Top three things to reduce ES and SD

[sgt.caldwell]

Everything the same and then the primers tested to give the smallest SD.Annealing necks and timming the oal, are some the the little things that are over looked.I've test so many rounds with a chonograph,that I think the primers are still the #1 issue.Find a good lot and buy a lot of them.The best shooting lot I ever had was a batch of winchester mag that gave 5-3 fps SD .I've loaded more than 2millon rounds and I'm still learning each year.New bullets new calibers,new powders.It will always be changing.Just be flexable and ready for whats next around the corner. Bill

 

[MNbogboy]

Lots of good points here..Rscott5028 says it best consistency..consistency..consistency....My minimal equipment puts out some amazingly accurate and consistent ammo(at least for me) if I put the time into it....I weigh every load down to the "kernal" and sometimes I scoop out one kernal out of the pan if I over trickle...I adjust neck tension frequently to maintain consistency and always sort bullets by weight and bearing length and cases by weight & volume...Anything that I can control to reduce ES & SD give me numbers in the single digits and teens most of the time...But sometimes you have to chalk it up to a mistake you make such as leaving one in the chamber too long or a different grip on the rifle........All good numbers take time both on and off the range....

I started hand-loading when I was a teen back in the 60s and am always open to learning new things....
The straw technique on the the trickler was the latest thing I learned on here about a year ago..(we didn't have the "net" back in the day)......Now with a clear McDonalds straw I can watch the clumps coming before i overcharge!
When I built my first automatic powder scale back in the early 80s I wish I would have had that "clear" straw back then....That powder scale used a conventional beam scale, 2 gearmotors, two modified tricklers and photoelectric sensors to fill and trickle the pan and stop when the beam blocked light to the sensors...It was large and clumsy and could only produces charges to .1 grain.....It was no faster than doing it by hand but you could start the second charge while you could actually do something else.....The second one I built was similar but used two stepper motors and digital technology ...The ability to vary motor speed made it faster but again clumping at the trickle stage often put you over by a .1 grain.....It was dismantled when I moved a couple of houses (and women) back and never put back together and finally lost amongst the moves.....If I ever build another I will use opto electronics, a little fuzzy logic, and a clear final trickler tube to reduce error of overcharges....

However my need for speed has gone past me like my youthfulness has and I am content with shooting a 1000 rounds a year or so now.....If I shot and loaded like the last guy posted I would have loaded 6 boxes a day 365 days a year for the last 45 years and I still would not have loaded 2 million rounds....

It is possible to have quality and quantity, but for the best quality you must give up some of the quantity.....Take your time and pay the most attention to detail.....

My .02,
Randy

 

[Bart B]

One thing that's often overlooked when testing ammo for velocity spread from hand held rifles fired from a bench is the shooter. I've seen a few dozen fps spread in average muzzle velocity between two people shooting the same rifle and ammo. The rifle was held with different pressure averages for each shooter. And one consistantly got lower extreme spreads than the other; he held the rifle more consistant in pressure against his shoulder than the other person did. If you do your own tests, you'll probably see that the harder the rifle's held into your shoulder, the faster the bullets leave.

Reducing velocity spread as well as the spread in peak pressure does not guarantee best accuracy down range. Best example I know of was when a few US Palma Team members were developing loads for Sierra Bullets' then new 155-gr. 30 caliber bullet back in 1991. Different powders, both ball and extruded were metered (not weighed) into cases primed with Fed. 210M primers in cases weighing about 170 grains. AA2520 ball powder produced the lowest spreads in charge weight, muzzle velocity as well as peak pressure. It was also the least accurate of all powders tested. IMR4895 produced average spreads in charge weight, muzzle velocity and peak pressure but shot those bullets the most accurate.

 

[rscott5028]

I 100% agree with BartB.

I would add that ES is a nearly useless stat.

SD does have meaning in the context of larger sample sizes.

Having a well established MV with low SD is useful for predicting drop at varying distances.

But, rifle precision, stock design, and shooting technique have a huge influence on actual results. Hence, straight bottom stocks on many benchrest and f-class rifles vs tapered hunting stocks that may be easier to position in hunting situations.

The point of my original post here wasn't to be cheeky. Rather, it's hard to improve that last little bit. But, it's easy to do just one thing wrong (inconsistent) and blow it.

-- richard

 

[Timber338]

Lots of great info here coming from a whole lot of experience.

For me, the single most important component that has yielded the best accuracy in my guns, is quality brass. When I shoot crappy brass, I can be using premium bullets/powder/primers/techniques and accuracy just sucks.

To me this means either Norma, Lapua or Nosler brass that is weight sorted and has neck thickness verified to be within +/- .0005" and trimmed to length. Once I load the ammo I sort by concentricity, and although I prefer the loaded ammo to be .002" or less runout, I have found no real-world difference in loads that are .008" runout or less.

This would probably not work for bench rest guys or the guys that are much better shots than myself... I don't do every last little reloading trick. My accurate guns are .30 cal or bigger, weigh between 7.5 and 9 pounds scoped, and all shoot 1/2 MOA as far as I shoot which is 1000 yds or less.

 

[Bart B]

My accurate guns are .30 cal or bigger, weigh between 7.5 and 9 pounds scoped, and all shoot 1/2 MOA as far as I shoot which is 1000 yds or less.

Is that the worst they shoot, in other words no groups' you've shot's been larger than 1/2 MOA at 1000? If not, that's excellent!!!

 

[Timber338]

Is that the worst they shoot, in other words no groups' you've shot's been larger than 1/2 MOA at 1000? If not, that's excellent!!!

Hell Ya I have shot worse than 1/2 MOA with my guns ! A whole lot worse! Just the other day I pulled a shot 6" right at 300 yds, and I knew it the second I pulled the trigger.

Key word being "I" ... not the guns fault. That's the beauty of shooting an accurate gun... when the bullet doesn't go where it's supposed to you get instant feedback on what you're doing wrong with your own technique.

I'm currently playing with my 7.5 lb 338-300wsm, and the heavy recoil requires a whole lot of focus and any little mistake gets magnified with a light gun. But as long as I do my part that gun is phenomenal... I am continually amazed when I walk out to my target and see group after group shoot so well.

Out to 600 yds I can hold 3/8 MOA more often than not, but when I start to go longer my own ability starts to come in to play. I guarantee that some of the guys here could shoot the gun much better than I do from 600 - 1000 yds. I guess my point is the gun is more accurate than I am, and since I can practice that's a good problem to have!...gun)

 

[Bart B]

Hell Ya I have shot worse than 1/2 MOA with my guns ! A whole lot worse! Just the other day I pulled a shot 6" right at 300 yds, and I knew it the second I pulled the trigger.

Key word being "I" ... not the guns fault. That's the beauty of shooting an accurate gun... when the bullet doesn't go where it's supposed to you get instant feedback on what you're doing wrong with your own technique.

OK, thank for the info. I now understand that your guns shoot 1/2 MOA through 1000, but you don't. I've not heard of nor read in print such accuracy issues explained that way before. But I would like to find out how the rifle's been proven to shoot 1/2 MOA through 1000 yards when you don't hold and shoot it well enough to break all your shots inside 1/10th MOA.

 

[Timber338]

But I would like to find out how the rifle's been proven to shoot 1/2 MOA through 1000 yards when you don't hold it well enough to do so.

I just don't hold 1/2 MOA at 1000 every time, 100% of the time like you asked, although I have done it quite a bit. Enough to feel confident that my rifles are capable. Is the standard definition of accuracy out to a given distance only based on 100% success? If that's the case then by all means my guns are not 1/2 MOA guns at 1000, and by definition I could then really only claim that they are maybe 2 MOA guns at 100 yards at best.

But I sure am happy with them especially my 338wsm! I thought others, especially here, would enjoy hearing about a gun that shoots really well and share some of my experience for how I was able to do it.

 

[bigngreen]

I just don't hold 1/2 MOA at 1000 every time, 100% of the time like you asked, although I have done it quite a bit. Enough to feel confident that my rifles are capable. Is the standard definition of accuracy out to a given distance only based on 100% success? If that's the case then by all means my guns are not 1/2 MOA guns at 1000, and by definition I could then really only claim that they are maybe 2 MOA guns at 100 yards at best.

But I sure am happy with them especially my 338wsm! I thought others, especially here, would enjoy hearing about a gun that shoots really well and share some of my experience for how I was able to do it.

How bout a new thread on that 338 WSM!!gun)

 

[Max Load]

Changing primers always helps me.

 

[Ludicrous]

So just how accurate are chronographs?

Sounds like lots of people put 100% faith in the data they spit out. How accurate would they measure one kernel of Varget velocity difference?

 

[Bullet bumper]

A powder type and load that fills the case.
A target quality bullet .
Precise neck tension from case to case .

 

[DougMH]

So just how accurate are chronographs?

Sounds like lots of people put 100% faith in the data they spit out. How accurate would they measure one kernel of Varget velocity difference?

The only one I trust completely is the Oehler 35p because it's basically 2 chronographs in one. I suppose you could use 2 chronographs from another mfgr in line.

While it's adjustable, the default for the primary chrony is 4'. The proof chrony is at 2' (in the middle). When you shoot, you get a reading from both the primary and the proof. If they're within tolerance, you're good to go. If they're too far apart, an * prints to the right of both readings and that reading is not in the calculations of ES, SD, Max, Min, Mean.

Again, you could do the same with 2 chronys, but you'd have to make the comparisons manually.