Can a shooter's mechanics and form influence velocity E.S.?

[DMP25-06]

Can a shooter's mechanics and form , when shooting , have a direct effect on the velocity of the bullet leaving the muzzle ?
The reason that I ask is that I can not seem to produce reloaded ammo that has a low extreme spread of velocity , even though I weight-sort my brass to less than +- .5 grains , bullets sorted to .1 grain , weigh all powder charges to exactly equal weights with a balance beam scale , cut brass to equal length , anneal after 3 firings , use Redding Competition full-length neck bushing die set , and micrometer seating die , and check bullet run-out on all loaded cartridges . I use a Magnetospeed chronograph for reading velocity .

My shooting routine is as follows :
From a concrete bench , I use a Caldwell heavy front rest and a leather rabbit-ear bag for the rear rest , and position my rifle exactly the same for each shot .
Shot #1 , I pull the rifle in tight to my shoulder , concentrate on a good , smooth trigger squeeze , and make certain that I am centered on target and send it .
Provided that I am on target as I should be ,
Shots # 2, 3, 4 , I will usually relax somewhat and shoot those 3 shots which will usually be touching each other , but not touching #1 .
Shot #5 , I find myself relaxing even more , trying to send it through the same hole as the cluster of #2-3-4 , and almost always it will be not touching the others .
Velocities will show #1 as the fastest , #2 ,3, 4 will be nearly the same velocity as each other , and #5 will be slower than all others , sometimes as much as 50 FPS slower than #1 , and 20+ FPS slower than #2,3,4 shots .
Is the fact that I am unconsciously relaxing , thereby offering less resistance to the recoil , possibly causing the difference in velocity , causing wider extreme spreads ?

The laws of physics state that "For every action , there is an equal and opposite reaction".
So , if I hold the rifle tight to my shoulder , bracing against the recoil , will the bullet's velocity be faster than those shots that I relax letting the rifle free-recoil against less resistance ?

Thank You All ,
DMP25-06

 

[bigngreen]

Yep, with a quality chrono you can see it easy, some rifle are more pronounced than others but you are definitely a part of your ES if your hanging on to the rifle.

 

[26Reload]

I would also say you are a big part of the equation....
Unless that rifle is really jumping you don't need to cram it to your shoulder...a nice squeeze to the shoulder is better for target shooting...
But oh boy does that first shot count....
Shoot a rifle for a short period before the rifle....although the trigger isnt gonna be the same...play the advocate and induce you anxiety on the Rim fire and see if you rifle shoots the first round where you want it....
Then let the barrel cool...shoot Rim fire again...shoot the rifle once every 5 minutes or so.....see if that changes poi.....

 

[DMP25-06]

Yep, with a quality chrono you can see it easy, some rifle are more pronounced than others but you are definitely a part of your ES if your hanging on to the rifle.

I thought that I was probably contributing to the spread .
Somewhat like shooting a 1911 pistol , if you have a relaxed grip and relaxed wrist , many times the pistol will not feed properly because it needs solid resistance to recoil against so that the slide will feed and lock-up .

 

[jbs2014]

Have you tried using the Satterlee method to find a range to work from?

https://www.65guys.com/10-round-load-development-ladder-test/

What do you use to anneal with?

I have only utilized a balance beam scale one time, will yours measure to .1 grains? If the beam scale is not capable of measureing down to the tenth of a grain it may be difficult to use the Satterlee method. I now use an RCBS chargemaster combo scale/dispenser and I check every 5th charge with a small Lyman digital scale to ensure that everything is metering to within .1 grain.

What cartridge are you loading for?

 

[DMP25-06]

Have you tried using the Satterlee method to find a range to work from?

https://www.65guys.com/10-round-load-development-ladder-test/

What do you use to anneal with?

I have only utilized a balance beam scale one time, will yours measure to .1 grains? If the beam scale is not capable of measureing down to the tenth of a grain it may be difficult to use the Satterlee method. I now use an RCBS chargemaster combo scale/dispenser and I check every 5th charge with a small Lyman digital scale to ensure that everything is metering to within .1 grain.

What cartridge are you loading for?

Hello jbs2014 ,

Yes , I have tried the Satterlee method , but I have not tried changing the bullet seating depth to see if that has an effect on E.S.

I have a flame-type annealing machine made by Mike's Reloading Bench ,
( mikesreloadingbench.com ), that I use with Tempilaq to achieve proper temperature .

I use an RCBS Chargemaster Combo to dispense the powder charge , and then I transfer that charge to my RCBS 10-10 Balance beam scale , to which I then trickle powder into pan until the beam perfectly zeros-out . If the trickler happens to drop 2 kernels of powder on it's final trickle , and the beam goes over zero , I will use a pair of tweezers to remove 1 kernel of powder , thereby balancing exactly at zero for the charge weight that I need . After I have filled all of my cartridge cases by this method , I will use an electric toothbrush touching the side of cartridge cases to vibrate and settle the powder inside the cases . Final inspection is to use a flashlight to visually inspect all cases to verify that they are equally charged before seating the bullets . After seating the bullets , I check the runout to verify straightness .

The cartridges that I load and shoot most often are :
6.5CM - Peterson Brass , CCI BR-2 primers , H4350 and RL26 powders , 147 gr. Hornady ELD-M bullets .

.308 Win. - Federal GM brass , Winchester LR primers , Hodgdon Varget and IMR 4064 powders , Sierra Match King 175 gr. bullets .

.300 Win. Mag. - WW brass , Winchester LR Magnum primers , Hodgdon H1000 and Retumbo powders , Berger 215 gr. Hybrid and Hornady 208 gr. ELD-M bullets .

And new toy , 7mm-.300Win.Mag. , that I am currently working on load development .
SIG .300WM brass , necked down to 7mm in 3 steps with neck bushings , Federal 215 Gold Medal match primers , Hodgdon H1000 powder , Berger 180 gr. Hybrid and Hornady 180 gr. ELD-M bullets .

Thank you for your interest ,
DMP25-06

 

[bigngreen]

Bullet seating depth is critical, should be way ahead of a lot of things when reloading for precision!!

 

[Gord0]

That whole physics, equal and opposite reaction stuff holds true!

 

[Will Gray]

When I was a kid in Louisiana my Pap took me to a shooting show. Herb Parsons was a demonstrator marksman for Winchester. He pointed out that if you shoot a 458 Winchester at a watermelon and pull the trigger really hard it matters: That watermelon was full of flash powder and was impressive.

 

[Deleted member 2357]

In my opinion reloading to a tenth of a grain picking powder Kernels out one at a time is like picking fly **** out of pepper.
If your concerned about accuracy, your biggest gain will always come from learning to read the wind, there's your biggest accuracy gain, not a kernel of powder lol.

 

[25WSM]

Are you lubing your necks before seating bullets? This is very important in getting good es/SD. Your first cold bore shot usually isn't going to be in your group. But the shift is consistent so just look at your groups and you will find out how much aiming corrections are needed. As far as your load slowing down on 5th shot goes. Barrel heat will expand your barrel and therefore you lose some pressure and you lose some speed. New brass and freshly cleaned brass will not have any lube in the necks. Try some graphite powder you will see how much more consistent seating feels too. When seating you feel one goes in harder or softer mark that case and you will see velocity variations. Shep

 

[Will Gray]

In my opinion reloading to a tenth of a grain picking powder Kernels out one at a time is like picking fly ---- out of pepper.
If your concerned about accuracy, your biggest gain will always come from learning to read the wind, there's your biggest accuracy gain, not a kernel of powder lol.

1/10th of a grain out of four grains of bullseye doesn't really matter: pistol accuracy; 1/10th out of a bottle neck cartridge load of powder does not matter much, but the idea of doing everything just the same from brass prep right through to precise trigger control does add up. Over 100yds the wind, and all the other factors of a shot definitely are more signifiant than the exact powder measurement.

 

[DMP25-06]

Are you lubing your necks before seating bullets? This is very important in getting good es/SD. Your first cold bore shot usually isn't going to be in your group. But the shift is consistent so just look at your groups and you will find out how much aiming corrections are needed. As far as your load slowing down on 5th shot goes. Barrel heat will expand your barrel and therefore you lose some pressure and you lose some speed. New brass and freshly cleaned brass will not have any lube in the necks. Try some graphite powder you will see how much more consistent seating feels too. When seating you feel one goes in harder or softer mark that case and you will see velocity variations. Shep

Hello 25WSM ,

Yes , I always lube the inside of my case necks , after seating primers and before filling cartridge case with powder .

To all of you who are responding :
I am not looking for 100 yard accuracy , my rifles and loads are more accurate than my shooting abilities , consistently less than .75 MOA at 100 yards . I am hoping to achieve more accuracy at long range .
I live in Fort Worth , Texas , and my basic load development is at a 100 yard range , and I can go to a tactical range that has steel targets , beginning at 700 yards and stretching out to 1700 yards , but there is NO accessibility to doing ladder testing at any of those distances .
I am asking for your advice and help in trying to bring my velocity extreme spread down to a range of 20 FPS , or hopefully lower , and I think that much of my variation in velocity is possibly caused by my shooting form , relative to rifle recoil resistance , or lack-of resistance .

Again , Thank you all ,
DMP25-06

 

[Dean2]

The Chrongraph you are using could easily be causing as much variation as anything else. I use Shooting Chrony products but they are extremely sensitive to setup, light and shooting angle. Unless your shots are going across the Chrono at exactly the same angle and spot on the pickups with consistent light you can easily get 100 FPS variation in a load that should have an ES of 5. This is far more likely to be inducing high ES than your shooting style, given all the other quality and appropriate prep work you have done to get ES in line.

If you have access try running some rounds through a Lab Radar and see what you get for ES without changing anything else. Other option is to test your Chronograph. Take some Eley Tenex ammo and shoot it across your Chrono. This is very high quality RF ammo and should show an ES of well under 10 FPS. If you are getting more than that it is the Chrono.