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GLShooter

Poor Mans Head Space Gauge and The Rich Guy Approach

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I've told several guys how to do it so now I'll just post it up. Maybe add it to the stickies and data base later.

This one is set up for 308. Your goal is to move the shoulder during sizing about 0.003 for your new Master Blaster AR10 with the 24' fluted bull barrel satin finished Black Hole tube.

The tools:

One caliper, your flavor
One 40 S&W , 10 MM or any case that will fit over the case neck and still interface the shoulder about midway. A 38/357 will work but it is tighter than I like.
Fired case.


4JXcjel.jpg


Notice the 40 S&W goes over the case neck and DOES NOT bottom out.


uosVxFh.jpg


The joined pair with the caliper measurement showing 2.4775


uy5MQUp.jpg

This is a point on your shoulder from a fired case. It is not the true datum line that is half way up the shoulder but it will work.

Now get your sizer in the press and start sizing the case. After it is sized measure as above, Your goal will be to read about 2.4745 + or -. That gives you 0.003 head space.

You may need about 0.001 more sizing because the general rule of thumb is the case will spring back about 0.001 and you may have to take that into account for 100% reliability.

This is in a auto chamber. A bolt gun only needs about 0.001 to 0.002 as the bolt will can in a sized case with it's extra leverage. Semis, pumps and levers don't have that camming ability and you must add in the extra 0.001 or so.

I size up a few and then drop the empty sized case in my chamber, drop the bolt with my own hand NOT with the buffer spring, as it CAN size the case as it slams on the case, and then check for easy extraction. If it is to tight then I tweak until it will come out without having o whack on the charge handle.

This will work on any non-belted bottle necked case. You CAN do it with belted Magnums and many do HS off the shoulder on them ignoring the belt for various reasons.

All you need is a case to slide over the neck and impinge on the shoulder on any of them. I Use a 7.62X39 on 6 PPC cases or 6 MM's if I am in a hurry or don't have the right set up from Hornady for that case family.

This method will increase case life as you aren't shoving the shoulder back as much as 0.015 when you crank that die down to the shell holder/plate.

Questions?

Greg

PS: Yeah, I know the two are not perfectly straight but even I need two hands to run a camera!! :124:

Edited by GLShooter
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:thumb:

 

I suppose this will still work even if your calipers dont have that custom view window.... :smartass:

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:thumb:

 

I suppose this will still work even if your calipers dont have that custom view window.... :smartass:

 

 

See I told them I was on crack!!! :bnb2:

 

Greg

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Great tip! Thanks! :thumb:

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Thanks for sharing this Greg. I haven't fully absorbed what you are showing here, but maybe after a bit it will sink in. I'm still new to the whole necked case reloading thing.

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Here is the professional set up that is what I have tried to copy on the cheap.:

 

Gauge/Tool for checking head space and distance to the lands with appropriate inserts.

 

DSC05152.jpg

 

Hornady bought these guys out. Mine, like most things in my reloading room, is old.

 

DSC05154.jpg

 

This is the special case for the day I used in these pictures. It is a fired case that has been drilled and tapped to fit on the end of the tools threaded segment.

 

DSC05150.jpg

 

Bullet seated in the special case to check distance to lands. This is a 6X6.8.

 

DSC05156.jpg

 

Here the 6MM insert is slipped over the bullet and the calipers are closed up. This gives me a reading from the base of the case to ogive of the bulets where it meets the lands. this gives me a number so I can move it in or out for less or more actual placement up in the lands for accuracy and functioning purposes.

 

DSC05160.jpg

 

A quick check of the COL on this one. As you can see it is way past magazine length for an AR15. This is a 500 yard load that will be fired single shot.

 

DSC05161.jpg

 

In this one I have replaced the bullet insert with a case shoulder measuring tool. This is what I emulated through the use of the 40 S&W case. Notice the readings. This was fired case that has not been resized. And yes this caliper has a cracked window too!! :flea:

 

DSC05163.jpg

 

The same case after a trip through my FL sizer. Notice that the measurement is less. This gives me enough clearance so chambering is 100%. I have found that this amount is more than adequate. The last thing you want in an AR is an ultra tight fit in the chamber with a Neck Sized only case. Bad things can happen quickly if your luck runs out.

 

DSC05164.jpg

 

I hope this clarifies any questions. I use these tools religiously in my loading. I can get away without using them but die set up is much faster with them. Sinclair also makes a tool that is a bit more involved that does not use the special cases and I am looking at buying one of those to try. I have heard good things about them from guys that I respect so believe they can't be all wrong.

 

Greg

 

PS: Would you like to learn about how to get that extra 0.001 sizing on your shoulders in about 2 minutes vs about 15 jacking with the die? :stirpot:

Edited by GLShooter

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*snip*

PS: Would you like to learn about how to get that extra 0.001 sizing on your shoulders in about 2 minutes vs about 15 jacking with the die? :stirpot:

 

Yes, please!

 

I'm still not too sure how the Stony Point gauge works, but I can search it up I'm sure. I understand the comparators and what you are doing by substituting the empty case though.

 

My first .223 loadings will be more straightforward, making bulk-type practice rounds. I'll full-length size (a lot of this brass didn't come from my rifles) and trim, then set up the seater to use the cannelure on my 55-grainers. I'll crimp separately.

 

Sound about right?

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Yes, please!

 

I'm still not too sure how the Stony Point gauge works, but I can search it up I'm sure. I understand the comparators and what you are doing by substituting the empty case though.

 

My first .223 loadings will be more straightforward, making bulk-type practice rounds. I'll full-length size (a lot of this brass didn't come from my rifles) and trim, then set up the seater to use the cannelure on my 55-grainers. I'll crimp separately.

 

Sound about right?

 

Yes it sounds good.

 

Greg

 

PS: I'll getthe camera out later and see what I can come up with.

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I use the Hornady "Stoney point" gauge for measing length to the lands. Have never messed with the other one though. Is this something I need to be concerned with if I am FL sizing my .223 brass with the RCBS AR15 dies?

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I use the Hornady "Stoney point" gauge for measing length to the lands. Have never messed with the other one though. Is this something I need to be concerned with if I am FL sizing my .223 brass with the RCBS AR15 dies?

 

The set up makes it so much easier to afjust the shouler movement. Since you have the main tool the HS insert will only cost you about $7.00.

 

Greg

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Thanks for posting this. Im going to try it today.

Im pretty sure that screwing the die in towards the ram will determine how much the shoulders are pushed back.

So far what I do is screw the die down until it touched the top of the ram and then I back off a little bit. Im thinking this distance I have backed off is where the shoulders would get pushed back. Hmmm.

 

When I resized and deprimed so far I had no problems but I probably wasn't bumping the shoulders back at all. Now I can measure to see.

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Ultimately you have the best individualized gauge in your rifle chamber but this speeds things up and gives you truly quantifiable numbers for reference. On new rifles I make up three cases that "fit" and go bang so I can set my dies up dead nuts. Three gives me an average. One is used to measure the distance to lands with the Sinclair tool. It is polished and engraved to put in my cartridge reference box along with my reference bullets. If you load for various chambers and don't want to buy extra sizers this method is the berries.

 

Greg

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This was very helpful and completed a mystery that was bothering me. I took a 357 case since the 45 case went all the way to the shoulder of the 308 case. I took the 357 case and took the average size of 3 fired cases which was basically 2.830. So thats the length of my chamber.

 

At first my die was pushing the necks about 2 to 3 thousandths too much so I backed it off a tiny bit and now its pushing the neck to 2.828 right in the middle of the distance you suggested between 1 and 3 thousandths back.

 

Towtruck had tried to explain it but the picture helped me understand. The new cases are cycling well.

 

Now I need to figure out what pistol case will work for my 223. All I have is cases from 357 45acp 9mm & 22 cal.

 

I can order a headspace gauge when I get the money. This solves the mystery now though.

Thanks.

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You want 0.003 on an auto rifle. For important shooting like game animals or SD then 0.005 is in order. About 0.0015 for bolt guns for play. For serious stuff like I have done 0.003-4 is what I use.

 

Greg

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