Tricks for low ES

[Jesse Jaymes]

Any of the Big Shots on here care to give some tips on getting lower ES?

Aside from optimum burn rate and case fill, are there any proven methods that show a measurable degree of lowering ES?

 

[Broz]

I am not a "Big Shot" of any sort but I will offer some things that have worked for me.

1: Ditch the " Shooting Chrony" and a few others that retail for $100 or less.

2: Make sure the Chronograph is located at least 18 ft from the muzzle. ( that does not mean 10' or 15' will work) does not apply to Magneto Sped units.

3: Change primers. Also if below 70 gr of powder try a standard primer instead of a Magnum.

4: Neck tension. Anneal brass and use a bushing die to control consistent neck tension.

5: Lube case necks prior to charging and seating bullets with Imperial dry case lube.

6: If all else fails change powder.

Jeff

 

[Sam Millard]

I am not a "Big Shot" of any sort but I will offer some things that have worked for me.

1: Ditch the " Shooting Chrony" and a few others that retail for $100 or less.

2: Make sure the Chronograph is located at least 18 ft from the muzzle. ( that does not mean 10' or 15' will work) does not apply to Magneto Sped units.

3: Change primers. Also if below 70 gr of powder try a standard primer instead of a Magnum.

4: Neck tension. Anneal brass and use a bushing die to control consistent neck tension.

5: Lube case necks prior to charging and seating bullets with Imperial dry case lube.

6: If all else fails change powder.

Jeff

All good stuff! I would add that precision bullet seating depth from round to round and consistent bearing surface length of each bullet can make a huge difference.

I would also expand on the brass issue. Don't assume a new bag or box of brass is full of uniformly annealed brass. Some lots are great and make consistent ammo, but I've worked with some that were so bad I ditched the whole lot. Annealing your own brass will at least eliminate a variable, which in the end is what we are all after!

 

[Jesse Jaymes]

Without becoming a Ford, Chevy, Dodge race.....can most powders give a low ES? Meaning, does anyone even bother with other powders than Hogdon Extremes? I see a guy asking about RL25. I've always heard most scrap the Alliant series and move on.

I'm not terribly old, but I've just never warmed up to anything IMR in a tin can. I've burned a lot of RL series. Lots of 22. I like 17 also. But I've never gotten "good" ES with any.

BTW- You're both the Big Shots of this forum. It's a good thing, not a jab

 

[Broz]

I have seen good ES with some RL powders. But the problem I have had was with temperature sensitivities. I have tested RL-15, 17, 19, 22 and 25 for this. None of these tested to be temp stabile enough for me to keep using them for a long range dedicated rifle. So yes, I prefer H - extreme powders like H-1000. Or some of the VV powders like N-570.

Jeff

 

[Sam Millard]

Like Jeff, I used some of the RL powders with great accuracy, high velocity, and low ES. RL25 in 300Wthby, RL22 in 300WM, and RL15 with heavy bullets in 223 specifically. Every one of these loads had velocity swings when the temp changed enough, though. It can be accounted for, but after finding loads with Extreme powders that don't change with temp, it's hard to justify using the RL powders anymore.

 

[KMD]

I use a chrony as a reference, but not as gospel truth.
ES is an excellent indicator to consider when determining the consistency of a load. However, I still prefer to let the rifle and the target tell me which load is in the node, or 'sweet spot'. Testing loads at distance, on a viewable target, to confirm which prints the least vertical spread is what I use to make a final judgement on. The target don't lie, but a chrony can be a fickle tool...

Barrel harmonics have plenty enough to do about accuracy potential, and being in the 'node' of a barrel's oscillation could make a higher ES load actually be MORE accurate/repeatable than a single digit ES load that falls outside that 'node'. If the larger velocity spread is squarely within the 'node' of the barrel's harmonic 'sweet spot', you will see less vertical dispersion than any load outside that 'sweet spot', regardless of what your chrony is tellin' you...
Just sayin', don't put all your LR eggs in the low ES basket! Prove it on target to make sure those sweet lookin' ES #s translate to miniscule vertical spread in your LR group. After all, that's the whole point!!

Regarding bushing sizing, I find it advantageous to take the extra time to 'clean up' and turn the necks of my LR brass. When employing a bushing die on 'un-trued' (un turned) necks, the bushing is indeed making the outside neck diameter consistent. The kicker is, The 'true ID' of the bushing will be now pushing any eccentricity (inconsistency) in the neck 's thickness toward the inside of the case neck. Anyone who's measured factory brass case necks on a dial indicator will know how potentially out of whack factory brass neck thickness can be! High end brass is alot better, but not immune to subtle high & low points of neck thickness. Anyhoo, sizer bushings can't make that eccentricity disappear, it needs to be cut away, via neck turning...

With 'trued', turned necks, you can be confident that your bushing is working optimally toward dialing in a consistent neck tension around the entire circumfrence of the necks. That will translate to a more even release of the bullet, upon firing...and should net you teeny, tiny groups for the extra effort...

Good luck & good shooting!

 

[Cahunter805]

Some very good info given already. I'd also add that using good brass or thorough brass prep can help. I always deburr flasholes and uniform primer pockets as well as vld chamfer all case mouths. I agree with Jeff on the hodgdon extreme powders.
Also be sure your measuring oal off the ogive with a comparator and not off the bullet tip.

 

[Sam Millard]

I use a chrony as a reference, but not as gospel truth.
ES is an excellent indicator to consider when determining the consistency of a load. However, I still prefer to let the rifle and the target tell me which load is in the node, or 'sweet spot'. Testing loads at distance, on a viewable target, to confirm which prints the least vertical spread is what I use to make a final judgement on. The target don't lie, but a chrony can be a fickle tool...

Barrel harmonics have plenty enough to do about accuracy potential, and being in the 'node' of a barrel's oscillation could make a higher ES load actually be MORE accurate/repeatable than a single digit ES load that falls outside that 'node'. If the larger velocity spread is squarely within the 'node' of the barrel's harmonic 'sweet spot', you will see less vertical dispersion than any load outside that 'sweet spot', regardless of what your chrony is tellin' you...
Just sayin', don't put all your LR eggs in the low ES basket! Prove it on target to make sure those sweet lookin' ES #s translate to miniscule vertical spread in your LR group. After all, that's the whole point!!

Regarding bushing sizing, I find it advantageous to take the extra time to 'clean up' and turn the necks of my LR brass. When employing a bushing die on 'un-trued' (un turned) necks, the bushing is indeed making the outside neck diameter consistent. The kicker is, The 'true ID' of the bushing will be now pushing any eccentricity (inconsistency) in the neck 's thickness toward the inside of the case neck. Anyone who's measured factory brass case necks on a dial indicator will know how potentially out of whack factory brass neck thickness can be! High end brass is alot better, but not immune to subtle high & low points of neck thickness. Anyhoo, sizer bushings can't make that eccentricity disappear, it needs to be cut away, via neck turning...

With 'trued', turned necks, you can be confident that your bushing is working optimally toward dialing in a consistent neck tension around the entire circumfrence of the necks. That will translate to a more even release of the bullet, upon firing...and should net you teeny, tiny groups for the extra effort...

Good luck & good shooting!

I would be careful putting too much faith into ladder test or OCW test results that ignore ES. At short ranges like 600 yards, vertical spread caused by MV spreads is minimal. At 1000 yards, gravity will quickly show the folly of running high ES numbers regardless of the sweet spot in a barrel. Most folks run those tests at 3-400 yards.

As an example, let's use a 140 grain 6.5 Berger VLD launching @ 2810 fps Avg. MV. With an ES of 40 (which is higher than I would use for long range ammo), vertical spread at 600 yards would be .4 MOA (2.4")...at 800 yards, vertical spread would be .6 MOA (4.8"). Both of those numbers are no big deal, but when ranges get pushed out to 1000 yards, the spread gets bigger- .9 MOA (9.0"). At 1200 yards, the spread is 1.2 MOA (14.4").

If you cut the ES in half to 20 fps, the vertical spread of the shot will also be cut in half. That's about as well as a good shooter can hold at 1200 yards and further anyway. All of this is assuming a virtual one hole group at 100 yards, with no vertical spread induced by harmonics. Gravity can't be ignored...ES matters!

As far as turning necks, before you run out and invest in the tools to do it properly, check your brass to see if it will benefit from it. I sort brass for every barrel I'm shooting before I start loading it. If neck thickness runout is over .002", I put that case aside for set up or other testing. If the neck has .002" RO, the whole case body does, too. I turned necks once to "0" RO and shot them against brass not turned (with equal neck tension), and saw no difference in accuracy or MV numbers.

A better investment would be in a case annealer, with an added benefit of longer case life.

 

[KMD]

Sam, could you point out where I recommended "ignoring" ES?
To quote myself, "ES is an excellent indicator to consider when determining the consistency of a load."

My point was, to let the target ultimately tell which of your loads have the least vertical. The proof is in the puddin', so to speak...

Fact is, chronos can, do, and will, provide inaccurate data, on occasion. And for a variety of reasons. That is why I consider chrono data, to be a reference only, not hard, gospel truth data to base a decision solely upon. Again, the target don't lie! And, anyone who's had to 'tweak' velocity numbers on a ballistic calculator to get their LR dope to jive, knows that velocity #s are not set in stone by a chronograph. Nor, are factory b.c. values, for that matter, but that's another subject altogether!

I must disagree with you, that neck turning does not factor into accuracy. It might not, for you, but for many others, it matters greatly. If trued case necks and uniform neck tension offered no perceptible improvement in accuracy, why is it that the most accuracy OCD nuts of the benchrest world are so anal about turning their case necks?

By the time one measures & sorts case necks according to runout, IMHO, that time would have been better spent just turning them true! Its not hard, once you've got a turner set up. I turn necks with my cordless drill, while watching the idiot box. Don't get no easier than that!!!

Here's the logic I base my reasoning on, please don't take offense.

The path to eeking out all the accuracy you can, is to control every last detail you can, and leave as few tangibles to chance, as humanly possible. In that regard, I choose to make inconsistent neck thickness a complete non-issue ,by turning my case necks true to uniform size. One can argue that "it doesn't matter to me", but that's not to say there aren't any benefits to neck turning for anyone else. And the fact that neck turning is common practice amongst the most accuracy minded shooting pursuits should give a good indication that there's a definite benefit to it.
Considering that LR hunting is an accuracy game in its own right, it only makes sense (to me) to pursue every opportunity to make the best ammo I can. Its all part of the process...

Don't have any real big boomers to load for, 7WSM is the biggest. But, in that rifle alone, I have noticed a definite benefit to the LR accuracy from turning case necks for it. And this is a 'no turn' chamber, so shaving off just enough to skim the high spots off the necks, to achieve a true diameter all the way around. Could be, I just feel better knowing I'm making steps toward more 'perfect' ammo, but that alone makes it worth the effort...

If you say case neck inconsistencies don't matter in those big 300s and big 338s, then I'll defer to your expertise, there.

Not wanting to sound argumentitive, but I can't help but offer a differing opinion for others to consider.

 

[Broz]

I determine to turn necks or not only if the need is indicated buy the amount of bullet release the chamber will allow. Measure a loaded round and a fired round and if there is not .003" of difference in growth, then I will slightly turn the necks until I get a minimum of .0025" to .003" But,, also be aware turning necks for an already large chamber can be an accuracy killer, and result in over worked necks that stiffen early killing accuracy by promoting inconsistent neck tension if not annealing. Turning necks with no knowledge of chamber dimension also can promote cracking. Remember, bench rest rifles are often chambered with reamers that are designed with neck turning in mind. Not the case with rifles built to be a "no turn neck" chamber.

I only have to turn necks for my 6mm BR as I designed the reamer that way, that will be my last of those. My real long range rigs (300 win Mag and .338 Terminator) shoot very very accurately with Lapua brass and no neck turning to distances well past a mile. Close to 1 1/2 mile in the .338 Terminators case. My ES across reliable chronographs like my Oehler 35 or Magneto speed is often single digit for a 5 shot string. Vertical dispersion at 1000 yard plus follows suit. My results as I stated before from 3 different "Shooting Chrony's , a Pact, and another inexpensive chronographs was very inconsistent. I have proved over and over you may as well not own a chronograph if it is not a good one. Unless you just want to waste ammo and fool yourself chasing ES.

Annealing is a great asset to accuracy and consistent neck tension. That is if you are firing your brass more than 4 times with out replacing it. I will put annealing and a bushing die to control sizing over a one size fits all die and no annealing higher on the list than neck turning any day.

Jeff

 

[Sam Millard]

I once had to take a Dale Carnegie course for work (my first foray into the HR world). One of the first things they told us was to avoid telling someone they are wrong and to instead focus on their positive attributes. I will take a stab at that here...

KMD, the strengths I see in you are your wonderful prose and impeccable command of all things technical regarding firearms, reloading, and the acronyms that accompany any discussion pertaining to them. You are skillful at avoiding outright confrontation, with just the right amount of condescension and vagueness. I wish I could compose replies on internet forums as well as you do, but alas, I am a simple country boy who prefers to spend his time shooting in the woods.

I use a chrony as a reference, but not as gospel truth.
ES is an excellent indicator to consider when determining the consistency of a load. However, I still prefer to let the rifle and the target tell me which load is in the node, or 'sweet spot'. Testing loads at distance, on a viewable target, to confirm which prints the least vertical spread is what I use to make a final judgement on. The target don't lie, but a chrony can be a fickle tool...

Barrel harmonics have plenty enough to do about accuracy potential, and being in the 'node' of a barrel's oscillation could make a higher ES load actually be MORE accurate/repeatable than a single digit ES load that falls outside that 'node'. If the larger velocity spread is squarely within the 'node' of the barrel's harmonic 'sweet spot', you will see less vertical dispersion than any load outside that 'sweet spot', regardless of what your chrony is tellin' you...
Just sayin', don't put all your LR eggs in the low ES basket! Prove it on target to make sure those sweet lookin' ES #s translate to miniscule vertical spread in your LR group. After all, that's the whole point!!

Getting back to the OP's original question, he is right to be concerned with getting ES numbers as low as possible. For long range shooting, accuracy and low ES are both required. Having said that, you are better off having a rifle that shoots .5 to 1.0 MOA with low ES, than a rifle that shoots like a benchrest rifle in the .1s or .2s with high ES. Gravity is an undeniable factor on a bullet heading towards a target at 1000 yards or further...

As far as the neck turning, I can only comment on the testing I did with my rifles and ammo. I used my 7WSM, my long range 260, and a "normal" 270. All of the rifles except the 270 were already shooting under 1 MOA with decent ES numbers. Turning the necks down changed nothing. The brass I'm now using for the 260 is mixed with turned/unturned brass! By the time I started shooting the 30s and 338s, I knew it was a step I didn't need to take for LR ammo...

I know Rokslide is a gear oriented forum, so I wouldn't want to tell anyone that they shouldn't try turning their necks, but I will say that it made no difference for me or my rifles. IMO, you would be better off investing in a quality chrono like a MagnetoSpeed or Oehler, so the numbers you get from the muzzle are reliable. Truing your drops is an important step in long range shooting, but faulty velocity numbers can and should be avoided.

In the end, KMD sums it up quite well with "the proof is in the pudding". First round hits on targets at long range are that proof...

 

[Broz]

A priceless response Sam. In the name of avoiding conflict, remaining positive and supporting the lost art of actually shooting when it can be replaced with computer programmed responses on the internet.

Thanks
Jeff