BIT OV BOTHER..

Hi peoples,
Lately I've been back playing with the .223 and enjoying it,been a long time.
Anyways I'm loading up a few using BM2 powder and 55grn SP pills,cci primers.
The manual says the start load is 24grns and max is 26grns.
First three loads done at 24grns....very accurate...not speed tested.
Second three loads at 24.5grns....verry accurate....'' '' ''.
Third three loads at 25grns.......very accurate.... '' '' ''
Fourth three loads at 25.5grns......very accurate... '' '' ''
Fifth three loads at 26grns Max very accurate '' '' ''

Now for the punch line....All loads from the first three to the last have cratered primers.
No other pressure signs at all just craters. Pills are all seated to factory specs.I even tryed these loads again with pills seated just off the lands,no different,same results.
To be honest I cant understand why they all hit the same spot.
Any ideas why the primers are cratered on all loads?
Any reason ??
Cheers.

Suggest you post a clear, in focus, close up photo of a typical primer so we can see.

There’s cratered primers to worry (a bit) about, and cratered primers to take note off, and carry on regardless.

Loose firing pins fit, etc or excessive pressure, etc.

Do you get cratered primers with factory loads in that rifle? My 300 Rum craters primers with any load I have tried so it could be the firing pin or something else along those lines.
So long as your bolt lift is fine and the primers aren't flattening out in the primer pocket you should be alright.
I load 25 grs of BM2 with the 55 gr SP /WC and they crater like that too, my rifle is a Rem Mod 7 223

I had a model 7 Remmy that did that, oversized firing pin hole. Cratered everything from mild hand loads to factory. I just used it.

BM2 loads are accurate alright......suggest you try diferent primer just to see....and yes photos are needed...and how it handles factory rounds.somewhere in deep dark recesses I seem to recall CCI are softer primers than others????

If there are no other pressure signs like a shiny ejector mark on the rim, tight extraction or suchlike I wouldn't worry too much about it. If they cratered at start load its a pretty good sign its the firing pin hole. My Rem M7 .223 does it and otherwise tolerates quite warm loads.

Thanks guys..No to factory loads cratering,
No to bolt being hard to lift etc.

First pic is of starter load= 24grns
Second pic of two at 26grns=Max and one at 25grns.

Bottom pick looks like start loads....top pick looks like start loads except the one on the right which is starting to lose the radius at the edge of primer.
None look "hot" to me but the one on the right in top pick is starting to build pressure.

Primers are not a reliable indication of pressure tho.....speed is.
If data indicates x pressure and speed at x load then you can be fairly confident if you are achieving x speed from same lenght barrel then with the same powder you will be getting the same pressure.....within cooeee at least.

Have you tried a different manufacturers Primers with the same loads ?

Primers have a nice radius shoulder. I'd suggest not a pressure issue or they would be square to "chef's hat" shaped. Looks like a larger firing pin hole and possibly a soft primer. If you are concerned or get pierced primers, I'd switch primers first. Try a federal or a CCI. I had a similiar issue with my tikka with few pierced Rem no 7 primers. Switched primer brands to CCI and Federal and now all good.

Yeah I feel that I should not be too worried it's just that it is a bit weird that it is with all loads.
Factory ammo is normal all good there.
Guess I'll stick to one load and turn a blind eye as such?? I have struck some real hot loads with real dangerous shit happening aways back so yeah certainly not too stressed about these loads.
I may try another primer brand but have far too many CCi here.
Thanks for the input,appreciate it.

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Originally Posted by doinit

Yeah I feel that I should not be too worried it's just that it is a bit weird that it is with all loads.
Factory ammo is normal all good there.
Guess I'll stick to one load and turn a blind eye as such?? I have struck some real hot loads with real dangerous shit happening aways back so yeah certainly not too stressed about these loads.
I may try another primer brand but have far too many CCi here.
Thanks for the input,appreciate it.

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Just carry on shooting live stuff, and then post up a report.

Greetings Doinit,
An important piece of information would be the chronographed velocity. This would give you more information than 24 hours of gazing at primers. 26 grains of BM2 is a bit over max listed at 25.6 grains for the 55 grain projectile. You don't give the type of projectile and I assume they are lead jacketed type. If your velocity for the 25.5 grain load was around 3,250 fps in a 24 inch barrel then the pressure would be similar to the 50,000 CUP of the Hodgdon/ ADI load. In my experience .223 primers tend towards cratering but neither of my .223 rifles show the level of cratering as on your loads. Mine are primed with Federal 205 primers and loaded equivalent to yours. I have read that CCI 450 primers are much harder in the cup than their standard ones and have been used to get over cratering problems. A packet of 100 450 primers would tell you if it is just the primers or if you have a rifle problem. In my opinion gazing at primers is like gazing at the entrails of a chicken. you can tell that the cartridge has been fired and that chicken is dead but not much more. A chronograph would be more help.
All the best and Regards Grandpamac.

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Originally Posted by grandpamac

Greetings Doinit,
An important piece of information would be the chronographed velocity. This would give you more information than 24 hours of gazing at primers. 26 grains of BM2 is a bit over max listed at 25.6 grains for the 55 grain projectile. You don't give the type of projectile and I assume they are lead jacketed type. If your velocity for the 25.5 grain load was around 3,250 fps in a 24 inch barrel then the pressure would be similar to the 50,000 CUP of the Hodgdon/ ADI load. In my experience .223 primers tend towards cratering but neither of my .223 rifles show the level of cratering as on your loads. Mine are primed with Federal 205 primers and loaded equivalent to yours. I have read that CCI 450 primers are much harder in the cup than their standard ones and have been used to get over cratering problems. A packet of 100 450 primers would tell you if it is just the primers or if you have a rifle problem. In my opinion gazing at primers is like gazing at the entrails of a chicken. you can tell that the cartridge has been fired and that chicken is dead but not much more. A chronograph would be more help.
All the best and Regards Grandpamac.

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Gidday there Grandpamac...The barrel length on the rifle I use is 17 inches, bullet is a Sierra 55grn SP.
The load data I'm playing with is from Nick Harvey's Practical Reloading Manual.
For a 55grn pill he's saying start with 24grns of BM2 MV 3115.
Max with BM2 is 26grns.......MV 3300.
These MV's he's stating for those two loads are out of a 24inch bull barrel.
I'll give my loads the speed test some time just for giggles....
Cheers

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Originally Posted by Tahr

Just carry on shooting live stuff, and then post up a report.

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Far too long in the tooth now to be reporting in eh...........those days are gone .