Trying to reduce ES

[Miseryguts]

Hi, reloading 223 rem, and getting quite large spread (ES)of velocity. Just put a batch of 25 over the chrono, each with a measured load using a beam scale( thanks 1967spud)with COL to within +/- 0.001, Although the 100yard group was good considering the 3 o'clock gale that was blowing, the ES was 140 fps, which at 200 yards equates to round 0.5 inch variation of POI, and at 300 yards POI shift is about 1.7 inch which would probably be a miss on a crow (for me anyway, I'm not a good shot)
specs were:
52gn Hornady Amax over 25gn H335 to COL 2.230 Remington Case CCI primer
Vmax 3129 Vmin 2989 Vav. 3041 ES 140 Sd 35

Any suggestions more than welcome!

[srvet]

Try increasing the charge weight incrementally between min and max loads. Chronic each load and record the velocities for each charge. Look for the charge ranges where the velocity stays static and adjust seating depth around the middle of the flat spots

[Catch-22]

I'd also possibly check flash holes for any malformed brass on the inside which can affect primer flash distribution, and therefore pressure, building in the case at ignition.

Also, how are you sizing cases - neck only, F/L or a F/L bushing die? Inconsistent neck tension can also contribute to wandering pressures and velocities.

HTH

[Miseryguts]

srvet said;:

Try increasing the charge weight incrementally between min and max loads. Chronic each load and record the velocities for each charge. Look for the charge ranges where the velocity stays static and adjust seating depth around the middle of the flat spots

 

 

Good point, never thought of that, in fact, did not realise that was the way to go!

 

 

catch-22 said:

 

I'd also possibly check flash holes for any malformed brass on the inside which can affect primer flash distribution, and therefore pressure, building in the case at ignition.

Also, how are you sizing cases - neck only, F/L or a F/L bushing die? Inconsistent neck tension can also contribute to wandering pressures and velocities.

HTH

 

 

 

Sigh, so much to learn, so little time.

Sometimes I neck size, sometimes I F/L size, no idea which cases are which. I also crimp, would that not negate any variation in neck tension - surely if crimped, the force on the bullet should be the same? Looks like a long way to go, sigh.......

Looks like all the years of reloading hand gun ammo is out the window!

 

Thanks for the feedback

 

ATB MG

[Gandy]

in addition to the above I found the following in order made a difference to ES but, I'm sure some of the bench rest guys will know more:

1. Accurate weight of powder;
2. Flash hole de bur;
3. consistent neck tension (includes, anneal brass, possible neck turn, constant cut to length).

Hope this helps.

[triggersqueezer]

you just answered your own question pal.some neck some full .you will have internal case dimensions all over the shop.my advice is good quality f/l bushing dies like redding etc.

[gbal]

Agree on neck tension-it is at least as important as powder consistency-but very difficult to measure,so often goes unmentioned....forget cannelures in accuracy rifle reloading-and get good bushing dies-more consistent and you can control it.

Fiddle with powder/seating-but start with a near node grouping load- best not hot.... Pwder does not need to be better than .1grain,if that's what your. Scales deliver-at 4 kernels to .i,you won't see much target hole improvement aat this stage going to the next decimal place.

While on that,COL is misleading-bullets vary a lot more than your .001,CBTO (ogive) is a better measure....

Use quality brass,lapua-most of the prep has been done at the factory...but get your brass all consistent wrt firings/annealing/neck tensions/capacity.....all these affect velocity/neck tension-the main culprits for rising SDs...if you chrono-use a reliable/valid chrono like magneto-and. Closely check the ES brass-something is way out if it's a lot more than a decent SD (say 20fps,should be achievable (though your reloading gear/proceedure/consistency is not known,of course.

Use quality bullets.

Remember,it takes a bit of testing to approach real accuracy-and good shooting rig etc....if you have satisfaction at 100,that is a start....just takes a bit of care-probably more than pistol-which won't give 1/2 moa at 100y,remember... All beeen through this...:-)

gbal

[banus02]

try murmon primers

[Catch-22]

try murmon primers

Once you've got a consistent reloading process nailed, if you're still experiencing the same/similar issues, I too would consider changing primers.

I've been using CCI250's and found my ES/SD to be all over the shop (like ES of 50fps). I wasn't happy, despite shooting 0.25" groups at 100m, so switched primers. I did nothing else to my reloading regime, and found I instantly got my ES down to single digits. BUT...I knew my loading technique/process was good, so I could rule that out as the culprit.

Work on the reloading technique first, then if necessary the individual components, one at a time.

[Malinois]

Watching and reading with interest as I've just had a similar experience with my 222. Velocity all over the place with carts loaded to the same spec. It's a vermin rifle a new T3. It's only fired 100 rounds. Other advice is saying it will be my brass as I'm using new PPU as it's likely to get ejected over the side of a truck.

 

I did a 7 shot string to get me on a target with a new scope.

 

3478

3496

3506

3506

3485

3465

3547

 

 

Ian

[gbal]

Catch- what happened to your groups when you got ES down?

 

Does not ES 50 ish and shooting .25 groups (at 100m) say something important-maybe that ES is not so important at short range,and/or that chrono might have been inaccurate? Or that ES is only two rounds,and the rest may be just fine-SD is really needed too,if not a shot by shot of velocity plotted against hole in paper.

Seems there is concern about 'ES' without corroborating target evidence in several reports ....and BR100y shooters don't seem concerned,don't even weight each charge.....

Holes on paper seem definitive-as with MV etc etc-though I'd want to check out to the modal range you shoot these loads to see what is happening where it matters.....is there a problem there...?

 

gbal

[jcampbellsmith]

I don't ever look at ES, however if I can get the SD down to less than 10 fps, I'm happy. Regards JCS

[Chanonry]

Hit the primary things first, that is where the biggest gains are to be made.

 

Brass with same head stamp at least, same batch ideally. Uniform resizing of all brass an absolute necessity - lets go full length so you can be sure you have everything in a common state .

 

Don't crimp. Lots of room for variation.

 

Weigh each load.

 

Make sure the bullets are seated to the same COAL, preferably off the ogive rather than just measuring the length.

 

Retest 10 rounds at that load over a magneto speed crony or some other high quality unit. Not some £100 piece of junk that's sitting 12 feet in front waiting to be shot.

 

You will not get consistent results without consistent attention to detail. Brass prep comes first in the rankings. Consistent OAL is probably second followed by making sure your loaded rounds are truly straight next, then you can get fancy...

[Elwood]

First rule of lowering ES or SD is only measure it from the fourth or fifth shot onwards, i.e. Make sure the barrel is properly fouled before you start.

 

ES of 140 is horribly high but if you started from a clean barrel it is quite possible.

[Catch-22]

Catch- what happened to your groups when you got ES down?

Does not ES 50 ish and shooting .25 groups (at 100m) say something important-maybe that ES is not so important at short range,and/or that chrono might have been inaccurate? Or that ES is only two rounds,and the rest may be just fine-SD is really needed too,if not a shot by shot of velocity plotted against hole in paper.

Seems there is concern about 'ES' without corroborating target evidence in several reports ....and BR100y shooters don't seem concerned,don't even weight each charge.....

Holes on paper seem definitive-as with MV etc etc-though I'd want to check out to the modal range you shoot these loads to see what is happening where it matters.....is there a problem there...?

gbal

I agree, ES isn't everything, only part of the picture - but as the OP noted the very high ES figure, it reminded me of similar past issues I was having.

I used a Magneto to determine ES&SD but don't recollect my SD unfortunately.

The groups at 100m were good, as previously noted, but I mostly shoot between 600-1200m so haven't been able to compare accuracy at 100m. At 600m, previous groups were good, majority holding in the 10 ring (shooting a 500m McQueeens target the MOD kindly supply...at silly expense! ). I did notice the odd vertical flyers here and there, which prompted me to get the Magneto out and that's where I saw inconsistencies. So I switch primers. Accuracy seems about the same, as far as I can tell at 600m, but seems just a little more consistent (going by high vis markers plotted on target).

Something I would like is to do is shoot paper and be able to take it away for study.

HTH

[ds1]

ES at shot range not an issue. At "long" range an issue. I could notice it at 500m in terms of vertical on the target. If you can get around 15fps ES that's a very nice place to be. Three things that helped me, presuming a sound reloading practice and good components - anneal cases every firing, seat the bullet above the neck shoulder junction (donut) both of these will help to get consistent bullet case neck tension and thirdly use a good chronograph- my chrony was showing erratic jumps compared to a lab radar measuring at the same time I think due to different light conditions sunny / cloudy even when using screens.

[cervusman]

I always use a neck expander for all my calibers I reload, regardless whether I am using flat base or boat tail bullets which helps to give consistent neck tension.

[triggersqueezer]

I always use a neck expander for all my calibers I reload, regardless whether I am using flat base or boat tail bullets which helps to give consistent neck tension.

 

expand then size down or custom size expander set to desired neck tension ?

[Andrew]

 

Good point, never thought of that, in fact, did not realise that was the way to go!

 

 

 

 

Sigh, so much to learn, so little time.

Sometimes I neck size, sometimes I F/L size, no idea which cases are which. I also crimp, would that not negate any variation in neck tension - surely if crimped, the force on the bullet should be the same? Looks like a long way to go, sigh.......

Looks like all the years of reloading hand gun ammo is out the window!

 

Thanks for the feedback

 

ATB MG

This. A properly** applied crimp will reduce ES. I have run many chrongraph strips comparing uncrimped and crimped brass usinf identical brass LOT's and loads and the ES has always been smaller.~Andrew

 

** Trim to uniform length, use a lee Factory Crimp Die.