Need Help with Type 38 Head Spacing

[madsenshooter]

The thickness of the semi rim on most factory ammo is a bit on the thin side in my opinion. I make my own brass from .303 or 30-40 with a .060 semi-rim. If the case of factory ammo goes all the way forward when hit by the firing pin, there's .010" headspace. There's a couple ways to keep the round from going all the way forward when struck. Maybe you can find a proper spacer with monofilament line, like they do rimmed .303. Or you could pull the bullets and seat them out into the rifling to hold the case to the rear. I have in the past greased the woefully small Norma cases so they wont grasp the chamber and will fireform back to the bolt face. Gotta remember not to set the shoulder back on those cases. I don't make a lot of 6.5x50, only one of my 38s still has it's original chamber, the others are 6.5x257.

[madsenshooter]

I see I commented on this before, skipped that page earlier!

[fguffey]

Head space: I am so lucky, my cases do not have head space. I use the length of the case from the datum/shoulder to the case head to off set the length of the chamber from the shoulder of the chamber to the bolt face. I do not expect anyone to understand any of that because it gets more complicated.

You have a protruding primer? What does that mean? It means you have clearance. The case is shorter from the shoulder of the case to the case head than the length of the chamber from the shoulder of the chamber to the to the bolt face.

Again, What does that mean? No one knows but the Shadow, he do. So someone should ask; "why is the primer protruding? Reason: The case head did not make it back to the bolt face when fired. WHY?

When fired the case locked to the chamber, with more pressure when fired the case would have stretched between the case head and case body. And that would have seated the primer.

I do not have any of these problems because I form my cases to fit the chamber.

And then it gets very complicated. (Back to clearance) I have fired rounds in my 8/06 chambers with .127" clearance; no protruding primers and no stretched cases between the case head and case body.

There are 'things I know' that a reloaders could do to understand what is going on when they pull the trigger; could do and 'do, most had rather talk tacky.

F. Guffey

[Sunray]

OP is 6 years old.
"...home made head space gauge..." There's no such thing. A headspace gauge is a precision made instrument that does not measure anything. It's simply a Go/No-Go gauge that tells you if a rifle is within spec.

[fguffey]

Head space: I am so lucky, my cases do not have head space. I use the length of the case from the datum/shoulder to the case head to off set the length of the chamber from the shoulder of the chamber to the bolt face. I do not expect anyone to understand any of that because it gets more complicated.

OP is 6 years old.
"...home made head space gauge..." There's no such thing. A headspace gauge is a precision made instrument that does not measure anything. It's simply a Go/No-Go gauge that tells you if a rifle is within spec.

"It's simply a Go/No-Go gauge that tells you if a rifle is within spec.."

A go/no go gage makes two measurements, one will go and the other will not go. And then there is the go-gage that is used to measure the chamber from the shoulder to the bolt face. It is not job to convince anyone that chamber go/gages have been made to measure the length of a chamber from go/gage length to go/gage length plus .250".

I was asked to make a set of go-gages that were go-gage length +.023". I suggested the collector/reloader allow me to show him how to measure the length of the chamber in thousandths from the shoulder of the chamber to the bolt face at no cost. He had 18 8MM57 Mausers with no way to measure each one.

F. Guffey

[PWC]

Since you are a young reloader, you may not have all the tools a ailable to you that the test of us do, hopefully a parent can help or has at least a caliper.

The length of the backed out primer is the amount of headspace. For safety, it should not be over .010, preferably
005.

Use your caliper to measure a just fired, new case, if it is less than .005-008 you can fire form new brass to your chamber by reloading with 60-75% of max load to make the brass "fit" your chamber. You can measure headspace with the primer set back (ok) or by putting masking tape (better) on a new unfired cartridge head, remove firing mechanism, place the cart in the mag and let the bolt strip it into the chamber. Add tape until you feel resistance or you can't close the bolt all the way.

Last good bolt closure is your working headspace.

Edit: Iforhot to say measure thethickness of the layers of tape, that is the headspace.

[fguffey]

The length of the backed out primer is the amount of headspace. For safety, it should not be over .010, preferably
005.

The protruding primer indicates head space? The protruding primer indicates clearance. Someone was complaining about this thread being 6 years old; after all these years and still reloaders do not know how to identify head space.

This is as slow as I can type; the protruding primer does not indicate clearance, the protruding primer indicates there is clearance.

F. Guffey

- - - Updated - - -

Last good bolt closure is your working headspace.

Head space is the distance from the datum to the bolt face.

F. Guffey

[JOHN COOK]

fguffy, have you published a book on headspace? If so how do I get a copy. I purchased a book titled “UNDERSTANDING HEADSPACE for FIREARMS. written by FRED ZEGLIN. It’s 52 pages of the best information I have read or had someone explain to me on headspace. By the way he doesn’t mention feeler gauges and all the extra comments you offer. Your comments are all bragging on how much you know and how stupid all other reloaders are and how superior your equipment is compared to other reloaders.



John in SC

[PWC]

Fguffey- Phil Sharp identified headspace as the distance between the cartridge head and the face of the bolt. He also said it could be called clearance meaning between the cartridge and bolt. He predated SSAMI I believe, and all the people I knew growing up, and still those I know now, understand for the reloader, headspace is the measurement of the distance between the bolt face and the cartridge head, most usually discussed for our reloaded rounds.

The measurement of the distance the primer protrudes from the head is a close approximation of what Phil Sharpe identified as "headspace". Using masking tape has/is an accepted alternate to find the distance between the bolt and cartridge, which most people understand to be headspace, but you prefer "clearance".

[JOHN COOK]

[Head space is the distance from the datum to the bolt face. [/QUOTE]

I agree with you on this statement.

John in SC