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| One of Us |
 I am new to the forum and was hoping that someone may have some views on an unusual problem I encountered recently. I have been working up a new load - 7mm rem mag using 61gns of AR 2213sc (Australian powder)and 162 Amax projectiles. They tested pretty well averaging around 3/4 MOA however two of the rounds formed pin holes with lots of soot and burn marks at the rear of the shell. The primer was ver flat and looked like a classic hot load - the strange thing was that 61 gns is supposed to be at the lighter end of the scale in temrs of the ADI Reloading manual. Has anyone expereinced anything similar ???? | ||
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| One of Us |
Sounds like your cases are streatching and you have incipient head separation. Jerry Liles | |||
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One of Us |
I believe the pin hole you're describing is around or in the primer. That's a pierced primer and indicates the load is too hot irrespective of what the reloading manual says. If the hole is in the side of the case as opposed to the rear of the case, then that would be an incipient head separation which would be sign of a case used too many times or of excessive head space. | |||
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| one of us |
I think that Grumulkin is right, except that I have seen this (pin hole around the primer pocket) with old brass. Ditch the brass and try new or known, once fired brass. Peter. Be without fear in the face of your enemies. Be brave and upright, that God may love thee. Speak the truth always, even if it leads to your death. Safeguard the helpless and do no wrong; | |||
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| One of Us |
thanks guys, but the brass was never used before and wasn't stretched at all. There is no head space issue either. The primer wasn't actually pierced, the pin holes were right on the edge of the primer and the pocket. In fact the damage looked more like a severe burn hole perfect in shape - never seen this before. A more experienced handloader told me it could even be that I have underloaded the rounds - apparently underloading can cause an oxy type burn through the back of the case around the edge of the primer pocket. Didn't make sense to me though as the flat primer and pressure marks on the base of the bass indictaed too hot a load, but the manual still states it is light??? The bolt face was actually burnt and has been pitted slightly. I am buggered if I know what is happening - any other thoughts? | |||
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| One of Us |
G'day sevenmill, Welcome to the forum! I'm an Aussie too and, the ADI info I have has you only 1gr up from the start load, max is listed as 64gr. It definitely sounds like a brass problem, not a load problem. One strange attribute of the 7RM is that different makes of brass can have as much as 10gr's difference in capacity, which has been known to cause hangfires and other strange events such as S.S.E (secondary explosion effect) with published loads. Your event sounds more likely to be a low pressure event that caused the primer to back out of the pocket and eject some gas due to it not sealing correctly. An increase in the load may help. What brand of brass are using? Is it all the same manufacturer? Cheers.  | |||
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| one of us |
7mil, Welcome aboard! The 7mm Rem. Mag. is known as a cartridge that can have "wierd" swings in pressure and I have experienced these also. Not pin holes nor pierced primers but all sorts of other indications that something was amiss primarily flattened primers and a ring of black soot around the primers as if gas was attempting to escape around the primer. That particular batch of brass was trashed and another batch obtained. Since the rifle in question is a Savage Heavy-Barreled Tactical the barrel was removed and re-installed with headspace about as perfect as we could adjust it and the RCBS F/L Dies & designated Shellholder perfectly adjusted to the chamber as well. In one case (pun intended) simply changing brass resulted in sterling accuracy and the flattened primer issue dissappeared; all these with loads several grains below max charges taken from several manuals. The rifle remains having a penchant for: 1. Much less than maximum charges 2. Only a couple of bullets (Speer 145 gr. Match HP's & Nosler 140 gr. BT's (not the ones I'd use for a all-round hunting load) 3. R-P cases; all other options and I've tried many, depict bizzare, head-scratching pressure indications well below published maximums. Good Luck in sorting your 7mm Rem. Mag. issue. Cheers, Number 10 | |||
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| One of Us |
I believe he said the primer was flattened. Low pressure loads cause the primer to back out. I also doubt it's a brass problem. If the primer was flattened and not backed out the pinhole leak indicates high pressure. There is another way to tell if it's a low pressure load. Look down the barrel after firing. Low pressure loads leave a lot of debris in the barrel. After firing a high pressure load, there will be little and probably no debris in the barrel. | |||
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| One of Us |
Yeah, I've seen it, got the burnt bolt faces to prove it. It'a harmless unless you keep it up for a long time. What's happened is some of your primers have defective cups; the metal is too hard/too thin so it blows out at the point of least support. I religated my brick of primers like that to low pressure loads - .30-30, .35 Rem - and all is well. | |||
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| One of Us |
Thanks Gerry, Grumulkin and 416 RigbyHunter (fellow Aussie), appreciate all the thoughts. The thing is all the brass was remington and unused albeit most were probably 5-8 years old. 416 RigbyHunter you are dead right, 61gns is not a hot load, but the flat primers (and I mean very flat does) do indicate high pressure. The primers were not pushed out at all. Interestingly a lower load (60gns) demonstrated pressure signs such as flat primers, but no pin holes and pretty good accuracy. What I don't understand is the ADI manual recommends a lower 58 gn starting charge weight for 160gn projectiles but for the heavier 162gn projectiles recommends a higher starting charge weight (60gns) - this is strange to me ?? I understood that in general the heavier the bullet, the lower charge weight assuming the same type of powder is used. What gives ?? | |||
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| One of Us |
thanks Jim C. It could very well be the primers as I changed brands to Winchester - they were all new but I normally use Federal. Another damn variable to think about. | |||
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| one of us |
Sevenmil: Here are a few comments that might help. 1. A notably flat primer is not at all unusual with normal pressures on the first firing of a new case. I won't go into the details of why, but discount the appearance of the primer. 2. Leakage around the primer is highly unusual and is not a result of pressures (either low or high), but rather of the fit between the primer and the primer pocket. 3. Winchester unplated primers tend to fit within the primer pocket somewhat loosly due to the lack of plating. They are the same nominal size as plated primers, but the lack of plating makes them a few thousandths smaller. Although I have not experienced the phenomenon you describe, I have to suspect, like Jim C, that it is a result of a mismatch between the primer pocket and the primer. Try switching to another brand of primers and see if this problem doesn't disappear. Note: The cases with which you have already experienced this phenomenon are probably damaged and should not be used again. | |||
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one of us |
I also think its a primer/ primer pocket issue. I have had a simular problem with a 25/06 with stretched pockets. The only other thing I can think of would be to double check your scale or powder measure to be sure 61 grains Is what you are getting. | |||
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| One of Us |
1. The times I've gotten pin holes and leakage it WAS from excess pressure and had nothing to do with primers, primer pockets or brass quality. 2. It's true that even at acceptable pressures, primers are flattened; it's mainly a question of how far out the flattening goes. If the flattening goes clear out to the very edge of the primer with not any rounded part of the primer at the edge thereof you know the pressure is about as high as you want it to be. Also, primers start out with shiny surfaces. When the pressure has increased enough that the surface isn't as shiny, you know you're approaching what should be maximum pressure. 3. Reloading manuals have been known to be wrong, at times powder is mislabeled so you're not really loading what you thought you were, etc. The bottom line, it's always best to check more than one manual and if you're having signs of high pressure reduce the load irrespective of what the manual says. | |||
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| One of Us |
Your's are Winchester, mine were Remington and a young friend recently brought some over to show me that were CCI. So, I doubt brand is the issue at all; it's likely you can buy a new batch of WW and have good stuff. Thing is, all the primer (and case) makers buy rolls of sheet brass and then stamp it into the right shape in house; there is little they can do to insure the alloy and thickness in the roll is precisely what they tried to buy so I don't blame the makers for a few failures from time to time. I probably could have returned my bad caps for replacement but it was one brick of three that had been purchased a few years before I tried them; I don't even remember where they were bought! So, I reserve them for low pressure stuff and am still using them with complete satisfaction for that. Nickle plating is maybe a couple of tenths of a thousanth thick, that's not enough to make any difference in seating. Hot loads will certainly expand primer pockets but it usually takes a few loads for leaking to show up ... unless you're REALLY on the ragged edge of a KABOOM! | |||
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Thanks guys - appreciate the thoughts. I am going to get rid of the brass and start afresh. I may also try some 150gn balistic tips and start with a lighter than recommended charge wt. Have you guys had good accuracy with 150 balistic tips in a 7mm rem mag? I use 125gn balistic tips in my 308 sporter Remington - shoots 1/2MOA and is brilliant on game - hopefully 150gn B/T may work well in the 7 mil?? | |||
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| One of Us |
Back in the '80s, I bought a new un-opened can of Du Pont IMR 4831. After trying a few "book" starting loads, I too had some very unusually flattened primers with the cups flowing around the the firing pin. But I also had bolt face marks on the case face. Come to find out the extruded 4831 powder also had some ball powder mixed in with it (who knows what), from the maker. Just for grins you might want to check that. Also had a brick of faulty Du Pont Remington primers with the anvils mounted un-even in the cup. They wouldn't fully seat in the pocket against the pocket face. Had some of them blow out too before I figured out what was going on. Not to long after Du Pont sold off the powder and component divisions. "The right to bear arms" insures your right to freedom, free speech, religion, your choice of doctors, etc. ....etc. ....etc.... -----------------------------------one trillion seconds = 31,709 years------------------- | |||
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| one of us |
sevenmil, there is a thread on 7mm RM handloads on the Favorite Load forum on this website. They speak highly of the Nosler 160 gr. Accubonds. I am trying them now. Peter. Be without fear in the face of your enemies. Be brave and upright, that God may love thee. Speak the truth always, even if it leads to your death. Safeguard the helpless and do no wrong; | |||
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| one of us |
Like Jim C. said.......when you get a pin-hole through the corner of a primer.....no matter what the load, no matter what the cartridge. They are a DEFECTIVE primer lot. Federal, CCI, Win, Rem, etc.......doesn't matter. They've all had bad lots, over the years. Just my $0.02..... Kevin | |||
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| One of Us |
Thanks Peter and Kevin. I am going to ditch the brass and primers and buy some new brass and federal primers and I may try the 160gr Accubonds. It was a new batch of powder, so I think there is no problem with that aspect. The starting charge wt is only 58gr of 2213SC, which makes sense (still can't work out why ADI recommends a higher charge wt for a heavier 162gr bullet-60gr)??? Based on all your feedback I think the loading data is simply wrong. 60-64gn of 2213SC for a 162 gr bullet is plainly too hot as recommended in the ADI manual.Perhaps I should try some American made powders instead of the Aussie stuff????? | |||
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| One of Us |
According to the Hodgdon data(which is the same as ADI), the 160gr projectile is a Nosler partition and the 162gr is a Hornady SPBT hence the different starting loads.
I don't think you can blame the data, I'd be changing primers first up and see how it goes from there. I had a similar situation with my 300SAUM (two primer leaks) and a change from Rem primers to CCI's solved the problem. | |||
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| One of Us |
guys I think you may be right in regard to the defective primer theory. Just did an autopsy on the cases with my local gunsmith and removed the primers and guess what, both pin holes were on the edge of he primer - has to be a dodgy batch of primers. I am dumping them and going back to Federal | |||
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| one of us |
7mil, Load up some of the new primers and let us know how you made out? Cheers, Number 10 | |||
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one of us |
You have defective primers. Some will blow out with light loads. Check your bolt face for gas cutting. You may see small pock marks, they look bad, but dont hurt anything. Happens with all brands of primers, but not common.  | |||
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| one of us |
After all these years on this board, I should know that arguing with a stump is a losing proposition, but oh well, its a slow morning, so here goes:
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| One of Us |
VERY TRUE! Few, if any, fully flattened primer cups are due to excess pressure, most are due to poorly resized cases that allow the primers to back out much too far. IF a reloader develops his load properly it won't matter if there is an 'error' in the listed loads and having only one manual is fine. Meaning, start low and only work up to book max unless you get excess pressure signs early. Of course starting low with intent to go to full book max no matter what destroys the safely of developing the load "right." 243, that's an excellant photo of the problem and it isn't from excess pressure OR headspace; it's a bad primer cup and all brands are subject to it. | |||
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one of us |
Verify the bullet seating depth as well. Not to the book but to the chamber. Freebore may be minimal. Headspace may be at max saami listed dimensions for this rifle. I ran into a situation where chamber dimensions differed between two 30-06's by enough that ammo loaded to one rifles dimensions wouldn't even fire in the other. My father was getting what he thought was high pressure signs in a .243 but his load of powder was below recommended starting point. He went to a slower burning powder and seated the bullets a little deeper and bumped into a great shooting recipe. Nate | |||
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| One of Us |
 Thanks 243win, that photo looks exactly like what happened to my rounds. I don't think there is any question now, it must be the primers. | |||
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| One of Us |
[QUOTE]Originally posted by sevenmil: There is no head space issue either. Didn't make sense to me though as the flat primer and pressure marks on the base of the bass indictaed too hot a load, QUOTE] "The right to bear arms" insures your right to freedom, free speech, religion, your choice of doctors, etc. ....etc. ....etc.... -----------------------------------one trillion seconds = 31,709 years------------------- | |||
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One of Us |
I have no dog in this fight. And I do not venture guesses at this distance as to what problem has been encountered here. I do know though that primers assuming a frosted and very flat look IS sometimes (not always) one sign of excessive pressures. I also know that primer leaks around the edges, very much like the one shown in the picture can be a sign of excessive pressure. Why does that sometimes happen? Because very high pressure gas is a wizard at escaping its confines. It also follows the path of least resistance. Sometimes part of that path, as well as being through the flash hole, is through the space around the primer cup, not through it, when it is a good strong cup. Often the hole which results is the result of gas cutting at the point the gas is escaping at from around the cup. You "modern" loaders can believe those are old-wives tales, or not. I don't much care. It is your right to use whatever load you dare. How many of us have read that to work up a load with components you haven't used in a particular gun before, one should start 5% below the minimum listed in books and edge up bit at a time from there? No matter which brass, powder, or primers are used, I still think that is a potently sensible rule. BTW, one of the rifles I once had trouble with was one of the very first Remington 7 mags ever made. A friend snagged it for me off the Remington production line in the first week of production. (I paid full price for it, he didn't steal it. But they were not yet available from dealers in California, where I lived at the time.) It turned out that rifle had almost NO throat in it, and it would never take book loads until I had the throat opened up. (The very first round was a disaster, not only because of the no throat problem, but because old P.O. Ackley sent me a load which proved to be way too hot even for rifles with ample throat.) My country gal's just a moonshiner's daughter, but I love her still. | |||
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| One of Us |
There is a lot more to charge weight than simply bullet weight. Bullets have differant ogives, differant boattail designs, some have cannelure's some dont, etc etc etc. All these things affect friction and pressure, so often times bullets of similar weights can have significantly differant load ranges. Curtis | |||
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One of Us |
I'm sure you meant 5% below maximum. | |||
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| one of us |
60.0gr is a maximum load for a 160gr bullet.Reduce you load to see if the primers still blow out.If the load was over maximum, the primer pocket should become enlarged. Different component=Different pressure. There was a big difference in rifles in 7mm rem mag when they first came out. Some rifles had tighter grooves than others. I know of 1 handloader shooting 2.0gr over listed maximum load data.
http://www.adi-powders.com.au/...ders-guide/rifle.asp I know from personal experence when Rem. 9 1/2 primer cups were blowing out for me. Reduction of the load did not stop them from venting. Even light cast bullet load would produce a pin hole in the primer like in the Federal 215M in the photo. | |||
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| One of Us |
60.0gr is a maximum load for a 160gr bullet.Reduce you load to see if the primers still blow out. 243winxb, That load data is from Hodgdon, the load data the original OP, as I, quoted is from the last paper published ADI manual and, 64gr of 2213sc is listed as max, as are a few manuals printed around the same time for H4831sc, the same powder. The problem is clearly faulty primers, as I expected, but unfortunately in my OP I put "brass" instead of "primer", I didn't catch it until now! Cheers. 
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| One of Us |
No, I meant exactly what I wrote. At 5% below minimum, there is no particular danger of SEE occuring, even with powders such as 7828 or 4831. Nor is there a possibility of the bullet not making it out the end of the bore. There IS always the possibility of that being too hot, however, as I found with my new 7 m/m Rem Mag I mentioned above. If a person blindly takes a minimum load from a book, then uses a different powder lot (possibly even now made by a different factory in a different country), a different make of bullet (even if the same weight), a different make of case, and a different make of primer, there is always the possibility that the new combination will be max or over-max in HIS different rifle.  | |||
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| One of Us |
My experience with pinholes is extensive. When I shot IHMSA silhouette the best load was in the 7mm TCU with Reloader 7 and a Remington 6-1/2 primer. That primer cup is made thinner than the 7-1/2 BR cup and would pinhole on every shot. Accuracy was so good that I accepted the the pinholes and erosion of the Contender's firing pin bushing as the bushings were easily replaced. The Remington 7-1/2 BR primer would not pinhole with the exact load, but accuracy was not as good. In every instance where loads were within the normal pressure range, pinholes are due to thin primer cups. The radiused edge of the primer is its weak point. This held true for certain primers used in other cartridges, such as the 6mm PPC. In large capacity cases too light a powder charge can cause a pressure excursion and be as dangerous as an overload. I had this experience with a Winchester Super Short Magnum that was underloaded with a ball powder due to a malfunctioning progressive loader. Similarly I experienced hangfires and excessive pressures with slow powders and standard strength primers, large charges of slow powders always require magnum primers. Do not assume that reducing the powder charge will correct the problem, it may exacerbate the problem. First try firing factory ammo, if there is no problem suspect the trouble lies with your loads and especially the primers. Secondly, try another brand of magnum primers, Winchester Large Rifle Magnum and Federal 215M primers are my choice for the 7mm Magnum. Flatness of the fired primer proves nothing, that appearance can be due to a weak cup, excessive headspace or even excessive pressure caused by too light or too heavy a charge. In my long range 7mm Magnum rifle I set headspace on the shoulder by expanding the neck to .30 caliber and then necking it back down until the bolt just closes. That increases the accuracy and eliminates any headspace problems. | |||
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It is not at all surprising that Rem 6-1/2 primers pinhole every shot in the 7 m/m TCU loaded "warmly". That is a pistol primer, and the 7 TCU is a rifle cartridge (a necked-up and sharper shouldered .223 Winchester with heavier bullets), even if chambered into a pistol. One of the reasons the primer manufacturers recommend not using pistol primers in rifle loadings is that the thin pistol primer cups are easily perforated by both the heavier firing pin falls of rifles, and by the higher pressures of rifle loads. As to lighter loads causing pressure excursions (also known as SEE...Secondary Explosion Effect IIRC), yes that can and sometimes does happen...when one is 10% or more below the recommended minimum loads, with heavy bullets and slow-burning or slow-igniting powders. That's why loading manuals often tell loaders not to go more than 10% below listed minimum loads. Moving slightly in subject, to non-magnum cartridges, a good primer to try there if one suspects primer thickness is his problem, is the CCI #34 military-spec primer. Intended to prevent slam-fires in semi and full auto rifles, the #34 primer has a cup much thicker than that of, say, Federal 210s. For magnum cartridges, the sturdiest civilian available primer cups I've found are the Winchester magnum large rifle primers. Ultimately, it is all a matter of "best guess", prior experience, and a bit of experimentation. ALL experiments involving intentionally created explosions in closed containers carry some degree of risk. The object is to use one's best judgement, his own and others' experiences, published information from reliable sources, and a small prayer to minimize the degree of risk. | |||
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| One of Us |
thank you all for your thoughts. I believe the issue was in fact the primer. Last weekend I changed to Federal primers,kept the 162 gr Amax projectiles but loaded slightly lower than recommended charge wt, only 58gns. No pin holes, no soot or excessive pressure signs - wow...3 groups of 4 were 0.25-0.30 MOA at 100 m, so looks like I have found the right load at last.Interestingly I also noticed that ADI removed their recommended loading data from their website for 162gr projectiles after I contacted them. I recon their original load data was too hot, but who knows???? I hope Amax's do the job well on our feral Aussie game (wild goats, pigs, foxes, etc). | |||
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| one of us |
Remington 6 1/2 primer is a small rifle primer. Not to be used in 222,223, others.  | |||
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