Big bore dinosaur
CGN frequent flyer
- Location
- NORT OF COW.TOWN.EH
10 round optimal powder charge is a great way to find longer more tunable nodes 6.5 SCOUTER
How do I get single digit ES/SD?
- Thread starter diegocn
- Start date
Better dies.(especially for seating.) Forster or Redding competition.
Consistent Neck Tension.
For what it is worth I have seen single digit numbers that didnt improve accuracy as much as one would think.
Consistent Neck Tension.
For what it is worth I have seen single digit numbers that didnt improve accuracy as much as one would think.
- Location
- Saskatchewan
THIS is wisdom and experience. Consider your actual goal. It's nice to measure ES/SD and useful up to a point, but if the tools are not up to the task, the measurement has a bigger variability than the goal. It's somewhat the same issue with hunters who measure each their powder charges to the tenth of a grain on a scale, instead of throwing charges with good technique from a reliable powder measure and using the scale to verify.
Some things just don't matter much to accuracy. Chasing smaller and smaller measurements does not always yield actual results when you shoot, especially when you're trying to measure stuff beyond the capability of the measuring equipment. But it feels good, so many do it anyway.
Munkey1973
CGN frequent flyer
- Location
- Regina, SK
Beg, borrow, or steal a better chronograph. (Lab radar... Magnetospeed)
I had an Shooting Chrony long ago.. then got a Magneto V4.... took both to the range and measured the same rounds simulatenously.
Big difference in repeatability.
Compared by magneto against a Lab Radar.. the LR confirmed that V4 was repeatable.
I basically gave my old Shooting Chrony away after that.
Then measure those loads again.
Take one shot groups.
The margin of error in the Chronograph is greater than single digit.
Even when you weigh everything to tenths of a gram, there's a margin of error in those measurements and there are always light differences in each primer, powder load, and bullet and even the barrel changes with each shot due to fouling and temperature changes.
Perspective.
The margin of error in the Chronograph is greater than single digit.
Even when you weigh everything to tenths of a gram, there's a margin of error in those measurements and there are always light differences in each primer, powder load, and bullet and even the barrel changes with each shot due to fouling and temperature changes.
Perspective.
Expander Mandrels and Neck Tension within AccurateShooter.com
https://www.accurateshooter.com/tec...ls from both,the necks before seating bullets.
https://www.accurateshooter.com/tec...ls from both,the necks before seating bullets.
Paper doesn’t lie, shoot at the distances you do and Go with best grouping. ES/SD Are irrelevant. What groups the best? And who cares if SD is huge? Unless you load for ES/SD then hope, think, that’s the best LR shooting you can do well…. Good luck.
I use the Chrono on a new gun, or a new bullet with a new powder, and run a straight up pressure test. All I want to know is where that combo maxes out, or what kind of speed ranges I can generally expect from that gun with whatever bullet weight.
Had a Chrony, very unreliable when it comes to what speed will show, bright day vs cloudy vs mixed sun/cloud, all can give you different results, throughout the course of the day. And you'll can some variance just in the difference between morning and noon and evening with the ammo anyway. I have an Oehler 35P and a Magnetospeed to use on that. They match up pretty well to each other.
After that, I shoot at paper, run 3-5 rds in a charge zone, at .010 off the lands, see what shows on paper. Something looks reasonably consistent, try some more with varying CBTO's, keep circling down to where I want the load to be or where I figure I can't get any more improvement out of it. Berger recommends trying at .010. .020, .030, .040, .050 off the lands ( they do sell bullets, so contemplate that thought). Barnes is a bit different, Nosler different again. Sometimes you do wind up doing that, sometimes you don't.
Some people go thru some really extensive processes on cases, neck turning and etc, some get really anal about charge weights, some about annealing and neck tension. Some fuss about sorting bullets according to lengths, as tips do vary on them, which can affect seating depth, some go as far as to trim and point them.
After I have gone thru as many checks as I can, and have a load working, then I'll chrono it again, to be able to work out the dope chart for it. At that point I don't care if it is 5fps or 20fps on the ES/SD, because it is doing what I want it to do already.
Sometimes it is the gun, bedding, ignition inconsistencies with the spring, sometimes it is the bags and the shooter, or just the shooter. Sometimes it is parallax on the scope, or loose mounts.
Had loads at 8fps ES, shoot 1-1/8", ones at 20-25fps ES at 1/2" to 5/8". I quit getting excited about it, if it does what is asked, good enough. Had loads I've fussed over to get 3/4" out of, others I just slapped together and got 1/2", no rhyme or reason, too many variables to play with it any more at that point.
Never change more than one thing at a time. Do the best you can with the brass to make it consistent, see if the bullets are seated consistently, and sorta straight, then work on finding a charge weight and bullet seating length variable if necc.
Had a Chrony, very unreliable when it comes to what speed will show, bright day vs cloudy vs mixed sun/cloud, all can give you different results, throughout the course of the day. And you'll can some variance just in the difference between morning and noon and evening with the ammo anyway. I have an Oehler 35P and a Magnetospeed to use on that. They match up pretty well to each other.
After that, I shoot at paper, run 3-5 rds in a charge zone, at .010 off the lands, see what shows on paper. Something looks reasonably consistent, try some more with varying CBTO's, keep circling down to where I want the load to be or where I figure I can't get any more improvement out of it. Berger recommends trying at .010. .020, .030, .040, .050 off the lands ( they do sell bullets, so contemplate that thought). Barnes is a bit different, Nosler different again. Sometimes you do wind up doing that, sometimes you don't.
Some people go thru some really extensive processes on cases, neck turning and etc, some get really anal about charge weights, some about annealing and neck tension. Some fuss about sorting bullets according to lengths, as tips do vary on them, which can affect seating depth, some go as far as to trim and point them.
After I have gone thru as many checks as I can, and have a load working, then I'll chrono it again, to be able to work out the dope chart for it. At that point I don't care if it is 5fps or 20fps on the ES/SD, because it is doing what I want it to do already.
Sometimes it is the gun, bedding, ignition inconsistencies with the spring, sometimes it is the bags and the shooter, or just the shooter. Sometimes it is parallax on the scope, or loose mounts.
Had loads at 8fps ES, shoot 1-1/8", ones at 20-25fps ES at 1/2" to 5/8". I quit getting excited about it, if it does what is asked, good enough. Had loads I've fussed over to get 3/4" out of, others I just slapped together and got 1/2", no rhyme or reason, too many variables to play with it any more at that point.
Never change more than one thing at a time. Do the best you can with the brass to make it consistent, see if the bullets are seated consistently, and sorta straight, then work on finding a charge weight and bullet seating length variable if necc.
.308Win is more than capable for precision shooting. You can play the calibre game all day long with every calibre out there as they all have their + & -.....
Are there better calibres than .308 sure but there are also better calibres than 6BRA.
Two lines of thinking
A 16" barrel is challenging
I'm wondering what's the most effective improvement I can make to my process to cut down ES?
- Remington 308 brass, full length sized through RCBS dies, trimmed to 2.005", but no annealing or other special preps.
- CCI #200 primer
- Powder charge of Varget
- (Nosler ballistic tip 168gr)
- Seating depth that's 0.010" off jam
Based on your chart your speed should be 2,575 and not your avg of 2,609, adjust your powder to get your AVERAGE speed to be 2,575fps.
Run a 3 shot test with the different charge weights to get your avg of 2,575. fine tune by .02
Once you have your 2,575fps using your 0.010" off jam which i presume you got from other tests, run a three shot seating depth test, starting at .004 jump and increase the jump my .003.
If your first two shots don't touch save the third and move on to the next depth.
If you are willing to blow up the whole process. in order of effectiveness
1. buy a high end scale (too costly)
2. Change powder Varget is on the slow end for 168gn bullets with your SHORT barrel, giving you bigger ES... search for either 8208xbr or ARcomp
3. Change primers. CCI# 200 are not a low ES primer search for S&B LR, Fed 210, CCI Br#2
If you can buy the high end scale but not the components, weigh sort the components you have to slower your ES/SD
Trevor
A 16" barrel is challenging
I'm wondering what's the most effective improvement I can make to my process to cut down ES?
- Remington 308 brass, full length sized through RCBS dies, trimmed to 2.005", but no annealing or other special preps.
- CCI #200 primer
- Powder charge of Varget
- (Nosler ballistic tip 168gr)
- Seating depth that's 0.010" off jam
Based on your chart your speed should be 2,575 and not your avg of 2,609, adjust your powder to get your AVERAGE speed to be 2,575fps.
Run a 3 shot test with the different charge weights to get your avg of 2,575. fine tune by .02
Once you have your 2,575fps using your 0.010" off jam which i presume you got from other tests, run a three shot seating depth test, starting at .004 jump and increase the jump my .003.
If your first two shots don't touch save the third and move on to the next depth.
If you are willing to blow up the whole process. in order of effectiveness
1. buy a high end scale (too costly)
2. Change powder Varget is on the slow end for 168gn bullets with your SHORT barrel, giving you bigger ES... search for either 8208xbr or ARcomp
3. Change primers. CCI# 200 are not a low ES primer search for S&B LR, Fed 210, CCI Br#2
If you can buy the high end scale but not the components, weigh sort the components you have to slower your ES/SD
Trevor
There's no secrets to this.
Use good quality components and reloading gear.
Lapua brass, berger projectiles and CCI/FGMM primers. Quality powder that's suitable to the cartridge(s) you are reloading for.
Reloading equipment: quality powder scale/thrower (I use autotrickler w/fx-120i), quality press (I use a co-ax), dies (Whidden is my preference. I FL size with bushings), etc.
Develop a simple and repeatable reloading process. Consistency matters, so do everything the same every time you reload. There's no secrets to single digit SD's besides what I've posted.
Use good quality components and reloading gear.
Lapua brass, berger projectiles and CCI/FGMM primers. Quality powder that's suitable to the cartridge(s) you are reloading for.
Reloading equipment: quality powder scale/thrower (I use autotrickler w/fx-120i), quality press (I use a co-ax), dies (Whidden is my preference. I FL size with bushings), etc.
Develop a simple and repeatable reloading process. Consistency matters, so do everything the same every time you reload. There's no secrets to single digit SD's besides what I've posted.
Is the object a low SD/ES or is the object accuracy? They are not the same thing.
If accuracy, at what range? The load that shoots bug holes at 100 might be terrible at 500.
If accuracy is the object, first develop a load that it is accurate at the desired distance.
Once you have that load, you can work on reducing the ES with minor tweaks, like cleaning up the metal round a punched flash hole.
The most important thing I can tell you is that short range groups mean nothing if the object is longer range accuracy. The barrel harmonics are critical to long range results but do not show up at 100.
20 shots of factory 308 match (Sierra 155) at 525 yards.
If accuracy, at what range? The load that shoots bug holes at 100 might be terrible at 500.
If accuracy is the object, first develop a load that it is accurate at the desired distance.
Once you have that load, you can work on reducing the ES with minor tweaks, like cleaning up the metal round a punched flash hole.
The most important thing I can tell you is that short range groups mean nothing if the object is longer range accuracy. The barrel harmonics are critical to long range results but do not show up at 100.
20 shots of factory 308 match (Sierra 155) at 525 yards.
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Is the object a low SD/ES or is the object accuracy? They are not the same thing.
If accuracy, at what range? The load that shoots bug holes at 100 might be terrible at 500.
If accuracy is the object, first develop a load that it is accurate at the desired distance.
Once you have that load, you can work on reducing the ES with minor tweaks, like cleaning up the metal round a punched flash hole.
The most important thing I can tell you is that short range groups mean nothing if the object is longer range accuracy. The barrel harmonics are critical to long range results but do not show up at 100.
20 shots of factory 308 match (Sierra 155) at 525 yards.
WOW! That's impressive....I'm guessing, 1/2 MOA @500 + yds? Well done, sir!
We used to make match ammo for target shooters and for the military/police.
It was tested by Bill Wylde in his rail gun mounted on a concrete bench.
Group was about .3 MOA in height. 18 of them were much better than that. Fliers!
It was tested by Bill Wylde in his rail gun mounted on a concrete bench.
Group was about .3 MOA in height. 18 of them were much better than that. Fliers!
You're trying to get single digit spreads with a chronograph that is only rated for 99.5% accuracy. (and that's pretty optimistic) That's plus or minus 13 fps at your velocity.
See the problem? You could have zero spread and still show a 26 fps extreme spread. Or you could rattle off a string that met your goal and it wouldn't prove a thing.
I think there should be a competition where everyone mails in their chronograph print-outs, detailed records of their case, powder and primer weights on a certified lab-scale and naturally they would need to some standard method of determining cartridge runout, and everyone would need to show the measured seating pressure on each cartridge. They could run everything through a computer algorithm and mail out the medals and nobody would even have to travel to shoot and get beat by "lesser" ammo.
Shooting just confuses thing.
I don’t use a chrony, so I’m not trying to advocate the use of then, but in Bryan litz Modern advancements in long range shooting(Vol 1 or 2 can’t remember) they tested most chronographs and the Chronys were very precise but not overly accurate. I.e they give very accurate ES/SD but the actual velocities are not accurate. Actually they give more accurate SD/ES than Magneto speeds.
Not meaning to correct you but I found it interesting
