COL

[chipchip]

How come Hornady and Hodgdon give different COL's for the same bullet. For the 6.5 creedmoor 140 Amax. Hornady says 2.800, Hodgdon says 2.820. What gives.

[schmellba99]

Those are the COAL's that each respective company used on their test ammunition.

Depends on the type of rifle used as to what you'll load your length to. I worry more about the ogive to case head dimension than I do OAL, unless the magazine is what becomes the constraint.

[green_MTman]

.020 is not a big difference either

[steve4102]

Forget the OAL listed in the manuals, find the best OAL for your rifle. Some manuals do not even list the OAL tested it is that unimportant.

Our Moderator Brian has some good advice found here.

http://thefiringline.com/forums/showthread.php?t=548523

[Sevens]

How come Hornady and Hodgdon give different

A proper source (such as a load manual) will give ALL of the information on their test. Not because you must repeat it to the letter. They include it... because it's relevant.

They tell you which primer they used, but you aren't stuck using only THAT primer. They tell you the length of the barrel they built the data around, but you will use the length of barrel your rifle has. They tell you the ambient temperature when they ran the test because all of it actually affects the results of the test... but it's obvious that we don't have to shoot only when the ambient temperature matches what the load manual reports.

For the same reason... you can pick up four different load manuals and find four different "maximum" loads. If the four are different, and you don't pick the absolute lowest of the four, then it's obvious you're making a load that's OVER PUBLISHED MAXIMUM! At least, in one or two sources.

Stick to the time-tested methods for building safe loads and you'll be able to make quality, safe ammo.

And while you're at it--
follow the lead of those published professionals, and document all that you do. If it's a decent load, you'll need that info to improve upon it. If it's a phenomenal load, you'll need that info to replicate it.

Perhaps most importantly...
If it's a terrible load... documenting it well should help you to avoid repeating it.

[PA-Joe]

The shape of each bullet is different so each maker has their own COLs.

[Brian Pfleuger]

Originally Posted by Sevens

A proper source (such as a load manual) will give ALL of the information on their test. Not because you must repeat it to the letter. They include it... because it's relevant.

Well, I've never seen a source that comes close to giving ALL the information from their test.

I don't recall a single one that gives environmental conditions though some might.

They virtually all (except Nosler, THANK YOU NOSLER), leave out the single most important (IMO) information they could give me.... case capacity.

For instance, Nosler's data suggests that the cases they used for .204Ruger only hold 29.9-30.6gr. My cases in my gun hold 33.1gr.

It's no wonder that they show a max load of 26.5gr Benchmark under a 32/34gr, for example.

You know what pressure that load makes at 33.1gr case capacity? It's barely a starting load.

[Unclenick]

PA-Joe hit it. Note that for bullets to be loaded to the same distance from the throat of the rifling—a factor that affects pressure, barrel time, and bullet centering in the bore—the shape of the ogive (sides of the nose) changes the COL, as shown below.

[steve4102]

Originally Posted by Brian Pfleuger

They virtually all (except Nosler, THANK YOU NOSLER), leave out the single most important (IMO) information they could give me.... case capacity.

For instance, Nosler's data suggests that the cases they used for .204Ruger only hold 29.9-30.6gr. My cases in my gun hold 33.1gr.

Brian, what exactly does the "Case Capacity" in Nosler data mean?

Does it mean fired empty case capacity, similar to what we type into Quickload, or does it mean remaining case capacity after the bullet is seated?

I am of the opinion that it is the latter, after seating.

If you look at their data in almost every instance the heavier the bullet the less case capacity, even though they are using the same brass.

Take their 30-06 data for example, same Nosler Brass, with the 125gr bullets they list 67.7gr H20, with their 200gr Bullet they list 59.4gr H20.

Help me understand what good this data is to the handloader? When I check case capacity of fired cases, I can determine which cases have more and which cases have less case capacity, then I can adjust my loads or Quickload Accordingly.

I have no simple way to determine how much room or case capacity is left after I seat the bullet, why is this data useful?

[Unclenick]

Case Water Capacity is the weight of water in grains that fits in a case under the seated bullet. So it changes with how deeply the seated bullet sticks down into the case.

Case Water Overflow Capacity is how much water fits in an empty case, level with the mouth; no meniscus (and no bullet).

[steve4102]

Originally Posted by Unclenick

Case Water Capacity is the weight of water in grains that fits in a case under the seated bullet. So it changes with how deeply the seated bullet sticks down into the case.

Case Water Overflow Capacity is how much water fits in an empty case, level with the mouth; no meniscus (and no bullet).

I'm aware of that, but how is Nosler's seated bullet capacity data useful to the handloader, especially when they do not list the "Overflow Capacity" to go along with it??

In other words, "How can a handloader apply Nosler's data to the Bench?

[Brian Pfleuger]

I think they mean over-flow capacity, Steve.

If you see their .22-250 data, they show a capacity of 40.9gr for 34/35gr bullets and an OAL of 2.350 and a capacity of 43gr for the 40gr at OAL of between 2.280-2.350. Then, at 50/52gr they show a capacity of 42.6gr at OAL of 2.350. That wouldn't make any sense if they were going by remaining capacity.

.243Win data is similarly inconsistent.

[steve4102]

I think they mean over-flow capacity, Steve.



If you see their .22-250 data, they show a capacity of 40.9gr for 34/35gr bullets and an OAL of 2.350 and a capacity of 43gr for the 40gr at OAL of between 2.280-2.350. Then, at 50/52gr they show a capacity of 42.6gr at OAL of 2.350. That wouldn't make any sense if they were going by remaining capacity.



.243Win data is similarly inconsistent.

As posted above, check out their 30-06 data.



If it is "Over Flow" then Nosler Brass varies by over 8 full grains from case to case. Their 125gr has an "Over Flow" of 67.7gr and their 200gr has an "Over Flow" of 59.4gr. That there is some pretty crappy brass if it has an "Over Flow" case capacity with that much variation.



Not only crappy, but down right unsafe.

[Brian Pfleuger]

Maybe so, but there's no consistency that you would expect from heavier and heavier bullets seated in the same cases and to nearly identical OALs. Most of their bullets are standard variations of lead core, copper jacket. If they were giving the capacity after the seated bullet then it should steadily decrease as weight increases unless the OAL is getting longer and longer but OAL are nearly the same and capacity seems random.
I guess you'd have to write them and ask.

Here's some comparisons.

For their 110gr Varmageddon, they show a case capacity of 65.1gr. That bullet is 0.920" long and seated to 3.130 OAL. If that capacity is after seating, the over-flow capacity would have to be 70.5gr.

The 125gr BT Spitzer is 1.060" and they seat it to 3.320 with an over-flow of 67.7gr. The over-flow would be 71.8gr.

Their 150gr BT Spitzer is 1.280" and they show it seated to 3.320 with a case capacity of 62.7gr. The case would have an over-flow capacity of 71.0gr.

The 180gr BT Spitzer is 1.376" and they seat it to 3.330. They show a capacity of 63.9gr. The over-flow would have to be 73.8gr.

The 200gr Partition is 1.350" long and they seat it to 3.320 and a capacity of 59.4gr. The over-flow would have to be 69.3gr.

So, I don't know if that helps or not. You've still got an over-flow spread of 4.8gr. A lot better than 8 but still a lot.

[schmellba99]

So after reading all of this, I'm still not sure what the value in the information is with the case capacity, or at least the information provided by Nosler.

Help me out here - and keep in mind that I'm generally a simple minded person.

[steve4102]

It has No value to the handloader.

If the Nosler's case capacity was "Over flow" or Grains of water in an empty fired case it would have pupose, but it is not, it is grains of H20 under the seated bullet. IMO this info is by far more useless and confusing than any OAL data.

There is no practical way for a handloader to check H20 capacity under a seated bullet.

[Brian Pfleuger]

I'm still not convinced that's what it is.

It doesn't make sense either way. Either their cases are ridiculously heavy and low capacity, far heavier than would be reasonable, or they are lighter and higher capacity than any other brand, which is the opposite of every measure I've heard in Nosler brass.

It's easy as 2+2 to check with QuickLoad.

I guess I'll have to send them an email and ask.

I can't imagine why they'd publish capacity with the seated bullet. It's an extremely uncommon number and would never be the expected default. Given the relative complexity of calculating it without QuickLoad it's a number that few reloaders would bother with and would serve virtually no purpose at all.

No matter what it's supposed to be, it seems to me that it can't be correct. It's either very low capacity with 8gr fluctuation or very high capacity with over 4gr fluctuation. Neither makes sense.

[steve4102]

Originally Posted by Brian Pfleuger

I guess I'll have to send them an email and ask.

I would appreciate that.

I sent one a few days ago and I also Asked Nosler on their Forum, so far no reply. I will post a reply if I get one.

[steve4102]

I received a response from Nolser today.

Here is their very detailed and lengthy response.

In response to your question:

That is the remaining capacity after the bullet is seated.


Have a great day,

Nosler FAQ

In case you are interested, here is the question I asked.

In you new #7 manual you list "Case Holds" "XX.X gr Water"

In my experience there are two type of H20 case capacity measurements.

One being "Case Water Capacity" which is the weight of water in grains that fits in the case under the seated bullet.

The other and more useful to the handloader is "Case Water Overflow" which is how much water fits in an empty fired case, level with the mouth; no meniscus (and no bullet).

The "Overflow" method allows for the handloader to determine which headstamps have more internal capacity and which ones have less internal capacity so he/she can adjust load accordingly.

By looking at your data I would have to assume that you are using the "Water under the seated bullet method. I say this because even thought you are using the same Nosler brass your case capacity data is different with different bullets. For example your 30-06 water capacity ranges from 59.7gr of H20 to 67.7gr of H20 with identical Nosler brass.

Am I correct in assuming you are using the weight of water in grains that fits under the seated bullet? If so why and what use is this to the average handloader?

I can tell you that on several loading forums many a handloader are confused as to what your water capacity actually means.

Take your 223 data for example, you have H20 capacity ranging from 26.5gr to 28.2gr H20. Most handloader that check internal capacity by the "Overflow method" have about 30+gr H20. They interpret your data to mean that your "Overflow capacity" is 26.5gr, therefore they must reduce their loads considerably to accommodate your reduced capacity brass.

Some clarification would be good.

Thanks

Steve

[Brian Pfleuger]

Strange. Well, that's not nearly as interesting. Pointless for most people. Pro big deal with QuickLoad but useless for most folks. I don't know why they even bother. (Plus it still doesn't make sense)