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Old 02-23-2008, 06:33 PM
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Kali Komrade Kali Komrade is online now
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Default Headspacing 101

Field Method (aka Quick and Dirty Method)

Primer: Why is it important to headspace the Browning 1919a4.

1. Proper function of the weapon, which includes proper feeding and less wear to the internal portions of the gun.
2. To avoid case ruptures. (This is not as critical but can be fixed with a case rupture removal tool or Ez-Out)
3. To avoid case head separation and blown top covers and injury to others.

In addition to the above I prefer to store my 1919a4 in Incomplete Lock-Up to ensure that I always force myself to headspace every time I take to the firing line, also by doing this it relieves the spring tension on the trigger/disconector so that the spring is not kept under load all the time and comes in more positive contact with the sear.

Step 1. Determine what type of Barrel Lock Spring you have on your gun. Open the top cover of your gun draw the bolt reward and that will draw the rearmost portion of the barrel breech out of the trunion. Samples of a USGI Lock Spring and a Izzy Lock Spring Below.

To keep the action open you may insert a spent cartridge case in the side of the bolt at the rearmost portion of the cocking slot. See Below.

If you have the Izzy Lock Spring you will either have to Convert it which we will cover in another article or you will need one fine tipped flat head screwdriver and one medium screwdriver. If you have a USGI you will simply need one medium screwdriver or your Browning 1919a4 tool.

Step 2. Get to Incomplete Lock-up

This is Complete Lock up

This is Incomplete Lockup (Note in incomplete lock up the adjusting notches are visible on the barrels breech just forward of the barrel extension)

Now this is the point where you folks that have Izzy barrel lock springs may just throw your hands up. The best way to accomplish headspacing on this spring while in the gun is taking your fine screwdriver and prying out on the tab locking the barrel lightly then with the other hand or other set of hands adjust the barrel clockwise or counter clockwise per the instructions one click at a time to accomplish this task.

2a. If you have Incomplete Lock Up already: What your going to do is to turn the barrel clockwise if looking from the breech to the muzzle one click at a time and check it each time by pulling the bolt back of inch and letting it go until it goes into full lock up. (Now that you have Complete Lock Up proceed to Step 3)

2b. If your in Complete Lock Up already: Rotate your barrel counter clockwise if looking from the breech to the muzzle one click at a time checking it each time by pulling the bolt back of inch and letting it go until you get incomplete lock up and then go back to Step 2a.

Step 3. Now that you have complete Lock up you have your basis for adjusting to the headspacing for the caliber and barrel you are using. Rotation of the barrel is clockwise from the breech to the muzzle.

3a. 30-06 will require 2 clicks no more.

3b. .308/7.62x51 will require 3-4 clicks no more. I prefer 4 clicks. 3 clicks tends to run the gun a little sluggish.

3c. 8mm will require 0-1 clicks no more. Use caution when using 8mm ammunition some ammo does not chamber as well as others.

3d. 7.62x54r from information received so far its 2 clicks no more. (we need more info.)

Step 4. As a precaution I check the first case I fire inspect it see if there is excessive case stretching and compare it to an unfired cartridge. If you suspect the case is stretching excessively adjust your headspace one click counter clockwise to tighten the headspace.

WARNING if you over tighten your headspace and it can cause the rear most portion of the case to extend out of the barrel breech and it will cause a case head rupture and blow your top cover and cause injury.

Step 5. If everything looks good. Go Smoke a belt and enjoy. Remember check your headspace often for Your Safety and the Safety of others around you.

If you have any information to improve this tutorial to benefit out community please contact me here...
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Old 02-23-2008, 06:47 PM
A. Stull

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Outstanding tutorial Kali. I think it is very important that you posted this, as headspacing can not be overstressed when dealing with the brownings.

Let's keep everyone safe here.

Headspace- If you don't understand it, don't operate the browning until you do!
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Old 07-17-2009, 02:58 PM

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Will the .30 cal head space gage work on the .308?
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Old 07-17-2009, 03:51 PM
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Kali Komrade Kali Komrade is online now
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Default Yes...

Yes... It certainly will... Not to familiar with it myself as I used the quick and dirty method here but I'll run you through it in brief...

Your going to back in your barrel all the way then what your going to do is wrack the action to reset the firing pin then what your going to do is insert that gauge from the bottom into the T-slots this is the slot the rim of the cartridge slides down and close the bolt on it... Make sure you don't pull the trigger as doing so the firing pin will break when it hits the headspace gauge...

Then what your going to do is start opening up the headspace until the gauge is held in by friction only not tight not falling out but right at the point that if you loosen it one more click it will drop out... Then your at zero headspace from there you turn it two more clicks out for 30-06 or 3-4 clicks out for .308... I hope that helps...
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Old 07-17-2009, 04:39 PM
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After you long tutorial, .308 gages work Just fine !

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Old 07-17-2009, 07:05 PM
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Kali Komrade Kali Komrade is online now
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Default Oops...

Originally Posted by anm2_man View Post

After you long tutorial, .308 gages work Just fine !
Oops my bad.... Low blood sugar... My mind can't concentrate... Then yeah they will work... on both... I was thinking more in the aspect of how it would work...
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Old 05-25-2010, 12:32 AM
kd5oldx kd5oldx is offline
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quite helpful, thanks
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Old 01-31-2012, 11:57 AM
LiveFreeAndShoot LiveFreeAndShoot is offline
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Great text version of the You Tube video, this is excellent as it shows the Izzy spring process too!

Quick question, the post says that this should be done "often". Not sure what that means.. Like most of us I want to stay right on top of the proper operation and maintenance of everything I shoot. I will clearly do this as the last thing before opening fire on range day, but since I take groups to the range to try and introduce them to the fun that this obsession, er, avocation can bring, I can see going through 2000 rounds (even though my 1919A4 is semi-auto only) over the course of a range day. Should I be doing this every 1000 rounds? 2000? Any thoughts?

Thanks so much for the work on this info! Can't tell you how much it helps rank newbies like myself! Not to mention helping to keep my friends from having a really bad day on the range... Idea is to bring them into the community (and the voting booth).. Not send them to the ER... I hate it when that happens..

Someday.... Someday.... I will have a cheap hobby... Or not..
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101, headspacing

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