Home Forums Reloading Varmint Rifles Sub sonic .223

Up checking to see if I could catch the varmint ravaging my trees and got to wondering..

I was reading the BRS article about 223 twist, 55gn Vs 62 etc

One reference to weight and twist was that the original design was such that the fmj bullet would start to tumble (keyhole) when it hit something vs poking a pinhole. So it was designed to be just barely stable.

Then they got mission scope creep and wanted it to do sharpshooter work too. So the gave it a faster twist.

When loaded for subsonic do you get the tumble back with the faster twist?

Also, would you use small pistol primers since max pressures are estimated around 4,000 CUP and the cup thickness difference of small pistol vs small rifle is something like 0.002-0.005"?

As I understand ballistics and terminal performance the tumble is a product of bullet design-spire point fnj versus round point of flat melt...which both go through on a pretty straight line...the pointy bullets in 'solid' configuration don't tend to do that.

And for those kind of pressures, I would think a small pistol primer would be fine.

From what read it seemed the bullet wouldnt tumble until it t hit something.
Anyway
I found a reference to an equation for the relationship between velocity, twist rate, bullet length....
I should probably ask Mathman about it since the source was someone referring to another article..but it still didn't touch on stability.

Funny thing is I remember from long ago hearing the story I read about the 223 but for .45.
But maybe that is just military ammunition design.

4 grains of Blue Dot small pistol primer

or 3 grains of Tite Group....small pistol primer..

can only verify these in a bolt action...

SF .........

U using a filler in the case for those loads

SF NEVER uses fillers and either powder is not position sensitive...especially in a 223 case... at least not big enough
may need filler in a bigger case.. but then again since I don't use filler, I'd use a smaller case...

picked up a 17 Fireball barrel not long ago... I'm looking to see what a 17 Fireball case and a charge of 3 or 4 grains of Blue Dot will end up yielding....got some of those discount priced 25 HPs from Midway that Ingwe posted us on....like 2000 of them...

20 Fireball is where it's at (Vartarg)

Them dammm 17's are to small for my fat fingers

I have a high mileage 20 PT barrel at Pac-Nor right now....should end up at 23.5"

Gonna rechamber to 20 VT....I currently have a 20 VT (high mileage) running now since 2006

They are also building me a new 20 PT barrel.......16 week wait.....

28"...Salvage large shank...full cylinder pipe.....10 twist/3 groove........

Another 18# dog gun.......I don't carry it far.....from the Toyota.........

Tikka, thought you were varminting out of a Lexus SUV nowadays...

I was thinking about doing a 17 Rem, trying to decide on a Howa Mini Action, or a Model 70 Featherweight...
or maybe a Ruger 77.. going to be a walking varminter rig...

need one like a hole in the head... but someone told me recently I must have a hole in my head...
so I thought, what the hell not...

Thanks for the loads Seafire.

A side question
I have some once fired FC 223 Rem.
Some has blue sealant and circle spaced at 120 degrees.
FC circle Rem Circle 223 circle (going clockwise)
Others are unsealed with no circles.

Do the circles indicate something?
Such as military and crimped?

I know Olin seals (red) their 9mm fun box, but it is not crimped.

Old Man, that is just a sealant they put on the primer.. nothing to worry about...

when reloading... remove the primer and it will accept another with no issues...

Thanks again. There was a press mark (the natural light is better today) around the primer, but after recapping and sizing hand spinning a counterink; then 5/16" flat head; then t-25 bit did a nice job of cleaning it up. (3/16 flat head & t-30 work nicely for large primers)
Tested by pressing in a spent primer in a few.
No problem
Thanks again.

Bit of a low trajectory
.

I don't know.... something like that I consider that load being for duty at 50 yds or so...

1000 to 1100 fps MV....

squirrels or other varmints in the yard for instance...

I have used 5.4gr of Trailboss under 55gr Ballistic tips. It's very quiet, but wont cycle in an AR without some addition efforts. I tried 75gr Hornady HPBT with 5.7gr as well. Fun without much noise.

It works fine. Thanks for the reference points.
Real quiet.
Just need to adapt I suppose.
Need too think about where to set things to index for fast and slow.
Maybe playing with JDM is in the cards.
Glad to test before I catch the tree eaters in action.