Tighten Primer Pockets??

[MAinAR]

Opinions, thoughts?? Saw this over on Longrangehunting.com

Seems several of the guys there are using this redneck method of tightening primer pockets successfully.

https://www.youtube.com/watch?v=19XmgETCWOE

Thread is here: http://www.longrangehunting.com/forums/ ... ow-152361/

 

[bigedp51]

This method does not make the primer pocket "smaller" all it is doing is crimping the mouth of the primer pocket. Meaning the primer pocket is still oversized except for the mouth of the primer pocket.

One of the over pressure signs is to measure the base of the case just above the extractor groove. If the base expands over .001 you have exceeded max chamber pressure and the elastic limits of the brass.

Below is a exaggerated example of what happened to the base of the case and the primer pocket. And if the primer leaks and erodes your bolt face their is no redneck fix for that.

The fix for oversized primer pockets is to buy new brass. Below is my scrap brass bucket and 95% of these cases are factory loaded "once fired" Federal .223/5.56 cases with over sized primer pockets.

I use pin gauges to inspect the primer pockets, this pin gauge is .0005 smaller than the max allowable diameter of the primer pocket. And if this pin gauge enters the primer pocket the case goes in the scrap brass bucket.

Below is a Lee depriming tool and if any cases feel on the loose side when priming it is tested with it. If the primer moves with just finger pressure the case is scrapped.

The photo below was posted at a AR15 reloading forum and is the result of ignoring loose primer pockets.

I also load for my sons rifles and dad isn't going to be blamed for etched bolt faces.

So keep your standards high for primer pockets and don't let a loose primer pocket screw up your bolt face.

 

[hubcap]

bigedp51, I like that pin gauge method. Can you buy such a gizzmo or did you make it? I have been trying to find a good way to check primer pockets for a long time. I have used dial calipers but it is difficult at best to get an accurate reading. The pin gauge thing is cool I think.And welcome to the forum. Darn good first post.

 

[MAinAR]

OK. Agree with all the above,,,,,,but IF NO gas escape then bolt face WON'T look like pics posted above....,, RIGHT. No gas bypass no cutting right. Can tell you that if primer pockets are loose at say .2105 or bigger it will get you another loading on brass. Have tested and will work.

I realize a lot here don't want to LEAN on pressure, but I have found most cartridges to be to be deadly accurate at upper pressures.

Did you read and watch the all the video and all the thread. Primers that will FALL out can be tightened up enough to get another loading, and no gas bypass as shown in pics, in high pressure 300WM. And note that he starts off stating "this will not work with over pressure rounds"

With brass like it is to come by today, well just think. No do NOT shoot a cartridge that MAY let gas by, BUT there is a way to contain also and gain a loading or 2.

Whole key is to CONTAIN gas.

 

[bigedp51]

bigedp51, I like that pin gauge method. Can you buy such a gizzmo or did you make. I have been trying to find a good way to check primer pockets for a long time. I have used dial calipers but it is difficult at best to get an accurate reading. The pin gauge thing is cool I think.And welcome to the forum. Darn good first post.

You can measure your primers and look at the charts below and order several pin gauges to fit your needs.


Vermont Gage Steel No-Go Plug Gage, Tolerance Class ZZ (Inch)
http://www.amazon.com/Vermont-Gage-Stee ... rmont+Gage

 

[cloverleaf]

One mans opinions, below ......(cant say for sure if he's right but makes sense to me) CL

https://www.youtube.com/watch?v=orJdUR_X67M

 

[bigedp51]

The method I use above is used for my AR15 rifles, a over gassed AR15 still has pressure in the barrel as the bolt starts moving to the rear. If the primer pocket is loose this pressure can pop out of the primer pocket where it can fall into the trigger group and jam the rifle.

On a bolt action you can be a little more lenient with how loose the primer pockets gets. "BUT" if you want the brass to last then do not push the brass past it elastic limits. Below is a animated image of what happens as the cartridge is fired. The air space between the rear of the case and the bolt face is called head clearance. And this is the distance the primer can be pushed out of the primer pocket to meet the bolt face. Meaning a good seal is required to keep the primer from leaking. And your brass is a expendable item and your bolt face isn't.

Note, your head clearance is equal to your shoulder bump and on a bolt action you want .001 to .002 shoulder bump when sizing your cases.

 

[MAinAR]

One mans opinions, below ......(cant say for sure if he's right but makes sense to me) CL

https://www.youtube.com/watch?v=orJdUR_X67M

Still agree completely. Just asking for opinions because the days of cheap abundant brass are over with. But can 1-2 more loading's might be had.

A lot of factory loadings will exhibit just what ammosmith video show as over pressure, as well as most Nosler factory loadings. Just got done pulling bullets on Nosler trophy grade ammo and God only knows what primer they used on this batch. What I do know is it is not any of the BIG 3-4 manufacturers, bet they were not made stateside!

And measuring case expansion, are you kidding me, with some of the chambers I am seeing cut from the big name makers is ridiculous. If the chamber is overcut by .005, guess what brass is gonna be larger than .001!

Still open to opinions here. We wait for bullet or brass to be available for months so need to get all we can from them.

 

[JD338]

bigedp51

Good post with pictorial.
I agree with you completely. I too have tossed a lot of brass over the years due to loose primer pockets.

JD338

 

[nvbroncrider]

Brass is cheap man. A bolt for a AR will run you $200-250 a bolt for a bolt rifle $300. It's just not worth it.

 

[MAinAR]

Brass is cheap man. A bolt for a AR will run you $200-250 a bolt for a bolt rifle $300. It's just not worth it.

WHUT?

Not talking just AR's here, you bought brass for 280 AI or 7STW lately? Won't take long to pay for bolt with these brass.....when you can get them!

OR better yet get you some 28 Nosler brass. Talking about safe easy method to get 1-2 more loadings!!

 

[bigedp51]

Brass is cheap man. A bolt for a AR will run you $200-250 a bolt for a bolt rifle $300. It's just not worth it.

WHUT?

Not talking just AR's here, you bought brass for 280 AI or 7STW lately? Won't take long to pay for bolt with these brass.....when you can get them!

OR better yet get you some 28 Nosler brass. Talking about safe easy method to get 1-2 more loadings!!

MAinAR

Your the one pulling the handle of your reloading press and if your happy with your results that is all that matters. I can also tell you not all cartridge cases are made the same and vary in hardness. You have two choices, find a brand of brass harder in the base or not load so hot and over stress your brass.

The vast majority of the .223/5.56 cases in my scrap brass are Federal. This is because these Federal cases had softer brass in the base and had a thinner flash hole web. Both of these factors made these cases worthless for reloading and they had over size primer pockets after just one firing. In another forum one of the members measured the Rockwell hardness of .223/5.56 cases. Lake City had the hardest brass followed by Lapua and the bottom with the softest brass was Federal.

Bottom line, if you don't load your cases too hot the primer pockets won't stretch.

 

[nvbroncrider]

Brass is cheap man. A bolt for a AR will run you $200-250 a bolt for a bolt rifle $300. It's just not worth it.

WHUT?

Not talking just AR's here, you bought brass for 280 AI or 7STW lately? Won't take long to pay for bolt with these brass.....when you can get them!

OR better yet get you some 28 Nosler brass. Talking about safe easy method to get 1-2 more loadings!!

Yes sir I have a 280AI. And it ain't cheap but if you replace the bolt you must also re-headspace the rifle and possibly have some smithing work if you can't do it yourself. So that will add to the cost. I'm not a fan of pushing the limits that much.

 

[FOTIS]

Actually .0005" case head expansion is too much pressure

 

[bigedp51]

There is a "little" wiggle room depending on the cartridge and chamber pressure. But again if you don't load hot you won't stretch your primer pockets.

Simple Trick for Monitoring Pressure of Your Rifle Reloads
http://www.hodgdonreloading.com/reloadi ... le-reloads

My practice AR15 rounds kill the paper targets just fine at 50,000 psi and the Lake City cases will last a long time.

 

[Elkman]

Great information all, very informative, great advice.

 

[MAinAR]

To be clear ALL my loads are at reasonable pressure levels and was only asking for opinions because we all have brass that could be loaded a couple more time if primers were tight enough. All the above pressure info above is spot on and completely understand it and agree with the methods, as stated more than once.

But you CAN get another loading or 2 from brass that has had pockets stretch but that the brass was otherwise usable, a LOT of factory ammo's stretch primer pockets on the first firing, not enough to not hold primer usually, but have stretched to .208 -.209.

Again not talking about using brass that has been greatly over pressured.