Help me understand what I am seeing.

[dellet]

Okay, maybe I am confused. Maybe you can educate me. If I gave you a loaded round, that the case was known to be at the minimum SAAMI spec. What would you do with it to determine the headspace in the rifle you fired it

You already have your answers.

A fired case from your chamber measures 1.4615”, that will probably .002-.003” short of your actual chamber dimension. Brass rarely grows to full chamber on first firing.

Compare that number to SAAMI minimum, the spec sheet has been posted. Spoiler, your chamber will be within spec for headspace, the Savage rep is correct.

If you have .011” headspace after sizing, it’s your fault. The sizing die is not set correctly for minimum set back, maximum base to shoulder length. The die is set minimum brass to shoulder.

You need to learn to read the SAAMI spec sheets as well as a reamer print, only then will all this make sense. For instance if you look at the specs for maximum cartridge base to shoulder, it’s 1.4666” while the minimum chamber is 1.4636”. So you can be within SAAMI spec and have any where from a .003” crush fit or as I said earlier .014” space.
This is why you assume nothing, and measure everything if you load your own.

If you want to argue freebore length with savage, you might have a leg to stand on, because again it is not a true SAAMI chamber. Good luck with that. It before you say it is out of spec, you’ll need a measurement. Heads up you can’t use cartridge base to ogive, you will need to measure shoulder datum to where the lands start to rise off groove diameter.

 

[Pirate69]

To the OP. What is keeping you from using a go/no go gauge to check the headspace and to simply reset the headspace, if needed, using the nut on the barrel?

A HS check and reset, if necessary, would be very easy to do. And that would satisfy me as to having a safe rifle that I could sell and feel good about it. But is that reset masking another problem. Remember that there has been an increase in freebore while Savage says the HS is good. The measurements I have taken indicates greater than 10/1000" in one case and 6/1000" in another. Which one is correct? Probably neither one. Savage has serviced the rifle and it is unclear why the increase in freebore with a HS that is still reported as good. I don't want to do any changes until Savage can explain why the increase in freebore with a HS that is still reported as good. I want them to correct anything that needs to be corrected if the service was inadequate. As to the HS question, I am just trying some things to see what results I get and maybe learn a thing or two and sharing the information. And it seems to be working as I am getting lots of comments back. Believe me, the final measurement will be a gauge going into the chamber.

 

[243winxb]

freebore

https://www.brownells.com/reloading...s/sinclair-chamber-length-gage/?sku=749000811
This will find the maximum chamber length.Most times it will be .010" longer then maximum trim length.
BRASS TRIM LENGTH SHOULD NEVER BE LONGER THEN 1.760 inches, for 223/5.56.

The .224 cylinder or free bore is .025" long. SAAMI standard.

More @ SAAMI

 

[Pirate69]

I think there have been some concerns that my full length die was oversizing the brass and that was generating the excessive headspace measurements. In other words, a case with a shoulder datum less than the minimum SAAMI spec. One of my measurements used a full length sized case to approximate the minimum SAAMI spec. This is what the die manufacturers say about the potential to oversize. If I am reading this correctly, it is saying a die should not resize a case to a dimension less than the SAAMI. Sorry to poke this hornets' nest.


2. Forster Products — Bushing Full‑Length Sizing Die Instructions

Link:

https://www.forsterproducts.com (navigate to Bushing Full Length Sizing Die instructions)

Relevant Documentation:

Forster states that their FL bushing dies size the case “just enough to fit in a minimum‑sized SAAMI rifle chamber.”

This confirms:

• Dies are not minimum‑dimension cutters

• They size toward minimum chamber fit, not minimum cartridge spec

• They intentionally avoid over‑working brass



3. RCBS — Full‑Length Die Set Product Page

Link:

https://www.rcbs.com (search: “Full-Length Die Set Group D”)

Important Note:

RCBS states their FL dies bring brass “to SAAMI minimum cartridge dimensions.”

This is the exception, not the rule — and even RCBS acknowledges in tech support emails (not publicly posted) that brass spring‑back prevents true minimum sizing.

Lee Precision explicitly states

• FL dies are cut above SAAMI minimum

• Minimum sizing would shorten case life

• Dies are cut to the middle of the SAAMI range

Forster documentation confirms

• Dies size brass “just enough” for minimum chambers

• Not to minimum cartridge dimensions

SAAMI confirms

• Manufacturers are free to cut dies anywhere within the tolerance band

• Minimum sizing is not required

RCBS provides contrast

• Their dies aim for minimum, but brass spring‑back prevents true minimum sizing

 

[243winxb]

The .224 cylinder or free bore is .025" long. SAAMI standard.

But not set in stone. Can be longer or no freebore at all. Custom chambers.

To measure, i take a flat base bullet and put in case, nose first. COL needs to be long as possible, before chambering the dummy round.

Light hold on the bullet can be done my making the neck slightly oval.

Test a few times, till the close to the same measurement is seen, a few times.

 

[243winxb]

A tool like the Hornady comparator has nothing to do with the rifles headspace/ correct term is "Head Clearance."

Hornady comparator is to compare fired brass to full length sized brass. Nothing Else.

 

[243winxb]

Used to check headspace of the M16 rifle. If bolt closes on this field gauge, the rifle should be taken out of service and repaired.
This type of gauge does not require the removal of the extractor and ejector like other gauges , when checking the headspace.



See bottom of page for the difference in the 3 Headspace gauges

 

[243winxb]

This Wilson gauge measures minimum & maximum head to datum length. Can check trim length also. Does NOT check case body diameters. Can be hard to see.

The Hornady comparator is much more precise.

 

[DShortt]

To the OP- may I suggest you verify that the head space is within spec using GO and NO GO gauges first.

Then establish your FLS die setting. I'm not going to open yet another can o' worms in this thread by suggesting exactly how for obvious reasons.

Then set about determining your freebore.

And remember what was said in post #65.

As long as the freebore length allows you to load a bullet length that the rate of twist is adequate to stabilize, that exact length isn't an issue. It may not be exactly what you had in mind. But if it is serviceable/usable, it's really not an issue.

 

[243winxb]

Freebore- I like the bullet to seal the bore, before the bullets base leaves the case mouth. Less blowby, longer barrel life. (my thinking)
My Savage Axis info said a Sierra 69 gr match bullets is best in their 9 twist barrel rifling. It shoots well.

When a free bore is to long and large in diameter, powder will not burn correctly. Should see soot and unburnt powder. Lower then normal velocity. Accuracy will be poor.

Online, there was a 260 Rem, custom barrel with a freebore problem. Cut to long & large. The fix was barrel setback & rechamber.
When you tell the gunsmith, chambering your rifle, its for long heavy bullets, your going to get a looong free bore.

Seen a factory Savage 6.5CM, where Hornady factory ammo would not allow the bolt to close. Short freebore.
Rifle returned to Savage for adjustment. Her dad seated a few factory rounds to a shorter COL. This worked also.

 

[JLittle]

Find a local smith with go and no go’s. The chamber is likely on the large end of the Saami spec so everybody’s factory rounds will fit. The factory new sized brass is likely on the small end of the Saami spec so it will fit everybody’s chamber. Reloading dies are generally made to size to fit all of the above. And use of reloads will likely void the factory warranty of most firearms manufacturers. Freebore and headspace do not correlate.

 

[swd]

A HS check and reset, if necessary, would be very easy to do. And that would satisfy me as to having a safe rifle that I could sell and feel good about it. But is that reset masking another problem. Remember that there has been an increase in freebore while Savage says the HS is good. The measurements I have taken indicates greater than 10/1000" in one case and 6/1000" in another. Which one is correct? Probably neither one. Savage has serviced the rifle and it is unclear why the increase in freebore with a HS that is still reported as good. I don't want to do any changes until Savage can explain why the increase in freebore with a HS that is still reported as good. I want them to correct anything that needs to be corrected if the service was inadequate. As to the HS question, I am just trying some things to see what results I get and maybe learn a thing or two and sharing the information. And it seems to be working as I am getting lots of comments back. Believe me, the final measurement will be a gauge going into the chamber.

Savage would have to make a .083" mistake in setting headspace -if- the same reamer was used to explain that much increase in freebore. Which while possible is highly doubtful. Manufactures like Savage, Remington and Winchester have LOTS of reamers, all in different states of condition including free bore length and diameter depending on how many times they have been used and re ground. There is a 99.999% probability the free bore is different because a different reamer was used.

If your questioning headspace checking it with gages, including taking the ejector in and out, is about a 5 minute job. And is the VERY first thing any gunsmith would have done when presented the question. And would have saved you a lot of time and frustration.

If the headspace is long or short it's quick and easy to set correctly. The freebore will only move as much as the change in headspace, if there is any change in that dimension.

So #1 if you have a headspace question the first thing to do is check it with the appropriate go/no go gages.

#2 If you send a factory rifle back for work that involves putting a reamer in the existing chamber you have about a 50/50 chance of any and or ALL of the chamber dimensions including freebore, neck diameter etc. coming back different. It might be slight, or in your case a lot in the FB dimension.

#3 dimensions and tolerances in dies, factory ammo and factory rifles are all over the place. Don't trust any of them as being in spec. Ammo and new brass is always short and usually by a LOT so it fits in everything. Dies, now there's probably the most inconsistent, all over the place tool we regularly use. Always check for the proper amount shoulder set back and never ever assume touching the shell holder is the correct place to be.

 

[DShortt]

Savage would have to make a .083" mistake in setting headspace -if- the same reamer was used to explain that much increase in freebore. Which while possible is highly doubtful. Manufactures like Savage, Remington and Winchester have LOTS of reamers, all in different states of condition including free bore length and diameter depending on how many times they have been used and re ground. There is a 99.999% probability the free bore is different because a different reamer was used.

If your questioning headspace checking it with gages, including taking the ejector in and out, is about a 5 minute job. And is the VERY first thing any gunsmith would have done when presented the question. And would have saved you a lot of time and frustration.

If the headspace is long or short it's quick and easy to set correctly. The freebore will only move as much as the change in headspace, if there is any change in that dimension.

So #1 if you have a headspace question the first thing to do is check it with the appropriate go/no go gages.

#2 If you send a factory rifle back for work that involves putting a reamer in the existing chamber you have about a 50/50 chance of any and or ALL of the chamber dimensions including freebore, neck diameter etc. coming back different. It might be slight, or in your case a lot in the FB dimension.

#3 dimensions and tolerances in dies, factory ammo and factory rifles are all over the place. Don't trust any of them as being in spec. Ammo and new brass is always short and usually by a LOT so it fits in everything. Dies, now there's probably the most inconsistent, all over the place tool we regularly use. Always check for the proper amount shoulder set back and never ever assume touching the shell holder is the correct place to be.

I still bet Savage replaced the barrel with production stock if Savage did anything.
Obviously, the same reamer and machine set-up would not have made the replacement barrel. So it makes sense that the dimensions don't match the original, particularly if the original was out of spec in some way.

Nor does it make sense that someone would set the barrel and reamer up to re-cut the chamber and perform whatever machining needed correction on the original barrel when they have a warehouse full of barrels on hand that just need installation and head spacing via the barrel nut system.

 

[dellet]

All of your questions can be answered by looking at the reamer prints below. Everything from bolt face to cartridge neck end is the same. Everything from case neck end to lands is different. This is how you change freebore without changing headspace.

The same can be done simply with a dedicated throating reamer.

Again will point out your measurements seem to be for a 5.56 chamber which is not uncommon in cheap factory rifles chambered in 223, and some not so cheap ones also.

 

[swd]

I still bet Savage replaced the barrel with production stock if Savage did anything.
Obviously, the same reamer and machine set-up would not have made the replacement barrel. So it makes sense that the dimensions don't match the original, particularly if the original was out of spec in some way.

Nor does it make sense that someone would set the barrel and reamer up to re-cut the chamber and perform whatever machining needed correction on the original barrel when they have a warehouse full of barrels on hand that just need installation and head spacing via the barrel nut system.

Yea, it's probably easier to grab a new one out of the pile. Although it would be easy to just run a reamer in by hand with some lube but doubtful they'd bother to. The original barrel probably got tossed in the scrap pile.

 

[dennisinaz]

This whole discussion needs put on pause until he checks his headspace with a gage.

His concern is the great increase in freebore. This would suggest that Savage used a different reamer than the original chamber. It's very unlikely that they would work on a rifle with a chamber problem and not set it correctly.

As far as setting up dies. You should always contact the shell holder. Mic McPherson shows in his excellent book how doing otherwise allows a significant variance in head space between various cases based on the brass softness etc.
His solution was to use the Redding shell holder sets that have different thickness.

To the OP. Get s hold of a set of gages and check your chamber. No point in speculation.

 

[Aaron23]

I’d probably just look at the ads for the rifle and see if it says safe for 5.56 ammo.

Many manufacturers chamber closer to 5.56 specs than 223 for safety reasons. I think you’ll find the base to lands measurement you have now is more likely 5.56.

That’s what it sounds like to me (with my admittedly poor reading comprehension skills wut I have).

He had a nice and tight chamber and the factory honked it out in both directions.

Agree with what another member said about getting gauges and actually measuring stuff... At bare minimum a go gage.

 

[TA17rem]

This will find the maximum chamber length.Most times it will be .010" longer then maximum trim length.
BRASS TRIM LENGTH SHOULD NEVER BE LONGER THEN 1.760 inches, for 223/5.56.

or .020 or .030 or less in some cases. you never know what you got till you look at each chamber. Thanks to Al N. I got that all squared away.

 

[Aaron23]

Thanks all. Next step is the NoGo gauge and then maybe a discussion with Savage. I had major back surgery on 10/20/25. Two rods, four spacers and eight screws. Compounded my problem with a fall on 1/15/26 that resulted in a compression fracture of the back. Currently wearing a solid molded back brass to support the back while the fracture heals. I am moving slow and only short distances. The rounds I shot recently was an adventure.

Wishing you a speedy recovery and luck with your Savage as you get it all sorted out.

Going to suggest a Go gauge first if you only have the finances available for a single gauge. It is easier to add thicknesses of tape to the back of a go gauge and get a measurement than it is to remove material from a nogo gauge to get a measurement...

That lower step on my Dillon case gauge here is dead perfect with a 1.4636 .223 REM HS GO gauge.

 

[SKWERLZ]

I'd still bet that if the original barrel was in fact out of spec, they replaced it in whole from production stock. I very much doubt they'd bother with cutting/rechambering the original barrel.

I concur.