Primer fit

[thermaler]

I just finished inserting primers into about 50 Nosler 308 cases which have been fired once. I cleaned and checked them and did not find any signs of any distortion--I also resized them and deburred/chamfered the necks (didn't need any trimming).

There were about three cases were the force needed to insert the primer seemed significantly less than all the others. It could be just a coincidence in how the shell holder lined up--the point is should I be concerned; and if so what should I do about it?

thanks in advance!

[glassbeaver]

Primer pockets get loose. It's just what happens (especially if you load em hot). My rule if thumb is if they don't fall out when I tap em on my bench, they're good enough for me. Been doing it for years. Has not affected accuracy or velocity with me and I still have all my face parts. If it concerns you though I think it's hart that makes a tool that tightens them up. I shoot 308 as well and use lapua brass.

[thermaler]

Primer pockets get loose. It's just what happens (especially if you load em hot). My rule if thumb is if they don't fall out when I tap em on my bench, they're good enough for me. Been doing it for years. Has not affected accuracy or velocity with me and I still have all my face parts. If it concerns you though I think it's hart that makes a tool that tightens them up. I shoot 308 as well and use lapua brass.Thanks--I did in fact tap them as hard as I dared (ya never know) and nothing budged--there were a few loads I did the last firing that approached compression though were still not at the max load. I just got in a shipment of 308 brass from lapua and I will switch to that next round of reloads. Looks like great stuff.

A few years ago I fired a 308 nosler factory custom round from store-bought packaged ammunition--and the primer cap blew off the case inside the chamber of my AR10--the case and bolt got moderately stuck but I was able to loosen both without major force/problems and the weapon has operated flawlessly since then. Ever since that event I've been a bit nervous about primer caps in nosler cases--though it may have had nothing to do with the primer itself.

PS--I shoulda mentioned they were Federal LR primers

[bigedp51]

I have some Federal .223 cases with loose primer pockets, I use my Lee Universal decapping and depriming die when the primer feels loose when seat the primers. I place the case in the Lee die while holding the die in my hands, if by just using finger pressure the primer pops out then the case is tossed in the junk bucket.

If you let a loose primer in your reloaded case it can leak high pressure gas that will etch and erode the bolt face and damage the bolt. Buying new cases is cheaper then having the bolt replaced.

Below is a AR15 bolt face that has been damaged by loose primers and high pressure high temp gas leakage. And this is why I carefully check my primer pockets if they feel loose.

http://i122.photobucket.com/albums/o254/bigedp51/M16A1Bolt_zps41615ed0.jpg

The type rifle you have and the amount of headspace along with a loose primer pocket will determine if you blow a primer.

Below watch the primer move as it is being fired, gas pressure forces the primer to the rear and as pressure increases the case stretches to meet the bolt face.

http://i122.photobucket.com/albums/o254/bigedp51/deform.gif

A primer can move by the same amount of head clearance or "air space" you have behind the case when fired.

http://i122.photobucket.com/albums/o254/bigedp51/HEADCLEARANCE-a.jpg

[glassbeaver]

Well my bolt face definitely doesn't look like that lol. Just wanted to throw out another option. You can use wolf or Tula primers. They are slightly larger. I started using them when I got my ultrasonic cleaner as it seems that super clean primer pockets don't have that snug seating feeling that ones just brushed out do. They work great for me (used to use 210m). Also some reviews on the hide stating they have seen more consistent performance from them. Oh yeah, they're cheaper too lol. I think tubbs wrote that he uses them in his 6xc goodness. Throwing it out there. Another option if it concerns you.

[thermaler]

Big ed--I want to see if I understand this correctly; are you saying after you seat your primer you insert the decapping pin into the case and push on it to see if the primer falls out? Up till now I've been reluctant to touch anything on the business end of the primer which could conceivable cause friction.

The cap that blew off in my AR 10 was factory-made ammo--not a reload. Generally misfires of quality ammo takes me by surprise--but it does happen.

PS--great illustrations, BTW

[bigedp51]

Big ed--I want to see if I understand this correctly; are you saying after you seat your primer you insert the decapping pin into the case and push on it to see if the primer falls out? Up till now I've been reluctant to touch anything on the business end of the primer which could conceivable cause friction.

The cap that blew off in my AR 10 was factory-made ammo--not a reload. Generally misfires of quality ammo takes me by surprise--but it does happen.

PS--great illustrations, BTW

Yes I push on the primer from inside the case and see if the primer comes out with just finger pressure. At AR15.com there always a discussions about popped primers and reloads, with some types of Federal cases having loose primer pockets after the first firing. Meaning its an ongoing problem and gas guns put more force on a fired primer on ejection if the rifle is over gassed. I'm rejecting over 50% of my once fired Federal cases because of loose primer pockets.

The Federal cases are a problem because of their thinner flash hole in the web and pressure distorts the base. These cases have crimped primers but when the crimp is removed for reloading many of the cases have primer pockets too loose to reload.

http://i122.photobucket.com/albums/o254/bigedp51/FCvsMilbrasssectioned_zpse9aa074d.jpg

The moderator in the reloading forum uses a Lee decapping tool made for the Lee Loader and pushes the decapping tool with hand pressure to check the primers. You are not dealing with sweating nitro in dynamite and hammer blow force is needed to set the primer off and a slight pushing force is not going to set off a primer. (read link below)

http://i122.photobucket.com/albums/o254/bigedp51/testprimers_zps1fc15fcf.jpg

FIRING PIN IMPACT STUDIES

http://www.davidtubb.com/davidtubb/content/graphics/pdfs/DT_firing_pin_impact_studies.pdf

[thermaler]

OK--thanks for that--I really appreciate your thorough and complete answers. : )

Now the AR 10 fires 308/7.62 so I'm wondering if this situation really applies to 308 as well, although I've heard that Nosler uses Federal cases for their brass (don't know if that covers all their brass). The other thing is I know the federal eagle budget stuff in 223 is pretty crappy--I have a bunch myself but don't intend on reloading it, and also that federal has flooded the market with their Lake 5.56 mil surplus stuff in ammo cans--which I also have.

I guess what I'm getting at is the thinner flash hole area a problem with ALL federal brass--including the 308 (my AR 10 loves the federal golden match king) or is it just a problem with their American eagle budget stuff?

[stomp442]

I also do the tap test and use my lee trimmer run down the case to see if I can push the primer out easily. I also have the hart tool mentioned and it works great and will get you a couple more firings out of the case.

[JCalhoun]

Primers will vary in size also.

[thermaler]

Primers will vary in size also.Coincidentally, I've heard Federal primers--which are what I'm using--tend to be thin-skinned/shorter as well.

[thermaler]

All fired today with no apparent problems--I will examine the cases more closely when I clean and prep them for the next loading.

[Predator1]

Do you guys feel that extremely loose pockets hurt accuracy? I loaded some cases that when I seated the primers it took nothing to push them in. I was able to push the primer back out by hand with a long pin with no resistence. I actually did fire a few of these and I had some big flyers but I wasn't sure which case the flyer was from.

[bigedp51]

Do you guys feel that extremely loose pockets hurt accuracy? I loaded some cases that when I seated the primers it took nothing to push them in. I was able to push the primer back out by hand with a long pin with no resistence. I actually did fire a few of these and I had some big flyers but I wasn't sure which case the flyer was from.

On a bolt action all you need to worry about is if the primer will seal the primer pocket and prevent gas leakage. On a gas gun like the AR15 a loose primer pocket will cause the primer to fall out and into the trigger group when fired. This can jam the trigger group and even cause the rifle to go full auto and neither is wanted in a shooting match. To save wear and tear on my brass fired in my AR rifles my practice ammo is loaded to lower pressures. BUT as you can see in the bolt face photo from an AR rifle high pressure gas leakage will damage your bolt face when not being fussy about your hand loads and primer pockets.

To answer your question at AccurateShooter.com they are more concerned with extending the life of their Lapua cases and use methods to tighten their primer pockets and I have read nothing relating this to accuracy problems. With the exception of gas leakage at the primer pocket causing pressure variations and flyers. The military 5.56 ammunition is loaded to higher pressures and is fired in chambers that are slightly larger in diameter which may cause more base expansion when fired.

Last night I loaded 250 rounds for my ARs from once fired crimped Lake City brass and there was a wide variation in primer "feel" when seating primers after removing the crimp. Pushing on the primer on these cases is the only sure way I know to check a seated primer.

[kelbro]

If they go in too easy, I mark them with a sharpie and toss them after I shoot them. Bolt guns only.