Head space

[MikeCTX]

Same way I did mine, including using the gauges and tape. One hint, don't do what I did last weekend - had some loads that were showing me pressure signs (bright marks and tight bolt - found the issue) but was afraid I might not have gotten the headspace correct so tried the go gauge again - good idea, but I had forgot to take the tape off and when the go gauge would not close, figured I had messed up and took the rifle apart and re-head spaced it again. Then found the tape....good practice but gave me a little fright at first.

BTW - problem was dumb one, had just a bit of Imperial wax from sizing on a few cases, it seems to be what caused the issue. The cases in question all felt 'wet' after firing and seem to have a film on them when I resized them. Like I said dumb mistake and I was lucky. Lessons learned the hard way make a BIG impression.

[possum1]

Bet it was easier to get apart the second time or was it a factory assembly ?

[319]

I finally put my first Savage together last night. 6.5X284 on a Mod 12 action. I watched the vids(Thanks for posting those links!) and every thing went very well. The tape worked like a charm. I wouldn't have believed it would keep the bolt from closing unless I had seen it!! Now I have to suffer through waiting for brass and dies. Soon the Mod 12 will be a 260(when McGowen trades me 1:8 I ordered for the 1:9 they sent!) and the 6.5 will be on a Mod 112 in a Joel Russo stock that he did for me last year. I can't wait to get out shooting!

[Pete K.]

Hey Ace,

Does that avatar of yours look just like you?

If Ace says "yup" then I have a dog for him...

[img width=600 height=354]http://img.photobucket.com/albums/v64/pdexter46/TNBIRDDOG2.jpg[/img]

Just funnin' you Ace and no harm intended. But seriously... about your avatar..???

Pete ;D

[Dirk]

Good one Pete! ;D

[~Ace~]

NOT Cool to be postin a mans Dawgs without Askin !

[possum1]

That just aint right ;D

[bigedp51]

After reading this posting I would like to add a few facts, the average American new unfired cartridge case is approximately .002 (two thousandths) shorter than minimum head space for a given caliber.

A fired case that has been full length resized “should” be under minimum head space BUT this depends on the accuracy of your shell holder dimensions, the accuracy of your resizing die and “how” the die is set up in the shell holder.

How do I know this, I have been reloading for over 40 years and I have gauges to check the length or cartridge head space.

[img width=600 height=450]http://i122.photobucket.com/albums/o254/bigedp51/IMGP5130-1.jpg[/img]



Knowing that a new unfired case is approximately .002 shorter than minimum head space and “if” you have a set of vernier calipers you could use an unfired case to setup your barrel for proper head space.

Step 1. Take the case you plan to use and measure the case length with your vernier calipers and write the measurement down.

[img width=600 height=450]http://i122.photobucket.com/albums/o254/bigedp51/IMGP0710.jpg[/img]

Step 2. Take a fired spent primer and partially start the primer in the primer pocket.

[img width=564 height=450]http://i122.photobucket.com/albums/o254/bigedp51/IMGP0704.jpg[/img]

[img width=600 height=450]http://i122.photobucket.com/albums/o254/bigedp51/IMGP0706.jpg[/img]

Chamber the case, eject and re-measure the case length, you want this measurement to be approximately .004 to .005 larger than your first case measument. What you are striving for is a head gap clearance or air gap between .002 and .003 thousandths at the rear of the case and the bolt face.

Below, an example of excessive “head gap clearance” or the “air gap between the rear of the case and the bolt face on a .303 British Enfield.

[img width=600 height=272]http://i122.photobucket.com/albums/o254/bigedp51/9-2.jpg[/img]

I reload and prefer tight head space because it helps prevent stretching and thinning in the case web area of the case and helps promotes accuracy, BUT sometimes the word head space means nothing.

[possum1]

I reload and prefer tight head space because it helps prevent stretching and thinning in the case web area of the case and helps promotes accuracy, BUT sometimes the word head space means nothing.

Is it feasible or SAFE to try and get .000 head space ? May be a dumb question I don't know, but I am a stickler for PERFECTION

[bigedp51]

I have one Stevens 200 which I was contemplating replacing the barrel on and why I joined this forum and 12 military Lee Enfield .303 rifles. On the Enfield's which I have experimented on with setting the the head space from -.003 to + .020 or three thousandths under minimum head space to twenty thousandths over zero head space.

Military head space settings for the Enfield rifle are .064 min to .074 max, commercial American SAAMI head space is .064 min to .067 max and .071 field max.

Now to your question “Is it feasible or SAFE to try and get .000 head space ?” It is possible BUT safe depends on your definition of safe. It is perfectly safe to have .000 (zero) head space sitting at the shooting bench shooting small holes in paper targets. On the other hand it is very stupid and dangerous to have .000 (zero) head space on a rifle you are hunting Cape Buffalo with.

You actually set .000 (zero) head space when you fire form your cases and neck size only, when you full length resize you want the cases approximately .002 smaller than chamber head space to ensure chambering in hunting conditions.

On a military British Enfield with the head space set at the maximum of .074 and with a cartridge rim thickness of .058 you have a head gap clearance or air gap of .016. This overly large head space setting is to ensure the cartridge chambers under combat conditions.

At .000 (zero) head space with neck sized cases and shooting my Enfield at the range in subzero weather, cold cartridges and a warm chamber were causing condensation. The condensation droplets froze and prevented the case from chambering.

So yes you can set your rifle at .000 head space BUT variations in case manufacture (length), dirt and debris and weather may prevent you from chambering your cartridge.

On the Enfield rifle some long range rifles were accurized in the UK by Fultons of Bisley with the bolt “kissing” the rear of the case, BUT each case was checked with a rim thickness gauge to ensure chambering.

Head space comes in three flavors, tight on target and bench rest rifles, medium on hunting rifles and large on military rifles. With the adjustability of setting the Savage/Stevens rifles head space you can set your own “sweet spot” where you want to............................................

The trick is making sure your cartridge cases chamber under the conditions you are shooting and just as important to reloaders is that the case is not stretched and warped on firing.

With the rimed .303 British case I can cheat the word “head space” with a rubber o-ring that holds the case against the bolt face when fire forming and then neck size only thereafter.

[img width=600 height=450]http://i122.photobucket.com/albums/o254/bigedp51/IMGP6290.jpg[/img]

Below is what happens to your cases when fired in a chamber with “long” head space.



By using the o-ring method of fire forming your .303 cases you are setting a “zero” head space condition and this prevents case stretching on older rifles where the head space can no longer be adjusted.



After fire forming these cases they will head space on the shoulder and not the rim and by neck sizing only you will have .000 or zero head space. (I just don't use these cases to hunt Cape Buffalo)



The funny part in this head space discussion here is that in an Enfield forum you would be burned at the stake for talking about setting your head space to “zero head space” by the collector purests who say “.074 is good enough for me” (.016 head gap clearance) ::)

[possum1]

very very interesting. When the head space is tight ( when other things aren't contributing ) the bolt will close tight or with some force ? correct ??

[lineman69]

i have been reading this for a while and still a little leary about setting this barrel myself.my situation is this i have a redding indicator die for a 6.5 x 284 after measuring the headspace gauge and a new unfired case i find the headspace gauge to 4 thou. bigger so wich should i use to set this barrel?

[possum1]

Sound's like to make you comfortable use the gauge. A fired case would be better, like they told me you can alway's redo to the fired case. I was very uncertain about doing it myself. It seem's easier to me than changing my auto oil and I call myself a mechanic

[~Ace~]

"Headspace" is a happy medium that should allow most all Factory and in spec handloads to chamber.... and if you plan to shoot Factory Ammo, setting it loose with a gauge is fine. If you want the Most out of your rifle, and you reload.... Setting the HS off a FIRED and Resized In Your Die case is the way to do it. Your setting it to YOUR specs. Accuracy is sure to be helped at lease some, Brass life is Really helped.

[axaviere]

anyone have this happen? i got the headspace set, put the barrel in the blocks and started to tighten the nut and the nut, lug and receiver turned. i had to take it apart, reset the headspace and try and figure if clamping the receiver would be better when i retighten it all... anyone?

[Dirk]

With a Savage, it's always better to hold the receiver when tightening the nut. I leave the go gage in with bolt closed and hand tighten the barrel, then while holding the receiver (I use rear entry action wrench) I tighten the nut with a barrel nut wrench. I do not make it gorilla tight.

[woosum]

Man, WHAT A SITE!!!. ..This is awesome. Lots of folks round here gonna benefit from all your knowledge guys ;D THANKX!!

[hotbrass]

With a Savage, it's always better to hold the receiver when tightening the nut. I leave the go gage in with bolt closed and hand tighten the barrel, then while holding the receiver (I use rear entry action wrench) I tighten the nut with a barrel nut wrench. I do not make it gorilla tight.

Where do you buy a rear entry action wrench?

[Dirk]

http://www.sinclairintl.com/product/...-VisesWrenches

[hotbrass]

Cool! I can make one of those in no time. And virtually no cost!

I have seen another one for a 700 action with a T handle. I like this one better.

Thanks!

[Stefan]

So in summary and correct me if I'm wrong,
For factory ammo a guaged HS is sufficient.
For greater accuracy a fired and sized case is desired.

I prefer neck sizing only and absolutly hate full length sizing.
Thinking about it I would need to full length size if I went this method for HS since just neck sizing would potentialy cause issues with differing chamber dimensions if I'm correct.

I am over thinking this probably.

[bigedp51]

If you watched the video of the gunsmith with the chamber reamer he was using a "GO" or minimum head space gauge, and this is how a trained professional would do it. Us poor folks could use a new unfired case which would be approximately .002 smaller than the "GO" head space gauge. By placing one layer of scotch tape across the base of an unfired case you would be at approximately the same "gauge" reading as a real "GO" head space gauge.

Or to put it in simpler terms if you use an unfired case to set your head space you will be .002 "UNDER" minimum head space.

If you put one piece of tape on the end of the unfired case you will be right at "GO" or minimum head space.

If you use two pieces of scotch tape and the unfired case you will be + .002 over minimum head space.

This is not rocket science, on the British .303 Enfield at the maximum head space of .074 and a American made case with a rim thickness of .058 you will have .016 head gap clearance or "air space" between the case and the bolt face.

My point bring here you have to make up your minds if your building a bench rest rifle or just a super accurate multipurpose rifle. The bottom line is don't over do head space, a Remington M40 7.62 sniper rifle would NEVER have the head space set as tight as you are talking about here and they are still making head shots at 800 yards.

On top of this without a RCBS Precision Mic to measure your fired cases and head space control shims for your reloading dies, your dies, shell holder and reloading press setup could be off as much as .002 to .003 very easily. On top of this Redding makes "Competition Shellholders" in + .002. +.004, +.006, +.008 and +.010 designed for minimum resizing meaning the shell holder are .002 to .010 thicker than a normal shell holder.

The bottom line here is American cartridge cases run on the small side and if you try and chambered a Lapua, Norma or Prvi Partizan case the bolt might not close or be very tight. You can always fire form your cases to be a custom fit to your chamber and rifle.

[rjtfroggy]

OK let me see if I have this right.
I just installed a new Shilen 260 rem barrel on a 111 action using brand new factory cases that I FL sized and measured for length to be sure they were the same. Then I put a piece of masking tape on one and that made it .003 longer, I tightened the barrel down on the first case until the bolt closed with a little resistance not forcing but snugly. Then I put the longer case in and the bolt would not even come close to closing.
So now I have a barrel that is head spaced tighter than factory and may not feed all factory ammo. Is this correct?
I also set my oal by setting a lightly lubed bullet in the case mouth on the long side then gently chambered , ejected, measured, then subtracted 0.020 from the chambered length and made this my starting point for loading ammo.
Am I missing something or doing something incorrectly? I am new to changing barrels but not to reloading and I am always ready to learn something new.

[Blue Avenger]

You got it! All my guns that I have rebarreled are set up this way.

[rjtfroggy]

Greg, so if I understand correctly I now have a rifle basically set up for bench rest comp. so accuracy should be relatively easy to acquire, with just some adjusting of my seating depth and my load(if needed).
Also am I to believe that if I buy some factory ammo it will not chamber. Not that I plan on buying it but you never know could be on a trip and need to purchase ammo.
This the second rifle I set up this way and so far getting centered on paper has been a lot easier with fewer shots being needed to zero.
I posted a target from this 260 in my post "new build with pictures". It isn't the best looking group but considering the weather conditions at the time and the fact that there is only a total of 35 rounds down the tube I don't feel it is too bad.Each flier is after scrubbing the barrel clean, one more range session should clear that up, after a few more rounds the barrel will be shot a little dirty for consistency, We will see.