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Safety Question (Safe Loads)...
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I'm still working on trying to find that magic load for my .300 Win Mag AI. I'm working with 190 grain VLD's (hunting bullets). I have plenty of load data for the 180 grain and 200 grain bullets...is it safe for me to assume I can split the difference on the published loads for the 190 grain Berger Bullet. (for example: if the max load with a 200 grain bullet was 70 grains of powder and the max for a 180 grain was 15 grains, could I assume that 72.5 grains would be safe for the 190's?). This is assuming a similar bullet design. Thanks!
Comments
that is called "interpolation" and for the most part will work. Back off 5% from the interpolated value, and work up. However, I never find the most accurate load at or near max load, it usually comes in a few grains under max load.
My problem is that I cannot find any concrete info on the proper load data for the .300 Mag AI. The PO Ackley books say to use the 300 Weatherby load data but that's quite a bit hotter than the .300 Mag. I'm almost afraid to jump up that high.
Don't worry so much about what the book says for max. I've seen the book wrong with my rifles many times either way.
You really need to find the max load for your rifle. What you need to interpolate and work up from is a starting load. edit: You find the max load for your rifle by working up a ladder.
Don't worry so much about what the book says for max. I've seen the book wrong with my rifles many times either way.
JustC and Sandwarrior, I understand what you are saying but how do I determine the max loads for my rifle's chamber? I don't have any concrete data on what kind of velocities I should be getting and the Ackley cases don't show pressure signs very well. Should I be looking for my velocities to spike or plateau? Should I just take a wild guess and aim for a certain max velocity? I'm doubting I'll get 3100 fps with the 190 grain VLD's...but then again, I really don't know.
Thanks!
Just look for all the normal pressure signs. Flattened primers (and to what degree) expanded base of case just above the belt (tough to chamber because of that). Also when reloading see if there is a groove/ring being cut on the inside of that spot. Hard extraction/wipe on the case head.
Anyhow, I posted this on another post of yours I didn't know if you went back and read it:
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Eric,
I've found something very helpful over the years with various Ackley cartridges. Everybody I know who shoots them don't shoot them for extreme performance, they shoot them for better case life, which adds to consistency of accuracy. I generally see a lot of improvement from the Mauser and .250-3000 based cases. Mostly because the biggest jump believe it or not is in the case wall expansion not from blowing the shoulder forward to 40 deg. In most of those cases improved performance is necessary simply because you've gone to a much increased case volume. In the .300 WM to the .300 WM AI you're not jumping all that much in volume.
Then:
The second thing I will recommend is running a ladder from known mid-level loads up to about 4-5 gr. over max published for the .300 Win Mag. I suggest basing all interpolations off the Win Mag case. Don't use the WBY case as it has different flow dynamics. My favorite powder in my .300 was H1000. It pretty easily got my 208 A-max's and 210 Bergers up to the prescribed velocities I wanted.
Now, when I say ladder, this is what I suggest. I just read the whole thing by TresMon over on Snipers Hide forums. I believe he posts here as well.
Anyhow, Load one shell at mid range load for .300 WM. The next 1 gr. more and so on until you get to max for the .300 WM for that powder. Then proceed in .5 gr. increments. Normally for this you load in 1% increments of the max (.8 gr.) but since you are down a ways it's going to run a little faster at the bottom end. And get you to where you need to be without wasting bullets.
Assuming you mean Berger 210's I went with the Sie. 220 RN load off the Hodgdon website. they use 73-78 gr. So load the first @ 75 gr. the second, 76 third, 77 fourth 78 (max), fifth 78.5 (above max) sixth 79, seventh 79.5, eighth 80, ninth 80.5, tenth 81, eleventh 81.5, etc, up to 85 if you want to go that high. In this case you know you are going to pull a couple so might as well go up.
Now for shooting them:
TresMon strongly suggests 600 yds. Not all that easy to get that far in a lot of places. So, if you can, 300 will suffice, 200 if you have no other choice. But go out as far as you can, whatever range. What you'll do is shoot these bullets from the low end to the high end. On one large piece of paper so that you can track the bullets upward POI's. At some point the bullets tend to cluster at one elevation. This is the accuracy node you are looking for. At any sign of too high of pressure, stop. Save all the hotter loaded bullets for pulling at home and then reloading them.
Note: I used to chase this on a chronograph. I would find the velocities that sometimes tended to run closer. That gave me good accuracy at long ranges. But, I think this physically seeing the harmonics in action is really the way to do it.
Also Note: You can bring the chronograph, but just record velocities. It'll save bullets when using a rough calculator to determine drops later on. Don't think you need to use the chrono as a tool to set which load. That is done by watching the harmonics in action.
To explain this, as the barrel sends a shot downrange and aborbs the released energy it vibrates. That vibration is just like a wave in the water. The barrel moves along in a sine wave. That accuracy node is where your barrel (muzzle) tends to hit top of the sine wave...literally. The sine wave the barrel creates is to a degree, limited by the materials natural flex. Meaning within a certain band any 3-6 or even seven bullets will bring that barrel up to the top of its sine wave then stop at the natural flex of the barrel. Anything lower or higher may have the bullet poi's coming back down. Or going increasingly left and right. In summary what you are doing is timing the barrel harmonics.
When you find the right load range verify it by loading three bullets each in .5 gr increments starting one grain under the middle of the groups and ending one gr. over. That's fifteen more bullets. Shoot those at three targets, one of each weight at each target. remember to mark each hit. Evaluate which ones grouped the best and that's your load.
I tried to get through this without being too long. e-mail me if you have questions or stay on. You can get some more good answers.
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That's what we are saying. There is not concrete data, even the well known calibers, what the max for your rifle is.
Just look for all the normal pressure signs. Flattened primers (and to what degree) expanded base of case just above the belt (tough to chamber because of that). Also when reloading see if there is a groove/ring being cut on the inside of that spot. Hard extraction/wipe on the case head.
Anyhow, I posted this on another post of yours I didn't know if you went back and read it:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Eric,
I've found something very helpful over the years with various Ackley cartridges. Everybody I know who shoots them don't shoot them for extreme performance, they shoot them for better case life, which adds to consistency of accuracy. I generally see a lot of improvement from the Mauser and .250-3000 based cases. Mostly because the biggest jump believe it or not is in the case wall expansion not from blowing the shoulder forward to 40 deg. In most of those cases improved performance is necessary simply because you've gone to a much increased case volume. In the .300 WM to the .300 WM AI you're not jumping all that much in volume.
Then:
The second thing I will recommend is running a ladder from known mid-level loads up to about 4-5 gr. over max published for the .300 Win Mag. I suggest basing all interpolations off the Win Mag case. Don't use the WBY case as it has different flow dynamics. My favorite powder in my .300 was H1000. It pretty easily got my 208 A-max's and 210 Bergers up to the prescribed velocities I wanted.
Now, when I say ladder, this is what I suggest. I just read the whole thing by TresMon over on Snipers Hide forums. I believe he posts here as well.
Anyhow, Load one shell at mid range load for .300 WM. The next 1 gr. more and so on until you get to max for the .300 WM for that powder. Then proceed in .5 gr. increments. Normally for this you load in 1% increments of the max (.8 gr.) but since you are down a ways it's going to run a little faster at the bottom end. And get you to where you need to be without wasting bullets.
Assuming you mean Berger 210's I went with the Sie. 220 RN load off the Hodgdon website. they use 73-78 gr. So load the first @ 75 gr. the second, 76 third, 77 fourth 78 (max), fifth 78.5 (above max) sixth 79, seventh 79.5, eighth 80, ninth 80.5, tenth 81, eleventh 81.5, etc, up to 85 if you want to go that high. In this case you know you are going to pull a couple so might as well go up.
Now for shooting them:
TresMon strongly suggests 600 yds. Not all that easy to get that far in a lot of places. So, if you can, 300 will suffice, 200 if you have no other choice. But go out as far as you can, whatever range. What you'll do is shoot these bullets from the low end to the high end. On one large piece of paper so that you can track the bullets upward POI's. At some point the bullets tend to cluster at one elevation. This is the accuracy node you are looking for. At any sign of too high of pressure, stop. Save all the hotter loaded bullets for pulling at home and then reloading them.
Note: I used to chase this on a chronograph. I would find the velocities that sometimes tended to run closer. That gave me good accuracy at long ranges. But, I think this physically seeing the harmonics in action is really the way to do it.
Also Note: You can bring the chronograph, but just record velocities. It'll save bullets when using a rough calculator to determine drops later on. Don't think you need to use the chrono as a tool to set which load. That is done by watching the harmonics in action.
To explain this, as the barrel sends a shot downrange and aborbs the released energy it vibrates. That vibration is just like a wave in the water. The barrel moves along in a sine wave. That accuracy node is where your barrel (muzzle) tends to hit top of the sine wave...literally. The sine wave the barrel creates is to a degree, limited by the materials natural flex. Meaning within a certain band any 3-6 or even seven bullets will bring that barrel up to the top of its sine wave then stop at the natural flex of the barrel. Anything lower or higher may have the bullet poi's coming back down. Or going increasingly left and right. In summary what you are doing is timing the barrel harmonics.
When you find the right load range verify it by loading three bullets each in .5 gr increments starting one grain under the middle of the groups and ending one gr. over. That's fifteen more bullets. Shoot those at three targets, one of each weight at each target. remember to mark each hit. Evaluate which ones grouped the best and that's your load.
I tried to get through this without being too long. e-mail me if you have questions or stay on. You can get some more good answers.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Thank you. I don't think I saw this before. Looks like some very good information.
quote:Now for shooting them:
TresMon strongly suggests 600 yds. Not all that easy to get that far in a lot of places. So, if you can, 300 will suffice, 200 if you have no other choice. But go out as far as you can, whatever range. What you'll do is shoot these bullets from the low end to the high end. On one large piece of paper so that you can track the bullets upward POI's. At some point the bullets tend to cluster at one elevation. This is the accuracy node you are looking for. At any sign of too high of pressure, stop. Save all the hotter loaded bullets for pulling at home and then reloading them.
Would you mind clarifying how I am going to see a "cluster" using only one bullet at each loading?
quote:Meaning within a certain band any 3-6 or even seven bullets will bring that barrel up to the top of its sine wave then stop at the natural flex of the barrel. Anything lower or higher may have the bullet poi's coming back down. Or going increasingly left and right.
Are you referring to 3-6 loads (as in powder charges), or bullet weights?
quote:When you find the right load range verify it by loading three bullets each in .5 gr increments starting one grain under the middle of the groups and ending one gr. over. That's fifteen more bullets. Shoot those at three targets, one of each weight at each target. remember to mark each hit. Evaluate which ones grouped the best and that's your load.
Again, could you please clarify how I find the right load range. If I'm only firing one bullet per grain of powder increase, how do I determine the correct load range (back to the cluster question).
Thanks again! This is really good info!...and it's put into layman's terms that I can understand.[8D]
I do believe I forgot to say. USE THE SAME AIMPOINT for all shots. Don't change your aimpoint. Let the bullets fall where they may.
What you will find when you load a batch and shoot them that way is that the bullet hits (poi's=point of impact) will start low on your target and move up in say 2"-3". When the barrel muzzle starts reaching that harmonic where it is at the top of the sine wave, you go through a pressure region that all those shots tend to land in one area.
Like I've said before, I used to chase this with velocity and it kind of worked. Don't. If you bring a chrono, and I recommend you do, just use it for ballistic calculations for later. Don't modify your load to fit the velocity as I have. Just find where they cluster (on the target) the best. Use the middle of that POWDER load range for the second ladder. you will probably want to use at least a 24" tall paper and depending on wind where you're at 15"-20" wide.
Edit: One last note, you start the powder runup from midrange of the standard .300 Win Mag. Don't interpolate from another case. Run 5-6 grains over that max. When you get to max of the standard case start loading in .5 gr. increments. When you see pressure signs stop. That is your load range. PULL the remaining bullets that are hotter.
Also remember you do this starting with the bullet into the lands at least .010". That will bring on the most initial pressure. If you back the bullet out, you won't get the pressure spike like you would if it was pushed into the lands. After you find the cluster you can fine tune the load by changing seating depth.
Eric,
I do believe I forgot to say. USE THE SAME AIMPOINT for all shots. Don't change your aimpoint. Let the bullets fall where they may.
What you will find when you load a batch and shoot them that way is that the bullet hits (poi's=point of impact) will start low on your target and move up in say 2"-3". When the barrel muzzle starts reaching that harmonic where it is at the top of the sine wave, you go through a pressure region that all those shots tend to land in one area.
Like I've said before, I used to chase this with velocity and it kind of worked. Don't. If you bring a chrono, and I recommend you do, just use it for ballistic calculations for later. Don't modify your load to fit the velocity as I have. Just find where they cluster (on the target) the best. Use the middle of that POWDER load range for the second ladder. you will probably want to use at least a 24" tall paper and depending on wind where you're at 15"-20" wide.
Edit: One last note, you start the powder runup from midrange of the standard .300 Win Mag. Don't interpolate from another case. Run 5-6 grains over that max. When you get to max of the standard case start loading in .5 gr. increments. When you see pressure signs stop. That is your load range. PULL the remaining bullets that are hotter.
Also remember you do this starting with the bullet into the lands at least .010". That will bring on the most initial pressure. If you back the bullet out, you won't get the pressure spike like you would if it was pushed into the lands. After you find the cluster you can fine tune the load by changing seating depth.
I think I understand you. Thanks! I'm going to try that my next time out...This would save a LOT of ammo! I've got about 50 rounds loaded that I'm going to shoot today. I'll start over with your method with the next batch I load.[:)]
the only sign that shows up in Ackleys is loose primer pockets. Most everything else will not appear until you are wayyyyyy over max. Keep a feel for the primer pockets lossening up.
Yup, that's why it's a good idea to write down the load on the side of the case with a sharpie. So, when you get back from the range and don't get right back to reloading you know which cases were too hot.
Also, I did mention in another post somewhere's, that the Ackley cases may give better performance, but the main reason comp shooters use them is for better brass consistency and life.