Mikecr
Well-Known Member
Bolt thrust is higher.
Keep the chamber free of oil, and be sure that your bolt head is for magnums (heavy duty lugs).
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Does anyone know at what pressure sticky bolt lift occurs?
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Keep the chamber free of oil, and be sure that your bolt head is for magnums (heavy duty lugs).
Rich Coyle
Well-Known Member
Doesn't that just about include most modern rifles? My Savage .223, back in the 1990s used the same action as the 7Mag. They merely used a smaller front in the bolt. Weatherby uses magnum actions for everything. Pierce uses "heavy lugs". What Remington 700 doesn't use their magnum action?
Mikecr
Well-Known Member
I have no idea about the differences of action bolts to cartridges.
Bolt thrust and SAAMI max pressures are proofed higher with magnums. A double whammy. So personally, I would like assurance that my bolt lugs would not be flexing a lot at max loads.
But it could very well be that all bolts are strong enough, I don't know.
The factory company I would trust to follow is Savage. Whatever they do, it's right.
I did have a WSM savage action once, and it had a larger tenon than a 223 action. I would be surprised if the bolt head was the same thickness as a 223 bolt head. Just didn't notice at the time & it was stolen before my use..
Bolt thrust and SAAMI max pressures are proofed higher with magnums. A double whammy. So personally, I would like assurance that my bolt lugs would not be flexing a lot at max loads.
But it could very well be that all bolts are strong enough, I don't know.
The factory company I would trust to follow is Savage. Whatever they do, it's right.
I did have a WSM savage action once, and it had a larger tenon than a 223 action. I would be surprised if the bolt head was the same thickness as a 223 bolt head. Just didn't notice at the time & it was stolen before my use..
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Carey Farmer
Well-Known Member
Standard (eg 30-06) Savage bolt lugs are 0.442". Magnum is 0.500". Ultra magnum (WSM, RUM, Nosler, etc.) is 0.550".
I'm pretty sure Savage .223 bolt heads use the same lug length as standard, but not positive.
Older post but a very interesting one.
If I were to build a 30-06 on a 50bmg action, it could probably safely contain extremely high chamber pressure.
(Assuming there was an appropriate fantasy powder to use).
So what would be the visible signs of overpressure ?
Not even knowing or caring what the actual pressure was that was causing this visible sign, maybe it's 100,000psi.
In theory, if you had a tight enough chamber that would not allow any brass expansion, what possible visual sign
of overpressure could even exist ? (Now I know such a tight chamber has other disadvantages, just posing it as an example)
I guess my point is that a strong enough action would be perfectly safe under much higher pressure than SAAMI.
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This begs the question: Which actions are inherently stronger, able to withstand more pressure ?
Mauser ?
Rem 700 ?
Sako ?
Weatherby ?
Defiance ?
Etc.
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MagnumManiac
Well-Known Member
The truth here is, that different brands of brass become elastic at different pressure, which is what causes sticky bolt lift.
Sticky extraction is different again, and clickers are different again.
A few of my rifles never click, get sticky extraction or sticky bolt lift, but at around 70,000psi, measured using the Pressure Trace II, they all exhibit primer cratering, next step above this pressure level, say 80,000psi, they will start to get ejector marks. I actually never push my rifles to the point of sticky bolt lift, this level is beyond the elastic point of the brass and is unpredictable and unsafe.
I pushed both Norma and Lapua cases to Proof load levels, 95,000psi-100,000psi and the cases were ruined with expanded primer pockets.
Cheers.
Sticky extraction is different again, and clickers are different again.
A few of my rifles never click, get sticky extraction or sticky bolt lift, but at around 70,000psi, measured using the Pressure Trace II, they all exhibit primer cratering, next step above this pressure level, say 80,000psi, they will start to get ejector marks. I actually never push my rifles to the point of sticky bolt lift, this level is beyond the elastic point of the brass and is unpredictable and unsafe.
I pushed both Norma and Lapua cases to Proof load levels, 95,000psi-100,000psi and the cases were ruined with expanded primer pockets.
Cheers.
Wachsmann
Well-Known Member
I sure everyone else has chimed in already but sticky bolt lift for me had always happened after I had ejector swipes. So to me sticky bolt lift is way over pressure. I've ran a gun with very very light ejection swipes and it was just slightly over max book charge. I don't do these things anymore. You load can change so fast with temp it's just not reliable. I found the most reliable, accurate charges around it at 75% to 90% of book max. Maybe even lower and about high as 95% book max. There definitely a given sweet spot for every rifle and brass combo. I used to run my 300 RUM maxed out with a 220 ELDX on some RL26. It shot good till I hit about 65 degrees. Now I'm looking at a much milder load that will still have some HP but nothing that recking the brass after a few reloads.
cabelasken
Well-Known Member
With the cost and availability of brass as it is today, I started to back off on some of my hunting loads a couple of grains from my previous max charges. In some cases I lost a little accuracy and in some I gained - but not by much in either case. My barrels will probably be a little happier too.
I am now at the point of stopping my pursuit of edge of pressure loading. Ejector marks are very common when pushing for velocity on my rifle. Too many brass cases going in the garbage.
Haha me too. Chemical plant?
Lately I've just been looking at max velocities listed and try not to exceed that. Nosler data for one tends to be on the warm side. Hogdon is usually lower. If you notice they also list the pressure at max. That is because they pressure test all their data. The bullet companies don't always. At least that is what a friend who is a ballastician for one of the major bullet companies told me.
Carey Farmer
Well-Known Member
Mostly oil and gas. Worked in one field that had shut-in wellhead pressures near 10,000 psi. Worked in another that had gas re-injection compression to 5000 psi.
memtb
Well-Known Member
Quote: I used to run my 300 RUM maxed out with a 220 ELDX on some RL26. It shot good till I hit about 65 degrees
You just clearly stated the reason that "all" of my load development is done at 90+ F, giving several hours for the rifle and cartridges for the rifle and cartridges to reach ambient. The rifle and cartridges "are not" placed in direct sunlight!
The loads are the tested again at temperatures resembling those expected on a hunt. If necessary, it can be re-zero'd at this time!
I do push my loads to pretty high pressures, and am subject to shooting my rifle at anytime during the year……I don't want or need unwelcome surprises. memtb
