Full length sizing and headspacing

[Germz]

SKIP TO 1:00 MARK


Please educate me as to what tools are available to gauge the correct headspacing for my specific rifle chambered in .223

Do they make tools that check this besides generic gauges like


I've seen something that looks like a .223 cartridge on a stick that gets inserted into the chamber but am having trouble googling it.

Thanks for the input gents.

[Ghost_Maker]

this is what your looking for.....

http://www.hornady.com/store/OAL-Gauges/

if u shooting a bolt gun im sure it wouldbe useful.....

[C3nt3rMa55]

This is what you need in order to set your shoulder back accurately when setting your FL sizing die

http://m.hornady.com/store/Lock-N-Load-Headspace-Kit-With-Body-1-Each

[Germz]

Yea thats what I was talking about.

Really where I'm confused is:
I'm under the impression that depending on how tightly the barrel is seated into the upper receiver body defines how tight your headspace will be. I didn't smith my upper so I'm looking for a tool that will give me the exact OAL for my rifle so I know what specs to trim and size to.

I've fired my AR a ton with factory ammo with no probs leading me to believe a generic headspace gauge will work, but I think specifics will provide better results.

[C3nt3rMa55]

You get your headspacing measurements using that tool and brass that has been fire formed to your chamber, then you use the other tool with the dummy rounds, the first tool that was linked to to find the proper oal for your rifle by finding where the riffling starts and backing off a bit.


Here's a good article explaining shoulder set back and headspacing.

http://bulletin.accurateshooter.com/2007/11/tech-tip-shoulder-bump-how-much-is-enough/

[J-cat]

Really where I'm confused is:
I'm under the impression that depending on how tightly the barrel is seated into the upper receiver body defines how tight your headspace will be. I didn't smith my upper so I'm looking for a tool that will give me the exact OAL for my rifle so I know what specs to trim and size to.

You misunderstand.

Headspace is the distance from the bolt face to the middle of the shoulder. It is set at the time of chambering, not at the time of assembly of the upper receiver.

The easiest way to set-up your sizing die is to get a set of Redding Competition Shellholders. They are set in .002" increments to get your shoulder bumped within .002" of the zero clearance setting. With the assumption that your standard shellholder is a +.000" unit, you screw the sizer down against the +.010" shellholder and size the case. You try to chamber it. The bolt should not close. So you try the +.008" shell holder and so on until you find the one that sizes the case enough for the bolt to close easily. In my rifle, the +.008" shellholder causes a zero clearance fit, so I use the +.006" one for smooth operation.

That way you don't need gauges, probes, magic fairy dust, etc. It is simple and easy.

[BLR81]

You misunderstand.

Headspace is the distance from the bolt face to the middle of the shoulder. It is set at the time of chambering, not at the time of assembly of the upper receiver.

The easiest way to set-up your sizing die is to get a set of Redding Competition Shellholders. They are set in .002" increments to get your shoulder bumped within .002" of the zero clearance setting. With the assumption that your standard shellholder is a +.000" unit, you screw the sizer down against the +.010" shellholder and size the case. You try to chamber it. The bolt should not close. So you try the +.008" shell holder and so on until you find the one that sizes the case enough for the bolt to close easily. In my rifle, the +.008" shellholder causes a zero clearance fit, so I use the +.006" one for smooth operation.

That way you don't need gauges, probes, magic fairy dust, etc. It is simple and easy.

Certainly, that works, and I might do it that way if I were shooting Competition. I prefer to measure fire-formed brass with my Hornady LNL Headspace guage, then adjust the dies to simply set back .002 from that measurement.

Most of my fired brass will rechamber anyways, so on my bolt action rifles I mostly neck size anyways as to not work the brass as much. But when it does get to the point that it needs to be FL resized then I revert to the .002 measurement.

[not-fishing]

All this is fine but remember the true test is the size of your groups.

at least it is for me

[RandyD]

There is a lot of good advice above. The tool Ghost Maker linked you to is to assist you in finding where the lands begin in your barrel, and so that you can seat bullets the proper distance from the lands. The tool C3nt3rMa55 linked you to is to assist you in measuring the headspace using a fired cartridge from your rifle. This is the most accurate means of measuring your headspace. The method suggested by J-cat is a trial and error method, it works but you are left without an accurate measurement. When setting the headspace on a reloading die, generally you want to set the cartidge's headspace back .001-.002, on other actions such as a lever, pump or semiauto, you would want to set the cartridge headspace back at least .003 to insure smooth functioning.

[JagerDog]

Certainly, that works, and I might do it that way if I were shooting Competition. I prefer to measure fire-formed brass with my Hornady LNL Headspace guage, then adjust the dies to simply set back .002 from that measurement.

Most of my fired brass will rechamber anyways, so on my bolt action rifles I mostly neck size anyways as to not work the brass as much. But when it does get to the point that it needs to be FL resized then I revert to the .002 measurement.

I don't think I've had a piece of fired brass from rifle "X" that wouldn't rechamber in rifle "X" unless there was something hugely wrong indicated by flowing brass and enlarged primer pockets.

[GeoffLinder]

Another very easy and very accurate way to set headspace (shoulder bump) properly for YOUR rifle is to use a gauge like the one in the link below. You take a fired but unsized case from your rifle and measure with depth probe on a caliper to see where the case head sits compared to the step in the gauge. Then size a case and measure it same way. Keep adjusting sizing die until a sized case is 1.5 to 2.5 thousandths below where the unsized case was. Done!

http://www.lewilson.com/casegage.html

If you want the ammo to run in most any AR, then set die for about 3 to 3.5 thousandths below where a fired case measures.

[fguffey]

[FLIGHT762]

Another very easy and very accurate way to set headspace (shoulder bump) properly for YOUR rifle is to use a gauge like the one in the link below. You take a fired but unsized case from your rifle and measure with depth probe on a caliper to see where the case head sits compared to the step in the gauge. Then size a case and measure it same way. Keep adjusting sizing die until a sized case is 1.5 to 2.5 thousandths below where the unsized case was. Done!

http://www.lewilson.com/casegage.html

If you want the ammo to run in most any AR, then set die for about 3 to 3.5 thousandths below where a fired case measures.

While the Wilson case gauge works well (I own 3 of the Dillon drop in gauges) I've used them for many years, I eventually bought the Hornady LNL head space gauge set. For very near the price of one of the Wilson/ Dillon style gauges, the Hornady set will measure the shoulder bump on nearly every common cartridge out there. The Wilson/Dillon gauge will only measure the shoulder bump on one cartridge caliber (or a family such as the 308/,243,/260 and 7/08).

The other issue I've had with the Wilson/Dillon drop in gauges is that if you have a slightly bent case rim, the case will not drop into the gauge. You don't have that issue with the Hornady LNL headspace gauge set.

It's just my opinion that your money is better spent on the Hornady gauge set than the Wilson/Dillon style gauges. These gauges measure the distance/length of the case shoulder datum line. I've found the better term for this measurement is shoulder bump rather than using the terms "Headspace" or "Case Comperator". Makes it simpler as to what measurement you're referring to.

[fguffey]

[fguffey]