Here to ask the experts about head space.........


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duck911
October 1, 2011, 10:05 PM
Hi all!

Having a few conversations on other forums about head space in a .260 Savage I just built. There is a lot of conjecture, plenty of guys saying "just buy the Go Gauges" and others who think my logic is flawed.

As I am new to the headspace game I thought I'd ask you all since this in my experience is the most knowledgeable group of reloaders in the internet.

So to start: SAAMI minimum head space for the .260 is 1.630. Maximum is 1.640. That much I know. And as a reloader exclusively, and never intending to shoot factory ammo in this gun, I suppose I really don't care!

Instead, using my Hornady headspace bushings, I properly measured a piece of 7MM-08 brass that I resized down to .260 from the head stamp to the datum line (for the uninitiated, the tools are BUILT to do this).

My brass, sized by my dies sized down to 1.620. I then headspaced my Savage build to this piece of brass, making it so I have slight tension while closing the bolt.

2 pieces of tape on the end of the brass makes it 1.625. Again, measurements made using the bushings and my micrometer. The bolt BARELY closes with force on this piece of brass.

In my mind, I made my own go and no-go gauges. As I plan on always FL resizing my brass using those dies, and will NEVER use factory ammo, I think I am good to go.

Seem reasonable?

--Duck911

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243winxb
October 1, 2011, 11:01 PM
I properly measured a piece of 7MM-08 brass that I resized down to .260 What was the measurement before sizing? Was the 7mm-08 new brass or fired? Its odd that your die would push the shoulder back that far. ( 1.620") The minimum is 1.627" when looking at SAAMI. http://www.saami.org/PubResources/CC_Drawings/Rifle/260%20Remington.pdf

243winxb
October 1, 2011, 11:14 PM
I am no expert, but i think it should not be done this way. :scrutiny: I set my rifle barrel on my action with new Lapua brass.http://forums.accuratereloading.com/eve/forums/a/tpc/f/2511043/m/5491033361

gamestalker
October 1, 2011, 11:30 PM
Maximum head space variance is to be no more than .006" off zero. In other words, the variance or run out between the go and no go gauges is never more than .006". But .006" is the maximum allowable run out and would be considered a bit too much for most taste.

Although many reloaders including myself, are loading and shooting high powers that are well beyond the industry standard of .006". But those are exceptions, not the optimum standard. Building one and not making certain it is as tight as can be, defeats the whole concept of the term "custom rig" in my opinion.

If it was my build, I would want to build it as tight head spaced as possible. This is one of the most important integrities of any rig, especially high operating pressure cartridges like this one. I would spend the money, go, no go gauge it at the very least. Other wise you may find yourself trying to figure out why your brass is doing unusual things.

duck911
October 1, 2011, 11:53 PM
What was the measurement before sizing? Was the 7mm-08 new brass or fired? Its odd that your die would push the shoulder back that far. ( 1.620") The minimum is 1.627" when looking at SAAMI. http://www.saami.org/PubResources/CC...0Remington.pdf

First, I am confused because nowhere in the SAAMI spec I am looking at does the number 1.627 exist. ( http://www.saami.org/PubResources/CC_Drawings/Rifle/260%20Remington.pdf )

But the whole point of my post is, this should only matter if you're planning on firing factory ammo, and I am not.

--Duck911

duck911
October 1, 2011, 11:57 PM
If it was my build, I would want to build it as tight head spaced as possible. This is one of the most important integrities of any rig, especially high operating pressure cartridges like this one. I would spend the money, go, no go gauge it at the very least. Other wise you may find yourself trying to figure out why your brass is doing unusual things.

Thanks Gamestalker...

I am curious about your statement, because it seems to contradict the idea of a tight head spaced chamber on a custom rifle.

If you want "as tight a headspace as possible", wouldn't you headspace off a FL resized piece of brass from your own dies?

It seems to me (and is the main point of this post) that sizing to SAAMI minimum spec, defeats the purpose if you know right off the bat that your brass, sized in your own dies, is significantly shorter than from breech face to datum line than the minimum spec.

I'm not arguing, just trying to understand :o

--Duck911

243winxb
October 2, 2011, 12:16 AM
My point is , did your die push the shoulder back on sizing? If it did, you are OK. A fired case will at times get shorter on firing, giving a false reading. On FL sizing, the body must be sized smaller to push the shoulder forward. First, I am confused because nowhere in the SAAMI spec I am looking at does the number 1.627 exist. The cartridge drawing lists length to datum line of 1.6340" - .007" this = 1.627" But the whole point of my post is, this should only matter if you're planning on firing factory ammo, and I am not.
Yes i get that. Just make sure your FL die has pushed the shoulder back on the sized case.

fguffey
October 2, 2011, 12:53 AM
Duck, the term and concept of head space is owned by a very large group of possessive reloaders? I make go, no and beyond gages from a go-gage, I check chamber length as in 30/06 with a field gage, I check head space with a feeler gage. I make 26 head space gage in thousands from +.012 to shorter than a minimum length case to +.014 thousands longer than a minimum length/full length case and I can check head space on a 30/06 with a 280 Remington case and everyone knows the bolt in a 30/06 chamber will not close on a case that is too long for the chamber.

I am interested in knowing what you refer to as being a collar.

I am sure the Savage’s adjustable chamber has been discussed, I do not shoot gages I shoot ammo, none of my chambers are adjustable, for that reason I adjust the length of the case, the rest of the head spacers chamber a round, pull the trigger and become fire formers, I form first then fire, that gets me once fired cases, and I make datums, I collect datums and I purchase datums, the rest of the head spacers draw little lines with arrows, like it is right there.

F. Guffey

fguffey
October 2, 2011, 01:01 AM
"A fired case will at times get shorter on firing, giving a false reading"

It does not happen, it never happens.

Who measures before and after? I do., It did not happen to Hatcher, it did not happen to me when I fired 8MM57 AMMO IN A 8/06 chamber, and, I do not believe you are going to ask me why, Hatcher had .080 thousands head space, I had .127 thousands head space, but then I am not one of the possessive head spacers.

F. Guffey

bigedp51
October 2, 2011, 01:24 AM
duck911

Minimum headspace is 1.630, if you set your headspace below this you run the risk of your resizing dies not being able to push the shoulder back far enough when you full length resize your cases.

If you set your headspace below 1.630 the only way you will be able to resize your cases is if you make your shell holder shorter than .125 and that means turning it in a lathe or lapping the shell holder.

Your modifying your rifle to fit your cartridge cases when you should be fire forming your cartridge cases to fit your rifle.

My Stevens 200 is .002 over minimum headspace and I wouldn't think of touching the barrel nut. You are making the same mistake many of the "Brotherhood of the Nut" are making and that is setting your headspace too tight. The last person who did this next question in the forum was asking why his cases wouldn't fit his chamber when he full length resized them. (because partial resizing makes them longer)

You have chamber headspace standards for a reason and you have reloading dies made to standards. If you change the rules, you may not be able to play the game due to equipment failure.

Don't ask me how I know all this, BUT this shell holder is .004 shorter than normal standards for a rifle .002 "under" minimum headspace. ;)

http://i122.photobucket.com/albums/o254/bigedp51/IMGP6943.jpg

Walkalong
October 2, 2011, 10:29 AM
The last person who did this next question in the forum was asking why his cases wouldn't fit his chamber when he full length resized them. (because partial resizing makes them longer)
Improperly partially full length sizing can make them longer. Properly PFL sizing bumps the shoulder at least.001. Partial full length sizing is just FL sizing to the mimimum. At least keeping the shoulder where it is, or bumping it back .001 or so. (.003 max in my mind)

But yes, until the die shoulder contacts the brass's shoulder inside the die, the case's shoulder is farther forward (longer) because the sides have been squeezed in and the shoulder has been pushed forward. A mistake that many have made because they never measure anything.

I am starting to find it irritating when f guffey jumps in and criticizes all of the "ignorant" "internet" reloaders just because they may not do things like he does. There is more than one way to skin a cat, or measure things.

fguffey
October 2, 2011, 02:41 PM
"I am starting to find it irritating when f guffey jumps in and criticizes all of the "ignorant" "internet" reloaders just because they may not do things like he does"



"ignorant" "internet" Had I said that.....? Ignorant is simply not knowing, happens to the best, the ones I have sympathy for are those that choose to remain that way.



"Improperly partially full length sizing can make them longer. Properly PFL sizing bumps the shoulder at least.001. Partial full length sizing is just FL sizing to the mimimum. At least keeping the shoulder where it is, or bumping it back .001 or so. (.003 max in my mind)"



So I will ask you how do you adjust the sizer die to bump? .001, .002, .003 or even .004, when I starting irritating reloaders on the Internet they were making wild guesstimates of a turn in degree or fractional turn of the die, like back the die off 1/4 of a turn, now that I have your attention, apply that answer to the answer you just gave,



Datum line, after all these years 'line' has been replaced with an arrow, again a question has been asked, the person asking has participated on other forums, again, there is the vain attempt to vie for attention, me? I believe the person asking the question should get the best possible answer, if that irritates you improve your answers, my sympathy does not not extend to the person that does not know, my sympathy goes out to those that refuse to know and or does not want to know.



Again, how do you adjust your die, go back and search the archives,, 1 turn = .7142857, why bother, I suggested if the adjustment is critical, verify, if the re loader is going to verify, go straight to the verifying tool the feeler gage, the standard, the transfer, the companion tool to the press, the feeler gage, still some choose to know, others refuse to make an attempt.



F. Guffey

fguffey
October 2, 2011, 02:52 PM
In the best interest of the person asking the question I suggest grinding the shell holder and or die is a bad habit, anything that is accomplished when compromising the integrity of the die
or shell holder can be duplicated with the companion tool to the press, the feeler gage, if the reloader insist on grinding use the feeler gage to determine the amount of material removal required.



Again, the feeler gage when adjusting dies can save the reloader $40.00 dollars when considering purchasing Redding Competition shell holders, the feeler gage gives me 10 options between .000 and +10, Redding shell holders offer 5, and for those that measure before and after, there is a good chance at least three of the Redding shell holders are off .001, for me? That is not a problem.



F. Guffey

Walkalong
October 2, 2011, 03:50 PM
So I will ask you how do you adjust the sizer die to bump? ................ making wild guesstimates of a turn in degree or fractional turn of the die, ..........................Again, how do you adjust your die, go back and search the archives,, 1 turn = .7142857, why bother, I
You know that I do not "turn and guess" as you say. I measure everything. You know that, as I have posted how I do it. ;)

I have never said your way is wrong. I have only posted how I do it, which is the same way thousands of reloaders do also, and is taught in load books. You are the only one who seems to have a problem with folks who do not use feeler gauges to do it. One point though, feeler gauges do not take into account brass spring back if you only check against the die and shell holder and do not check the sized brass.. :)

fguffey
October 2, 2011, 05:38 PM
Duck, I said I make datums, I also said I use datums, I said I purchase datums, that statement does not get the attention of the ignorant on the Internet, I mention datums because you listed 1.630, 1.640, 1.620 and 1.625, the first answer you received was DATUM like you either understood the meaning or should know the meaning or the person giving the answer is repeating something they read on the Internet.

The datum, outside of reloading is ‘MEASURED FROM’, for a reloader understanding ‘measured from’ is complicated when the ‘measured from’ is measured off of a tapper like the shoulder or case body. A cylinder that is tapered is a cone, the cone has varying diameters, the 308 W datum is .400, again the datum is a round hole, the hole for the 308W is .400. There are a lot of tools that are manufactured using the (Datum) round hole to take measurements, all the measurements you listed 1.630, 1.640, 1.620 and 1.625 are to be taken from a datum of .400, most purchase comparators, some comparators are incorrectly listed as being a head space gage, I refer to the tools sold to measure case length from the head of the case to the shoulder as nice, not necessary, just nice. That assessment of being nice and not necessary changes for those that can not drill a hole or measure the diameter of a hole.

The datum on the taper of the 308 W and .400 diameter of the hole: The .400 is (for me) arbitrary, there is nothing written that says I must choose SAMMY'S specifications as in using or choosing the .400 number, Again, I am not a fire former, I form first then fire, when measuring the length of a case from the shoulder to the head of the case I can use any diameter between the shoulder/neck juncture and the case body/shoulder juncture, the 3/8 (.375) diameter round hole for the 30/06 works, all the reloader is required to do is measure before and after using the same datum/round hole.

After forming a case that chambers measure the gap between the shell holder and bottom of the die can be measured with a feeler gage, the measurement can be used to verify sizing cases for that chamber.

F. Guffey

bigedp51
October 3, 2011, 01:51 AM
Walkalong

I am starting to find it irritating when f guffey jumps in and criticizes all of the "ignorant" "internet" reloaders just because they may not do things like he does. There is more than one way to skin a cat, or measure things.

"Feeler gages? We ain't got no feeler gages. We don't need no feeler gages! I don't have to show you any stinkin' feeler gages!"

http://www.youtube.com/watch?v=nsdZKCh6RsU&NR=1


http://i122.photobucket.com/albums/o254/bigedp51/7-17-201055522PM.jpg

http://i122.photobucket.com/albums/o254/bigedp51/7-17-201054345PM.jpg

http://i122.photobucket.com/albums/o254/bigedp51/7-17-201054719PM.jpg

"Feeler gages? We ain't got no feeler gages. We don't need no feeler gages! I don't have to show you any stinkin' feeler gages!"

http://i122.photobucket.com/albums/o254/bigedp51/IMGP4385.jpg

Funshooter45
October 3, 2011, 04:55 PM
In the products above, the shims are pretty much the equivalent of a feeler gauge set. The Redding shellholder set is a very expensive way to do the same thing as a $6 set of feeler gauges. Actually, I do use the feeler gauges and they work perfectly to adjust the amount of sizing I want on the shoulder. For $6, I can use any combination of feeler gauges to get a limitless varaiation of sizing.

One thing though, fguffey mistakenly said that one turn of a standard die is .7142857". Well, just to clarify for any who are considering these pointless discussions and are confused, one turn of a die actually raises or lowers the die by 0.07145827". Simple typo for sure, but it's important for someone thinking about it for the first time. And whether you use feeler gauges or some other method, it is important to consider the precision and repeatability of your adjustment. If you want to push the shoulder back by exactly 0.002", not 0.003" or 0.004", you need some way of dialing that amount in. One turn of a die as previousl mentioned is 0.071". So a half turn is 0.036", and a 1/4 turn of the die is 0.018". So, a mere 1/16 turn of the die is 0.0045". Who can tell what a 1/16 of a turn is? And that gives you 4 thousandths difference.

fguffey
October 5, 2011, 09:20 AM
Funshooter, forgive, you are correct, and it could/should be pointed out Skip’s shims require the die to be removed from the press when adding or removing shims. If in my possession there is a die with the lock ring secured to the die...it is not my die, I adjust my die every time. Back to Skip’s shims and the reloader that purchased them, after setting up the die to .000 and shims are added the reloader could/should verify the adjustment with a standard (the feeler gage is a transfer and a standard). Back to wild guestimates, guestimates can be used if verified, And that brings up the most difficult technique for a reloader to understand, why make an adjustment then take the time to verify with a feeler gage? Logic says skip (pun intended) the guestimate and go straight to the transfer/standard/verifying tool, the feeler gage. Again Skip’s shims require the removal of the die, so to help Skip I suggest the reloader use a feeler gage first to determine the ‘off the shell holder’ adjustment THEN! remove the die to install shims ONCE.

Or as suggested, mindlessly grind the shell holder and or die, again.

1858 purchases a set of the Redding Competition shell holders, bless his heart, those things locked him up, as I said do not be surprised if at least three are off by .001 thousands.

Duck, I said ::Duck, the term and concept of head space is owned by a very large group of possessive reloaders?”
Some are possessive, then there are those that are obsessed,

http://forum.accurateshooter.com/index.php/topic,3754346.150.html

Head space and fire forming and the slide and glide shooter,


http://www.odcmp.org/1101/can.pdf

Funshooter, good to hear from you.

F. Guffey

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