300 PRC update

[category_theory]

from VV. PS: these numbers are by them stated as for a 26" barrel, you will notice N570 is quite a bit higher at all the loads.

G
View attachment 7994169

Sorry that’s not what I was asking…. The 560
Numbers from GRT show much lower than nominal pressures for the max charge shown above (VVs website). The simulations show that you could push the max charge much higher than VV is showing here…. I was wondering if anyone has tried to…

 

[georgelza]

Sorry that’s not what I was asking…. The 560
Numbers from GRT show much lower than nominal pressures for the max charge shown above (VVs website). The simulations show that you could push the max charge much higher than VV is showing here…. I was wondering if anyone has tried to…

Ahhh
Ok, interesting.
G

 

[abn31c]

I'm getting ready to test 220 LRHT with h1k and 565. H1k has always given me the lowest ES/SD. 31.5" Bart, 9 twist. But I've only run about 3k rounds of 300 prc. There are others here with more experience.

 

[Pete Cefalu]

Curious, was / is being nudged to N565... but looking at the numbers for N570, it looks better.
For now it will be either ELDM 225gr or 230 A-Tip's down a 24" barrel.

comments.
G
... off topic, sort of, was surprised to see neither N565..N570 or any of the Vihtavuori powders listed in the Hornady reloading manual (10th edition).

I'm guessing because Berger(competitor) is in bed with VV.

 

[atepointer]

I also have several friends with the savage elite and 30" bbl that were roasting me and my 26", which is why I went with a 30". My safes also wont allow it to stand up straight. But I run the Area 419 sidewinder self timer which is a tool-less removal to switch over to a can. They sell a protector cap for the muzzle adapter which is how I stow it. Suppressor and brake stay in the bag. JAT

What kind of performance are these guys getting with the Savage 300 PRC? Action/bolt/chassis opinion or any their MVs I'd love to hear if you have please. Any chance to see the dif with 4" more barrel/mv at distance say 1mile +? Thanks

 

[Taylorbok]

What kind of performance are these guys getting with the Savage 300 PRC? Any chance to see it at distance say 1mile +? Thanks

Same as any other 300PRC with 30" barrel.

 

[Pete Cefalu]

What kind of performance are these guys getting with the Savage 300 PRC? Action/bolt/chassis opinion or any their MVs I'd love to hear if you have please. Any chance to see the dif with 4" more barrel/mv at distance say 1mile +? Thanks

I apologize(again). That was with my 300WM vs their 300WM's. I own 3 RPR's and forget. However, owning 26", 28", and 30" barrels, I successfully predict 25-30fps per inch of pipe when reloading from published data using shorter test barrels. Hope this helps

 

[georgelza]

What kind of performance are these guys getting with the Savage 300 PRC? Action/bolt/chassis opinion or any their MVs I'd love to hear if you have please. Any chance to see the dif with 4" more barrel/mv at distance say 1mile +? Thanks

The Savage Elite Precision, 30" is accurately repeatedly hitting target 1mile + consistently, similar on the 28" as they're pushing the 245 and 250 bullets, that keep speed and direction in wind over those distances, the 225 and 230's battle, you can't push much more than those out of the 24", 26 is like border line, from what I'm seeing from the other guys, past weekend competition results.
G

 

[atepointer]

I apologize(again). That was with my 300WM vs their 300WM's. I own 3 RPR's and forget. However, owning 26", 28", and 30" barrels, I successfully predict 25-30fps per inch of pipe when reloading from published data using shorter test barrels. Hope this helps

That's great thanks. I'm just dreaming.....all over the place with various 7mm flavors, 300NM/PRC it goes on and on....

 

[georgelza]

That's great thanks. I'm just dreaming.....all over the place with various 7mm flavors, 300NM/PRC it goes on and on....

so many options, what are we to doooooo
G

 

[georgelza]

curious... I've seen a couple of people mention they working out the pressure... comparing they load/pressure against the SAAMI numbers, comparing it to numbers as per attached.
how do you work out the pressure?
I've got a friend that has a spread sheet, where he calculates the burn rate/time, and compare that against the projected speed of the bullet, determining that against the time that the bullet is in the barrel, and relating that to the burn rate, determine how much unburned power goes out the front (aka wastage).
other than quickload and GRT, does anyone have a spread sheet that does this...
G

 

[Dm1995]

Hey i dont know if this is in the right place.
Two questions
First does the bergara rifles being based on the rem700. L/A fit in a acis ax foldable chassis?

Also, does the 300 win and 300 prc interchange ? Like a 357 will shoot a .38 special?

Thanks

 

[Hey You]

WINMAG AND PRC ABSOLUTLEY NOT INTERCHANGABLE.

 

[atepointer]

so many options, what are we to doooooo
G

I have a buddy who is a reloading genius and he's put maybe half a dozen potential candidates up for consideration for our range which taps out at 2k/sea level. Going to let him simmer on that for a bit and will follow his lead at some point.

 

[georgelza]

I have a buddy who is a reloading genius and he's put maybe half a dozen potential candidates up for consideration for our range which taps out at 2k/sea level. Going to let him simmer on that for a bit and will follow his lead at some point.

please do share what he suggests...
your 300 pic, what barrel length?
G

 

[georgelza]

Hello btuse,

My recent background is....I'm a 1 mile benchrest shooter and 1k benchrest while trying to do as many ELR comps as I can. I work a job that sometimes pushes 70+ hours a week. I only really ever get to shoot at a match.

So, you have a 30" barrel. You will find some of the faster powders like H1000 will show a slower velocity in the 30" because the kaboom ran out of juice and the pressure spike is waning and the friction of the bullet in the barrel are starting to over come the pressure....thus slowing you down. It's like the inverse of powders like Retumbo in a shorter barrel where you get to a point where no matter how much powder you add....you don't get any more velocity because the powder isn't burnt before it leaves the barrel...usually manifesting itself in a nice fireball.

We like to match powder burn rate, powder density, and powder energy to our specific cartridge. Aka, we want the powder to burn the entire length down the barrel with our particular projectile. We don't want any wasted powder flashing off at the muzzle. We want the powder to fill as much of the air space in the brass as possible so when we tilt the round on its side you don't change the potential initial pressure by how the powder lays in the case. You don't want an air pocket at the back...between the powder and the primer flash hole when doing high angle shooting. (problem with the 300nm) We want a powder that gets a safe initial pressure spike of 65k psi or less and falls off slowly.

Each powder has unique physical and chemical traits that we have to adjust for. Even the same powder from lot to lot....or the same powder loaded on the bench on days of extreme humidity change.

When it comes to the 300PRC...give me a high BC, heavy for caliber bullet that is very consistent from one bullet to the next and let me drive it from 2880fps to 3000fps and I'm a happy man. I find 2900fps and a 245gr EOL is my happy spot.


I'm supersonic to 2,000 yards. I've found the 230 A-tip, 245 EOL and the 250 A-tip to transition to transonic and subsonic out to 2500yds very accurately. I've won matches out to 2500yds with my 300PRC. It's not the best selection for that distance....but out to 2000yds I'll take it over most things. I also pull barrels for comp at around 1200 to 1400 rounds on them.

Have a great day,

B2

hi b2lee

2 questions.

1. get the idea this might be something you can assist me with, please cast your eyes over:

Math about pressures, bullet speed/time in the barrel etc

Cross posting, sorry, thinking this deserves a more generic chat/thread. curious... I've seen a couple of people mention they working out the pressure... comparing they load/pressure against the SAAMI numbers, comparing it to numbers as per attached. how do you work out the pressure? I've got...

www.snipershide.com

2. on my powder choice, I'm between N565 and H1000, and being more nudged towards N565... but low and behold, my poor eyes saw the cousins called N570... and seeing the numbers... wondering why not... might it be that N570 would give these numbers in a 26" barrel, but not in my little (I'm to short... 24") exhaust.

G



G

 

[Taylorbok]

@georgelza @8pointer it has nothing to do with the name on the cartrdge it's about the ability to launch a heavy high BC bullet at high velocity. A 300 PRC and 300 RUM or 300 NM shooting the same bullet at the same velocity have the same trajectory, simple. You may be able to get a bit more velocity out of one or the other.

Yes I would run N570 in a 300PRC,

 

[georgelza]

Yes I would run N570 in a 300PRC,

as much as I agree, think this is actually one of those subjects that falls under a it depends, its not just the caliber, it's depending on the bullet weight and the barrel length, which then define the powder used and how much.

as said, get the idea in a 24" for a 230 gr N564 would be good option (not discounting H1K) while a 230 or 250gr in a 26" would suit N570 and for 245/250gr in a 28"+ barrel Retumbo would be the go to.

G

 

[triumph001]

as much as I agree, think this is actually one of those subjects that falls under a it depends, its not just the caliber, it's depending on the bullet weight and the barrel length, which then define the powder used and how much.

as said, get the idea in a 24" for a 230 gr N564 would be good option (not discounting H1K) while a 230 or 250gr in a 26" would suit N570 and for 245/250gr in a 28"+ barrel Retumbo would be the go to.

G

Sounds like you need to buy a bunch of different powders and shoot your rifle with as many combinations as possible. Please report back with your findings. I’m sure someone else will eventually order a 24” barrel by accident.

 

[abn31c]

Sounds like you need to buy a bunch of different powders and shoot your rifle with as many combinations as possible. Please report back with your findings. I’m sure someone else will eventually order a 24” barrel by accident.

This...

 

[b2lee]

You will find that in a 24 inch barrel....you won't be able to get the speed you are looking for...and will see a large fireball at your muzzle because the burn rate for N570 is slow enough to where you aren't getting close to a full powder burn in that short of a barrel. I personally wouldn't run anything slow like N570 or even Retumbo until after 30 inches..and I found Retumbo to be horrid in my personal testing.

N565 in that 26-28" barrels....you will most likely find that in the 22-24" barrels that H1000 is a nice burn rate that offers you a better speed with lower pressure than other powders. I personally run RL-26 in a 29.5" barrel. I've had several barrels on this thing and 28-30 inches...RL-26 has been the go to powder for me. I don't give one flying whatever for what a book says....or what GRT says....you have to know why those numbers are what they are. Each rifle is a unique biosphere and you have to feed it what it likes. You have to shoot AT DISTANCE and not some 100yd group. You have to understand everything that is involved to make that bullet/cartridge....cause that peak pressure, retain that inertial pressure.....that burn rate to a certain length in your barrel....achieve that bullet speed.....cause that harmonic.....

Several of us have great success with different answers to that question...because each rifle is different....and different combinations can get you to where you want to go. We must understand the HOW and the WHY things do what they do....and feed the gun exactly what it wants.

For me...that is 76.0gr of RL-26....Lapua brass with a 2thou shoulder bump....trimmed .003" less than the start of the throat.....with a 245gr Berger EOL going about 2900fps in a 29.5" barrel....seated to a depth of where the bullets boat tail junction is .003" longer than where the Neck/Shoulder junction is...with a certain neck bushing.....with the brass annealed to a certain AMP Code.......with a certain mandrel opening the mouth....and the gun just smiles everytime I pull the trigger.

 

[abn31c]

Retumbo sucks in this cartridge.
Just my opinion.

 

[georgelza]

You will find that in a 24 inch barrel....you won't be able to get the speed you are looking for...and will see a large fireball at your muzzle because the burn rate for N570 is slow enough to where you aren't getting close to a full powder burn in that short of a barrel. I personally wouldn't run anything slow like N570 or even Retumbo until after 30 inches..and I found Retumbo to be horrid in my personal testing.

N565 in that 26-28" barrels....you will most likely find that in the 22-24" barrels that H1000 is a nice burn rate that offers you a better speed with lower pressure than other powders. I personally run RL-26 in a 29.5" barrel. I've had several barrels on this thing and 28-30 inches...RL-26 has been the go to powder for me. I don't give one flying whatever for what a book says....or what GRT says....you have to know why those numbers are what they are. Each rifle is a unique biosphere and you have to feed it what it likes. You have to shoot AT DISTANCE and not some 100yd group. You have to understand everything that is involved to make that bullet/cartridge....cause that peak pressure, retain that inertial pressure.....that burn rate to a certain length in your barrel....achieve that bullet speed.....cause that harmonic.....

Several of us have great success with different answers to that question...because each rifle is different....and different combinations can get you to where you want to go. We must understand the HOW and the WHY things do what they do....and feed the gun exactly what it wants.

For me...that is 76.0gr of RL-26....Lapua brass with a 2thou shoulder bump....trimmed .003" less than the start of the throat.....with a 245gr Berger EOL going about 2900fps in a 29.5" barrel....seated to a depth of where the bullets boat tail junction is .003" longer than where the Neck/Shoulder junction is...with a certain neck bushing.....with the brass annealed to a certain AMP Code.......with a certain mandrel opening the mouth....and the gun just smiles everytime I pull the trigger.

Hi @b2lee, thanks. as hinted, was thinking that maybe the 24" was too short for N570, so my "guess" at this time was correct. I'm interested to get to know not just the answers, but the math etc behind the answer, understand how to work out the pressure and the pressure curve and timing, for the various powders and then see how that fits into the rifle.

interesting comment on N565, got the impression from allot of people that it might be perfect for my 24", but now your nudge to rather stick to H1k. As you say, I will have to find out what my rifle like, so many as per triumphs semi sarcastic comment above, buy one point of each and see what it prefers, performs best with.

to what extend would the bullet weight impact the powder selection, thinking a heavier bullet might utilise more powder/pressure to get going.
aka a N565 in 24" and a R215 would be a fire blowing monster, but that same powder with a 250gr bullet (no i;m not planning to in 24") but that combination might have more kickback at the pressure, slow this down that nano second, thus reducong the flame blower.
G

 

[Pete Cefalu]

Hi @b2lee, thanks. as hinted, was thinking that maybe the 24" was too short for N570, so my "guess" at this time was correct. I'm interested to get to know not just the answers, but the math etc behind the answer, understand how to work out the pressure and the pressure curve and timing, for the various powders and then see how that fits into the rifle.

interesting comment on N565, got the impression from allot of people that it might be perfect for my 24", but now your nudge to rather stick to H1k. As you say, I will have to find out what my rifle like, so many as per triumphs semi sarcastic comment above, buy one point of each and see what it prefers, performs best with.

to what extend would the bullet weight impact the powder selection, thinking a heavier bullet might utilise more powder/pressure to get going.
aka a N565 in 24" and a R215 would be a fire blowing monster, but that same powder with a 250gr bullet (no i;m not planning to in 24") but that combination might have more kickback at the pressure, slow this down that nano second, thus reducong the flame blower.
G

Have you fired your rifle yet? I'm looking for your post with original question and cant find it. Not sure if all of this is in theory only? B2lee pretty much spelled it out several times. Can you share where your at with what you have and where you want to go? I by no means am trying to be rude, just lost in the War and Peace.

 

[abn31c]

Have you fired your rifle yet? I'm looking for your post with original question and cant find it. Not sure if all of this is in theory only? B2lee pretty much spelled it out several times. Can you share where your at with what you have and where you want to go? I by no means am trying to be rude, just lost in the War and Peace.

Lol, at some point you have to stop fantasizing and stick it in the hole...let the magic happen.

 

[georgelza]

btuse/abn31c
I actually clearly stated before no, waiting for my license, components are just crazy expensive/impossible to get. So we can’t just try 5 different loads, I need to do as much homework before hand and try and end with 2 most probable’s.

And ye I’d love to be able to send it myself… but not yet. So mean time… as everyone here normally also say… do your home work… so now that’s what I’m dying to do.

G

 

[Pete Cefalu]

Lol, at some point you have to stop fantasizing and stick it in the hole...let the magic happen.

The magic for me was the ignore option. i was starting to question my sanity. I wish him the best.

 

[georgelza]

Lol, at some point you have to stop fantasizing and stick it in the hole...let the magic happen.

will, as soon as I get my license and allowed to collect my rifle.
G

 

[georgelza]

You will find that in a 24 inch barrel....you won't be able to get the speed you are looking for...and will see a large fireball at your muzzle because the burn rate for N570 is slow enough to where you aren't getting close to a full powder burn in that short of a barrel. I personally wouldn't run anything slow like N570 or even Retumbo until after 30 inches..and I found Retumbo to be horrid in my personal testing.

N565 in that 26-28" barrels....you will most likely find that in the 22-24" barrels that H1000 is a nice burn rate that offers you a better speed with lower pressure than other powders. I personally run RL-26 in a 29.5" barrel. I've had several barrels on this thing and 28-30 inches...RL-26 has been the go to powder for me. I don't give one flying whatever for what a book says....or what GRT says....you have to know why those numbers are what they are. Each rifle is a unique biosphere and you have to feed it what it likes. You have to shoot AT DISTANCE and not some 100yd group. You have to understand everything that is involved to make that bullet/cartridge....cause that peak pressure, retain that inertial pressure.....that burn rate to a certain length in your barrel....achieve that bullet speed.....cause that harmonic.....

Several of us have great success with different answers to that question...because each rifle is different....and different combinations can get you to where you want to go. We must understand the HOW and the WHY things do what they do....and feed the gun exactly what it wants.

For me...that is 76.0gr of RL-26....Lapua brass with a 2thou shoulder bump....trimmed .003" less than the start of the throat.....with a 245gr Berger EOL going about 2900fps in a 29.5" barrel....seated to a depth of where the bullets boat tail junction is .003" longer than where the Neck/Shoulder junction is...with a certain neck bushing.....with the brass annealed to a certain AMP Code.......with a certain mandrel opening the mouth....and the gun just smiles everytime I pull the trigger.

Thank you.

G

 

[georgelza]

let me ask,

so my understanding... powder burn speed implies it takes longer to build pressure, implying you need a longer barrel for it to be effective,
powder volume just defines the volume of pressure build, not the speed on the curve ramps.
thinking how pressure works, volume A in a large space would take longer to reach a pressure point to push a projectile out at speed X vs volume B in a smaller space.
Other way round is a larger volume of powder in a large space vs a smaller volume of powder in a smaller space, Initial pressure before the bullet pops might be the same, the difference here being after the initial pop, the larger volume would continue longer up that pressure curve, especially useful in a longer barrel, with a higher weight projectile.

how far of the base would I be?

G

 

[brianf]

let me ask,

so my understanding... powder burn speed implies it takes longer to build pressure, implying you need a longer barrel for it to be effective,
powder volume just defines the volume of pressure build, not the speed on the curve ramps.
thinking how pressure works, volume A in a large space would take longer to reach a pressure point to push a projectile out at speed X vs volume B in a smaller space.
Other way round is a larger volume of powder in a large space vs a smaller volume of powder in a smaller space, Initial pressure before the bullet pops might be the same, the difference here being after the initial pop, the larger volume would continue longer up that pressure curve, especially useful in a longer barrel, with a higher weight projectile.

how far of the base would I be?

G

Pic/attachment isn’t down loading so this might be repetitive.

There is also the volume of gas after the burn.

In theory you can make the case/pressure vessel so small that one grain of powder creates a immense pressure.

But the amount/volume of gas created would not be enough to move the bullet out of the barrel as it’s a burn not a explosion.

 

[georgelza]

pic/attachment is the powder burn speed pdf of 2020, sure everyone has it.
100% on your amount/volume addition/comment.
Larger caliber/longer barrel require more powder to keep pressure long enough on projectile's ass, without it being a pure flame thrower out the front of unburned powder..

aka pressure curve with a spike far enough time wise down barrel to build up maximum speed generating enough force to accelerate projectile

G

 

[Thriller]

Update. Shot my first buck with 300 PRC
212gr ELD-X at 2850 FPS
160yds broadside shot
Result was devastating double lung pass through with a giant exit wound approximately 3.00” wide.

Also loaded up some 200gr Partitions over 79.0gr MagPro. Will try them next.

This thing hits hard.

 

[SDeadeye]

Chalk up one more deer for the 300 PRC. About 100 yards with a 208gr. Berger LRHT at 2,900 ft/s. Quartering towards me, entrance just in front of the near side shoulder and exit in the ribs behind the far side front shoulder. Fist size hole in the near side ribs, but the shoulder itself was fine. Took out the top of the heart and lungs and then the exit was only 1-1.5". The bullet must have pretty much exploded inside the rib cage, so that worked about perfectly.

 

[TM6]

Congrats on the deer gents, nice shootin!

TM6

 

[EMCA]

Hello everyone.
I have a Bergara hmr 300 prc with the bolt click problem.
Buy the 300 prc Aw2 reamer.
The other day I came home. I sent the rifle to Bergara along with the reamer and they did the job for me.
Today I have been testing and I still have the problem, although much less.
Brass fired in their 4 firing .534" at the .200 line
Brass full with wilson die .532.5" in the .200 line
-should I be seeing .535" on the .200 line after reaming?
-Do I have the problem with the wilson die that does not recalibrate enough?
-It seems that people can continue using the same brass after the bolt click problem or should I buy new brass?
Thank you all

 

[Northman623]

Bump

 

[Taylorbok]

@EMCA are you getting clickers or what is your issue?

 

[EMCA]

@EMCA are you getting clickers or what is your issue?

I continue with clickers.
Although less than before, but there they are.
I'm going to try a redding body die.
I think my dai wilson doesn't recalibrate enough

 

[babyguppy]

probably one of the best explanations I've read in a very long time, thank you, thank you.
makes me understand why I'm being nudged by friends in my 24" barrel to go H1000 and/or N565.
and why my friend with his Savage Elite Precision and the 30" barrel swears by Retumbo.
and why the wife better not become aware that I'm already looking at rebarreling to 28" ... simple reason for not longer... my gun safe won't hold a rifle longer, with a brake on it...

G

not sure if you've seen the burn chart. not all powders are listed, but enough to give you an idea.

 

[Pete Cefalu]

You will find that in a 24 inch barrel....you won't be able to get the speed you are looking for...and will see a large fireball at your muzzle because the burn rate for N570 is slow enough to where you aren't getting close to a full powder burn in that short of a barrel. I personally wouldn't run anything slow like N570 or even Retumbo until after 30 inches..and I found Retumbo to be horrid in my personal testing.

N565 in that 26-28" barrels....you will most likely find that in the 22-24" barrels that H1000 is a nice burn rate that offers you a better speed with lower pressure than other powders. I personally run RL-26 in a 29.5" barrel. I've had several barrels on this thing and 28-30 inches...RL-26 has been the go to powder for me. I don't give one flying whatever for what a book says....or what GRT says....you have to know why those numbers are what they are. Each rifle is a unique biosphere and you have to feed it what it likes. You have to shoot AT DISTANCE and not some 100yd group. You have to understand everything that is involved to make that bullet/cartridge....cause that peak pressure, retain that inertial pressure.....that burn rate to a certain length in your barrel....achieve that bullet speed.....cause that harmonic.....

Several of us have great success with different answers to that question...because each rifle is different....and different combinations can get you to where you want to go. We must understand the HOW and the WHY things do what they do....and feed the gun exactly what it wants.

For me...that is 76.0gr of RL-26....Lapua brass with a 2thou shoulder bump....trimmed .003" less than the start of the throat.....with a 245gr Berger EOL going about 2900fps in a 29.5" barrel....seated to a depth of where the bullets boat tail junction is .003" longer than where the Neck/Shoulder junction is...with a certain neck bushing.....with the brass annealed to a certain AMP Code.......with a certain mandrel opening the mouth....and the gun just smiles everytime I pull the trigger.

Hello B2lee, are the MV's you're stating chronographed or trued? I finally got to get out to the 1200 meter plates this weekend and was surprised to record trued velocities of 60-70 additional fps with the 250 AT's on 300PRC, and +90 with 230's in 300WM. I'm only trying to load to 2050 yards, as that's the end of the runway at my club. I have a decent air pocket already with the H1000 and H4831SC with 30" bbl w/7.5GT. I'm asking because of concern what powdering down will do to my single digit SD's. I'm using this/these combo because I have good supply of each, and waiting to beef up the 565 and 26 supply. Thx for the consideration.

 

[b2lee]

Hello B2lee, are the MV's you're stating chronographed or trued? I finally got to get out to the 1200 meter plates this weekend and was surprised to record trued velocities of 60-70 additional fps with the 250 AT's on 300PRC, and +90 with 230's in 300WM. I'm only trying to load to 2050 yards, as that's the end of the runway at my club. I have a decent air pocket already with the H1000 and H4831SC with 30" bbl w/7.5GT. I'm asking because of concern what powdering down will do to my single digit SD's. I'm using this/these combo because I have good supply of each, and waiting to beef up the 565 and 26 supply. Thx for the consideration.

So...you are 'truing' a velocity that was measured by a device that can measure muzzle velocity to within 1% of a FPS?.....or something like that. So, here's my question...what are you using for BC? Are you taking the data off the box....or are you shooting them over a high end doppler radar and truing your BC that way?....then truing your velocity from a known BC?

Also....not quite relative to this conversation because you said 1200yds....but depending on how close your actual Personal Ballistic Curve is to the G7 model...which is not as close as you would believe....but using a G7 model to plot longer range shot falls apart because the A-Tips and other modern bullets are better ballistically than the G7 plot....If you don't understand what I 'm saying...don't worry...most don't.

But....once we start pushing past 1200-1500 yards...you will see your Ballistic Calculators estimations start being further and further off than your Point of Impact....and then you adjust the BC and/or Velocity...and now at 1 mile it is great...but it is way off inside of 1,000 yards.

So....we either go back to manual dope records of our extended ranges....or we start using custom and personal data curves for our rifle, our loads, our bullets.

ELR is so much fun....wait until a shift in humidity changes where you perceive the target to be....fun fun.

 

[Taylorbok]

So...you are 'truing' a velocity that was measured by a device that can measure muzzle velocity to within 1% of a FPS?.....or something like that.

So....we either go back to manual dope records of our extended ranges....or we start using custom and personal data curves for our rifle, our loads, our bullets.

1% error on 3000 is 30. That is significant at a mile, there is still reason to true. even those fancy dancy Doppler have error. I’ve had good luck with truing velocity at Mach 1.2 and then BC out side of that.
I played around with doing some of each an essentially meeting in the middle and that seemed to work not bad also

 

[Pete Cefalu]

So...you are 'truing' a velocity that was measured by a device that can measure muzzle velocity to within 1% of a FPS?.....or something like that. So, here's my question...what are you using for BC? Are you taking the data off the box....or are you shooting them over a high end doppler radar and truing your BC that way?....then truing your velocity from a known BC?

Also....not quite relative to this conversation because you said 1200yds....but depending on how close your actual Personal Ballistic Curve is to the G7 model...which is not as close as you would believe....but using a G7 model to plot longer range shot falls apart because the A-Tips and other modern bullets are better ballistically than the G7 plot....If you don't understand what I 'm saying...don't worry...most don't.

But....once we start pushing past 1200-1500 yards...you will see your Ballistic Calculators estimations start being further and further off than your Point of Impact....and then you adjust the BC and/or Velocity...and now at 1 mile it is great...but it is way off inside of 1,000 yards.

So....we either go back to manual dope records of our extended ranges....or we start using custom and personal data curves for our rifle, our loads, our bullets.

ELR is so much fun....wait until a shift in humidity changes where you perceive the target to be....fun fun.

So I chrongraphed 25 rounds on Labradar to 2854 which i plugged into AB calculator using their CDM. the rounds went significantly high.
I adjusted firing solution to POI=POA at 1312yards(1200meters), which is as far as I had available(i think the Elite 5700 requires 1500 or so?)
Once I adjusted MV to meet drop(turret setting) I went to prove it with 1st shot impacts at 1193,1094, and 984 yards(8" round plate). the new velocity entered was 2910. I am not complaining or bragging; I was just wondering how you got to your velocities. I've done the process with a .308 win and do understand truing MV should be done as close to trans without entry, and truing BC should be done in subsonic flight. I've noticed most do not bother with truing an AB CDM, as it rarely is necessary. Hope this helps. Also, I have no interest in running this setup inside 1000 yards

 

[b2lee]

I meant .1 or 0.1% accuracy of a Labradar. 3fps is closer than your Standard Deviation is going to be....much less your extreme spread.

Fancy Dopplers...the kind that we can't afford...have error rates well below that...

99.999% of shooters aren't doing...or even understand...what it takes to shoot precision at distances at 1mile and further.

 

[Schw15]

So I chrongraphed 25 rounds on Labradar to 2854 which i plugged into AB calculator using their CDM. the rounds went significantly high.
I adjusted firing solution to POI=POA at 1312yards(1200meters), which is as far as I had available(i think the Elite 5700 requires 1500 or so?)
Once I adjusted MV to meet drop(turret setting) I went to prove it with 1st shot impacts at 1193,1094, and 984 yards(8" round plate). the new velocity entered was 2910. I am not complaining or bragging; I was just wondering how you got to your velocities. I've done the process with a .308 win and do understand truing MV should be done as close to trans without entry, and truing BC should be done in subsonic flight. I've noticed most do not bother with truing an AB CDM, as it rarely is necessary. Hope this helps. Also, I have no interest in running this setup inside 1000 yards

At what distance do you start to play with bc? Seems like there's always some tweaking or turning to some point

 

[Pete Cefalu]

At what distance do you start to play with bc? Seems like there's always some tweaking or turning to some point

the Kestrel gives you exact yardages for both MV and BC. However, my personal experience with applied Ballistics Custom Brag Models have been positive.

 

[Pete Cefalu]

I meant .1 or 0.1% accuracy of a Labradar. 3fps is closer than your Standard Deviation is going to be....much less your extreme spread.

Fancy Dopplers...the kind that we can't afford...have error rates well below that...

99.999% of shooters aren't doing...or even understand...what it takes to shoot precision at distances at 1mile and further.

OK, so is it safe to say you tru your velocity before each match? And if so, do you chrono at all?(don't really need to once you have loads worked up)

 

[Taylorbok]

I meant .1 or 0.1% accuracy of a Labradar. 3fps is closer than your Standard Deviation is going to be....much less your extreme spread.

Fancy Dopplers...the kind that we can't afford...have error rates well below that...

99.999% of shooters aren't doing...or even understand...what it takes to shoot precision at distances at 1mile and further.

I honestly thought it was 1% but it is .1 on Labradar. Or that’s advertised anyways. That actually changes my opinion a bit but doesn’t change the fact that I’ve been having great success truing MV. Next time I have a chance I’m going to try adjusting just the BC and see how that works out comparatively.

 

[b2lee]

OK, so is it safe to say you tru your velocity before each match? And if so, do you chrono at all?(don't really need to once you have loads worked up)

I'll slap a magneto speed on and get the muzzle velocity...and check my zero....all this the day before. My load development is 20 rounds or less now a days on a new to me modern cartridge. As for spinning on a new barrel...sure I'll get that 80 rounds on it to season the barrel and get the velocities to stabilize....but I rarely have to adjust seating depth..and then it is only say 3-6 thou at the most.