Primer question

[Dennis6474]

I ran into something today that I have never heard about in my limited reloading experience.

I loaded some .243 brass that had been used before. I started about 7% below max. I usually use CCI primers but the store was out so I bought some Winchester primers.

I noticed that they seemed to go in to place rather easily but did not pay much mind. They looked ok. The first shot when I opened the bolt the primer was missing from the case. Of course it was still in the gun but fell out when I opened the bolt. Out of the next several rounds I had it happen again so I stopped shooting.

The cases have not had anything done to the primer pockets. They were deprimed and cleaned prior to loading.

What is going on??

[Adamantium]

Primers vary slightly from brand to brand. Some are hotter, some are harder, some are larger. I'm surprised you found that the CCI were larger, with small pistol it is the other way around.

My advice is to pull those bullets and pop out the primers. Switching back the CCI when you can seems like the obvious choice.

[zxcvbob]

What if you seal those primers -- the ones already loaded -- with cheap fingernail polish? That should glue them in place, and prevent hot gas leakage that could harm the bolt face. (then I'd stop using them with that brass)

[mrawesome22]

Federal brass?

[Dennis6474]

Not Federal. Winchester brass. I think that they had been reloaded a couple of times and turned once.

I might try the nail polish. I have 1,000 of these primers and will try them in something else.

[mehavey]

I loaded some [Win] .243 brass that had been used before.... seemed to go in to
place rather easily.... first shot when I opened the bolt the primer was missing....

'Sounds like expanded primer pockets before you loaded this time.
What were the previous (and current) load combinations?

[F. Guffey]

“I started about 7% below max’

I have claimed there is a difference in shell holders and no one ask “different in what way”

As to your statement with 7% below max., What if it was the load used the last time the case was fired?

If no one measures the diameter of the primer pocket before firing or if no one measures the case head diameter before firing there is no way to determine why the primers are loose, I have lost primers in the action of a rifle, no mystery, the case head increased in diameter, the primer pocket hole increased in diameter, the flash hole increases in diameter and the case head thickness shortened between the head of the case and bottom of the cup. And time is a factor, I would not not neck size a case that indicated that many different pressure signs, time is a factor.

Measure before and after, and it is possible to measure the diameter of a primer, and it is possible to crimp a primer.

F. Guffey

[m&p45acp10+1]

In some cases primer pickets can loosen up. Some reloaders swage thier primer pockets for this reason. I have as of yet to enounter that problem. From what the manuals say it usualy a sighn of high pressure.

Most times my problem is neck splits from multiple reloads. YMMV.

[black mamba]

I have used WLR primers for 30 years. My old batch was nickel colored and seated with some considerable resistance. A couple years ago I finally ran out and bought a new batch, which was brass colored. The newer brass colored primers seat much easier, so they are either slightly smaller in diameter or softer, more easily squeezed down by the primer pocket. Still great performance, and I've yet to have one fall out, but they definitely seat with less force on the old Rockchucker.

[Sevens]

Even a primer that goes in much easier should NOT be falling out of the primer pocket. Pressure from the load flows in to that primer cup and the cup fills out the primer pocket due to that pressure.

If those primers are falling out, that brass is BAD, unless there's a chance that somehow, a thousand really bad and out-of-spec primers managed to come out of the Winchester facility that produced them. (even though I don't know if ANYONE has ever seen such an occurrence.)

I think if we were talking about Tula primers or something that might have come out of a factory that also houses the local post office, livestock feed mill, bakery and medical center in some village between two peaks in the Ural Mountains, we'd have a chance that some poorly dimensioned primers arrived on the last boat.

Winchester primers falling out of your brass? Your brass is bad and the pockets are out of spec.

I'd suggest that you try different brass.

[FrankenMauser]

I'm with Sevens on this one. Toss that brass.

If you want to double check, before tossing it...
Measure the primers.
Winchester LR primers should have a cup diameter of 0.2110" to 0.2120".

I'm willing to bet they'll mic out to about 0.2115", and the brass is bad.

[Dr. Strangelove]

I have claimed there is a difference in shell holders and no one ask “different in what way”

Yep, my RCBS hand primer won't properly seat primers unless I us RCBS shell holders, they seem to be a cat hair shorter than my Lee shellholders.

[Slamfire]

If the primers were secure in their pockets before firing, but fell out after, I think that is a pressure problem, not a primer problem.

[Dennis6474]

I think that the best idea is to toss the brass.

I am going to try several other brass with different headstamps to see if the primer goes in any different. These primers are brass colored. I am careful to watch for high pressures so I don't think the brass had ever been subject to high pressures.

The primers seemed secure when loaded but as I said they went into place very easy. In fact I kept looking at the brass to see if the primer was in place correctly.

The loads were not anywhere near a "hot" load. Vel was around 3250 which for a .243, 100 gr bullet out of a 24" barrel should not be exceptional.

Anyway, Thanks for the information. I am impressed with the knowledge that is available here. It is going to make my reloading a lot more enjoyable.

[Dennis6474]

Just come in from going thru my brass and guess what.... F. Guffey...you are right. The primer pockets are big. .231, .227, .237 also several case heads are out of spec. .483, .478, and .480. I had never checked the pockets before, but I will from now on.

I do not know why these are so different. I went thru all my brass and only found three cases that were bad out of 100.

Anyway, It just gives me one more step in my reloading. CHECK THE PRIMER POCKETS.

[mehavey]

The loads were not anywhere near a "hot" load. Vel was around 3250 which
for a .243, 100 gr bullet out of a 24" barrel should not be exceptional.

If one believes the Hogdon data site, that load is definitely "warm" (if not truly hot).
What was your actual powder/weight?

[Dennis6474]

45.4gr IMR 4831 for the first one to lose primer. I was shooting 3 rounds and only one primer came out. I checked that one and it was over sized.

The next one was one of 3 loaded with 45.9 gr and it to measured over sized primer pocket. I did not shoot the next set of 3.

[Sevens]

43.0 grains is Hodgdon's published maximum for a 100gr bullet in .243 Win with IMR-4841. Their max load shows under 3,000 FPS for that bullet. Your load was 2.4 grains over that particular published load.

Where was the published data you are referencing when you claim that this load is 7% under maximum?!

You have seen classic pressure signs. Actually, you were given a very nice gift, it only cost you a few pieces of brass.

I'm hoping you've picked up something in all this.

[jmundy]

If you have any of these rounds still loaded you may want to break them down. It appears from looking at the Hodgdon site you are at least a couple of grains over maximum.

Here's what they list for your loading:

Cartridge: 243 Winchester

Bullet Weight (Gr.) 100 GR. SPR BTSP

Manufacturer IMR

Powder IMR 4831

Bullet Diam. .243"

C.O.L. 2.650"

Starting Loads
Grs. Vel. (ft/s) Pressure
39.2 2733 43,500 CUP

Maximum Loads
Grs. Vel. (ft/s) Pressure
43.0 2947 50,800 CUP

[mehavey]

I normally regard (IMR)4831 as a fairly benign/slow-burn powder that's hard to overload. (My `06 loves the stuff).
But you should be expecting a max load of it to give you low-mid 2,900's for velocity, not 300-350fps over that.

----- Uncle Nick might weigh in here w/ a better analysis, but here's my take:

Both IMR/Hodgdon and Sierra max out at 43.0 gr/IMR4831 for a 243Win/100gr bullet.
http://accurateshooter.net/Downloads/sierra243win.pdf
Hogdon predicts ~51,000 CUP for that 43.0 grains (Sierra does not specify).
Both predict 2,900-2,950fps for velocity.

Bramwell provides a decent list of CUP-v-PSI specs for cartridges here:
www.shootingsoftware.com/ftp/psicuparticle2.pdf
Note that 51,00CUP ≈ 60,000psi as the 243Win case limit.

When I have a disparity between predicted velocity and measured velocity, I generally use the cube of the velocity
ratio to estimate actual pressure. In the case you mention (3,250/2,950)-cubed give me a multiplier if 1.34 for pressure
... meaning ~80,000 psi in this instance.

...bad juju if you're really running that hot, and it certainly explains the primer pockets

+1 to JMUNDY's recommendation to pull the bullets from the rest of the lot, and go w/ a lower powder charge
until you get into the 2,950-3,000fps (-) regime.

[Edward429451]

In some cases primer pickets can loosen up. Some reloaders swage thier primer pockets for this reason.

Really? Tell us how that works.

[mehavey]

Right here...

http://www.midwayusa.com/Product/911...primer-pockets

But for myself, I regard enlarged primer pockets as a personal communique from God,
... and I don't try to finesse the messenger.

[mrawesome22]

[Dennis6474]

I used the IMR data that showed 46.0 gr max with a vel. of 3010 and 51,800. That is from a 22" barrel and that is what I have not 24" as I indicated before. I also was using OCW, Dan Newberry's procedure. I did not have any other signs of pressure such as a flattened primer or hard bolt lift, or anything that I am aware of that would show high pressures

My Hodgdon Data Manual No. 26 shows 44.0 gr max with 3007 and 50,600. So I used the high amount and backed off 7% as per OCW.


This has been a real experience and I certainly learned something. I really appreciate the time you all have taken.

[mehavey]

I just got back to the house and ran a QuickLoad Calc:

243Win/22" barrel
Nosler 100gr PartitionSP
IMR4831/45.5gr
WWcase(53.8grH2O)
OAL=2.650 (most manuals' recommendation)
3,130fps
74,000psi ( )

~~~~~~~~~~~~~~~~~~

If you want to save both barrel & brass but retain velocity, try

RL-25 working up to 47.4gr for 55,000psi/3,000fps
IMR 7878 (ditto-ditto) to 45.0gr < 55,000psi/2,960fps
RL-22 (ditto-ditto) to 45.3gr < 55,000psi/2,940fps

Those give best combined fill, burn, and velocity of common-available
powders for practical pressures of 53-55,000psi. Most accurate
(at whatever final loading/velocity) is by experiment at this point.


postscript: I have found I really like N560 for these kind of applications.
It doesn't burn as completely as the above suggestions, but somehow that
doesn't seem to matter to the resultant accuracy.
QL tells me I'd try working up to N560/45.7gr for 53,000psi/2,960fps
if you have nothing else to do on a Saturday afternoon.