Fireforming Win 7.62x39 brass and CFE 123SST groups

[45r]

Loaded some win 7.62x39 brass under sierra 85hp's with 29.3 grains 2230.
They went into .710 inch at 100 with a 2825 fps average.
Loaded 123sst's over 31.5 CFE at 2.25 in hornady brass and got .810 5 shot group average at 2474 fps and 38 fps ES.
7 shot group went .910.
Most accurate group is still 85 grain sierras with H-322 at .610 5 shot group.
Going to try some 95 grain V-maxs when they come in.
The upper seems to be breaking in pretty good.

[LRRPF52]

Very nice results indeed, including fire-forming loads.

What barrel make and length do you have again?

[45r]

I have one of the 18 inch Liberty barrels from the GB.
Mine is shooting well.
I seated short around 30 thou in the beginning and cleaned the barrel every 5 to 10 rounds with JB's,hoppes #9,etc.
I used a .243 nylon brush with a JB embedded patch over it on a pistol rod with a lot of brushing and it smoothed the throat out.
I cleaned the barrel with a rifle rod and #9 after that.
I can seat the 123 sst's to 2.25 now.
Now that it's broke in I'll use Barnes copper solvent to clean barrel followed by montana extreme refined bore oil.
I'll use JB's every 100 rounds or so now.
I got some IMI brass to ready to fireform with 28.6 2230 and the 85 grain sierras.
I'm hoping the 95 grain V-max shoots good.
Then I'll have 3 bullets to chose from.
I'm wanting to get a Lilja,Krieger,or bartlein barrel now.

[jose]

Does that compress the CFE?
Thanks

[45r]

I tap the brass until the powder settles down as far as it will go.
It doesn't seem to be compressed.
My next CFE load with the 123sst's I'm going to seat at factory length of 2.245 and use 31.4 grains CFE and use a sonic toothbrush to settle the powder.
The rapid vibration from the back of the old brush touching the brass settles the powder fast.
The accuracy was good from the last load but I'd like to bring the ES down for long range shooting.
It doesn't matter for shots under 300 where most game it taken though.

[explorecaves]

This was a good read if you want to save those bullets…. http://bulletin.accurateshooter.com/...thout-bullets/

[rasp65]

I wouldn't recommend it for a gas gun as the cream of wheat leaves a thick layer of carbon in the barrel. I did it to fire-form for a couple of single shots I was reloading for so I didn't have to worry about the gas system. It took a lot of scrubbing to get the gunk out.

[45r]

I locktited my gas block so I can't do the cream o wheat method.
I don't have many brass to fireform.
I just wanted to know what works if brass becomes hard to get.
I shot some more 123 sst's again today with a crimp this time to see if it would lower ES.
31.4 grains CFE shot 1.6 inch but ES was only 10 fps with COL of 2.245.
It averaged 2474 fps.
It was around 12 degrees and I couldn't get comfortable and my hands were freezing from digging brass out of snow after each shot.
I warmed up my hands and shot some loaded up to 31.8 grains CFE and got 1 inch with the same COL of 2.245 and the ES was 22 fps.
It averaged 2504 fps and I had to settle the powder down to get it in without compressing too much.
There was a 30 fps jump in velocity so pressure is probably still low enough but can't go higher due to compression.
I think I'm going to settle on 31.5 grains CFE under the 123 sst's loaded to 2.250 and apply a light crimp.
It averages 2474 also but shot under an inch.