Setting headspace

[Lucky Shooter]

I'm working on a new 22-250 barrel and would appreciate any opinions
on how much/little headspace-----as compared to the GO GAGE.

This work is not for the general public and I think of SAAMI and the GO GAGE as
references, rather than absolute requirements.

I plan to use some unfired Win brass and have compared their headspace with
the GO GAGE------typically at about .007" shorter than the reading with the
GO GAGE.

My normal headspace ranges from a slight bolt-drop drag to a light crush fit
on a typical short piece of brass.

Other folks prefer to use the GO GAGE, in spite of the shorter brass.

The choice for reaming HS is open----logical reasons on how this is done ?

Will appreciate opinions.

A. Weldy

 

[dsculley]

I don't consider SAAMI when I set the headspace on my rifles unless I want the option of shooting off the shelf ammo. On my current F-Class rifle (6.5x47L) I set the headspace with a piece of unfired brass so that I had ~0.002" of clearance. This way, when I fire the brass and then re-size I am putting back to factory spec. My brass has lasted a long time this way.

Some say you must use a Go Gauge, but it is your rifle, do as you wish. I see no downside to the way I set mine. If I were to sell the rifle, I would disclose to the buyer how I did this so he would have the option of shooting it as is or reset headspace with a go gauge (not that I think anyone would be shooting factory ammo in this rifle!). Why would you want to allow your virgin brass to be expanded by 0.007"?

 

[ballisticxlr]

Basically the same as above but I set up for zero headspace. What that amounts to is I pick 1 case from a lot of new brass (for unbelted stuff) and set up to run zero headspace on that. My brass lasts forever that way and a case even a little out of spec won't chamber so my fired shots end up really consistent even if I do a stupid somewhere in the process. I will normally neck size only leaving a little donut near the neck/shoulder junction unsized to act as a center and keep doing that until chambering requires more force than a gentle push on the bolt handle. I think we all understand that this process makes the rifle we end up with OUR rifle and not one that should be expected to eat either retail ammo or anyone else's handloads.

it might cost me a few seconds at a match now and then but I like this system.

 

[riflewoman]

Rather than set your headspace to unfired cartridge cases, think about setting your headspace to fired cartridge cases that have been FL sized the way YOU like to have them sized in your dies. Other than that SAAMI minimum. That way you know your ammo will chamber.

 

[msinc]

I have to ask...what's the problem with SAAMI specs??? Been barreling actions for close to 40 years and haven't blown myself or anyone else up using SAAMI specs.
However, as long as you can:

A. Measure the cases for shoulder length.

B. Adjust your resize die so the cases match whatever you have set the chamber to.

C. Set the chamber size.

.......then you can make it just about anything within reason you want. The issue comes in when you want to sell the rifle, or as pointed out already, use factory ammo.
Personally, when I barrel an action I always have it so the empty bolt just closes on a go gauge and I can feel the take up. This is what I have always referred to as "zero" headspace or minimum headspace. The chamber matches the go gauge. As far as "advantages" or why, yep, with me there is always the real possibility that I might sell it. In fact, it is way more likely than me shooting any factory ammo. It's hard enough to find bullets that will shoot these days...I know the factories cannot make ammo that will do it!!!
All that said, if you have brass that is .007" longer {.003" out of spec.} than the go gauge I would load those with the bullet touching the lands for the first firing to make sure the case head is against the bolt. If there is some advantage to having the case flop around in the chamber loose I don't know what it is. I set the chamber at minimum or zero on the go gauge and size my cases to zero or -.001" under for all my bolt guns. If they end up -.002" I will still load and shoot them.

 

[yotehater]

The problem is the new undersized brass. If you set headspace there you might have trouble getting std sizing dies to size the brass back enough. I like to neck up a caliber and create a false shoulder to fireform that short brass. Now if you go the custom die route set it anywhere you like.

 

[Lucky Shooter]

Thanks for all the replies. I don't have any problems with SAAMI but am concerned
that the unfired factory brass is about .007" shorter than the GO GAGE.

As their name implies, SAAMI is about manufacturing rather than reloading.

Yotehater, I didn't even think about the possibility of a chamber so short that the
sizing die can't set the shoulder back enough----thank you for mentioning that.

It seems that the easy answer for me is to cut the chamber a bit short and lengthen it
if required.

A. Weldy

 

[swd]

I cut most of my chambers to go plus .002”. You might loose .0005”-.001” when you snug up the barrel. That .007” short new brass will only be short once

 

[msinc]

.........It seems that the easy answer for me is to cut the chamber a bit short and lengthen it
if required.

A. Weldy

You believe it's easier to chamber a barrel twice than to simply seat the bullets touching the lands so the cartridge is held safely against the bolt face only for the first firing???? I know this sounds confusing, but you are safe as long as the case head is very close to or against the bolt face and the bullet keeps it from moving forward in the chamber. The shoulder does not have to be touching, it is of course correct when it does, but if this wasn't safe or even slightly questionable I promise you I would never suggest it.
Buddy, it would seriously make more sense to throw the bad brass away and try again with new/different cases then to chamber a barrel twice, but .....do as you wish.

 

[NorCalMikie]

I don't bother to use gauges anymore. All my rigs (except my gas guns) are chambered for wildcats and are set on the snug side. The less you move that brass when sizing, the longer it lasts. Also depends a lot on the type of die you use. I use bump dies and the brass doesn't get a chance to grow so almost no trimming needed, ever. None of my rigs will chamber factory loaded ammo. I've tried it on my 6 BR. If I can rechamber a fired piece of brass with no issues, I'am good to go.
IMHO, too much excess room in SAAMI chambers. If you learn NOT to push the shoulder back too far when resizing, you can get by using SAAMI specs.
Standard dies, shoulder gets moved too far, round gets fired and shoulder blows out. With that happening 4 or 5 + times, all you'll have to think about is "how do I get that broken case with the head gone out of my chamber"?

 

[varget204]

I buy MANSON Precision Go Gages,and use .001-.002 shim stock,or paper/tape on back of Go Gage for the No-Go Gage,that gives me Minimum Headspace,Sammi is usually .010 difference,i set mine at .002 max,More accurate .Less case stretch,i bump shoulders .002,they always fit chamber.If you have a Max chamber,bumping cases that far.you are more apt to get stretched cases and casehead seperation,long before a Minimum chamber would

 

[Lucky Shooter]

Thanks again msinc.

I'm an old hand at seating bullets into the lands for fire forming new cases. I've had
quite a few 22-250's with factory chambers but this will be the first one I've done
for myself. I've had ample opportunities to blow shoulders slightly forward.

I've learned a few new things since starting to do my own barrel work----one thing
is that most new factory brass had shorter headspace than the SAAMI gages. The
magnitude of these differences surprised me-----never even gave it a thought before.

The future sale of the rifle is no concern to me.

Just need to make a smart choice between blowing shoulders forward or cutting a shorter
chamber to match the brass. As usual with shooters, there are differences of opinion.

A. Weldy

 

[carlsbad]

If factory ammo will never be fired, then Sammi spec is somewhat meaning less. You can make it toward the long end if you want a couple grains more boiler room. Some make it short,or even shorter than sammi, to avoid overstretching the brass on first use.

If I am chambering a barrel that I already have a die set up for, I make it match the old barrel. If I have more than one rifles in this chamber, or the customer has more than one, I make them match each other so the dies will shoulder bump for both.

 

[dminn1]

Here in lies the beauty of the barrel nut system for those of us without access to lathes or the skill to chamber a barrel ourselves. With very little work we can set and reset headspace to match any brass we may want to use or if we are selling a rifle to set headspace to SAMI spec.

 

[yotehater]

Thanks again msinc.

I'm an old hand at seating bullets into the lands for fire forming new cases. I've had
quite a few 22-250's with factory chambers but this will be the first one I've done
for myself. I've had ample opportunities to blow shoulders slightly forward.

I've learned a few new things since starting to do my own barrel work----one thing
is that most new factory brass had shorter headspace than the SAAMI gages. The
magnitude of these differences surprised me-----never even gave it a thought before.

The future sale of the rifle is no concern to me.

Just need to make a smart choice between blowing shoulders forward or cutting a shorter
chamber to match the brass. As usual with shooters, there are differences of opinion.

A. Weldy

I wonder sometimes if some of the brass hitting the market for reloading has been rejected for factory ammunition as too short on SAAMI specs. Hardly anything is thrown away, just sold off as seconds.

 

[Texas10]

When I first installed my X-Caliber 22-250 barrel I used a new piece of Lapua brass instead of a headspace gage. And upon first FL sizing of the fired brass, I found my die bottoming out before bumping back the shoulder. So I had to buy a go gage and re set the barrel to a slightly longer chamber, which got me thinking about increased case capacity. Hmmmmmm.....

 

[tomswede]

The brass is probably to spec. For it to always fit they have to be shorter than the min headspace gage. Given some variation .007 does not seem that excessive. Never had any issues with setting head space to min, fire the new cases and then size for .002-.003 shoulder set back depending on application.

 

[Lucky Shooter]

I have found that, without modifying the sizer die or shell holder, that I can't resize my brass any shorter than SAAMI minimum.

Since this rifle will eventually belong to family, I'll stick with standard dimensions rather than modifying things.

I never realized that sizing dies had such a limit but now I know.

Thanks for all the help.

A. Weldy

 

[Dusty Stevens]

If you go .007 short youre losing capacity plus limiting your sizing die choices. Go with the actual gage, fireform your brass and always be happy.

 

[Lucky Shooter]

Thank you Dusty----after looking at the real numbers, that's what I'll do.

I'm glad I took the time to go through this and clear up some misconceptions.

A. Weldy