Headspace gage bushing help

[Broken_Reticle]

So one of my new goodies I got recently is a headspace gage. Now I can measure to my cases correctly. I checked out Tresmon's post and my gage doesn't sit back as deep as his. As you can see in the image below.

Here is Tres's

Now I am not sure what he is measuring but it looks to be a belted case of some kind and the shoulder profile might be different.

My cases are measuring 1.69. they are 308 win brass out of a savage FP10. Is this what other people are getting or does it not mater since it is bumping back the shoulder .002 relative to the gage?

Thanks for the help guys.

B_R

 

[JByrd]

Re: Headspace gage bushing help

It doesnt matter,its your gauge for your chamber.


As long as you know what your fired case is, and work off that your good to go

 

[hdbiker1]

Re: Headspace gage bushing help

Those so called headspace gauges are really comparators. What you are doing is comparing your fired brass with your sized brass to make sure you are bumping the shoulder back to your intended specs. On a bolt gun, usually .001-.002 less than your fired brass.

 

[Broken_Reticle]

Re: Headspace gage bushing help

Ya I misspoke in the thread title.. I was looking at the midway site when I was typing, they call what I have a headspace gage. ya I should have said comparator. I just wanted to make sure I was understanding the spirit of what I was measuring. like you said in comparing the two measurements and not getting stuck on where the measurement was coming from.

 

[FLIGHT762]

Re: Headspace gage bushing help

Your gauge is a Hornady Tresmon's is a Sinclair. Just a different brands. His gauge uses a tapered shoulder, yours, uses a straight edge. Makes no difference, both measure the amount of shoulder bump, which is what you want to do. I use both.

 

[Broken_Reticle]

Re: Headspace gage bushing help

Thank you sir.
I love Tres's posts. just saw the difference and since there isn't really instructions, leaves it up to interpretation.

 

[waste_knot]

Re: Headspace gage bushing help

Are you zeroing the caliper after you mount the conparitor. It should indicate a very close value to true headspace.

 

[Broken_Reticle]

Re: Headspace gage bushing help

I am using a dial caliper. So I have a spreadsheet on my phone that I just type the measurement into and it minuses out the comparator for me.

My comparator and anvil together is 2.16 I think from memory.

I weld so I didn't want to have to worry about leaving a set of digital calipers laying on the table and frying the puppy when I ground to the table. I have ruined a couple wallets worth of credit cards by forgetting it was laying on the table when I did this. hahaha.

 

[427Cobra]

Re: Headspace gage bushing help

First off I don't like the Sinclair unit, it's cone shaped and I find it doesn't work as good as the Stoney Point/Hornady unit, BR decap your fired brass, primer flow can/does give erroneous readings, it doesn't matter if your using a digital or old style dial caliper, measure all your unsized fired brass, your going find some are a tad longer than others, use the long cases to set up your FL die, don't do any subtraction, stop worrying about what the actual HS is minus the tool, set up your FL die so sized brass is .001-.002 shorter with your HSG.

 

[Broken_Reticle]

Re: Headspace gage bushing help

Oh when I set up my dies I don't plan on using the spread sheet. I was planning on doing what you said. But I do want to keep track of actual sizes in my reloading journal to track brass. After reading posts on here I am going to sort all my brass by head stamp to try and keep powder volume and pressures more uniform.

 

[427Cobra]

Re: Headspace gage bushing help

I set n forget, sorting brass by head stamp is a good idea for precision ammo, blasting ammo(AR15 and pistol) I don't, the only things in my reloading journal are, caliber, type of brass, type of primer, what powder and charge weight, what bullet and its seating depth by ojive, after that I log group size and at what distance, average speed, SD/ES, and Enviromentals. Trim length really has no bearing on accuracy, it's a safety issue, I don't trim to book minimum, I trim .010 from the end of my chamber, Sinclair sells a cheap tool to check it, anybody who trims to book minimum is just burning up there chamber faster.