manual or recomendations on a good one? ..

Hey iceman, I have one of those and it has a lot of new Cartridges listed in it, which are not available in the old Manuals.

One particular thing caught my attention in it was they had "Reduced" the Powder for the 444Mar, because Marlin introduced their new Stainless and Laminated XLR Model with a slightly Faster twist Barrel. As luck would have it, I'd swapped an older(Slower Twist) 444Mar Guide Gun in on a new XLR. The MAX Loads for the XLR are the same as the Starting Loads in the older Manuals. And, surprise-surprise, the new Speer #14 Manual was right on the nose saying those Loads were now MAX in the XLR.

So, I'm a proponent of spending money on Manuals. Old ones are good for some rifles and new ones are better for some others.
-----

As far as your fretting over the Headspace issue, I'd encourage you to "try" two things before totally wasting money on any of the Headspace Measuring Thingys. If you are shooting a Bolt Action Rifle, try P-FLRing your cases. You don't need to buy a thing to use this Method if you already have a Full Length Die set. You get the best fit for your chamber possible and there is no "Thingy" to keep confusing you with different readings on the same Case.

And when you get ready to begin Seating Bullets, try converting OCL to ODL. Here you only need a regular old 0.001" capable Caliper, which any Reloader should already have. But if not, they are very inexpensive.

Best of luck to you.