Monitoring Bore Pressure 10ML-II

[MikePal]

What Ed is demonstrating ( with the use of pressure tracing) is how the risk of damaging your gun is reduced by using an effective load that brings the barrel pressure down below the Book Load recommendations. How is this a bad thing?
This is proof positive on what the barrel pressures are for a specific load and not just some willy nilly load recommendation by someone that knew someones second cousin twice removed.

excellent response..'Tip of the Hat' to you smokeeter !!

[terrym]

Are you using a computer model and chronograph to determine pressures? If this is the case I stand by my response. If you have actual equipment that accurately measure chamber pressure in your "particular" firearm then you could work up to higher pressures safely. Individual samples of the same gun can have differing internal dimensions which will affect chamber pressures so no computer program can account for this without actual measurement tools. The inexact process of manually seating a bullet into the powder charge alone has enough potential to affect chamber pressure. This is why competitive bench rest shooters weigh each case individually to maintain uniformity of chamber pressure and repeatable accuracy. Personally an extra few fps in a muzzle loader doesn't mean that much to me. But to each their own.
But let's be clear here. An American firearms manufacturer recommending a safe load in their product is not what I would consider a "Willy Nilly" load by amateurs. They have extensive and expensive laboratories for testing and also the constant oversight of lawyers covering their butts from frivolous law suits from basement ballisticians.

[ET1]

Terrym

You’ve obviously missed the point of using the pressure trace unit for monitoring pressure of certain loads. If you read up about the unit it can measure pressure in a cartridge rifle, shotgun and pistol loads if you like. This is more accurate than hoping to see signs on a brass cartridge. The blind factor of not knowing the pressure has been removed by this unit if setup properly.

If you are comfortable with remaining with RECOMMENDED loads then by all means I recommend staying put. You are not being asked to change anything you do but invited to follow if you desire to do so with the aid of today’s technology leading the way.
By the way a 43gr of the old 4759 produced over 35kpsi. Whereas this duplex of 10/60, 4759/4198 produced about 1Kpsi less pressure and 200fps higher velocity with a 250gr bullet. That extra 200fps is now ideal with an all copper bullet whereas the SST or SW would react more volatile at closer range.

Trying and using duplex loads is a choice and not being forced on anyone. Again if you wish to remain behind in what you believe is a safe sheltered environment then do so. I intend to move forward like Henry Ball did when he first pioneered the use of smokeless powder in the 10ML-II. He also had a lot of negativity expressed by others that it was a dangerous move back then.

Ed

[terrym]

Terrym

You’ve obviously missed the point of using the pressure trace unit for monitoring pressure of certain loads. If you read up about the unit it can measure pressure in a cartridge rifle, shotgun and pistol loads if you like.

Ed

Clearly I know nothing about this device. Do you have one? How much is this device worth? I have to wonder how feasible it would be for the average handloader to justify an expense like this. I am not doubting such a device is available and functional. My point is in a muzzle loader you have no metallic cartridge to contain the powder charge in the chamber. Also the seating of the bullet is an inexact process, no bolt face to lock up in the exact same dimension every time time the firearm is locked and loaded. So, given these variables repeating the exact same chamber dimensions and therefore chamber pressures is a problem. How does this device compensate for this? It would seem to me that this would be almost impossible since you can't guarantee the exact same chamber dimensions when manually seating a bullet. How does it compensate for the various sabot profiles and dimensions? All these variables make bells go off in my handloader's mind. Educate me on this device?

[smokeeter]

following the same train of thought, what makes the recommended book loads from savage any safer?
at least with the experimentation with slower powders and duplex loads that are measured with this tracing equipment the margin is even lower.
The savage was tested to 80,000 psi and a recommended 50,000 psi max. is leaving a good buffer.

[ET1]

Terrym

First off I do have a pressure trace unit that interfaces with a laptop. A strain gauge is attached over the bore chamber area on the barrel that measures the amount of metal stress along with the attached PT unit translates that into pressure for the lab top to record on a graph. Check the site for some info on cost and further questions about the unit and requirements involved.
Also 5% load error won’t affect the safety of a 10ML-II as we are at least 40Kpsi away from yield strength. 5% with a brass cartridge rifle that is much closer to using max pressure is another story and you can’t compare the two.
The amount of difference in 2-different firearms (10ML-II) is not significant enough for concern because again we are at such a lower pressure range from detrimental max to begin with.

Quote:
“Also the seating of the bullet is an inexact process, no bolt face to lock up in the exact same dimension every time time the firearm is locked and loaded.”
The bullet has no land engraving so why is bullet position of any importance?
Regardless the PT units function is to measure pressure regardless of other parameters. So if pressure is altered in any way the barrel stress experienced will reveal it to the strain gauge.

Jaycee you show your ignorance again about users and experimenters. There are all kinds of users out there that carelessly experiment, double load, etc and you are not going to stop them with hiding accurate information that could be provided. They do exist and will continue to do so. This will not plant any ideas that don’t already exist in their heads or what they come up with.

When I start posting about duplex loads I will provide the most accurate info I can produce with whatever tangible evidence I can provide.
Use it or don’t use it will be up to the shooter of a 10ML-II to decide but he won’t be blind and worrying about unknown bore pressures.


Ed

[jaycee]

Jaycee you show your ignorance again about users and experimenters. There are all kinds of users out there that carelessly experiment, double load, etc and you are not going to stop them with hiding accurate information that could be provided. They do exist and will continue to do so. This will not plant any ideas that don’t already exist in their heads or what they come up with.

When I start posting about duplex loads I will provide the most accurate info I can produce with whatever tangible evidence I can provide.
Use it or don’t use it will be up to the shooter of a 10ML-II to decide but he won’t be blind and worrying about unknown bore pressures.

Absolutely NO IGNORANCE shown here , just stating what "I have also seen over the years " and one that happened not far from my place , "experimenters trying duplex loads , actually a couple of farm lads " blew up a brand new CVA ML , one ended up in a coma for a few days .
There have been a few guys that blew up their ML's at the club by experimenting with something that they knew nothing about.
I keep mentioning "the inexperienced" somehow this isn't getting through to you, you can keep on with what you are doing as you have experience and the necessary equipment to do it , but ! you make it sound as if anyone can do it.

One thing you should do is CAUTION EVEREYONE , that this is not for all to proceed with , as it can be very dangerous.

This is very similar to metallic rifle cartridge reloading , where some have picked up a pound of powder with no idea if it is compatible with the cartridge they are trying/going to reload . the use of the wrong powder can have disastrous results.
Loading Manuals have cautionary notices in them about using non published loads and their dangers, some loads are not recommended to be used in older guns , other cautions are ;use maximum loads with caution or loads less than minimum charge shown are not recommended.

I have yet to see you cautioning anyone to use your loads with care , ie;
So my first trace for duplex in the future will be the 10/60grns of 4759/4198. So anyone that has remaining 4759 wanting to extend its usage you may want to consider going this route. What I don’t know is if the old or new 4759 was used for this trace but resulting velocity should reveal this.
Also be prepared for additional recoil with extra weight of powder and higher velocity than 2300fps. To reduce velocity I would just start with reducing the main 4198 a few grains at a time.

[ET1]

Terrym

To partial answer some of your questions;
No it is not cheap.
No it is not user friendly for learning how to use.
No it does not come with a lab top which you will need.
But priceless to have for safety reason alone.

The 2-screens below provided as an example by the manual is what you will work with for recording. Also note you tell it what case thickness if any is used say with a CF casing so that it adjusts for allowance of the brass casing.

Barrel Setup PT.JPG Barrel Pressure Screen.JPG



Ed

[MikePal]

I keep mentioning "the inexperienced" somehow this isn't getting through to you, you can keep on with what you are doing as you have experience and the necessary equipment to do it , but ! you make it sound as if anyone can do it.

One thing you should do is CAUTION EVEREYONE , that this is not for all to proceed with , as it can be very dangerous.

Jaycee, this thread, is in a continuing series of discussion Ed has been contributed to us in the Muzzle Loader forum. The regulars here who are participating in them are well versed and experienced. This particular one is discussing the means to measure the pressure aspects of working up a duplex load. I no way has it implied that unskilled shooters should go out and mix powders.

So to have to warn people continuously "don't do this at home' would be as annoying and as pointless as watching those after the commercial breaks on TV...and are not really required.

[ET1]

Jaycee

First off, yes I’m quite aware there are inexperienced individuals out there that know better of what not to do. I have no control over their actions if they get careless or want to go off on a scary tangent. So what does this have to do with me for providing accurate information to work with. Do you think I would purposely post a dangerous load?

Using this equipment anyone can learn to operate it just like learning how to operate a computer or operate a lathe or use a muzzle loader. I’m not going to discourage anyone of not trying what I have found to be a safe duplex load.
Yes manuals have published safe loads for the inexperienced. Usually you would see the wording recommended and not specifying the limitation. So tell me why the manual is not worded with the word limitation?

Why would I caution the use of a safe load? To add a caution is like saying I have doubts about this load when I do not. That would be like inviting a person to enter a safe room and tell them to be cautious when they enter. Does that make sense to you?

I don’t have a problem with anyone pointing out safety but you haven’t mentioned anything with good reasoning that would make me consider unsafe about duplex data being shared especially backed by Pressure Trace Readings.
The only time I will use the wording “Proceed with Caution” with a load if it falls within 40K to 45K. I will not post duplex loads over 45K because even I won’t use them.


Ed