Firearm & Gun Forum - FireArmsTalk.com

Firearm & Gun Forum - FireArmsTalk.com (http://www.firearmstalk.com/forums/)
-   General Rifle Discussion (http://www.firearmstalk.com/forums/f18/)
-   -   Blowing primers out (http://www.firearmstalk.com/forums/f18/blowing-primers-out-31081/)

E-Rez 08-29-2010 09:42 PM

Blowing primers out
 
I'm in the process of sighting in a rifle and the last two rounds out of six had the primers "falling" out. I've been shooting guns for over a decade and have never seen this. Faulty ammo or gun? It's a Savage 114 Classic 270 and I'm using cheap blue box Federals.

http://sphotos.ak.fbcdn.net/hphotos-..._6436234_n.jpg

Waiting on a diagnosis before I shoot any more...don't wanna risk damaging the gun.

375shooter 08-29-2010 10:13 PM

It's a possibility that the gun has an oversized chamber, specifically in the region of the case rim. The pressure during firing could be expanding the head to the point that the primer pockets are enlarged enough that the primers are able to fall out. I would contact Savage's technical department.

joshfireart 08-29-2010 10:44 PM

its a pressure issue dont shoot any moor. send it to savage or your gun smith and have them check it out. pretty rare to have it be a factory ammo problem. there dose appear to be primer flow

cpttango30 08-29-2010 11:54 PM

DON'T SHOOT IT ANYMORE.

You are having one of 2 problems.

1. the factory ammo was loaded wrong and you are runing over pressure.

2. Something is wrong with your gun.

I would say it is a factory ammo problem myself. All of the primers in the picture show signs of HIGH pressure. The ring around the firing pin dent is where the primer is flowing into the hole on the face of the bolt.

I would get some different factory loads and set the sucker in a lead sleed and put a string on the trigger and fire 2 or 3 rounds of while hiding behind a very solid object. Check them primers on that lot and go from there. If you are seeing issues like this with a different brand of ammo then take that gun back there is something wrong if you don't take that ammo and cal the manufacture.

Tuner 08-30-2010 12:44 AM

First question is what is your cleaning procedure for the rifle. Did you do a good bore cleaning when you put it up last. If the bore was allowed to rust bullet fouling could build up fast. Shots 5 & 6 blew primers. Was the barrel hot and did you allow the cartridge to cook in the chamber for some time prior to shooting which could have heated the powder jacked up the pressures. Combination of the two might possibly add to the pressure but me thinks that is a stretch.

I would call or email Federal and ask if they have had any recalls on that lot of ammunition. The lot number should be on the box of ammo. If you have a michrometer I would mike the bullets and see what they are; a .270 bullet should mike .277.

My guess is that if you have properly maintained the rifle and you never had a problem like this in the past you have an ammunition problem and I would make that call to Federal.

E-Rez 08-30-2010 01:44 AM

I started shooting a different box of ammo before the "faulty" box (started with 150 gr and switched to 130 gr after four shots). The 150 gr loads also show that the primer is going back into the firing pin hole.
http://sphotos.ak.fbcdn.net/hphotos-..._6140478_n.jpg

I talked to my gunsmith over the phone and he said all the same things that have been brought up here. I will be taking it to him to look at tomorrow afternoon.

I did notice that in both boxes of ammo the ring around the firing pin dent and the ejector mark got worse as the gun heated up...

Tuner - the gun is two weeks old and has only had 10 rounds put through it today. I cleaned it after I brought it home and in between shots while breaking it in.

Tuner 08-30-2010 03:27 AM

Quote:

Originally Posted by E-Rez (Post 340972)
I started shooting a different box of ammo before the "faulty" box (started with 150 gr and switched to 130 gr after four shots). The 150 gr loads also show that the primer is going back into the firing pin hole.
http://sphotos.ak.fbcdn.net/hphotos-..._6140478_n.jpg

I talked to my gunsmith over the phone and he said all the same things that have been brought up here. I will be taking it to him to look at tomorrow afternoon.

I did notice that in both boxes of ammo the ring around the firing pin dent and the ejector mark got worse as the gun heated up...

Tuner - the gun is two weeks old and has only had 10 rounds put through it today. I cleaned it after I brought it home and in between shots while breaking it in.

That pretty much rules out excessive fouling or damage to the bore! Primers are not necessairly a good indicator of pressure. A soft primer cup will show what could be interpreted as high pressure when in fact things could be normal; however, blown primers that happend in your first post is another story all together.

Your second box of ammo appears to be the same make, Federal and if it is the same Lot Number you have really not changed anything. It would be interesting to see what a box of Win. or Rem. ammo will do. Do you have any problems chambering a round? I can't imagine it happening but I suppose a manufacturer could have a barrel slip through that did not get throated and bullets were being jammed into the rifling causing excessive pressures.

I would hope you have a good smith, not just someone that sells guns and mounts scopes, to evaluate the rifle. I would personally contact both Savage and Federal, explain the age of the gun, number of rounds fired, what happend and email them pictures. Something is not right and one of the two needs to come up with the answer. I certainly hope you are wearing good safety glasses when you fire that rifle.

Please let us know the final answer you get.

cpttango30 08-30-2010 09:08 AM

Quote:

Primers are not necessairly a good indicator of pressure. A soft primer cup will show what could be interpreted as high pressure when in fact things could be normal; however, blown primers that happend in your first post is another story all together.
Tuner is right on with that statement. ALso federal primers are known in the reloading world to be softer than just about any other primer.

So it may end up being that you have a nice tight chamber and the factory loads are at the upper end of the load spectrum and the federal primers are soft. Though the primers that fell out are scary.

Let me ask how was the bolt lift on the 2 shots were the primers fell out? Was the bolt stiff did you have to use more than your thumb and index finger to rotate the bolt and pull it back?

Also let us know what goes on from here on.

E-Rez 08-30-2010 10:59 AM

No problems chambering. I honestly couldn't tell if there was any more force needed to lift the bolt as my other savage rifle has a heavy bolt lift. As you probably know, the firing pin is cocked as the bolt is lifted, hard to do this with just a thumb and finger - for me at least.

It might be a while till I can contact Savage since they close at 4 pm eastern and I get off work at 3:30 pm central...darn the luck!

Thanks for hanging in there with me.

Tuner 08-30-2010 11:56 AM

What cpt--30 said about bolt lift is good, understand the cock on opening resistance, but does there appear to be any additional drag or resistance?

Things that will usually cause too much pressure that come to mind:
1. Tight chamber-- doesn't allow the cartridge to expand and release the bullet when fired, pressures jump.
2. Bullet pushed into the rifiling-- bullet does not get a "running start" to overcome the rifling engraving process and pressures jump.
3. A tight barrel, drilled and reamed smaller then typical diameter -- takes more pressure to push a bullet down the barrel. Because the rifle is new we will assue it is smooth and not fouled excessively.
4. Too much powder for the cartridge bullet combination.

To check 1 & 2 above a smith would probably have to do a chamber cast with cerosafe and then mike the neck dimensions and measure the amount of lead in the chamber. I don't think using a set of go no go headspace gauges will tell you much here as they measures the distance from the base of the cartridge to a point on the shoulder where the headspace is measured, not the diameter of the neck. In fact headspace gauges do not have necks on them.

To check 3 he would probably "slug" the barrel with a soft lead plug and then mike the slug which should come out to .308.

There is not much one can do about the loaded ammo, even if you pullled a round down weighing the powder isn't going to tell you much as you will not know what type of powder it is and it could very well be a non standard powder that is bought in bulk and charges adjusted by lot by the manufacturer.

Please keep us posted.


All times are GMT. The time now is 05:18 PM.

Copyright ©2000 - 2015, Jelsoft Enterprises Ltd.