223 single digit S.D.

[6fatrat]

I am having trouble getting single digit standard deviations in my 223 prone rifles, 5 shot strings.
I can easily do it with my 308's and 243's.
Steve Bair

 

[Dgd6mm]

I've been told many times from a few that getting single digits in a .223 is hard to achieve. I really haven't tried, but want to so I'm going to follow your thread and hope to learn some knowledge on this subject.

 

[shoot4fun]

I am having trouble getting single digit standard deviations in my 223 prone rifles, 5 shot strings.
I can easily do it with my 308's and 243's.
Steve Bair

This eludes me as well.
I have done primer testing and many different component combinations without success.
I have a Krieger 7.7 twist that gets fed 80 grain bullets and a Krieger 6.5 twist that is fed the 90 grain bullets. They both exhibit higher SD but usually only one round of a string will be the cause.
Not sure what powder you use but I have tried Varget, Shooter's World Precision and the new RL15.5 and all have shown about the same results for both velocity and, ultimately, SD.
Both are shooting well so I have chosen to try and forget about the anomaly.

 

[crowsnest2002]

I've been told many times from a few that getting single digits in a .223 is hard to achieve. I really haven't tried, but want to so I'm going to follow your thread and hope to learn some knowledge on this subject.

I'll be watching this as well.

 

[crowsnest2002]

I've been told many times from a few that getting single digits in a .223 is hard to achieve. I really haven't tried, but want to so I'm going to follow your thread and hope to learn some knowledge on this subject.

I'll be watching this as well.

I recall an article that was older. The article went through the tedious task of volume sorting brass, bullet measurements and sorting. It said about due to the capacity of the small case there is less room for deviation between each case.

 

[Dgd6mm]

I recall an article that was older. The article went through the tedious task of volume sorting brass, bullet measurements and sorting. It said about due to the capacity of the small case there is less room for deviation between each case.

This is about all I know in a nutshell.

 

[CharlieNC]

I just retired a fclass barrel that shot great on the target until throat erosion took over. SD was 10 the only time I checked velocity after a match where it performed well. If the target wasn't happy I might have used a Chrono to help diagnose problems, but would not chase it if otherwise satisfied.

 

[sfinn1]

Having shot the .223 in Service rifle and F Class, the Holy Grail in ES and SD is a tough one to accomplish. I think most shooters settle for the load that excels on target.
I believe the .223 may not have an ideal combustion chamber. Now, I have a question. Does one achieve better numbers with lighter bullets? Say. 52gr. compared to 90Gr.
A similar cartridge, the .222 was used in benchrest. Wonder if they had good numbers. I imagine chronographs were hard to come by back then and they also shot at shorter ranges.

Steve

 

[urbanrifleman]

Try hard jam.

Low Sd seems to follow less neck tension, or a lot more.

Less neck tension and very hard jam many times will low spreads. As it changes the pressure curve. I suspect you have varying neck tension.

Also, this seem silly but champfer your cases inside with a vld reamer.

 

[tomswede]

Did an experiment this fall. Using once fired Nammo cases from the same batch.
R15 powder, Rem 7 1/2 primers and Sierra 80’s.
Using regular dies my 10 shot SD was approx 20
The same load but with the cases body sized followed by a neck sizing in a Lee collet die got me down to 8.7.
A limited test but made me think that the neck tension was the key.

 

[urbanrifleman]

Did an experiment this fall. Using once fired Nammo cases from the same batch.
R15 powder, Rem 7 1/2 primers and Sierra 80’s.
Using regular dies my 10 shot SD was approx 20
The same load but with the cases body sized followed by a neck sizing in a Lee collet die got me down to 8.7.
A limited test but made me think that the neck tension was the key.

Same time post!!!

 

[dcali]

I’m not sure it’s possible to be honest. Nor do I really think it’s necessary. Wind becomes a problem before SD does. With smaller cases, you need to be more preciese with everything. That will get you close, but getting under 10 (with a legitimate sample size) consistently is tough.

 

[crowsnest2002]

Did an experiment this fall. Using once fired Nammo cases from the same batch.
R15 powder, Rem 7 1/2 primers and Sierra 80’s.
Using regular dies my 10 shot SD was approx 20
The same load but with the cases body sized followed by a neck sizing in a Lee collet die got me down to 8.7.
A limited test but made me think that the neck tension was the key.

I would say that annealing, and using method above would help control that neck tension. The brass is probably one of those variables we have little control over. I also guess, how far down this rabbit hole do you want to go? For me user error at my club matches doesn't warrant excessive control on those variables for me lol. I do like to read about different techniques so I can glean things that I might want to consider though. That is the enjoyable part of all of this.

 

[Rocketvapor]

Wind call errors and E.S. (minus any obvious fliers) are sort of equal with a wind call error of between 0.5mph and 1mph and an E.S. of 20fps at ranges up to a few hundred yards.
If you call a 5mph wind 4 or 6, wind matters. If you are good and call a 5 mph wind 4.5 or 5.5 then E.S. matters.
Try your favorite calculator with a good bullet, 80VLD, 2800 and 2820fps, 300 yards, and 5, 5.5 and 6 mph full value wind.

 

[gstewart]

It is doable, one needs to be careful with loading practices.

Recent velocity testing with VV N-135 with a LabRadar.

Date​

Temp​

Rifle​

Bullet​

Case​

Weight​

# rel.​

Grains​

Powder​

Primer​

Primer lot​

Jump​

Nb. shots​

Average​

ES​

SD​

2021-10-24​

10​

NesB1

Ber 85.5

Lapua​

96,1​

2​

23,2​

N-135​

CCI BR4​

+10​

10​

2873​

14​

4.5​

2021-10-24​

10​

NesB1

Ber 85.5

Lapua​

96,1​

2​

23,0​

N-135​

CCI BR4​

+10​

10​

2860​

16​

4.7​

2021-10-24​

10​

NesB1

Ber 85.5

Lapua​

96,1​

2​

22,8​

N-135​

CCI BR4​

+10​

9​

2848​

15​

4.1​

2021-10-24​

10​

NesB1

Ber 85.5

Lapua​

96,1​

2​

22,6​

N-135​

CCI BR4​

+10​

10​

2836​

17​

5.2​

 

[skeeljc]

The problem with the .223 Remington is the short neck. Most loads require the base of the bullet to pass through the neck/shoulder junction. That is the problem with the .223 Remington.

 

[karrarararararar]

The only time I've managed to get single digit SD's has been with Reloder 15.5

 

[CharlieNC]

It is doable, one needs to be careful with loading practices.

Recent velocity testing with VV N-135 with a LabRadar.

Date​

Temp​

Rifle​

Bullet​

Case​

Weight​

# rel.​

Grains​

Powder​

Primer​

Primer lot​

Jump​

Nb. shots​

Average​

ES​

SD​

2021-10-24​

10​

NesB1

Ber 85.5

Lapua​

96,1​

2​

23,2​

N-135​

CCI BR4​

+10​

10​

2873​

14​

4.5​

2021-10-24​

10​

NesB1

Ber 85.5

Lapua​

96,1​

2​

23,0​

N-135​

CCI BR4​

+10​

10​

2860​

16​

4.7​

2021-10-24​

10​

NesB1

Ber 85.5

Lapua​

96,1​

2​

22,8​

N-135​

CCI BR4​

+10​

9​

2848​

15​

4.1​

2021-10-24​

10​

NesB1

Ber 85.5

Lapua​

96,1​

2​

22,6​

N-135​

CCI BR4​

+10​

10​

2836​

17​

5.2​

Interestingly that 85.5 VLD is a bullet that I and shooting buddies have not been able to achieve comparable accuracy vs other Bergers.

 

[tomswede]

Wind call errors and E.S. (minus any obvious fliers) are sort of equal with a wind call error of between 0.5mph and 1mph and an E.S. of 20fps at ranges up to a few hundred yards.
If you call a 5mph wind 4 or 6, wind matters. If you are good and call a 5 mph wind 4.5 or 5.5 then E.S. matters.
Try your favorite calculator with a good bullet, 80VLD, 2800 and 2820fps, 300 yards, and 5, 5.5 and 6 mph full value wind.

The only reason I started looking at SD was that I felt I had a bit of vertical issues at 600. That combined with a bit of wind and 9’s come too often. At shorter ranges it’s not worth the trouble to try to get it down ( at least not for the events I shoot)

 

[shoot4fun]

The only time I've managed to get single digit SD's has been with Reloder 15.5

Are these numbers produced with 80 or 90 grain bullets?
I'm working up 223/90VLD loads with 15.5 now. It definitely has potential.
BTW, my barrel is 26" and wondering about barrel length used in your test.