Load data determination

[mefizto]

Greetings all,

I am new to center-fire reloading, and I have found many different loading data for .221 Fireball. When I run them via QuickLoad, the results are significantly different regarding pressures, velocities, etc.

Thus, I have a question of how does one determine the charge to use? Does one use the maximum allowable pressure and leave a reserve of, e.g., 15-20%? Or does one look at external ballistics vis-a-vis the intended target?

Let us say that one has two different aims - one, target at 150 yards, and two, critters at 225-250 yards. It would stand to reason, that different charges, bullets would be indicated.

Kindest regards,

M

 

[K22]

I would look at or obtain the published data for the maker of the bullet you are using. I would start at the lower end of the range for the powder you've selected. Some of the published data contains information on the most accurate powder tested for that bullet. This powder would be good place to start but don't start at the maximum even if the data shows it to be the most accurate load. Start at the low end and work up looking for pressure signs.

I would set the COL at .020" from the lands for initial testing and keep it there. Once once you find a charge that works well you can vary the COL to try to refine accuracy but I'd go no closer than .010" from the lands. If your rifle has a lot of free bore such at the Remington's, the COL has to be adjusted so that enough bullet is inside the neck to provide adequate bullet tension. A good rule is one bullet diameter inside the neck.

A load that shoots precise at 150 yards should also do well at 225 to 250 yards. Depending on the size of the "critters" you are hunting there can be little difference between the requirement for a precise target load and precise hunting load such as in the case of hunting varmints and predators. Loading only for the highest velocity will not be the most effective load, you have to strike a balance between accuracy and terminal performance leaning more toward accuracy especially for long distance varmint and predator hunting. The highest velocity doesn't do you any good if you don't have enough accuracy to hit the vitals of the critter.

If you are talking about formal match shooting especially bench rest where the requirements to be competitive are severe then that changes the equation. Match bullets would be more appropriate but are not the best choice for hunting. Those loads should be developed independent of your hunting loads.

 

[mefizto]

Hi K22,

thank you for the reply. I do understand the concept of starting at the low end. But maybe I have not expressed myself correctly.

When you wrote "Once once you find a charge that works well", are you suggesting that at the selected COL, there will be a pressure/velocity, that will give the best accuracy? And that the accuracy can be further improved by varying the COL, or does one need to start again with the charge determination? If the latter, and two combinations of COL/charge are sufficiently close, how does one select one?

BTW, coming from air rifles rim-fire, it has not been my experience that once a rifle shoots well at distance X, it will "also do well" at X+.

No, I am not concerned about bench-rest accuracy, but finding the best one, a specific rifle is capable.

Kindest regards,

M

 

[Straightshooter1]

I'd suggest not focusing much on COI, but rather the BTO so that you get more consistent distances from the lands. As suggested, work low (not too low) and get to as close to 100% of case capacity as consistency will allow.

Yes, there will be a pressure/velocity that will work best, usually referred to at a "node" (which is where the barrel is in sync with the pressure/velocity). There can be more than one node, like one that at a lower pressure and another at a higher pressure/velocity.

Yes, accuracy (or more precisely, "precision") can be improved by varying the seating depth (moving the COL or BTO).

 

[Zero333]

Stay within published data and find the most accurate load for the rifle.

Start at minimum recommended charge weight and in 1 or 2 % increments work up towards max to find the load your rifle likes.

 

[Rsadams]

Stay within published data and find the most accurate load for the rifle.

Start at minimum recommended charge weight and in 1 or 2 % increments work up towards max to find the load your rifle likes.

This....

 

[mefizto]

Hi Straightshooter1,

thank you for the reply. By BTO you mean cartridge Base To Ogive, correct. Yes, the nodes are what I was so inartfully referring. If there are more than one, how do I select among them?

So the load and BTO are to some extent independent, correct?

Hi Zero333, Rsadams,

thank you for the replies recommending the ladder step.

Kindest regards,

M

 

[Zero333]

You're welcome.

At the beginning you wanna keeps things simple.
The first time you sit on a motorcycle shouldn't be lined up on the grid to race.
Same thing applies to handloading

 

[piie]

Hi Straightshooter1,

thank you for the reply. By BTO you mean cartridge Base To Ogive, correct. Yes, the nodes are what I was so inartfully referring. If there are more than one, how do I select among them?

So the load and BTO are to some extent independent, correct?

Hi Zero333, Rsadams,

thank you for the replies recommending the ladder step.

Kindest regards,

M

By no means an expert here - basing on what I have read and observed only.

Nodes are linked to bullet velocity and barrel length - for a certain length of barrel, there will be nodes or times/velocities that will cause the bullet to exit the barrel where the muzzle has returned to the horizontal after oscillating in a roughly sinusoidal fashion due to the shock wave created by the powder exploding.
Although there are theoretically multiple nodes for a specific length of barrel, the velocities - especially on the higher end, are not necessarily safely obtainable for your cartridge, powder and bullet combination.
You're going to look for the node that is closest to your optimal case fill, ideal OAL and safe pressure/velocity.

How do you "find it"? Search for optimal barrel time calculators, and remember - barrel profiles differ, so a 24" barrel with a fluted profile will have different node barrel times than a heavy straight barrel, so they are typically "indications" only. The way I use them is to try and "guess" a good load in quickload based on previous measured/observed data.

As you should know, for quickload you will need to know what your barrel length is, what your cartridge volume is, your seating depth, bullet type, powder used and some other variables I cannot recall now.

You should first try to have a properly calibrated powder "setup" in your quickload - meaning that you should adjust your powder burn rates etc so they match your measured velocities.
For instance, you get some load data from your bullet manufacturer. You do a small ladder test somewhere in the middle of the range they state, and then you go and shoot and measure velocities. Then you go into Quickload and you enter the variables you actually loaded, and compare the predicted velocity with what you observed.

If they do not match, or are at least fairly close, you can tweak the powder properties. Once you have it setup so quickload shows you the same velocity as what you observed at the range, you can perhaps test this again by using quickload to "calculate" you a hotter load that is perhaps closer to your node barrel time - note the predicted velocity and then shoot and verify your velocity with the predicted velocity. When those match consistenly to within a few fps, then quickload can be used to "predict" which set of variables will give you a safe load close to a node. You will see that each "solution" in Quickload gives you the barrel time in ms - you can tweak your powder and seating depth to decrease/increase this time until it closely matches your predicted node from your calculator. Always keep things within the safe predicted pressures tho!

 

[jimmymac]

Zero333 nails it. Perfect advise for a new reloader.

 

[mefizto]

Hi pile,

thank you. I have read Chris Lang's paper on optimal barrel time and adjusting the QuickLoad, and your post put everything in perspective. So despite your claim of not being "an expert here", I have the false impressing that it all makes sense.

Hi Zero333, Jimmymac,

thank you.

Kindest regards,

M

 

[Straightshooter1]

Hi Straightshooter1,

thank you for the reply. By BTO you mean cartridge Base To Ogive, correct.

Yes.

Yes, the nodes are what I was so inartfully referring. If there are more than one, how do I select among them?

I think different shooters will have difference reasons. For example, someone will want to have a maximum (safe) velocity for shooting long distance without much concern for brass longevity. Someone else may only be shooting at 300 yds or less and maximum velocity is not important and being able to reuse brass a maximum number of time is desirable. So, one person would choose the high velocity node and the other would choose a lower node.

So, you select based on what's of most interest to you.

So the load and BTO are to some extent independent, correct?

Hmmmm??? Not exactly. If by "load" you're referring to the powder charge, the load and BTO are separate but work in concert. Changing the load can effect what BTO is used and BTO can effect just what the load might be. They both will effect effect velocity and in finding an accuracy node.

 

[Rsadams]

You're welcome.

At the beginning you wanna keeps things simple.
The first time you sit on a motorcycle shouldn't be lined up on the grid to race.
Same thing applies to handloading

Once again...THIS.... Safety is the most important part of reloading.... Once you get everything figured out you can tinker around some , till then it's best to stay with published data and work up then maybe some bullet depth settings to fine tune... I use Sierra matchkings and they don't mind a jump so once I find my charge I do some very simple bullet depth settings and done... I am not shooting serious competition so my reloads normally shoot as good as myself and my equipment can shoot..

A cronograph is very nice but let the targets tell the story at the end of the day....

 

[mefizto]

Hi Straightshooter1, Rsdadams,

regarding your replies, I am still not sure about the interplay of the COL/BTO and the charge. If they are interdependent, it would seem to me that the development should be done with multiple combinations of CLO/BTO and charge.

Regarding the safety, I will never exceed or even come close to the recommended maximum, my goal is just the opposite, to find the lowest charge at the acceptable accuracy.

Kindest regards,

M

 

[K22]

Hi K22,

thank you for the reply. I do understand the concept of starting at the low end. But maybe I have not expressed myself correctly.

When you wrote "Once once you find a charge that works well", are you suggesting that at the selected COL, there will be a pressure/velocity, that will give the best accuracy? And that the accuracy can be further improved by varying the COL, or does one need to start again with the charge determination? If the latter, and two combinations of COL/charge are sufficiently close, how does one select one?

BTW, coming from air rifles rim-fire, it has not been my experience that once a rifle shoots well at distance X, it will "also do well" at X+.

No, I am not concerned about bench-rest accuracy, but finding the best one, a specific rifle is capable.

Kindest regards,

M

With all due respect - you're making this way more complicated than necessary.

Sometimes varying the COL can improve group size once you find a powder / bullet combination that shows promise but this is not absolute. For safety and functionality reasons I set my COL so the bullet does not contact the lands with allowance in variation in bullet ogives. At least initially in load development, I wouldn't focus on COL. This is refinement issue once you found a load combo that works well.

I've learn over many years of reloading that the factor that affects group size more than any other is the bullet you select assuming you are using a powder that is suitable for the caliber you are loading for.

As I stated in my previous post - start with a bullet / powder combination that the published data recommends as the "most accurate" tested. Start at the low end and work up. For most cartridges there are time tested powders that work very well with specific bullet weight so you don't need to reinvent the wheel so to speak.

Your target will tell you when you hit the right charge weights. If you want to refine the load you can try varying the COL, or changing the primer. Sometimes the primer you select can make a significant difference.

 

[Oso]

You like to deep dive... as stated above K.I.S.S. is where you want to start. Your steps for reloading:
1) Barrel Twist - determine your barrel's twist rate to determine what size/weight bullets it can stabilize.
2) Bullet Selection - pick a bullet that fits your intended need (distance and use) as well as budget. Buy a box (100) to determine if your gun will shoot it well. You may find that you buy a couple of different types to try out.
3) Max COAL - determined by the rifle's chamber and the bullet's ogee that you selected. What is the Cartridge Overall Length (COAL) ... when the bullet touches the barrel lands (max COAL). You can use a Hornady Case Length Gage or there are some other simple low-tech solutions to determining this. Keep in mind that each type of bullet (size and manufacturer) will have a different profile (ogee) resulting in a different COAL specific to that bullet in your rifle. This will differ from rifle to rifle even if machined with same reamer.
4. COAL Restrictions - if you are planning to load from a magazine (internal blind magazine or external drop box magazine) this magazine length may be your limiting factor to your Max COAL

At this point it is good to lock down a couple of lesser variables that you can fine tune later. Otherwise, there are too many variables that will cause you some OCD.

5. Bullet Jump - most rifles like a slight jump (.002" - .004") off the lands. Just lock down a jump for now. You can play with it later to see if more jump or no jump works the best. Don't start with Zero jump when load developing, because this can create a large pressure spike that could be dangerous at higher charge weights. Refer to #4 ... your rifles setup may force a COAL and the corresponding jump. If this happens and the resulting COAL is too short then your only option is load rifle single shot (don't use the magazine).
6. Primer Selection - pick a quality primer that is readily available (CCI, Winchester, Federal, etc.). You can play with this later to fine tune.
7. Powder Selection - You will find that any number of powders will produce good results. There are more than enough recommendations to choose from. You are shooting a factory barrel so most powders will do just fine...only buy a #1 container and try it out. Refer to the powder manufacturer's load data library... yes the max load has a safety factor built in. However, keep in mind that the favorite/proven recipe from another shooter might be to hot for your rifle because of different chambers and free bore. Cautiously work up any powder charge. This is especially important is small cases where a small increase in powder weight can be significant as a % of the case's capacity.
8. Load Development - finding your nodes... technology is great if you have access to it otherwise you can go old school and do what is called a ladder test to determine your rifle's nodes based on the specific bullet you have selected. Lots of articles and it is really easy.
9. Velocity - Identify a velocity you want to chase and target the node that closest matches your goal.

Remember - you most likely will end up buying several different types of bullets and powders before settling on one that is best in your gun. This is a slow cautious process, and not a sprint.

 

[Webster]

Greetings all,

I am new to center-fire reloading, and I have found many different loading data for .221 Fireball. When I run them via QuickLoad, the results are significantly different regarding pressures, velocities, etc.

Thus, I have a question of how does one determine the charge to use? Does one use the maximum allowable pressure and leave a reserve of, e.g., 15-20%? Or does one look at external ballistics vis-a-vis the intended target?

Let us say that one has two different aims - one, target at 150 yards, and two, critters at 225-250 yards. It would stand to reason, that different charges, bullets would be indicated.

Kindest regards,

M

The Berger reloading manual has 6 pages of 221 Fireball data. One page for each bullet wt. About 8 powders listed for each wt.

 

[Straightshooter1]

Hi Straightshooter1, Rsdadams,

regarding your replies, I am still not sure about the interplay of the COL/BTO and the charge. If they are interdependent, it would seem to me that the development should be done with multiple combinations of CLO/BTO and charge.

Basically (and to KISS with regarding only these two items), yes. . . there will be multiple combinations. Typically, one will keep the COL/BTO fixed until a charge is found that gives one good results. Then to improve on those results one can then keep that charge fixed and fine tune the results by moving the COL/BTO to where one gets the best results. Moving the COL/BTO is like a "fine tuning" of the cartridge.

Note that in both cases of moving the COL/BTO or changing the charge, it's mostly about the change in the pressure being produced within the cartridge. The way the powder burns and the pressure within effects the unique response each rifle chamber, barrel and even the bullet reacts.