ajpelz
Member
Didn't your OAL get reduced by the same .030"? I am mystified on how you can seat deeper and maintain OAL.
Seating depth versus OAL
- Thread starter Skip Sackett
- Start date
Didn't your OAL get reduced by the same .030"? I am mystified on how you can seat deeper and maintain OAL.
smith crazy said:
If they don't agree with you, then they know nothing, right?
This is what I mean by being arrogant. You always come at these posts like you are the only one with any knowledge. A lot of us, have been at this a long time too. You can say what you want about it all, but now you are the one who is giving bad advice to newbies who may be reading this thread. Bearing surface length, and bullet composition have just as much to do with pressure as depth of seating. All three are equally important. Pressure doesn't peak until the bullet has engaged the rifling, plain and simple. Sure there is some presuure upon ignition, but it hasn't reach maximum until the bullet is being held back by the rifling.
dennis40x
US Veteran
Jelly,
I just got a book from NKJ_Nut as a prize. It is Phil Sharpe's book on Handloading (reloaders need not read!)
Remember, this isn't for those that get bullet x, find recipe y and use the exact components to build bullet z. I'm not saying there is anything wrong with that, don't get me wrong, and this isn't "aimed" at Dennis, many folks just want bullets that shoot and don't experiment one iota. I mean this, that's fine. They are re-loaders.
I read that book years ago. Sharpe's jargon from the nineteen-thirties is nettlesome.
I know you're not pecking at me. A shooter I am, I am and freely admit that Reloading allows me to shoot. It's I'd rather be shooting than Handloading.
Still no one directly talks about the expansion ratio which is volume. The OAL is normally a do not exceed standard measurement but I've also seen minimum OAL addressed in loading data. The minimum OAL addresses issues in regards to pressure.
As for a rifle that is bolt guns and gas guns for match shooting the OAL is normally a limiting factor in gas guns. My bolt guns are throated to exceed the standard specified OAL but that's a story for a different time and place.
Some times these group discussions' be whizzing contests
OP
Skip Sackett
US Veteran
Duplication was what I was after.
Yes, and it does seem like it is confusing. The point of my comment was this though, a seating depth difference of .030" increased the velocity by 100fps.
Let's say that the bullet SHAPE made the bullet sit that much more in the case. Seeing as I don't have a bullet stretcher I can't make both situations occur at the same time.
Now, if you happen to purchase bullets, as in the first picture I posted, from one manufacturer and some from another and they have a bullet stretcher ( ) you can end up with the situation you describe.
That is the point that I am speaking to. I know that there are other factors that play a part in pressure changes. I'm not speaking to those at this point. They are to be considered and I alluded to that in the original post.
Look at the picture of the two plated bullets. That is my point. It could be more egregious than those two bullets portray.
The old timers understood this. That is the reason that Elmer and Sharpe designed their bullets like they did. Same weight as nominal bullets for caliber but a whole lot less in the case. They filled that void with powder.
This thread isn't going to be a whizzing contest Dennis cause, I'm out of here!
Handejector, please delete my account!
Yes, and it does seem like it is confusing. The point of my comment was this though, a seating depth difference of .030" increased the velocity by 100fps.
Let's say that the bullet SHAPE made the bullet sit that much more in the case. Seeing as I don't have a bullet stretcher I can't make both situations occur at the same time.
Now, if you happen to purchase bullets, as in the first picture I posted, from one manufacturer and some from another and they have a bullet stretcher (
) you can end up with the situation you describe. That is the point that I am speaking to. I know that there are other factors that play a part in pressure changes. I'm not speaking to those at this point. They are to be considered and I alluded to that in the original post.
Look at the picture of the two plated bullets. That is my point. It could be more egregious than those two bullets portray.
The old timers understood this. That is the reason that Elmer and Sharpe designed their bullets like they did. Same weight as nominal bullets for caliber but a whole lot less in the case. They filled that void with powder.
This thread isn't going to be a whizzing contest Dennis cause, I'm out of here!
Handejector, please delete my account!
I think Skips OP was aimed at the fact that just because data might be for a certain bullet weight, not all bullets of the same weight are of the same length. And yes that can have an effect on pressure.
As others have stated there other factors that will also effect pressures, such as bearing surface, bullet composition and hardness, temperature, chamber dimensions, barrel fouling and etc.
But let's look at the data given both in print and on the 'net. Most of them don't give a clue as to what any of these variables are. They list a lead bullet of a certain weight with no information of seating depth, composition, bearing surface or etc. And I know they are well aware that there are people out there that don't care to find out either, they will use it regardless starting at the max load. And it usually doesn't cause a problem. Usually, but occaisionally, in a worst case scenario, some poor fool will blow his gun up due to a lack of caution or attention. Always start at the starting loads if you are using any component other than the data was derived with. Inculding bullet, primer, firearm etc. It you read their disclaimers this is what they use to save their butts.
And a word of caution too. Just because you aren't getting the velocities a data source lists for a certain bullet, doesn't mean you aren't getting the pressures. This isn't a green light to add a little more powder until you get the same reading on your Chrony at the local range as they did in their lab.
As others have stated there other factors that will also effect pressures, such as bearing surface, bullet composition and hardness, temperature, chamber dimensions, barrel fouling and etc.
But let's look at the data given both in print and on the 'net. Most of them don't give a clue as to what any of these variables are. They list a lead bullet of a certain weight with no information of seating depth, composition, bearing surface or etc. And I know they are well aware that there are people out there that don't care to find out either, they will use it regardless starting at the max load. And it usually doesn't cause a problem. Usually, but occaisionally, in a worst case scenario, some poor fool will blow his gun up due to a lack of caution or attention. Always start at the starting loads if you are using any component other than the data was derived with. Inculding bullet, primer, firearm etc. It you read their disclaimers this is what they use to save their butts.
And a word of caution too. Just because you aren't getting the velocities a data source lists for a certain bullet, doesn't mean you aren't getting the pressures. This isn't a green light to add a little more powder until you get the same reading on your Chrony at the local range as they did in their lab.
m657
Member
re: "It's usually safer to load 5 test rounds than 1,000 that are too long, too hot, or too weak."
...oh sure.....NOW you tell me......
...oh sure.....NOW you tell me......
acl864
Member
...and sometimes these contests become personal and spread across several threads and that is unfortunate. Differing opinions are the lifeblood of any forum. If we all knew everything and agreed all the time this forum would be useless and deserted... FWIW
I often experiment with different bullets, powder, primer combinations. To be honest I do little else. Now I'm casting my own as well and this is just going to add one more variable to the mix. This thread served it's purpose. I'm going to be more attentive to ALL of the variables at the bullet end of the cartridge that can affect pressure. Thanks.
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