mod 12 benchrest installing new 6br barrel bolt snug to unfired lapua case then added 002 shim as a no go which it was
is this headspacing
thanks vano
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mod 12 benchrest installing new 6br barrel bolt snug to unfired lapua case then added 002 shim as a no go which it was
is this headspacing
thanks vano
The average commercial case is .002 shorter than minimum headspace, if you add a .002 shim your headspace will be at the minimum or GO.
Below is a RCBS Precision Mic for the .308/7.62
[img width=600 height=450]http://i122.photobucket.com/albums/o254/bigedp51/IMGP5130-1.jpg[/img]
The zero pictured below is minimum headspace or GO
[img width=600 height=450]http://i122.photobucket.com/albums/o254/bigedp51/IMGP5157-1.jpg[/img]
Below the Precision Mic has a new unfired Wincheater .308 case in the gauge, the gauge shows the case to be .002 shorter than minimum headspace.
[img width=600 height=450]http://i122.photobucket.com/albums/o254/bigedp51/IMGP5254.jpg[/img]
Below is a military 7.62 NATO case in the Precision Mic, military cases are .0015 longer than civilian commercial cases and approximately .0005 shorter than minimum SAAMI headspace. Military headspace is longer than commercial SAAMI headspace and the cases are slightly longer and thicker in the base web area
[img width=600 height=450]http://i122.photobucket.com/albums/o254/bigedp51/IMGP5256.jpg[/img]
To answer your question if you use a cartridge case to headspace your rifle you will be .002 UNDER minimum headspace (too tight) if you use a .002 shim you will be at minimum headspace or go.
NOTE: The act of dry firing a fired case will shorten the case approximately .001 each time you dry fire the case (drive the shoulder back) You are also warned to never use cases that were used for reduced loads again for normal pressure loads because the case will be much shorter than normal and case head separations can and will occur.
You do not need to set your headspace as tight as many of you are, the act of fire forming your cases will blow out the shoulder and make your cases a custom fit to your chamber.
I shoot and reload for the .303 British Enfield rifle, the military headspace settings are so "loose" (up to .020 head gap clearance) I put a rubber o-ring around the base of the case to hold the case against the bolt face to fire form my cases.
[img width=600 height=450]http://i122.photobucket.com/albums/o254/bigedp51/IMGP5096.jpg[/img]
[img width=600 height=450]http://i122.photobucket.com/albums/o254/bigedp51/IMGP6290.jpg[/img]
Now here is some "headspace" information to think about. (about a half inch too much)
http://i122.photobucket.com/albums/o.../image006e.jpg
http://i122.photobucket.com/albums/o...natoin3006.jpg
BIGEDP51, Excellent presentation! This is the "good stuff" you don't get from r/l manuals or, for the most part "gun writers". Particularly, the caveat of judging cartridge headspace from under powered loads. Thus the advice from posters cautioning to use headspace gauges(at the very least a go-gauge plus tape) on 1st builds. Don't know if it's Big ed p51 as in mustang or big edp as in electronic data processing or what? But Enjoyed the post, Dale
Vano, everything I have read said to use a fired case, not virgin brass.
Please keep in mind that headspace is a subjective thing. SAAMI headspace measurement is used as a industry standard, so that the Win 308 ammo you buy is PA is the same size as the Federal 308 you buy in Montana. If you reload and just neck size, after fire-forming, headspace becomes mute. Headspace way too long (>.002) and you may get case separation, headspace too short and you can't close the bolt.
BIGEDP51, Excellent presentation!
Bill
A fired case can be ANY length depending on the head gap clearance or the length of the chamber. A re-sized case can be a crap shoot also depending on the dies and how the press is set up.
You can check your head gap clearance or the "air gap" between the rear of the case and the bolt face with a new unfired case and a spent used primer.
First measure your unfired case with a vernier caliper and write the measurement down.
[img width=600 height=450]http://i122.photobucket.com/albums/o254/bigedp51/IMGP0710.jpg[/img]
Next seat the spent primer just starting it 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]
Now chamber your test round and slowly seat the primer as you close the bolt. Remove the test cartridge and remeasure the case again. Now subtract your first case measurement from your second case measurement and this will give you the "airspace or gap" between the rear of the case and the bolt face.
I myself would want .002 to .003 as this would give you minimum headspace (GO) to .001 more than minimum headspace.
Remember when you re-size your cases in a full length resizing die the brass has only one direction to move and that is forward. If you set your headspace too tight the re-sized case may be extremely tight fitting or the bolt might even refuse to close.
They make headspacing shims for reloading dies and shell holders to help you resize your cases to your proper length.
[img width=600 height=350]http://i122.photobucket.com/albums/o254/bigedp51/7-17-201054719PM.jpg[/img]
[img width=600 height=410]http://i122.photobucket.com/albums/o254/bigedp51/7-17-201054345PM.jpg[/img]
[img width=600 height=244]http://i122.photobucket.com/albums/o254/bigedp51/7-17-201055522PM.jpg[/img]
If you set your headspace to short or "below" GO you run the chance of the case not fitting in the chamber. The average new case is .002 smaller to ensure chambering and to make allowances for manufacturing tolerances.
I set one of my Enfields headspace to below GO (.002 under) and in very cold weather firing the rifle caused condensation droplets to freeze inside the chamber and my reloads refused to chamber. "Headspace" serves a purpose and that is to allow any newly manufactured cartridge case to chamber in your rifle. Proper fire forming will take the "slop" out of your cases, set your headspace at minimum headspace (GO) or .002 to .003 over minimum.
Below as an example is SAAMI headspace settings for the .308 Winchester.
308 Winchester (SAAMI) Gauges
GO - 1.6300"
NOGO - 1.6340"
FIELD - 1.6380"
U.S. Military 7.62 NATO Gauges
GO - 1.6350"
NOGO - 1.6405"
FIELD - 1.6455"
If you use a new .308 case to set your headspace your headspace will be 1.61 and .002 under minimum, on any commercial factory rifle your headspace is set between 1.630 and 1.634. That is anywhere between .002 and .006 thousandths larger than a new cartridge case.
+ .003 over a new case would be about perfect.
Note: On my British Enfields at the maximum headspace setting of .074 and a American SAAMI case I can have as much as .020 (twenty thousandths) head gap clearance for my cases to stretch. And you people are worried about .001 or .002 thousandths, I wish I was that lucky on a British Enfield rifle.
http://i122.photobucket.com/albums/o...estretch-1.gif
The rubber o-ring around the .303 rim makes the word "headspace" meaningless.
http://i122.photobucket.com/albums/o...frame_0001.jpg
Once fire formed the case headspaces on the shoulder
http://i122.photobucket.com/albums/o...oheadspace.jpg
bigedp51........ a great post...... lost of good stuff there
"The rubber o-ring around the .303 rim makes the word "headspace" meaningless."
Until it is so excessive that you get a case head separation because your o-ring doesn't provide any support past the web area of the cases.
Why not just seat your bullets long and fire form that way? Better yet why not get a #2, 3 etc. bolt head (assuming you aren't using a No.1 Enfield)?
And there is a big difference between loading for the 303 Brit and loading for more modern cartridges. Yes I use the "fireform to chamber dimensions" type of headspacing on many old low pressure cartridges, but I wouldn't want to do that with some of the loads folks are running in 6mmBR rifles.
You can use a new empty case to set your headspace and it would work, "BUT" several things could go wrong.
1. You take your rifle hunting and forget and leave "your" special ammunition at home and find out normal store bought ammo wont fit in your rifle.
2. You find over time your cases are getting hard to chamber and your decide to use a full length resizing die to bump the shoulder back only to find out your cases are now longer than when you started. You would need to lap your shell holder and remove a few thousandths to get the cases to chamber.
3. You sell the rifle to someone and he gets home and finds out his Remchester cartridges wont fit the rifle and he looks you up again and beats you to death with your old rifle.
Trust me, the shell holder below had .002 removed on a lathe and .001 removed by hand lapping in order to get a custom .270 to chamber a fully FL resized case to fit in the chamber. Just because yours truly wanted a tight chambered .270 rifle.
[img width=600 height=450]http://i122.photobucket.com/albums/o254/bigedp51/IMGP6943.jpg[/img]
Vano, to answer your question I would use a FL sized new case instead of an unsized case. That will be your "GO".Quote:
Originally Posted by vano
Then use .003"- .004" worth of shims(1or2 pcs of scotch tape) to make your "NO-GO.
If this is a barrel that has been shot before then using a fire-formed case as your "GO" would be good to use.
Or, you could buy or borrow a set of headspace gauges too, which should probably be best recommended for a first build.
Saami spec for the 6br case is 1.560". New Lapua brass measures 1.556-1.558" usually, so as you can see using a pc of unsized brass is gonna put you under spec like mentioned above.
Theres alot of great info being given here, but you're doing a 6br, not a 308 or a 303 Enfield.
Just as a test since you already have it heaspaced the way you mentioned, you should FL size your case then see if it chambers. I'd bet it either wont chamber or will be pretty tight. Then I'd re-set the headspace to the sized case.
If you want to read up some more on the 6br, here's a very good article with alot of info:
http://www.6mmbr.com/6mmbr.html#26585
My Enfields are headspaced at .067 or less,(.074 is max) my Remington and Winchester cases have a rim thickness of .058.Quote:
Originally Posted by Eric in NC
When fired without the rubber o-ring the cases will stretch .009 in the web area.
[img width=600 height=450]http://i122.photobucket.com/albums/o254/bigedp51/IMGP4521-1.jpg[/img]
[img width=600 height=450]http://i122.photobucket.com/albums/o254/bigedp51/IMGP4523.jpg[/img]
[img width=600 height=450]http://i122.photobucket.com/albums/o254/bigedp51/IMGP4513.jpg[/img]
Seating the bullet long does not work, the Enfield is long throated and also cordite ammo was used making the throat even longer. Creating a false shoulder on the neck to hold the case against the bolt face causes split necks because of the large military chamber.
Even a 174 grain round nose bullet will not touch the rifling.
[img width=559 height=450]http://i122.photobucket.com/albums/o254/bigedp51/IMGP6291.jpg[/img]
The American made .303 British cases have small base diameters and the o-ring has the added benefit of centering the case in the chamber and helps prevent "banana" shaped cases.
Headspace is governed by the cases you shoot and NOT the rifle.
Military cases have a larger base diameter.
[img width=600 height=254]http://i122.photobucket.com/albums/o254/bigedp51/thicker-2.jpg[/img]
Military cases have thicker rims.
[img width=600 height=233]http://i122.photobucket.com/albums/o254/bigedp51/thicker-3.jpg[/img]
And Military cases have thicker case walls.
[img width=600 height=385]http://i122.photobucket.com/albums/o254/bigedp51/thicker-1.jpg[/img]
I fire form my modern rifle cases at mid level loadings, and for my .303 I use .312 pistol bullets using reduced loads and the o-ring method to blow the shoulder out.
[img width=580 height=450]http://i122.photobucket.com/albums/o254/bigedp51/IMGP4691.jpg[/img]
Our American ammunition companies can't seem to figure how to make British military cases, the Remington case below has the shoulder of the .303 case a 1/4 of an inch too short.
[img width=260 height=450]http://i122.photobucket.com/albums/o254/bigedp51/twocases.jpg[/img]
The reason I use the rubber o-ring is because some brilliant people tell everyone to oil or grease their cases to fire form them which doubles the bolt thrust on your pet rifles.
[img width=318 height=450]http://i122.photobucket.com/albums/o254/bigedp51/TBOSA-1.jpg[/img]
[img width=600 height=207]http://i122.photobucket.com/albums/o254/bigedp51/TBOSA-2.jpg[/img]
[img width=600 height=398]http://i122.photobucket.com/albums/o254/bigedp51/oilcover.jpg[/img]
[img width=600 height=373]http://i122.photobucket.com/albums/o254/bigedp51/oilinchamber.jpg[/img]
Eric in NC
I'm 60 years old and have been reloading since I was 18 years old, I'm not stupid, retarded or brain dead.
If you want to teach me something about reloading then teach me how to reload these..................
[img width=600 height=450]http://i122.photobucket.com/albums/o254/bigedp51/IMGP6286.jpg[/img]
[img width=600 height=450]http://i122.photobucket.com/albums/o254/bigedp51/IMGP2800-1.jpg[/img]
wow
wow i like to come to your house an taste your reloading
111
pdog06 is spot on, do what he said and there will not be a problem. All the scotch tape that I have measured has been .002.
YES SIR !! From the very first post about head space from biged, which was a while back, I knew there was something about biged I liked and now he post a image of it. ;D
biged,No real need to make this a personal "who knows more" thread. There is more than one person on here that knows what they are doing, and the original poster asked a pretty simple question.
Great choice of beer ...Mmmmmmm!
Eric in NC wroteQuote:
Originally Posted by pdog06
And there is a big difference between loading for the 303 Brit and loading for more modern cartridges.
bigedp51 in P.A. answers about his "old" decrepit 67 year old Enfield rifle in a ancient out of date caliber.
"In a pigs a$$ there is" (the actual difference between the .303 and 6mmbr is 7,000 CUP and 300 fps and I didn't have a scope) ESAD!
[img width=487 height=450]http://i122.photobucket.com/albums/o254/bigedp51/range-day-2-1.jpg[/img]
Here is 10 shots before I moved the front sight.
[img width=536 height=450]http://i122.photobucket.com/albums/o254/bigedp51/range-day-target.jpg[/img]
Now who wants to talk about headspace and hand loads, and stay away from MY beer you drunks.
"IN A PIGS A$$"... "ESAD"... Really???
Why do you have to act like that. We're all friends here and try to help one another, not show up one another. If you wanna pump your chest out like youre better than everyone else then I suggest you try it elsewhere...Quote:
Originally Posted by bigedp51
I have noticed that when there is "friction" in a thread that most people avoid said thread because they do not want to become involved. This turns an otherwise informational and useful thread into a dead thread or a **** measuring contest. We can disagree, but lets do it respectively.
I posted a wisecrack about the beer because odd brand's of beer intrigue me, don't drink alcohol;long story. Don't understand what happened to this thread, I've PM'd biged several time's and he has always been professional and always helped me all he could. I think he is a stand-up guy.
Very simple folks.......buy the gauges and be done with it.
Vano, I sent you a PM
Biged - sorry I PO'd you - have many years of loading experience too. Load for the 303 Brit in several Enfields (including a Savage - I can reach the throat of all but one of them with 174 grain SMKs BTW) and a Winchester 95, also load for 577/450, 40-72, 40-82, 50-70 and many others in rifles quite a bit more than 67 years old so don't think I was bad mouthing your cartridge or rifle.
[img width=600 height=449]http://i220.photobucket.com/albums/dd314/erbeckerdite/USN-1.jpg[/img]
[img width=600 height=449]http://i220.photobucket.com/albums/dd314/erbeckerdite/dane1.jpg[/img]
[img width=600 height=372]http://i220.photobucket.com/albums/dd314/erbeckerdite/hunting2.jpg[/img]
Your method certainly works for your application - so does putting tape around the case head of 45-70 brass when forming it in a Danish Rolling block chamber, same thing using 32 Long in a Nagant revolver, a whole host of methods to form 7x57 brass in No1 Remingtons, etc. etc.
But it has little to do with what the poster asked and is not something I would reccomend to a new guy asking about setting headspace with his rimless cartridge (particularly on a gun like a Savage where you CAN set the headspace).
As trappst said - buy, rent or borrow the gauges. You can also use a fired and FL sized piece of brass (sized in your dies) if you want (assuming you are using rimless, non-belted cartridges).
And I will take on your 67 year old enfield with my 1867 Dane roller any time you want! ;)
vano here
thanks for the info
another piece of info i went to the range with this rifle it shot lapua ammo fine
if it chambers the shoulder bumped once fired brass all is well right?
load and shoot again right?
later vano
Yep - good deal.
bigedp51 is not POed and the Lee Enfield rifle has has adjustable headspace for over 110 years, which is a bit longer than you Savage and Stevens owners.
My No.4 Mk.2 below has two bolt heads fitted, normal military headspace for the Enfield is .064 minimum and .074 maximum. The two bolt heads below give me headspace settings of .067 for military ammo and .062 (.002 under minimum headspace) for American made commercial .303 cases.
[img width=600 height=450]http://i122.photobucket.com/albums/o254/bigedp51/IMGP1355.jpg[/img]
My comments about "in a pigs A$$" and "ESAD" are good old fashion GI humor, so if you can't take a joke stay out of the kitchen.
Besides my pet pig thought my jokes were funny!
http://i122.photobucket.com/albums/o...smilingpig.jpg
Read the article below from 6mmbr.com, this person has his 6mmbr set up a + .005 over minimum headspace.
(this would be +.007 using a new unfired case as a headspace gauge)
http://i122.photobucket.com/albums/o...cMIC_6BRAA.jpg
"Now I can use the 308 version of the RCBS Precision Mic to compare brass which has been fully sized in my 6BR body die with brass which has been fired in my chamber. With the spacer inserted, FL-resized cases mic 0.000” at the datum point on the shoulder. Using the same set-up, fire-formed cases measure 0.005”. In other words, my chamber has a headspace of +0.005" above minimum dimensions. This is fairly typical of a custom rifle set up for switch-barrel use."
Click on the link below.
TOOL TIP -- Headspace Measuring
http://www.6mmbr.com/6BRPrecMIC.html
Ain't it funny what a little reloading bench engineering can do for you. (why do you think I have and use a RCBS Precision Mic?)