Blaser R8 in caliber 8x68s
Reloading problem
- Thread starter petnyg
- Start date
I use of course the a caliber to measure til COAL, but I do not have the headspace gauge.what are you usig to measure your cases with, and COAL, a tape measure
Yes, I think I need to that... thanks.and this
Freeforester
Well-Known Member
A ‘very near’ gauge?what are you usig to measure your cases with, and COAL, a tape measure
I had a problem with using a Lee shell holder with an RCBS or Redding Die… the deck height on the Lee shell holder was out of industry standard spec 
whereupon it went in the bin. 
A switch to the same manufacture as the die fixed the problem
Cheers
Fizz
whereupon it went in the bin. A switch to the same manufacture as the die fixed the problem
Cheers
Fizz
You’ve missed the point I made.
Your original post mentioned you thought that you were possibly oversizing your cases to give too much ‘headspace’ (hence the problem with the primers).
A sizing die set to make firm contact with the shellholder will resize the case to the minimum industry dimensions (this may be more than is necessary or ideal) but it can’t oversize & push the shoulder back so much to result in headspace so great that you only get minimal indentation from the firing pin.
Re-check what you are doing with sizing if only to give yourself confidence that this part of your process is correct.
All that being said - your photo is visible now. Looking at the gap to the shellholder I’d be surprised if your cases are being sized to anywhere near minimum - this is absolutely ok - all you need to do is size enough to allow easy chambering in your rifle.
One cause of misfires can be incorrectly seated primers.
Compare your primer pocket depth to the height (thickness) of the primers. Using the two dimensions, seat the primers so that the feet of the anvil touches the bottom of the primer pocket. The primers will need to be a certain distance below the case head to achieve correct seating (the pocket/primer dimensions will tell you how much below the case head is needed).
If you still have some misfires then you need to look elsewhere. As mentioned in other posts, it could be the case that your firing pin spring is either on the weak side or there’s hard grease (or whatever) reducing the strength of its impact. The scenario here would have to be that the factory loads (which work ok) have more sensitive primers / thinner cups than the White City & CCI primers hence the firing pin can’t always fire the harder primer. Too short a protrusion of the firing pin could also have the same effect i.e. it works with sensitive primers but isn’t quite enough for harder ones. Both scenarios require an unusual chain of circumstances but they can occur.
As your ‘misfired’ primers fire at the second attempt I’d look to incorrect primer seating as the most likely culprit. Second would be checking everything is ok with the rifle.
Some months ago I had a few misfires with a previously reliable rifle. I’d started using a different brand of primer; it turned out that the height (thickness) of the primers were on average noticeably below the minimum allowed so when I seated the primers my normal distance below the case head the shorter primers weren’t touching the bottom of the pocket. Part of the force of the firing pin was being used to fully seat the primer hence the occasional misfires. To add to the problem the primer cups on the new brand of primers were 25/30% thicker than my normal brand - further reducing the impact on the primer compound.
Triggermortis
Well-Known Member
Thanks for the explanation.
Now I will re-check my sizing process and it makes sense that the issue is about the primers. I thought I solved that switching to another brand, but if the primers are seated incorrectly then U have to look here.
How can I make sure that they are seated correctly? I clean the primer pocket every time before primer seating and then I use the RCBS primer tool to seat and I make sure that I press hard enough so that the primer is so near to the bottom as possible.
Maybe I should try a 3. brand of primers?
Attachments
That’s not correct.
The thickness of a primer is typically less than the depth of the primer pocket. When a primer is seated so the feet of the anvil touch the bottom of the primer pocket, the primer will often be a few thousands of an inch below the base of the case. This is the ideal seating.
If seated exactly flush with the case head primers generally still work ok but it’s not how they ideally should be seated.
This of course assumes than primer pockets haven’t been deepened by someone appreciably beyond the recommended maximum depth.
It’s not difficult to find the correct seating depth.
Measure the depth of your primer pocket (take an average of a few).
Measure the thickness (height) of the primers (take an average of a few).
Just using some dimensions as an example - if the depth of the pocket is 0.135” & the thickness of the primer is 0.132” then you’ll need to seat so the top of the primer is 0.003” below the case head.
Some priming tools can be set to seat the primer to a specific depth but I don’t think your RCBS one can, in which case you’ll have to judge by measurement & later with experience by eye if the primers are seated to the correct depth. You don’t need to make it into ‘rocket science’ - the odd 0.001” here or there isn’t going to make any difference. The main message is your primers should be seated to a depth that lets the anvil feet touch the base of the pocket. This will generally result in the primer being below flush with the case head (i.e. slightly recessed), this is normal. It you achieve the correct seating & you still have misfires at least you know to look elsewhere for the problem.
All good reloading manuals such as Lyman & Hornady produce contain a chapter on seating primers - have you got & read such a manual?
You should seat the primer to the bottom of the primer pocket so the primer are lower than the base, if the primer are protruding it takes some energy from the firingpin to seat it proper.
Norfolk Deer Search
Well-Known Member
That’s a new one on meI had a problem with using a Lee shell holder with an RCBS or Redding Die… the deck height on the Lee shell holder was out of industry standard spec
A switch to the same manufacture as the die fixed the problem
Cheers
Fizz
Bavarianbrit
Well-Known Member
They are all supposed to be 1⁄8 of an inch or 0.125" in decimal inches deck height.
Bavarianbrit
Well-Known Member
Do you wear a blazer when you shoot your Blaser?
As above try seating your primers slightly deeper. The anvil requires support from the web at the base of the primer pocket to ensure it doesn’t ’back out’ of the primer, as the firing pins strikes the primer it’s purpose is to pinch the composition between the primer shell and anvil so any free movement of the anvil will reduce the sensitivity of the primer.
I’d imagine that your first firing pin strike is seating the primer to the full depth of the pocket which then supports the anvil, hence it ignites on the second attempt.
You could measure this with a vernier pre and post first firing pins strike to see if it’s correct.
I’d imagine that your first firing pin strike is seating the primer to the full depth of the pocket which then supports the anvil, hence it ignites on the second attempt.
You could measure this with a vernier pre and post first firing pins strike to see if it’s correct.
Cartridges resized with a Lee full-length die used exactly as instructed, gave me a failure rate of about 2% in one of my rifles. Factory ammo was fine. I noticed that the factory ammo had a little bit of the resistance when closing the bolt (just snug, not tight) but bolt closed on the lee-resized cases. I could add 7 layers of sellotape to a resized cartridge before the bolt couldn't be closed, and only one to a factory round.
Long story short, the Lee die seemed to be sizing to absolutely minimum length (checked with a case gauge) and that caused light strikes.
Solution would have been to wind out the die from the press by 0.1mm - but I sold the rifle before confirming. There was definitely nothing wrong with the rifle because I never had a misfire with factory ammo.
Long story short, the Lee die seemed to be sizing to absolutely minimum length (checked with a case gauge) and that caused light strikes.
Solution would have been to wind out the die from the press by 0.1mm - but I sold the rifle before confirming. There was definitely nothing wrong with the rifle because I never had a misfire with factory ammo.
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