Primers falling out

[Oldhand]

Hello, I'm new to 300 Blackout but have reloaded for thirty years. I heard one of the manufacturers of ammo for this caliber had a recall of their ammo for primers falling out. I have noticed on the Remington cases I have on hand some have an ordinary bottom and some have imprints around the primers pinching in the surrounding metal. I guess this is to hold in the primers. After removing the old primer and reaming the pocket round again is there something else required to hold in the primers?

[Oldhand]

I guess I should add I am using CCI small rifle primers, which seat the same as any other primer I have used. Guess I can just go out Friday and see what happens. I am using Nosler Custom Competition 168 grain HPBT over 18.8 grains of Accurate 1680. Using this bullet as it is what I have on hand from my .308.

[dellet]

I guess I should add I am using CCI small rifle primers, which seat the same as any other primer I have used. Guess I can just go out Friday and see what happens. I am using Nosler Custom Competition 168 grain HPBT over 18.8 grains of Accurate 1680. Using this bullet as it is what I have on hand from my .308.

The primers were staked when Barnes started loading for Remington, there had been a few problems.

As far as your load, I am not familiar with the Nosler 168, but I am enough with that weight and powder. As long as you are not severely compressed, or jammed into the lands, if your chamber and gas system are in spec, then there would be no reason for a primer to pop.

[Oldhand]

Thank you for your response. I am using a Remington 700 AAC SD so no gas system to worry about. My friend who got me into the 300 Blackout had purchased some ammo that was recalled and when I searched the subject here I found reference to primers falling out but no explanation as to why.

[threehundred]

"why primers fall out"

My limited experience has taught me that the only possibility of a primer popping out, is when the head space is too short, aka, too much space between the case head and bolt head/face. My guess is, since you are referring to factory ammo, somebody screwed the pooch when it can to Quality Controlling the head space specs.

From what I have learned, primers can not physically pop out when the bolt head/face is at the proper distance from the case head.

Unless, of course, there is some kind of catastrophic overall case failure from extreme and excessive pressure.

[Dr.Phil]

Primers falling out is fairly common in 300 BLK.

Higher pressure supersonic loads will frequently stretch the primer pocket to the point that it is loose.
So loose in fact, that just ejection of the case is enough for it to fall out.
This is exasperated when a suppressor is added.
The added & delayed pressure caused by a suppressor will blow it out during ejection.

As a standard practice, prior to loading, I place two small drops of sealant on the primers after they are seated.

I thin the sealant out using acetone and apply it with insulin needles.
(I had the needles for my dog, but they can be purchased at any drug store without a prescription.)

I have yet to have a primer fall out after adding the sealant.
The main reason that I'm so concerned by this, is that a popped primer can cause complete failure of an AR.
When one falls into the lower, it can disable the trigger.
When one makes its way into the cam path of the Bolt Carrier, it will seize the BCG.
(That is why MILSPEC ammo requires them to be crimped in.)

[dellet]

Primers falling out is fairly common in 300 BLK.

Higher pressure supersonic loads will frequently stretch the primer pocket to the point that it is loose.
So loose in fact, that just ejection of the case is enough for it to fall out.
This is exasperated when a suppressor is added.
The added & delayed pressure caused by a suppressor will blow it out during ejection.

As a standard practice, prior to loading, I place two small drops of sealant on the primers after they are seated.

I thin the sealant out using acetone and apply it with insulin needles.
(I had the needles for my dog, but they can be purchased at any drug store without a prescription.)

I have yet to have a primer fall out after adding the sealant.
The main reason that I'm so concerned by this, is that a popped primer can cause complete failure of an AR.
When one falls into the lower, it can disable the trigger.
When one makes its way into the cam path of the Bolt Carrier, it will seize the BCG.
(That is why MILSPEC ammo requires them to be crimped in.)

Does thinning the sealant just help in application, or will it actually seep between the primer and brass if there is an imperfection?

[Dr.Phil]

Does thinning the sealant just help in application, or will it actually seep between the primer and brass if there is an imperfection?

Both...
By thinning it, I can get it into the syringe and that makes the application much easier.
Thinning it also allows it to flow between the brass & primer much easier, without applying an excessive amount.

If you apply it like nail polish, it effects the contact between the case head and the bolt.
That can have an effect on accuracy as well as gum up your bolt face.

[r.tenorio671]

Does thinning the sealant just help in application, or will it actually seep between the primer and brass if there is an imperfection?

Both...
By thinning it, I can get it into the syringe and that makes the application much easier.
Thinning it also allows it to flow between the brass & primer much easier, without applying an excessive amount.

If you apply it like nail polish, it effects the contact between the case head and the bolt.
That can have an effect on accuracy as well as gum up your bolt face.

..curious, what ratio of sealant to acetone do you use?

[AR-300]

I use the ballistic tools primer pocket gauge. Check every piece of brass and those that allow the no-go gauge to enter are rejected and recycled. No loose primers since I adopted this technique.
Before doing this, I popped out a primer while seating a bullet in my press. I also had a primer get into the bolt carrier group locking up the rifle. Not a pleasant experience!