Case life question 308WIN

paulbshooting

Well-Known Member
Good afternoon
I am fairly new to reloading (one year in) and really enjoy it. For my 308 WIN I loaded new lapua brass two boxes to start with, N140, fed primers and nosler bullets. Fine tuned the load and overall length to suit chamber, am delighted with the results. I don't shoot many rounds, only for stalking and the odd fox / check zero or practice.
I haven't kept score of how many reloads I have done from the same batch of brass. I always full length size and clean in stainless pin tumbler with cleaner in warm water, then loading batches of 20 every so often.
Last weekend I was loading a batch and after following the same process noticed the primer pocket to take less force to seat the primer (assume going oversize?) and the bullet seating pressure also seemed less.
Any advice would be welcome on the primer pockets and assume the necks need annealing? Will this effect accuracy? I intend to test a few next weekend but keen to learn.
Thanks.
 

PeterH

Well-Known Member
Others will probably give more information, but basically it is generally the primer pockets working lose that signify the demise of the case. As long as you have some sort of feel of pressure on the primer that should be fine - worse case is when you hardly feel nothing and a tap of the headstamp sees the primer on the move, then it will have to be binned. The amount of firings achievable can depend on the quality of brass and equally the amount of pressure you are loading the case to.

Personally I like to keep a record of the amount of times fired as I need to consider annealing (annealing wont help primer pockets though) and rather than keep separate boxes duly labeled I simply mark the case with a sharpie each time I reload the case.
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Alantoo

Well-Known Member
I would agree with @PeterH

Are your loads very hot? i.e. at the top end or over of the published load data/pressure range?

Was the primer pocket looser on all the cases or just some? If you haven't been keeping track, could you have a few which have been 10 times reloaded mixed in with some with 4 or 5 times?

I have a few Hornady cases which I have been retiring (after shooting) if the primer feels a bit looser...I mark those with a sharpie with LP and discard them after use.

None of the my Lapua cases have developed loose primers pockets yet and some of those are over 10 times reloaded...both the Hornady and Lapua case necks have been stress relief annealed after 3 or 4 loadings.

The lack of neck tension does sound like they could do with an anneal.

Alan
 
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Outback

Well-Known Member
It is normal procedure to load and use 50 rounds then repeat , this is to ensure all cases receive the same amount of work maintenance and consistency some target shooters would get 13 reloadings out of the 308 but cases are consumables so by loading and working through them you will get consistency for there life then replace .
 

paulbshooting

Well-Known Member
Thanks for the responses. In hindsight I should have been more disciplined in marking the cases every time I reloaded / processed. I will have a mix of use with the brass as I process them when I get ten or so fired and have time to prep. There is still tension on the primer and neck / bullet but just less than when first used. I will monitor both and start scrapping off the brass when it gets worse. For the new brass in the future I will markup as recommended so more controlled. My load is 44.6 of N140 so not too hot? The primers are very flat after firing / squashed (if that makes sense!) so assume normal and with no ejection problems. Every day is a school day. Thanks.
 

Harry mac

Well-Known Member
Severely flattened primers should be ringing alarm bells. Are you using 150grn bullets?
If you're seating the bullets long, are they touching the rifling? Slackening primer pockets is also not a good sign.
Under normal circumstances, a 44.6 grn charge of N140 under a 150grn spitzer bullet shouldn't be flattening primers and loosening primer pockets.
 

caorach

Well-Known Member
As has already been said you might want to have a look over the whole process as there might be something not quite right somewhere, the other possibility is that as a beginner you've read about primer pockets becoming loose and are now noticing it despite it not being a problem. I worked up a load with a 150 grain bullet in my 308 using Lapua brass and after using this load for a long time I discovered it was giving me much more speed than I expected (3000fps). Like you I wasn't accurately accounting for each load on a case but I knew that some cases had been used a lot more than others and that I had 100 cases and had used more than 1,000 primers. It was a simple matter to observe that some cases had a goodly number more than 10 loadings on them. None of the cases showed any problems or pressure signs, in fact I'm still using some of that brass batch, apart from one that eventually split a neck.

My Blaser has a relatively short barrel and a rifle "produces" pressure for a certain amount of time and this, strictly speaking, provides the bullet with momentum. The mass of the bullet is fixed so increases in momentum are associated with an increase in speed and when I was seeing 3000fps then it was possible to conclude, despite the lack of any evidence at all from the cases, that my pressure must be a little on the high side. Needless to say I've backed off a little as I had no need for 3000fps or the additional pressure required to produce it, I got there entirely by following good practice and until I borrowed a chrono there were no signs that I had got there. This does highlight, however, that even with careful working up and nothing in the way of pressure signs it is possible to be working at, or perhaps beyond, where you'd like to be in terms of pressure and so by the time you are seeing pressure signs on the brass you could be somewhere quite risky. The other possibility is that you are seeing something perfectly normal but just don't have the experience to work that out, as a beginner I worried about a lot of stuff that experienced people looked at and said "that isn't a problem" or even "that isn't what you think it is..."
 

paulbshooting

Well-Known Member
Thanks for the advice. I shot a couple of factory rounds in the 308 at the weekend and the primers look the same as the reloads afterwards so prob don't know what I am seeing due to a lack of experience. The overall length was fine tuned after measuring with the Hornady tool and backing off. I ended up 20 thou off rifling / lands (from memory as load book at home) after some experimenting and to fit the Sako mag. This gave the optimum performance in terms of accuracy and consistency but have yet to chrono. Good advice to borrow or buy a chrono - any suggestions on what to buy would be appreciated. I am using a 150 grain Nosler BT.
 

creakybak

Member
As mentioned by paulbshooting - If you're reloading, invest in a chrono, it's an essential part of your kit - you need to know your speed as it helps in building your drop chart and is essential if you ever decide to go over to monometal rounds if you do begin stalking . You need to be travelling at minimum of 2,000 feet per second to expand properly in 308 Win, (I have one too). Enjoy the journey..! It's very addictive...
 

levigsp

Well-Known Member
As has already been said you might want to have a look over the whole process as there might be something not quite right somewhere, the other possibility is that as a beginner you've read about primer pockets becoming loose and are now noticing it despite it not being a problem. I worked up a load with a 150 grain bullet in my 308 using Lapua brass and after using this load for a long time I discovered it was giving me much more speed than I expected (3000fps). Like you I wasn't accurately accounting for each load on a case but I knew that some cases had been used a lot more than others and that I had 100 cases and had used more than 1,000 primers. It was a simple matter to observe that some cases had a goodly number more than 10 loadings on them. None of the cases showed any problems or pressure signs, in fact I'm still using some of that brass batch, apart from one that eventually split a neck.

My Blaser has a relatively short barrel and a rifle "produces" pressure for a certain amount of time and this, strictly speaking, provides the bullet with momentum. The mass of the bullet is fixed so increases in momentum are associated with an increase in speed and when I was seeing 3000fps then it was possible to conclude, despite the lack of any evidence at all from the cases, that my pressure must be a little on the high side. Needless to say I've backed off a little as I had no need for 3000fps or the additional pressure required to produce it, I got there entirely by following good practice and until I borrowed a chrono there were no signs that I had got there. This does highlight, however, that even with careful working up and nothing in the way of pressure signs it is possible to be working at, or perhaps beyond, where you'd like to be in terms of pressure and so by the time you are seeing pressure signs on the brass you could be somewhere quite risky. The other possibility is that you are seeing something perfectly normal but just don't have the experience to work that out, as a beginner I worried about a lot of stuff that experienced people looked at and said "that isn't a problem" or even "that isn't what you think it is..."
You have a bite. Can I ask what powder and bullet etc you were using.? Thanks
 

HandB

Well-Known Member
If you are getting flattened primers in factory loads as well as your home loads then you might want to check your bore has not become narrowed with fouling. I have had overpressure signs like flattened primers with factory cartridges in my Parker Hale T4. I thought it was excessive headspace. But I cleaned the bore of copper and now the primers are normal (although there is still some case ringing).
 

caorach

Well-Known Member
You have a bite. Can I ask what powder and bullet etc you were using.? Thanks
It isn't very exciting and I've commented on it here before but, basically, I bought some bullets that I could get a supply of (150 grain Hornaday Spire Points) and some power I could get (Reloader 15) and I went to the Alliant web site and worked up to their maximum load - there was no great skill or insight on my part as I simply used what I could get and the load data I could get. This shot way better than I could hold and so I simply started using it as my deer load, I also loaded up a lot of spire points at the Alliant minimum load, for practise and target use to save on powder, and they also worked just fine. I had, for what it is worth, concluded that as I was shooting deer I might as well hit them as hard as I could so I didn't spend much time with any of the intermediate loads and my working up didn't involve much worrying about accuracy, only pressure, as the rifle always shoots better than I do. I only neck size and after concluding that all this messing about with length is completely unsupported by the stats I just load them at the book length.

Over a number of years I'd fired quite a few (certainly many hundreds) of the max spire point load as, although I had a target and practise load, I often used them on targets etc. as well just depending on my inclination. As I've mentioned there were no pressure signs on the cases and many of the cases were loaded well in excess of 10 times, perhaps some as many as 20 times. However one morning I was at the range and there was someone there with a chrono and for a laugh we shot them over the chrono to find they were doing 3000fps. It is unlikely the chrono was wrong as it was giving sensible readings with all the other loads shot over it at the time so all I can say is that, by accident, I had a book load that was giving me 3000fps with a 150 grain bullet from a relatively short 308 barrel. They produce more recoil than my other reloads so I was vaguely aware they were leaving me quite quickly but many of my reloads are at or near minimum so this didn't cause me any concern. Simple physics dictates that this extra speed didn't happen by magic and I would, therefore, warn you that unless my rifle is capable of changing how time works then the only other possibility is that it is being subjected to more pressure than other, similar, rifles launching the same bullet at a lower speed.
 

paulbshooting

Well-Known Member
What's the best chrono to buy? Seen the clip on magnetospeed unit - quite pricey and heard they can increase group size? I want a chrono to give me the missing info but maintain groupings so any recommendations would be welcome, thanks.
 

caorach

Well-Known Member
What's the best chrono to buy?
It would be worth seeing if your local club or someone you know has one as unless you are going to make reloading a full time hobby then a chrono isn't really something you need to use on a regular basis, in my case once was enough and I've never used one since. The money you'd save by borrowing one would pay for some stalking for you and would also give you another gadget less to fiddle with, and in reloading that is always a good thing.
 

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