Why high ES??

[007hunter]

Curious why I get such high ES? Load was .223 22 grains of X-Terminator with CCI small rifle primer. Shooting 55gr Norma Tipstrike in brand new Norma Match brass. Minimum was 2455 fps and max was 2739 fps. Same load using TAC was better but still 120fps difference.

Is it just a powder thing? Xterm just not great for 223? Or is it something I'm doing?

 

[LaHunter]

Could be powder or primers. Could be the new brass. Brass that has been fired in your gun and sized / prepped properly should give more consistency

 

[peterk123]

I've often wondered if you get more consistency with powders that fill the case and are almost compressed.

 

[Q_Sertorius]

How are the groups?

 

[Shooter Mike]

I had a similar experience with with unreasonable ES. Eventually figured out my powder thrower was the problem.

Throw a bunch of powder and verify it on a separate scale.


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[tx_shooter]

Curious why I get such high ES? Load was .223 22 grains of X-Terminator with CCI small rifle primer. Shooting 55gr Norma Tipstrike in brand new Norma Match brass. Minimum was 2455 fps and max was 2739 fps. Same load using TAC was better but still 120fps difference.

Is it just a powder thing? Xterm just not great for 223? Or is it something I'm doing?

It is going to take a lot more information than that to start identifying potential issues.

1) What powder scale are you using?
2) Case prep method? Same lots?
3) The extremes; are they one or two or a signifiant % of the shots?

 

[flyfisher117]

I have had new brass show wild inconsistencies like this. The next load cycle it was fine.

I have had a faulty scale cause this too.

 

[cottonant]

While there are many variables I start with what Eric Cortina says:

Small groups but high ES - adjust powder charge or change powder.

 

[Vern400]

I have a load with 4064 and 55 grain bullets that works fine in long barrels/ bolt gun. But then my M4 has an ES almost 150 ft per second. Incomplete ignition possible due to light bullet, and incomplete burn due to 16 inch barrel. Went to CFE223 and ES is 24.

 

[Karl B]

280fps screams chronograph to me.

 

[wind gypsy]

Depending on how powder was measured/dropped - that would be my first guess.

 

[Billogna]

That charge seems extremely light. Which low case fill will cause big velo swings due to inconsistent ignition.

 

[007hunter]

How are the groups?

Slightly over 1".

It is going to take a lot more information than that to start identifying potential issues.

1) What powder scale are you using?
2) Case prep method? Same lots?
3) The extremes; are they one or two or a signifiant % of the shots?

Scale is a RCBS digital. I hand measure every load.
No case prep here as it was new.
I'll have to pay closer attention next time around see.

That charge seems extremely light. Which low case fill will cause big velo swings due to inconsistent ignition.

Max in my book with X-term is 23.5.

I'm going to load up some more with a higher charge and see if that helps.


More data to add now: All new brass. Small sample size.

23.0 of TAC with 55gr Norma Tipstrike 120 ES
24.5 of CFE with 69 RMR HPBT 44 ES
23.5 of CFE with 77 HPBT 52 ES
23.0 TAC with 77 HPBT 105 ES
23.0 TAC with 70 RDF 49 ES
23.0 TAC with 73 ELDM 75 ES


After more reading it sounds like 223 is just inherently tough to get the ES tight?

 

[tx_shooter]

Slightly over 1".

Scale is a RCBS digital. I hand measure every load.
No case prep here as it was new.
I'll have to pay closer attention next time around see.

Max in my book with X-term is 23.5.

I'm going to load up some more with a higher charge and see if that helps.


More data to add now: All new brass. Small sample size.

23.0 of TAC with 55gr Norma Tipstrike 120 ES
24.5 of CFE with 69 RMR HPBT 44 ES
23.5 of CFE with 77 HPBT 52 ES
23.0 TAC with 77 HPBT 105 ES
23.0 TAC with 70 RDF 49 ES
23.0 TAC with 73 ELDM 75 ES


After more reading it sounds like 223 is just inherently tough to get the ES tight?

Slightly over 1 inch may not be unacceptable depending on the platform and sights.

For the RCBS scale; are you calibrating it before every use? I chased heads and tails for a while before I started calibrating my RCBS Chargemaster after powering it on each time. I noticed the reloads immediately got better.

Also static electricity can give variations on powder throws.

 

[Billogna]

Slightly over 1".

Scale is a RCBS digital. I hand measure every load.
No case prep here as it was new.
I'll have to pay closer attention next time around see.

Max in my book with X-term is 23.5.

I'm going to load up some more with a higher charge and see if that helps.


More data to add now: All new brass. Small sample size.

23.0 of TAC with 55gr Norma Tipstrike 120 ES
24.5 of CFE with 69 RMR HPBT 44 ES
23.5 of CFE with 77 HPBT 52 ES
23.0 TAC with 77 HPBT 105 ES
23.0 TAC with 70 RDF 49 ES
23.0 TAC with 73 ELDM 75 ES


After more reading it sounds like 223 is just inherently tough to get the ES tight?

I'll admit I'm not familiar with that powder (X-Terminator). Your velocities are low in the original post. The upper range of your velo 2739 was close to what it should be for that charge weight tho. Average velo for 55 gain bullets tends to be in the 3100-3200 fps. range. The only published data I've found for that bullet however was with Norma's own powders and the max charge weight listed was similar to the weights you're using. Other similar bullets ( 55 grn, flat based tipped varmint bullets) suggest a starting load of 22 grains of A 2230 (functionally identical to X Terminator) for a velo around 2800 fps. Revisit your loading process. Check your charge weights against a proven mechanical beam scale if you have one.

 

[Terrapin]

New brass (especially 223) gives me higher ES than brass has been fired in my chamber a couple of times. Partly due to variations in internal dimensions and partly due to inconsistent neck tension. It seems to decrease a bit if I run the brass through a FL sizing die or an expansion mandrel, but I still don’t trust new brass for anything more than plinking.


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[AndrewMT34]

Try running an expander mandrel through your brass prior to seating the bullet. It should get you consistent neck tension.

My 223 - 77tmk load generally has an ES under 20 fps for 10 shot groups. Prior to using the expander mandrel it was in the 40's-50s fps (or even higher).