Bad winchester primers?

colonel3006

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I just started using imr 4064 for my 30-06 with winchester large rifle primers and 150 Hornady ssts. When I started out I used 48 grs of powder and bumped it up in 0.5 gr intervals until I got to 51.5 which gave me best groups and no pressure signs. Anyway, last week while deer hunting I shot my deer and thought I noticed a little puff of smoke come out of the action (remington 7400).I just got the chance today to shoot it again and 2 of the 4 shells have burnt holes on the side of the primer and a little soot around them.I know I didn't overload them as I measure every charge and manual says 53.6 grs max and I am almost 2 grs under that and I shot almost a box sighting in with that load and none showed that.The only difference is it was a different lot # on the first primers compared to the second.I have read on other sites of people having problems with winchester primers and was wondering if any one here has had these problems?
 
There have been a couple people on this forum who had the same issue as you.

Some have speculated that the cups were drawn unevenly.

Assuming you didn't overload, and that the primer pockets in the brass were not too loose, this could be another case of bad Winchester primers.

Contact Winchester and give them the lot number of the primers.
 
I definitely didn't overload,I did notice the primers were a little looser than remington brass which is what I used to use,but still required quite a lot force to seat them so I sure that isn't the problem either.
 
I definitely didn't overload,I did notice the primers were a little looser than remington brass which is what I used to use,but still required quite a lot force to seat them so I sure that isn't the problem either.


Let me guess. Federal?

Regardless, even if you have a loose primer pocket,you don't usually get a pin whole burnt through.
 
So you developed a load with mixed brass? While some of the loads in lighter, thinner brass may not show pressure signs, thicker heavier brass nay with the same load. The Remington 7400 action does not lock up like a bolt action rifle. Some rifles may show over pressure signs with starting loads.
To start with I would sort your brass by headstamp then cull the ones that are +/- 3 gr and start your load development again.
 
No I didn't use mixed brass.When I refered to the remington brass that was when I was loading with 4350 powder. When I started using the 4064 I started out fresh with brand new winchester brass since I had a bag sitting around here for quite a while. The only component that was the same as my old load was the winchester primers. The first 30-35 primers were from an opened pack and as I said I seen no signs of pressure with them. I than loaded 2 boxes with the new pack of winchester primers (which was a different lot #) and this is when I started having problems.
 
Colonel You have stated that you definetly didn't overload yet you have a leak around the primer. Pressure must be pretty high in that rifle. A max load in one rifle may be several grs higher or lower than another rifle. So what is listed as the max load in a manual may be a couple grs higher than what is max in another rifle. Typically pumps, levers and autoloaders will have a max load a few grs less than a bolt action. Suggest you back off a gr or two of powder or try a different primer
 
I had the exact same problem with Winchester large rifle magnum primers.
I had a great load but ran out of cci250 primers. Switched to Winchester, cut the charge down and loaded up a bunch in .5gr intervals.

My previous load was 77gr of rl-22, cci250 primers, 208gr amax.

So right now I'm just going by memory.... Testing these loads with Winchester primers... I believe it was at 74.5 gr that I popped a few primers, which also ruined my bolt face. 3-4deg temp.

I ordered up a bolt head from jerry, and went with 73grains, due to the component shortage I just settled there and spent more time shooting.
Fast forward a few months to a nice spring day, in the teens.
Pop pop pop. More primers pop. Can't remember if I replaced the bolt head at this time or if it was salavagable.

Pull the bullets, dump the powder, reload to another nice looking charge of 69.5 grains. So now I'm 7.5 grains below my cci primer charge that was good all year long.
Summer comes... Pop pop pop. There goes another bolt head. I believe the velocity drop from 77-69.5 was 180ish fps.

Get a new bolt head... 2nd or 3rd one now. Switch back to cci primers, back to 77gr or rl-22 and no more problems.
However I've now switched to h-1000, and really making these things cook.

An interesting note though. I'm using the same case weights/volumes +/- 1gr, same charge of 79.5gr h-1000 and my 208amax's are at 2811fps while the 210bergers are 3063fps. Both with 4fps sd. The amax's could uses a little tightening up, I'm going to
see if I can push them a little faster, if it will tighten the group. I doubt I'll reach the begets velocity before I hit exc waive pressures though. The lighter jacketed amax must be obturating more, more friction.
 
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There have been many reports of this happening with WLR primer:

002_zps65e84d6c.jpg


Had it happen in my M700. Wasn't a hot load...
 
I won't use Winchester primers in anything now other than greatly reduced loads and pistol rounds.

Had the same experience as OP and another fellow shooter had same problems with WLR.
 
Win primers have a soft cup which is a desireable feature if have an older rifle with a weak firing pin spring. However take a look at that primer picture. Instead of the corner of the primer being rounded like a new primer it is blown out to a square corner. That is one of the signs of pressure a reloader should be watching for. If you insist on loading to max pressures go to a mag primer which usually have a harder primer cup. In my experience the CCI250 primers are very good. Every loading manual on the market tells you if you change even one component start over at starting loads and work up watching for signs of excessive pressure.

There have been many reports of this happening with WLR primer:

002_zps65e84d6c.jpg


Had it happen in my M700. Wasn't a hot load...
 
That particular pic is just one I found on the web to illustrate the way they are failing. Google WLR pin hole and you'll find many reports of them failing in loads that people have shot years with WLR primers and never had a problem till recently.
 
Win primers have a soft cup which is a desireable feature if have an older rifle with a weak firing pin spring. However take a look at that primer picture. Instead of the corner of the primer being rounded like a new primer it is blown out to a square corner. That is one of the signs of pressure a reloader should be watching for. If you insist on loading to max pressures go to a mag primer which usually have a harder primer cup. In my experience the CCI250 primers are very good. Every loading manual on the market tells you if you change even one component start over at starting loads and work up watching for signs of excessive pressure.
In my case I dropped 7.5grains and still popped them. That's a little more than rediculas.
 
Pin holes in primers are rarely caused by a pressure problem--it is usually a defect in the primer cup or damage caused to the cup during seating--this is not usually a problem with commercial brass but happens sometimes with military brass when the crimp is not properly removed. Over 35 years of reloading I havew sen the pinhole problem with Winchester WLR primers, Federal large and small rifle primers and Remington small rifle primers. It can be a pressure problem when the load is altered so all precautions need to be observed.
 
This is an issue that rears it's ugly head from time to time.

While recently it is Winchester primers displaying the rupture, I have seen
this occur with RWS, CCI, Remington and the older Alcan primers.

It is NOT an overpressure issue, but rather, as some have pointed out,
a weakness or thin spot in the primer cup.

I would contact Winchester about this, making sure you state the lot #.
They are probably already aware of the problem.

Regards, Dave.
 
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