Why Hammer Bullets Are Always Faster

[fta0303]

Your post is meaningless to many of us. Why does "no pressure signs" NOT mean it's okay? What makes a load okay or not okay?

Pressure signs often don't appear 'til 80,000 to 85,000 psi. If you see pressure signs, chances are you are well over SAAMI cartridge pressure limits. All other factors being equal (like barrel friction or bullet bearing surface), equivalent pressure (not peak pressure) is directly related to velocity. But apparentlly Hammers don't have the same bearing surface as some other bullets, so their barrel friction loss is likely less.

I think reloaders should not use more powder than manual maximum. You are already extrapolating from the test barrel to your barrel. You really have no idea about pressure once you exceed book max; pressure rise isn't proportional to powder charge, especially near SAAMI pressure limits. There just isn't a good payoff for living on the wild side of manual loading data. That many people have and lived to tell the tale doesn't mean the next person will. All for a few extra fps?

 

[fta0303]

Which is why manufacturers publish load data. If the velocity you are seeing exceeds what is published for a similar bullet it is probably higher pressure.

I am not saying Hammers do not get higher velocity. I don't know and neither do the folks at hammer until they have pressure tested data. Maybe they do and have not shared it. I would like to see it and would gladly use their data.

Until then I have been using barnes tsx data for hammers as guide. This is what hodgdon, a powder company with pressure testing equipment, recommends.

Lou

There is pressure and pressure. SAAMI sets limits on peak pressure. The pressure that's effective for driving a bullet at a given velocity (effective pressure) is more of an average pressure over the time the bullet is in the barrel. Efffective pressure is a different beast than peak pressure. A flatter combustion pressure profile can allow increased velocity within the same peak pressure. Decreased barrel friction will allow higher velocity. Barrel friction is one of the forces that must be considered in the force balance that drives velocity; what force is not used to overcome barrel friction is available to increase acceleration within the gun..

 

[Lonewolf74]

I want to precede by saying I have NOT read through all 31 pages of this thread, so if the pressure reading debate has been settled please forgive me.

Now, it is my understanding from people much more knowledgeable than myself that reading pressure signs in your own rifle is the bottom line. It does not matter what the pressure actually is it only matters you know where your rifle is showing signs of pressure because that is where your rifle is starting to yield to the pressure.

It does not matter if the pressure is 30k or 130k if you're not seeing any pressure signs it means your rifle is no where near yielding to that pressure so it is safe.

SAAMI is a standard set to measure by, it doesn't mean your rifle is "safe" at that pressure spec, conversely it doesn't mean your rifle is unsafe above that spec.

 

[fta0303]

I want to precede by saying I have NOT read through all 31 pages of this thread, so if the pressure reading debate has been settled please forgive me.

Now, it is my understanding from people much more knowledgeable than myself that reading pressure signs in your own rifle is the bottom line. It does not matter what the pressure actually is it only matters you know where your rifle is showing signs of pressure because that is where your rifle is starting to yield to the pressure.

It does not matter if the pressure is 30k or 130k if you're not seeing any pressure signs it means your rifle is no where near yielding to that pressure so it is safe.

SAAMI is a standard set to measure by, it doesn't mean your rifle is "safe" at that pressure spec, conversely it doesn't mean your rifle is unsafe above that spec.

Most modern bolt actions will withstand huge pressures, way over SAAMI limits. But brass will not, it's the limiting factor in considering pressure, and the reason that SAAMI peak pressure limits are set at or below 65,000 psi. That limit also helps to ensure that your rifle continues to function reliably under all environmental conditions. Best to stay within manual max; certainly watch for pressure signs, but if you're seeing them, back off! If manual max shows pressure signs in your rifle, I'd assume something is wrong that needs to be fixed before you proceed.

 

[Varmint Hunter]

A chronograph is very "helpful" in determining acceptable pressure. Even if traditional indications of excess pressure are not present, achieving velocities well above book maximums is reason for concern. Like many have said before, "there no such thing as a free lunch". Excess speed is almost always accompanied by excess pressure.

And yes - this is a generality. There are always exceptions to the rules but accepting recognized speeds is a good way to achieve a happy ending.

 

[ButterBean]

Most modern bolt actions will withstand huge pressures, way over SAAMI limits. But brass will not, it's the limiting factor in considering pressure, and the reason that SAAMI peak pressure limits are set at or below 65,000 psi. That limit also helps to ensure that your rifle continues to function reliably under all environmental conditions. Best to stay within manual max; certainly watch for pressure signs, but if you're seeing them, back off! If manual max shows pressure signs in your rifle, I'd assume something is wrong that needs to be fixed before you proceed.

Opinions are just that and nothing else,and you are welcome to yours and by all means do what works for you but SAAAMI is a guide line that is way conservative, if there was ever a chance of a blow up I would have done it by now, the primer pocket will give up way in advance of that happening.
I want everyone to stay safe but if no one ever pushed the limits or did anything out of the norm it'd be a dull world, there's folks that live on the borderline and there are folks that are just boards

 

[MW204]

Opinions are just that and nothing else,and you are welcome to yours and by all means do what works for you but SAAAMI is a guide line that is way conservative, if there was ever a chance of a blow up I would have done it by now, the primer pocket will give up way in advance of that happening.
I want everyone to stay safe but if no one ever pushed the limits or did anything out of the norm it'd be a dull world, there's folks that live on the borderline and there are folks that are just boards

Are those Bean-Burns you're sporting now, they don't have 6.5 C in the middle we can't see do they?

 

[MW204]

Most modern bolt actions will withstand huge pressures, way over SAAMI limits. But brass will not, it's the limiting factor in considering pressure, and the reason that SAAMI peak pressure limits are set at or below 65,000 psi. That limit also helps to ensure that your rifle continues to function reliably under all environmental conditions. Best to stay within manual max; certainly watch for pressure signs, but if you're seeing them, back off! If manual max shows pressure signs in your rifle, I'd assume something is wrong that needs to be fixed before you proceed.

That's not bad advise for a novice reloader, but I do know the first signs of pressure, that being a heavy bolt or primer issues, and each rifle is different as you probably know.
Before I started loading Hammer bullets I paid close attention to load data and even if I had not reached max by the book if my rifle said hey buds that's too much powder for this load then i backed off or started fresh with another bullet, powder, or primer, of course I had a clean barrel.
But when I started loading Hammer bullets I listened to the experts on how to load them and of course I already had knowledge about pressure signs. In today's world I wouldn't tell most people how to reload because of people being people, but there are some on this sight that I'd share load data with and be comfortable using what they gave me. That doesn't mean I still wouldn't work up to it as I always do, but I also know they wouldn't give me something they felt it was unsafe.
I use a 178gr Absolute Hammer bullet and it's faster, a lot faster, than advertised load data for a 180gr bullet, but this bullet is designed to go faster with less pressure and it does. Did I find the pressure sign, I did and I backed off 1 gr of powder and I have no brass issues, nor any pressure signs with that load.

 

[JakeC]

Most modern bolt actions will withstand huge pressures, way over SAAMI limits. But brass will not, it's the limiting factor in considering pressure, and the reason that SAAMI peak pressure limits are set at or below 65,000 psi. That limit also helps to ensure that your rifle continues to function reliably under all environmental conditions. Best to stay within manual max; certainly watch for pressure signs, but if you're seeing them, back off!

Yes, the way I've explained it to people is that Saami/book max has to be at the realistic max for the weakest available rifle that it was originally chambered in. The 7x57, 284, and the savages come to mind. 43k for the poor savage 99! I would disagree politely about every modern gun being able to use max as a matter of course. Some action designs are still softer than others, and going from hot factory loads to minimally resized cases can reveal that book max isn't the ticket. Nevermind that 2 different manuals can have notably different max loads for the same basic configuration. There are variables to discuss in there of course, that's just my findings.

 

[fta0303]

As I said, walk on the wild side if you wish. I just don't see the point, yu don't gain enough to justify it. As for the "experts", I don't think any of them are true interior bsllistics engineers, or rifle design engineers. Engineers build in margins of safety, to account for what they can't control. Exceeding book max, you are eating into those margins, without even knowing what they are there for. As I said, you'll likely get away with it, but maybe your bolt sticks sometime in some critical circuamstance ? From the design, I'd expect Hammers to be faster at given pressure. But you don't have any idea how much. As an engineer familiar with design, I do try to stay within the design envelope. For sound reasons.

Yes, the way I've explained it to people is that Saami/book max has to be at the realistic max for the weakest available rifle that it was originally chambered in. The 7x57, 284, and the savages come to mind. 43k for the poor savage 99! I would disagree politely about every modern gun being able to use max as a matter of course. Some action designs are still softer than others, and going from hot factory loads to minimally resized cases can reveal that book max isn't the ticket. Nevermind that 2 different manuals can have notably different max loads for the same basic configuration. There are variables to discuss in there of course, that's just my findings.

Well, modern sort of means modern bolt action rifle, using modern steel, all of which can withstand pressures over SAAMI, SAAMI limits are drawn to protect those old rifles. Load manuals reflect their test barrels and testing methods.

 

[ButterBean]

As I said, walk on the wild side if you wish. I just don't see the point, yu don't gain enough to justify it. As for the "experts", I don't think any of them are true interior bsllistics engineers, or rifle design engineers. Engineers build in margins of safety, to account for what they can't control. Exceeding book max, you are eating into those margins, without even knowing what they are there for. As I said, you'll likely get away with it, but maybe your bolt sticks sometime in some critical circuamstance ? From the design, I'd expect Hammers to be faster at given pressure. But you don't have any idea how much. As an engineer familiar with design, I do try to stay within the design envelope. For sound reasons.

Well, modern sort of means modern bolt action rifle, using modern steel, all of which can withstand pressures over SAAMI, SAAMI limits are drawn to protect those old rifles. Load manuals reflect their test barrels and testing methods.

Well once again your wrong, we have far surpassed getting enough out of it to enjoy it, and I mean way past it.

 

[MW204]

As I said, walk on the wild side if you wish. I just don't see the point, yu don't gain enough to justify it. As for the "experts", I don't think any of them are true interior bsllistics engineers, or rifle design engineers. Engineers build in margins of safety, to account for what they can't control. Exceeding book max, you are eating into those margins, without even knowing what they are there for. As I said, you'll likely get away with it, but maybe your bolt sticks sometime in some critical circuamstance ? From the design, I'd expect Hammers to be faster at given pressure. But you don't have any idea how much. As an engineer familiar with design, I do try to stay within the design envelope. For sound reasons.

Well, modern sort of means modern bolt action rifle, using modern steel, all of which can withstand pressures over SAAMI, SAAMI limits are drawn to protect those old rifles. Load manuals reflect their test barrels and testing methods.

I'm no engineer so that's that, but I do have a question an engineer can answer easily, even most laymen can.
When talking about modern steel and brass, which one is going to show stress first, no matter how it's applied?
If your answer is brass, which it should be, then what everyone is saying about building up to pressure signs, whether it's above or below max, is very telling is it not?

 

[ButterBean]

I'm no engineer so that's that, but I do have a question an engineer can answer easily, even most laymen can.
When talking about modern steel and brass, which one is going to show stress first, no matter how it's applied?
If your answer is brass, which it should be, then what everyone is saying about building up to pressure signs, whether it's above or below max, is very telling is it not?

Yep the brass is the "Fuse" if you will

 

[jessej]

Sometimes you need to replace a 5 amp (hornady) with a 30 amp (lapua). Especially if the system will stand 200 amps.