misfire virgin, please help

I donno about that, I've seen multiple rounds on the ground in 'action bays' on civilian ranges.

You too , eh?

Reality vs. fantasy from a book.

Maybe the range rules at your range state that they are supposed to be disposed of, but my experiences in about half the Provinces, would contra-indicate the attestation of the fella living in a perfect world.
Look up any of the words that you don't understand. :)

Cheers
Trev
 
I donno about that, I've seen multiple rounds on the ground in 'action bays' on civilian ranges.

Our range has a drop tube to dispose of unfired rounds if one wants to use it...

Occasionally I have noticed live pistol rounds left on the ground after the Police have rented our range.
 
Try a primed case right now... no need for a range... if it goes bang look at the primer. If the primer has backed up, that is how much excessive head clearance (not to be confused with head space) your reload has in this chamber.

No. When the primer fires it generates enough pressure to force the case forward and primer back. It pushes the shoulder back. The primer protrusion is the sum of excess case headspace plus the increase caused by the shoulder push back.

What the OP can do is partially seat a primer (set primer on bench, place case over primer, and tap inside of case with a long bolt to get primer started). Then chamber this round and close the bolt. If the case comes out with significant protrusion, there is a headspace issue. The excess headspace could be the rifle or the case shoulders. My guess is the latter.

It is unlikely the firing pin protrusion got changed. That would cause the problem.

If the case shoulder is too far back, seat a cheap bullet upside down so it hits the rifling hard. This will keep the case head firmly on the bolt face and fire form the case without stretching.
 
Try a primed case right now... no need for a range... if it goes bang look at the primer. If the primer has backed up, that is how much excessive head clearance (not to be confused with head space) your reload has in this chamber.

No. When the primer fires it generates enough pressure to force the case forward and primer back. It pushes the shoulder back. The primer protrusion is the sum of excess case headspace plus the increase caused by the shoulder push back.

I stand by what I stated... when that primer backs up, it will measure how much excessive head clearance (not to be confused with head space) your reload has in this chamber. (In this chamber is taking into account any head space that rifle may have).

Is there really any difference in the end result between what you are saying and what I am saying?

"In this chamber" is taking into account the amount of what you call (incorrectly in my opinion) "shoulder push back".

The shoulder of the case does not push back unless you are doing that in a sizing die. The shoulder of the case is driven forward to contact the shoulder in the chamber.

Since I have used two different terms "excessive head clearance" and "head space" I will clarify the difference. It may be confusing to some. It took me a while.

Head space is a fixed measurement determined when the barrel is assembled to the action. It is measured with an exact measurement steel go gauge. The re loader can do nothing about changing this measurement.

The re loader can how ever change how the reloaded case fits in this chamber... how tight it fits or how loose by adjusting the sizing die... this is adjusting "case head clearance" which refers to the fit of the case in that chamber. Headspace can be adjusted by a gunsmith by machining the fit of the barrel and chamber to the action and bolt.

Terminology is important.
 
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You could always just look the word protocol up.

........

Cheers
Trev

Actually I did look it up - Websters Dictionary:
"Definition of protocol for English Language Learners. : a system of rules that explain the correct conduct and procedures to be followed in formal situations. : a plan for a scientific experiment or for medical treatment. : a document that describes the details of a treaty or formal agreement between countries."

I don't believe that experiencing a misfire or hang fire qualifies as a 'formal situation' .... unless of course you are David Niven -- who I believe may be the only individual to show up at a small arms range in formal dinner dress ('Tux') :)
 
I stand by what I stated... when that primer backs up, it will measure how much excessive head clearance (not to be confused with head space) your reload has in this chamber. (In this chamber is taking into account any head space that rifle may have).

Is there really any difference in the end result between what you are saying and what I am saying?

"In this chamber" is taking into account the amount of what you call (incorrectly in my opinion) "shoulder push back".

The shoulder of the case does not push back unless you are doing that in a sizing die. The shoulder of the case is driven forward to contact the shoulder in the chamber.

Since I have used two different terms "excessive head clearance" and "head space" I will clarify the difference. It may be confusing to some. It took me a while.

Head space is a fixed measurement determined when the barrel is assembled to the action. It is measured with an exact measurement steel go gauge. The re loader can do nothing about changing this measurement.

The re loader can how ever change how the reloaded case fits in this chamber... how tight it fits or how loose by adjusting the sizing die... this is adjusting "case head clearance" which refers to the fit of the case in that chamber. Headspace can be adjusted by a gunsmith by machining the fit of the barrel and chamber to the action and bolt.

Terminology is important.

If the case is of light construction (as in the OP's situation) the sequence goes like this:

Firing pin hits primer and drives case forward, against the shoulder, if it was not already firm against chamber shoulder.

Primer ignites, generating about 10,000 psi. This pressure drives the primer back out of the case and the case forward, shortening the case.

If the powder charge ignites, the pressure expands the case and, depending on pressure, pushes the case back to the bolt face with no case stretching (if it is a mild load) or the shoulder position stays forward and the case stretches back until it hits the bolt face.

There is a way to test this. Take an empty, primed case case and measure it in a gauge. Then fire the empty case and measure again. The case should now be shorter; compression of case caused by the primer.

I am quoting what I have been taught and assumed for years. I have never actually conducted a test to verify. I will do the test in the next half hour and report what I find. Perhaps you can do the same and report? You may have better tools than I do.
 
No. When the primer fires it generates enough pressure to force the case forward and primer back. It pushes the shoulder back. The primer protrusion is the sum of excess case headspace plus the increase caused by the shoulder push back.

What the OP can do is partially seat a primer (set primer on bench, place case over primer, and tap inside of case with a long bolt to get primer started). Then chamber this round and close the bolt. If the case comes out with significant protrusion, there is a headspace issue. The excess headspace could be the rifle or the case shoulders. My guess is the latter.

It is unlikely the firing pin protrusion got changed. That would cause the problem.

If the case shoulder is too far back, seat a cheap bullet upside down so it hits the rifling hard. This will keep the case head firmly on the bolt face and fire form the case without stretching.

Thanks Ganderite ... that makes sense ... would annealing a case neck so that it is fairly soft potentially cause the shoulder to be pushed back even farther. A smaller flash hole have an effect?
 
I ran the test. Used a factory Winchester 223 and a military 7.62. Pulled the bullets and measured the case headspace.

IMG_2299.jpg


IMG_2300.jpg


223 2 thou shorter than 0

7.62 2 thou longer than 0

Fired the cases.

223 is now 0. That is, the shoulder has moved forward 2 thou.

7.62 is now -1 thou. Case is now 3 thou shorter.

Maybe small primer does not have enough energy to compress the case? I would need to run 10 of these tests in several calibers before deciding I have proved something to myself. I won't be doing that.
 
I don't know if you would get better results with a case that was just fully sized and primed, pulling the bullet may change a dimension that is easily changed again.

I also have never heard of or suspected a case shoulder could be bumped back by the force of the primer... taking into account the springiness of brass...
 
I ran the test. Used a factory Winchester 223 and a military 7.62. Pulled the bullets and measured the case headspace.

IMG_2299.jpg


IMG_2300.jpg


223 2 thou shorter than 0

7.62 2 thou longer than 0

Fired the cases.

223 is now 0. That is, the shoulder has moved forward 2 thou.

7.62 is now -1 thou. Case is now 3 thou shorter.

Maybe small primer does not have enough energy to compress the case? I would need to run 10 of these tests in several calibers before deciding I have proved something to myself. I won't be doing that.

Maybe a slightly 'sloppier' chamber in the .223? Tighter extractor grip on the groove?
 
The primer does not "compress the case". It may expand the brass sufficiently to cause hs to shorten up a bit. Primer protrusion will usually equal head clearance but maybe not entirely since the firing pin may offer sufficient support to prevent the primer from contacting the breech face.
If a barrel is fitted conventionally, without a nut, there is no need for a headspace gauge for subsequent installations. The use of a nut simply allows the barrel fitter to avoid having the ream the chamber to a precise depth.
I suspect the gunsmith may have used a fired and re-sized case as a gauge and the case contacted somewhere other than the shoulder which gave him a false reading. he'll have to set it back to correct the headspace.
 
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