Don't recall ever having a primer not go off.

[44 AMP]

So the sight in for the Savage 6mm CR.

is this a controlled round feed or push feed rifle?

Spring loaded inline bolt face ejectors push chambered rounds forward to headspace limits before firing.

Doesn't this happen with push feed systems anyway? The round is pushed into the chamber until it is stopped by the headspace limit, and then the extractor snaps over the rim. The spring tension of the ejector keeps the case from moving back any, so its not "tight" against the bolt face surface, until gas pressure pushes the case head back, AFTER the firing pin has impacted.

I can see a case being driven forward by firing pin impact (to the point where the inner face of the extractor claw contacts the forward face of the case rim IF it doesn't get stopped by the chamber headspace point before that, IN A MAUSER style controlled round feed action. Just don't see how it can happen in a push feed system.

 

[308Loader]

LOL! nick made a funny

 

[308Loader]

so... for the rest of us reading this can we assume that their was a primer seating problem or rifle head space issue?

 

[Reloadron]

Yes, all of the above.

Ron

 

[Unclenick]

It's most likely, but IIRC we had posts by a couple of folks who had problems with Winchester primers of certain lot numbers getting an unusually large number of failures to fire awhile back. So it is possible to have a faulty primer. When the OP pushes it out, I will be interested to learn if perhaps the anvil is missing. I've found those loose in a box of primers at some time in the distant past. I don't recall what make they were, but one of our domestic brands. It won't have been Federal, as their sealant glues the anvils in position.

 

[Longshot4]

Im back from a bow hunt. Well after reading most of the reply's. I realize that the reason I figured the shoulder could be set back. When I was seating the bullet. I got in a hurry not watching all details and failed to have one case not all the way into the shell holder. The case jamed as it was out of alignment. I suspected a problem but didn't see any damage to the case. It fead into rifle chamber. Also the cases were new Lapua. I was using a Lee hand tool and found the primers were very tight. I lubed it and took a reamer to a couple pockets and found no resistance with the reamer. I have never had sutch tight primers. CCI BR-4 primers.

So I might not have seated primer. Although I tried firing rifle 3 times. After I remove the primer Ill try putting a fresh primer into the same case for a test fire.

I can do that tonight.

 

[Longshot4]

Well well well So that's it. Just like the old manuals preached. Now this is why I like the Forum.

I pulled the Hornady SST 100gr. bullet. I did destroy the bullet as far as I'm concerned. So I dumped the IMR 4350 and noticed it didn't all come out. So I taped it good. still in there. I loosened it up with a long metal pin that finally did it. That's right it was caked in the bottom of the case.
So this is what happened. I had lubed the cases in the neck with non traditional type petroleum lube. Even though I hear people don't size new Lapua's. Some necks were slightly out of round. So I put them in the wash of a couple drops of Dawn with Lemi-Shine. Towel dry then cu-tip check and hair dried. Normal would be lay in Sun for a few hours. There must have been 1 with a drop of water. BINGO! Primer looked normal as before. Tried to fire it. No luck, Punched it. Since it fell into the pit of pervious wasted primers I couldn't tell if it fired. I put a fresh primer in the case and pop.

One of the morals of the story is. Let cases dry. So you don't make dough of your powder and use proper lube.

So at the range I wanted to get the scope on the bull and see how far I could go with the test loads. loads showed no concerns. The new scope well I should have read the pamphlet before I left. MRAD is new to me but not any more.

 

[Bart B.]

is this a controlled round feed or push feed rifle?

Doesn't this happen with push feed systems anyway? The round is pushed into the chamber until it is stopped by the headspace limit, and then the extractor snaps over the rim. The spring tension of the ejector keeps the case from moving back any, so its not "tight" against the bolt face surface, until gas pressure pushes the case head back, AFTER the firing pin has impacted.

I can see a case being driven forward by firing pin impact (to the point where the inner face of the extractor claw contacts the forward face of the case rim IF it doesn't get stopped by the chamber headspace point before that, IN A MAUSER style controlled round feed action. Just don't see how it can happen in a push feed system.

A push feed action can chamber a cartridge with way to little headspace and its extractor claw may not snap into the case extractor groove. Way too much head clearance can cause this.

 

[Longshot4]

The Savage is a push feed. And that plunger has a heavy spring. I wonder if having a lighter spring would help accuracy. I'm sizing a tight chamber.

 

[Bart B.]

The Savage is a push feed. And that plunger has a heavy spring. I wonder if having a lighter spring would help accuracy. I'm sizing a tight chamber.

I doubt it would help.

I've taken the bolt face ejector and spring out of 3 push feed single shot prone match rifles and their accuracy stayed the same.

Two 308 Win and one 30 caliber magnum. No more ejected cases going to ground to get dirty. Pull out the fired case then box it.

 

[44 AMP]

A push feed action can chamber a cartridge with way to little headspace and its extractor claw may not snap into the case extractor groove. Way too much head clearance can cause this.

The way you used "headspace" in this statement confuses me. a bit. I agree an undersized cartridge could be chambered and if grossly undersized enough, be too far forward for the extractor to snap over the rim.

But, "too little headspace" = "insufficient headspace" and insufficient headspace is the term for when there isn't enough room in the rifle chamber to close on a "normal" round.

Too much head clearance because the case is too short to be stopped in the correct position is "excessive headspace" for that combination of round and rifle chamber. Meaning there is too much space in the chamber.

 

[Bart B.]

The way you used "headspace" in this statement confuses me. a bit.

Sorry 'bout that.

I was referring to the common use of headspace on a rimless bottleneck cartridge from its head to the shoulder reference, same way their chamber headspace gauges are measured.

 

[RC20]

So I might not have seated primer. Although I tried firing rifle 3 times. After I remove the primer Ill try putting a fresh primer into the same case for a test fire.

Once the primer is dented it is almost 100% not going to fire. There is no longer an anvil smack relationship there. It not only is a hit, its a smack against the anvil and the dent now stops that from occurring.

With a dent the firing pin extends all its distance hitting nothing.

Only exception are the did not get grasped right and it had too much move in the chamber as it was sized to small for that chamber..

 

[RC20]

Too much head clearance because the case is too short to be stopped in the correct position is "excessive headspace" for that combination of round and rifle chamber. Meaning there is too much space in the chamber.

Some military rifles had really generous chambers, head space and side space.

SMLE is one, best fix is to fire form and then do minim bump back.

1917 was another though it was a long chamber. Head space was not excessive, it was to specification, it was intentional though and SAMMI not only did not exist, they wold not have cared if it did.

Battle rifles are a different bird of a feather from a civilian versions of its caliber that do adhere to SAMMI.

 

[Dufus]

Once the primer is dented it is almost 100% not going to fire.

I disagree 100%. My experiences have shown this to be a false statement.

 

[Unclenick]

SAAMI exterior case dimensions for civilian cartridges of military origin reflect what the military did at the time the civilian version of the cartridge was introduced. The civilian market allows for expanding bullets, which causes some divergence, but the .30-06, .308 Win, and .223 Rem cases all have the same external dimensions and the same peak pressure specs their military counterparts used originally. Later military changes are not usually reflected by changes in the SAAMI spec, though.

 

[reynolds357]

I have decapped hundreds. Never had one go boom. The real danger is trying to remove live military primers.

 

[reynolds357]

I disagree 100%. My experiences have shown this to be a false statement.

Agreed. I have never had one not fire on second strike.

 

[Bart B.]

SAAMI exterior case dimensions for civilian cartridges of military origin reflect what the military did at the time the civilian version of the cartridge was introduced. The civilian market allows for expanding bullets, which causes some divergence, but the .30-06, .308 Win, and .223 Rem cases all have the same external dimensions and the same peak pressure specs their military counterparts used originally. Later military changes are not usually reflected by changes in the SAAMI spec, though.

In the mid 1960's, I asked Winchester why their 308 cartridge pressure spec was 52,000 cup while the military 7.62 spec was 50,000 cup. They said the reference pre-7.62 NATO cartridges they got from Frankfort Arsenal in the early 1950's produced 52,000 cup in their test barrel. Small chamber and bore/groove dimensions will cause that difference between military and commercial systems.

 

[Unclenick]

I think the slight increase in throat length and diameter for the 7.62 chamber that occurred between 1952 and 1954 may be responsible. The round that measures 50,000 CUP in military pressure and velocity barrel may well read 52,000 CUP in a SAAMI P&V barrel which still has the original chamber dimension.


Chamber Reamer Design Dimensions:

.308 Win commercial
Shank 0.4370
Base Diameter 0.4700
Shoulder Diameter 0.4550
Neck-1 0.3462
Neck-2/Case Mouth 0.3442
Freebore Diameter 0.3100
Pilot Diameter 0.2990
Min. Chamber Length/Base-to-Case Mouth 2.0250
Base-to-Shoulder 1.3540
Neck Length 0.3210
Freebore Length 0.0900
Rim/Belt Thickness 0.2000
Shoulder Angle 20*
Throat 1*45”

7.62 NATO
Shank 0.4670
Base Diameter 0.4725
Shoulder Diameter 0.4560
Neck-1 0.3460
Neck-2/Case Mouth 0.3460
Freebore Diameter 0.3110
Pilot Diameter 0.2990
Min. Chamber Length/Base-to-Case Mouth 2.0250
Base-to-Shoulder 1.3560
Neck Length 0.3200
Freebore Length 0.1500
Rim/Belt Thickness 0.2000
Shoulder Angle 20*
Throat 2.5*