setting head space

[chetc]

i have changed a few savage prefits over the last few years, going to be doing another one in a few weeks, i got thinking on the last ones i did, i set the head space with the firing pin installed, would it not be easier to leave out the firing pin and possibly get a better feel.
chet

[RP12]

The firing pin isn't protruding when it's cocked.

[Robinhood]

The ejector is something that can cause pressure on the gauge. But this is go... no go, not this feels a little loose or this feels a little tight. i do like mine set on the short end though. Factory stuff has always been good on bolt close.

[RC20]

Something of a split in group opening on that one.

Having worked with various actions and head space, I find zero need to remove anything.

As RH noted, as long as factory ammo fits, new factory brass will as well.

It really depends on if you reload and or want to match multiple chambers.

If you make it too long a new cartridge (factory or home made) will not fire as the case moves with the firing pin.

Once you get it close enough, then that is not an issue.

For reload you can even go long, gain a tad of space and once fire formed do minimal shoulder bump back and no issues.

I have had fun trying to fit a K-31 chamber to a new reamed 7.5 x 55 Swiss chamber. The shoulders on the gauges do not agree.

So it was fired brass form the K-31 and some trial and error before I got it.

Normally I would not care, I have NYY that I can use in the K-31, but if the K-31 won't shoot it I want to shoot it in what I call the 7.5 LW which is the PPU (same mfg, different arrival method)

Ergo I do want that match up.

There is an awful lot of misunderstanding on head space and a lot of error in the issues (or lack)

As RH noted, worst you get it too tight and nothing will fit.

[Deadshot2]

When I change a barrel I find that that's a good time to do all the other "maintenance" as well. I'll strip the bolt and reassemble after cleaning but stop short of installing the ejector plunger, spring, and pin. At that point I install the barrel and not having the ejector makes for a lot better feel. I don't worry too much about the bolt feeling a little loose on the GO gauge as long as it definitely does not close on the NO-Go.

FWIW, I find that factory brass (component or ammo) is a little short to begin with. Only deal with new brass about once per year when I replenish my stock.

[Blackthorn]

I strip the bolt head and remove the cocking piece and cocking piece sleeve. This leaves the firing pin in place and holds the bolt retention pin in place. Gives me a better feel for the gauges especially when I am using scotch tape as my no go gauge..
I have found that steel gauges and extractors don't mix every time either.. The gauges tend to be harder than the extractors.

[chop house]

I strip the bolt head and remove the cocking piece and cocking piece sleeve. This leaves the firing pin in place and holds the bolt retention pin in place. Gives me a better feel for the gauges especially when I am using scotch tape as my no go gauge..
I have found that steel gauges and extractors don't mix every time either.. The gauges tend to be harder than the extractors.

i just did one this morning with a manson go-gauge that has (apparently) an ejector cutout on the gauge head. since the gauge is 'captured' by the ejector (yes, i meant to say 'ejector') and will turn with the bolt head i put a bit of lube on the gauge shoulder. i originally intended to remove the ejector, but the pin was so stubborn i left it in place. however i still believe i got a good feel by simply removing the firing pin. when i was working the no-go end of things i forgot and put some forward pressure on the bolt handle... of course the pin fell out.

those hornady or similar headspace comparator sets are very handy in this situation also. they can't be trusted to give 'absolute' dimensions, but you can figure a correction factor from measuring your gauge and correlating with either saami or gauge manufacturer data. the collar is bevelled, so in my case all brass and gauges measured short, but now i know where to 'zero' my calipers for each comparator bushing. in this instance my hornady factory brass was only 0.002 short of go gauge. so, between the gauge, the known brass, and some tape the job got done with ejector in place.

[RC20]

Good deal. Pretty much my routine.

Kind of fun isn't it?

My only fight was 7.5 Swiss, I think the new chamber and the old chambers contours are slightly different, had a heck of a time matching the K31 chamber and the 7. Build chamber but did get it there.

And for a first, the 1911 7.5 had a very short chamber, usually military guns are generous on chamber.

The 1911 if I shot it much gets the NYY heads stamp the K31 and the 7.5 can share the PPU.

[tobnpr]

Setting headspace to minimum spec (as Savage does it at the factory) requires exact "feel" of the parts and nothing that adds tension to or restricts free movement of the bolt assembly- anything putting spring tension on it needs to disappear.

With the go gauge in place (assuming you're setting to SAAMI minimum spec), the bolt handle should not fall completely without MINIMAL resistance at the end of the bolt throw (this is where the "feel" comes in). You never want to force this. Very light resistance as the bolt lugs go fully into battery shows contact with the gauge, for minimum headspace.

https://youtu.be/3am9juINIOM