looked at some factory ammo n didn't see any ring on them
Signs of pressure?
- Thread starter Rilow
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Blackhawk
Well-Known Member
What I see on the case head appears to to be marks from the claw type extractor . IMHO they do not appear to be an indicator of the cartridge base making contact with the bolt face. There would be a flattening of the cartridge case head as it makes contact with the bolt. You will notice perhaps some radial striations as well as a ring from the primer punch protruding from the bolt itself onto your cases head.. You will also notice a slight flattening of the manufactures name and caliber on the case head. In extreme cases you will notice that grey powder residue as well as the primer being pushed out from flush along with marks from the bolts face making contact with the cartridge head itself.. Last you may or may not experience extraction issiues with your case while removing it from your rifle .A simple test is to mike your fired case at the base against a virgin case. Normally you will see about a .003" - .004" difference between the the two. (based on a 6.5 - 30 caliber round & .004" - .005" difference between magnum rounds) If you notice any more then I would decrease your load's powder by at least 5% and reestablish your load data.
As for the cratering of your primers I do not think that this alone indicates anything. Please let me qualify that statement!. Your primers do not show any signs of flattening.(notice your rounded primer edges). It can be several direct causes.
One it will depend on your rifles build and brand as well as well as the type of primer that you are using.(assuming that you hand load) Secondly it will depend on your rifles condition. Last it will depend on your choice of ammunition components.
I would change things up as far as primers go and assuming all else is OK then I would continue using your loads recipe, as it looks worthy to me and what I am seeing in your images. That small amount of primer cratering well it's just normal with some brands of firearms. I would not concern myself with it ,however just occasionally keep an eye on it.
Just remember your chronograph is your best friend. Watch your ES & SD numbers until they tighten up and you will have reached your optimum load !
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Blackhawk
Well-Known Member
What I see from your photographs on the case head there appears to to be marks from the claw type extractor . IMHO they do not appear to be an indicator of the cartridge base making contact with the bolt face. There would be a flattening of the cartridge case head as it makes contact with the bolt. You will notice perhaps some radial striations as well as a ring from the primer punch protruding from the bolt itself onto the cartridge case head . You will also notice a slight flattening of the manufactures name and caliber on the case head as well as primer flattening. In extreme cases you will notice that grey powder residue as well as the primer being pushed out from seated flush. Last you may or may not experience extraction issiues with your case while removing it from your rifle .A simple test is to mike your fired case at the base against a virgin case. Normally you will see about a .003" - .004" difference between the the two. (based on a 6.5 - 30 caliber round & .004" - .005" difference between magnum rounds)
As for the cratering of your primers I don not think that this alone indicates anything. Please let me qualify that statement!. Your primers do not show any signs of flattening.(notice your rounded primer edges). It can be several direct causes. One it will depend on your rifles build and brand as well as
IllinoisBurt
Well-Known Member
If you back off a grain or two and the ring disappears that will answer your question.
2700 with 180 grains should be very doable without pressure issues. Try a different powder. H4350 is good.
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No weight on the bullet being used. I would say that your are a little over pressure. Need to back down a little. Those primers are showing high pressure signs. The bolt doesn't need to be hard to open to be over pressure. When it's hard to open it's really over pressure. Diameter of the firing pin hole to the firing pin doesn't mean that much. It the pressure that pushing the primer back around the firing pin into the opening. Generally every rifle is different in handling pressure. A different bullet from different manufactures cause higher of lower pressures even with the same bullet grain weight. I haven't used all copper bullet in 18 or so years. At that time I tried Barnes copper bullets I couldn't get the groups nor velocity from the Barnes bullet as to a noslers in the same grains. At the same time I wasn't trying to shoot 1000 yards either.
SSS
Ingwe
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Kinda off topic but not really...but what are the long term effects to a rifle if you continue to use loads that are a bit high pressure...not bursting primers, no brass flowing into primer hole, but maybe noticeable bolt lift issues, etc
Burnt throat faster galled lugs
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Ingwe
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Even when bolt isn't sticking?
If the bolt isn't sticking I wouldn't worry about anything
Flat primers don't bother me a bit
Heavy bolt lift is when I go back
Flat primers don't bother me a bit
Heavy bolt lift is when I go back
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jjmp
Well-Known Member
2700 plus with that 181 Hammer is Fantastic speed. now refine your reloads to get better accuracy, HindSite's 1st Cousin is Common Sense .
I took a look at an older reloading manual on my desk. Sierra. 180 Grain SPBT it's calling out for 56 Gr of IMR 4350 developing 2800 fps. Using Winchester 8 1/2 primer. So that load should work. Again using copper bullets seem to run up the pressure. That with what experience I have with those type of bullets. I never had problems with Rem. Bolt faces unless we have gone over on powder or primers looking for max loads. I have experience that with any make of rifles. That is above what the reloading manuals call for that MAX LOAD. Once I creator a primer I am generally hit max. That's after finding max load. Then onto chronograph for velocity. If I am not happy with the velocity first I change also looking at groups. Still watching for pressure signs. Example: I an shooting 308 Norma Mag 165 gr Nosler SPBT @ 3300 fps and 338 Win Mag 200 Gr SPBT @ 3230 fps. Hot yes, but no firing pens primer creators. Both group under 1/2" @ 100 yds. No Chronograph no clue as to what you are doing down range.
SSS
SSS
IllinoisBurt
Well-Known Member
Bullet velocity and case pressure are not always equal, so using a chronograph to guess pressure is only useful if comparing with published book loads for the same components. In this case the book is showing around 60k with a max load in the 2700 fps range depending on the bullet profile for 180 grainers with big game. Honestly given the primer flow is not happening with factory ammo, I would switch to a different powder that gets similar or better velocity with less pressure at max per load data. H4350 has always been a good higher speed/lower pressure propellant for 30-06 loads and will easily top 2700 with plenty of room to spare. There are a bunch of others as well. Take a minute to flip through the 23 loads listed for 180 grain 30-06 on Hodgdons website will quickly show which powders tend to fit the application better for pressure/speed combo.
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