Loading the 62gr SS-109

[Steve_P]

Hi All,

I have a bunch of 62gr Steel core projectiles that I have started loading for my AR.
I just wanted to see if anyone else out there has loads to compare?

I started with:

Mixed LC brass trimmed to 1.750
CCI#400 Small Rifle Primer
23.0gr H335
62gr FMJ-SC-BT projectile seated to 2.255"

I did use a Lee FCD.

These shot 2735 fps with standard deviation of 28 fps from my AR.
Cycles the action just fine. Grouped fairly well at 75yds, but i just want these for plinking anyways.

I think I am going to step it up to 23.5 and see how that works out as well.

Gun notes:
Rock River Arms 20" AR-15 Flattop. 5.56mm chamber. Chrome bore and chamber.

What is everyone (anyone?) else using for this projectile?

Thanks,
Steve

 

[EddieCoyle]

A SD of 28! Nice.

 

[Steve_P]

A SD of 28! Nice.

Thanks. I think it probably could have been lower. I did these full-progressive on my Lee Loadmaster, for which the powder measure isn't exactly dead-nuts every time. I saw about a +/- .2 gr spread over the 60rds that I loaded (yes, i did measure every one as it was my first batch setup). I also had slight OAL variations of about .005 each way. i guess the stars just alligned just right...

Steve

 

[Scrivener]

I prefer Accurate powder for .223; 2230 or Reloder 7 for the 55's; 2230 or 2520 for the 62 grain bullets.

I thought 2460, being between those powders, would be the magic propellant for both weights. For whatever reason, it did not work well for me with the 62 grainers.

 

[Steve_P]

I prefer Accurate powder for .223; 2230 or Reloder 7 for the 55's; 2230 or 2520 for the 62 grain bullets.

I thought 2460, being between those powders, would be the magic propellant for both weights. For whatever reason, it did not work well for me with the 62 grainers.

I have not had much luck with the reloader 7 in my AR. It was inconsistent in cycling the bolt completely in my rifle.

Steve

 

[Scrivener]

I have not had much luck with the reloader 7 in my AR. It was inconsistent in cycling the bolt completely in my rifle.

How odd. I've never encountered that.

 

[Steve_P]

Granted, I did not do alot of workup on my reloader 7 loads. I worked up to the max load in the Sierra manual for the 55gr, and they were not fully stroking the gun.

I switched to H335 and Varget, depending on application, and have never had a problem.

 

[bpm990d]

Granted, I did not do alot of workup on my reloader 7 loads. I worked up to the max load in the Sierra manual for the 55gr, and they were not fully stroking the gun.

I switched to H335 and Varget, depending on application, and have never had a problem.

Don't forget that the rifle they used is different than yours. Max load was max in their rifle.

B

 

[Steve_P]

Don't forget that the rifle they used is different than yours. Max load was max in their rifle.

B

Very True...
Steve

 

[rep308]

Rifle: Bushmaster 20" 1:9 twist
Bullet: IMI 62 gn ss109
Brass: IMI
Winchester small rifle
powder 27.1 gn Win 748
velocity: 3010 fps

same load with 14" barrel - about 220 fps less

 

[Devils Paintbrush]

I have been using 19.7 grains of IMR4198 for the SS-109 bullets. I chose that powder because I did not really want to use compressed charges.

Sorry, I do not have a chronometer to give a fps, but it does cycle my 16" Bushmaster with no issues. I have a friend with a SBR that will not cycle consistently using this load.

I am using a 1.750 trimmed case length with Winchester primers and seating the bullet to the cannelure

I had been loading using my Dillon 650. I wanted to load some rounds using Lake City brass for a CMP match and measured every load (after dispensing with the Dillon powder measure) and noticed that the powder charge varied by as much as .3 grains using the IMR4198. It is a stick powder, and is fine for target loads as far as I am concerned.

Using the Dillon powder measure (not measuring every time) using mixed brass, I was able to score a 417 on a CMP match using that load. I will be interested in the next match using all LC brass with every round measured for weight.