Leaking Primer Pockets

[Jimbo357mag]

I went shooting today and noticed that 2 primers out of about 25 leaked on my low power (plinking) 30-30 rounds today. They weren't blow outs that can burn the bolt face but just some noticeable black on the case head and it was easy to see they leaked from the edge of the primer and primer pocket. None of my normal pressure target rounds leaked. I'm going to assume that this was probably because of weak primer pockets, like we talked about a little while ago with Selena and her idiot (sorry, but that's how she described him) brother. These cases had all been shot over 6 times and probably closer to 10 or 12 times so I just squashed them with a hammer and threw them in the scrap bucket.

I don't plan on doing anything different other than to keep a look-out for this primer leakage and for split case necks/mouths, which I also get once in a while with my older used brass. I guess I'm too cheap to not get the most use I can outa my brass, a habit I learned reloading revolver cartridges. :D

 

[Cheesewhiz]

Jimbo, you used rifle primers for these reduced loads, didn't you. (secondary and accusatory, DIDN'T YOU!!!!! is for a humorous affect)

I would try some pistol primers instead as the cups are a bit softer and will obturate (seal) with a weaker load better. I recommend either Remington or Winchester large pistol primers, Feds will probably be too soft, not a big fan of CCI's, JMO. Gas cutting is a really bad thing and it happens with powder puff loads and hard primers quite a bit.

 

[OldePhart]

I'm +1 with Cheesewhiz - sounds more like a case of primers not expanding to seal against the pocket. One can go too far in making mouse fart loads... :) You might try a bit tighter crimp...the idea being to get the initial pressure pulse up more quickly.

 

[Jimbo357mag]

Thanks, interesting, I never thought about light loads being more likely to leak. Rest assured that these are not any lighter than normal 'start' loads, 31.0 gr of H-4895 instead of 33.5 gr with a 150 gr Sierra bullet for a target/hunting load.

If I ever do make mouse-fart loads I will consider the Win-WLP primers I stock instead of the rifle primers. Who ever said old dogs can't learn something new? :D

 

[Rick Courtright]

Hi,

Jimbo, I haven't tried this, but have known a few frugal souls who've used either primer pocket sealer (the spendy stuff sold to waterproof the pockets) or much cheaper nail polish from the drug store to squeeze another loading or two from aged brass with loose primer pockets. I'm guessing it's a rather time consuming operation, but who knows, maybe you can learn yet another new trick? If so, please report back to the rest of us old dogs on the results, ok?

Rick C

 

[Ale-8(1)]

I think the cheese man has it.

The other possibility is "tired" pockets.

JMHO

:)

 

[Bucks Owin]

Reloading much used .30/30 brass is false economy IMHO, the round is notorious for stretching cases. (Did you trim EGO357?) One can "stretch" ( :lol: ) the use of same somewhat by carefully adjusting a FL size die for minimum headspace or neck sizing. (And before someone pipes up, yes I'm aware that it is a rimmed cartridge. Doesn't mean it can't be treated as rimless even with it's scant shoulder when resizing) EGO357 didn't mention the firearm used, but many M-94s, especially much used ones, can be a little loose in the headspace department and fired cases exhibiting slightly protuding primers aren't uncommon and give you a clue...

Brass work hardens over time. The two cases that showed a little primer leakage were not from "weak primer pockets" but likely due to a combination of hard brass, hard primers, (CCI?) "mousefart" pressures, old brittle cases...who knows? Throw them away! :shock:

Using a large pistol primer is not especially wise although many guys get away with it. Besides being designed for handgun pressures, they are about .008" shorter than rifle primers and could be subject to the malady of light primer strike.

All in all, if EGO357 is looking to build a reduced recoil 30/30 cartridge he should look into reduced load data using a powder like 4759 or 5744 etc that will keep velocity down yet pressures up to help his "weak primer pocket" problem. Or else bump his 4895 up a grain...He can discard his 2 leaky cases and replace them with once fired discards at nearly any gun range. Most .30/30 users don't handload.. :wink:

Oh yeah...glue?!? :shock: Not in my rifle!

Just my two centavos...

 

[Jimbo357mag]

I wasn't looking to fix anything in particular just thought I would bring up something to discuss. I do lightly size and trim my brass and thoroughly clean and inspect them every time I load them. I shoot them in a newer Marlin 336 with good headspace and reasonable chamber but with a rather short lead before the rifling. I shoot full power loads the first 4-5 times and then drop down to what I consider reduced shooting loads as above. This starting load gives me good accuracy and shoots POA for me. I loose a case every once in a while, usually do to a neck crack or split.

I have thought about shooting lead and mouse fart loads but haven't gotten around to that yet. Seems the lead bullets or lead with gas checks are almost as expensive as the Sierra bullets that I find to be the most accurate. I did try some 110gr bullets from my M1 30 Carbine but the accuracy was terrible. The 125gr hollow point Sierra's weren't much better. The best by far for my rifle has been 150 and 170gr Sierra flat points.

I appreciate the ideas and knowledge from you folks. I have learned a lot here. Just getting good at sizing those 30-30's took a couple of questions and answers here. :D

 

[Dan in MI]

I'm in the pressure too low to obturate the primer cups camp.

Rambling thoughts from someone that cut his teeth on wildcat rounds and have shot them for 30+ years.

You may be able to get your low power loads with a different powder. The powder you are using may be a little too slow. The pressure rise is just a hair too slow. It is high enough to allow gas to sneak past the primer before the bullet fully seals the bore and raises the pressure enough to seal the primer cup. Purely speculation, but if I was serious about making low power loads it would be something I would look into.

You could easily test your issue first by trying the same load with new, or near new brass. If you get the same smoke ring around the pocket then it's the load. If not, then blame the used brass.

Edited -- after actually reading Buck's post (I got lazy after reading the others)

His powder suggestion(s) falls in line with my rambling thoughts. I am a big fan of both powders mentioned and have been since the 80's. So much so I still DuPont 5lber's of 4759 and 5744 from the pre re-formulated days.

Regarding brass - if you are shooting your ammo in the same gun try neck sizing or semi neck sizing to keep from working the brass too much. Just size enough to bump the neck/shoulder just a tad instead of a total reform.

 

[Bucks Owin]

Good sizing advice Dan. I looked up the 30/4895/150 in the IMR powder .30/30 data section and although a little on the light side, looks like it should develop close to 30K pressure wise...

I absolutely LOVE SR-4759 for many applications. Apparently other silhoutte shooters dote on it too but I guess not enough to convince IMR not to discontinue it...again. :cry:

Use it sparingly amigo...

 

[Jimbo357mag]

I don't find any load data for (edit to correct) IMR SR-4759 or Accurate 5744 for the 30-30, where as there is tons of data and reduced load data for the 30-30 for H-4895. I have tried as low as 28.0gr and as high as max. 34.0gr with the H-4895 and they all shoot well. It is one of the most versatile powders of all time. ...and it's on the record as such. I also use Varget and W-748 for target loads.

btw, I have heard that 7 -9 grains of Unique makes a very light load in a 30-30.

Thanks again.

 

[Bucks Owin]

I don't find any load data for IMR4799 or IMR5744 for the 30-30.....

Uh, that's SR-4759 and you can find data quite easily...Try harder...like google :wink:

 

[Dan in MI]

As said SR-4759 (IMR) and MP-5744 (Accurate Arms)

Regarding Unique I am NOT a fan of any powder/load that doesn't fill more than ~50% of the case.

 

[Jimbo357mag]

I did look up some loads with those powders (IMR SR-4759 and Accurate 5744) and they look really good for lighter loads especially. If I was into casting rifle bullets they might be just great, but I'm not.
Still learning more. :D

 

[Dan in MI]

I am not opposed to using data by weight only and not bullet construction.

I've used SR-4759 in 7-Int-R (effectively 7x30 Waters) and 7 TCU since 1984 with only jacketed bullets. Probably spit a few out in 30-30 but I only owned that round for one summer so not a whole bunch. I cannot see any reason why you can't crank out some 30-30's with it. The 7-IR and 7x30 are based off a 30-30 so there is really no difference to speak of.

 

[Jimbo357mag]

A little more to add. I was priming some more 30-30 cases today, some brand new Hornady cases and some from my well used stock. I noticed the new cases required much more force to fully seat the primers than the used cases. I think this confirms my thoughts about loose primer pockets on some of the well used cases. If you find some smoke around the primer pockets on your used cases after shooting, it might be time to chuck them in the recycling bucket. :D

 

[andyo5]

Are you using a cutting tool to 'uniform' your primer pockets?
I used to do this until I realized it caused many of them to leak. I now leave them alone. One time when easier is also better.