Pierced primer!!

[lngstrt]

Striker sticks out .043. The bolt head angle is about exactly like Ed's diagram. The head itself, a #2, measures .633 anywhere I measure it. Right in the middle of the #2 range.

[Edward Horton]

Lngstrt

From everything you have told us so far every thing looks good , you just might have had a faulty primer. Keep shooting the rest of the box and see what happens.

I once bought a brick of 500 Remington primers and found out too late that lot number had been recalled. I was asleep at the switch when I was out shooting at the range and didn’t notice that some of the primers were rupturing which in turn eroded the face of the bolt. The good news was Remington repaired the damage for free and I now check every single primer after firing.

NOTE: Bradtx has many times in our forums stated the following very good advice, use Remington factory ammo as your “control” ammo to judge all other ammunition by.

If you plan to reload I would order Prvi Partizan loaded ammo that sells for around $13.00 a box of 20. The Prvi ammo case is .010 thicker than any other brand of ammo and the cases will last longer than any other brand when reloaded.

[lngstrt]

Ed

Sounds like a plan.

I have 8 rounds left in that box and 3 more boxes of S&B. Then I have 360 rounds of 1936 surplus.

I'll be looking for some Remington and I plan getting Prvi for the future. I've seen your comments on Prvi several times but ... ya shoots what ya gots!

Thanks all for the input

[srjg3432]

It is just possible that the cause is only a dud primer amongst the millions made each week.

I have had 3 examples of pierced primers

1 8mm milsurp
1 30-06
1 .303

The last 2 were reloads, fired from rifles I shoot a lot. We are talking about hundreds of rounds through a rifle, then suddenly, a pierced primer. In these cases, I don't believe its a rifle or firing pin fault, just that one in a million primer.

Hands up if you have ever had primers without the anvil in it, or no compound in it.
Not me personally yet, but its happened to friends and the above was found upon examination.

[jmoore]

Have seen 3 factory rounds w/ inverted primers, the latest (3 weeks ago), a Federal match 30-06.

[John Kepler]

All VERY good info in this thread! I would suggest one other area to check, which is the firing pin protrusion length. I've had a couple of rifles where it was excessive, and pierced primers are one of the results.

[Jim K]

While a very sharp and pointy firing pin can cause a true "pierced" primer, what we call a "pierced primer" is not the result of "piercing" at all; it is almost always the result of a weak firing pin blow.

The combination of the firing pin spring and the firing pin mass must be sufficient not only to fire the primer but also to prevent the internal pressure from pushing the firing pin back and forcing a tiny disc of primer metal into the firing pin hole, causing the "piercing."

Some guns have a mechanical block that keeps the firing pin from being pushed back, but most bolt guns, like the Lee-Enfield, do not. Also note that since that little disc of brass has to go someplace, it ends up inside the bolt. A single "pierced" primer will rarely cause a problem, but if there are enough, those tiny pieces of primer metal can block the firing pin and the rifle will not fire at all.

Incidentally, firing pin protrusion is never the problem, since no matter what the protrusion the firing pin will stop in the primer. No firing pin spring ever put in a gun has enough power to actually punch a hole in the primer. Firing pin protrusion needs to be controlled for other reasons, but not to prevent pierced primers. (Using a modified rifle, and under test conditions, I have created a firing pin protrusion of almost 1/4 inch, with no problems.)

Jim