How compressed can I go? TMK 69g .223?

[quikcolin]

Hey guys,

New reloader here. I’m building up some test loads using the following.

federal .223 brass (1.7450”)
CCI Sm Primers 450
Sierra Tipped Match King 69g bullets
Varget powder.
COAL is 2.260”

I just started to seat a bullet into my first, light charged bullet when I realized that I was compressing the powder quote a bit. Keep in mind this is the lights load (25.1g). The manual says that max load is 26.1, I planned to goto 25.9g. But after the first round I decided to stop and ask the question. Looking at my brass that’s filled with the different charges, the max charge I’m running 25.9g has Varget all the way upto the neck. See photo (the arrow indicates where it would be).

can I compress this Varget this much? Why would this low charge (as per manual) already be compressing?

please help.

 

[AIAW]

What is your OAL on those? That one in the picture looks like it’s seated a tad deep.

This is for a 5.56 or .223 chamber?

 

[quikcolin]

This is for .223, set to an COAL of 2.260”. Or were you asking what the length of the bullet is?

 

[AIAW]

This is for .223, set to an COAL of 2.260”. Or were you asking what the length of the bullet is?

Ok, so OAL to SAAMI spec.

Have you measured the distance to the lands for that barrel? You may be able to seat out further.

Typically cylindrical powders will compress a bit. Too much and you end up breaking the cylinders which alters the burn rate considerably, plus that whole pressure thing. There’s no set rule though. If you can’t fit the powder then you can’t fit it. Some will run lightly compressed and some heavy. Make sure to use a drop-tube for the powder charges if using a funnel.

Varget is good, but there are many other powders that would fit the .223/5.56 cartridge bullet weights also (Benchmark, H322, BL-C(2), TAC, IMR-4895.... etc, etc). Just an option - You might get a better case fill with a different choice.

 

[NighthawkCG]

What manual are you using? Does it have the TMK specifically listed at that OAL?

Others will know better, but you probably need to run a longer COAL with those. The TMK is around .982 vs .900.

Either that or use a different powder.

Keep digging for loads to compare to and start way low if needed and work up.

You can also try settling the powder a bit in the cases by tapping it. This can sometimes help it lay down better and not get crunched.

 

[quikcolin]

Sorry should have mentioned this is for an AR15. I have measured off the lands, but the mag won’t allow for longer than 2.260.

 

[quikcolin]

What manual are you using? Does it have the TMK specifically listed at that OAL?

Others will know better, but you probably need to run a longer COAL with those. The TMK is around .982 vs .900.

Either that or use a different powder.

Keep digging for loads to compare to and start way low if needed and work up.

You can also try settling the powder a bit in the cases by tapping it. This can sometimes help it lay down better and not get crunched.

I’m using the Sierra loading manual. It is the AR15 specific page and all test loads were done to 2.260

 

[Codiekfx400]

Get a old retired electric toothbrush and hold it against the outside of the brass after charging the powder. If you want max velocity switch to Benchmark or 8208xbr.

 

[quikcolin]

I think what I’ll do is use this Varget as another option with my Hornady VMax 55g bullets (which I had 1/2” groups with when using CFE223 powder).
buy something else to use with the 69g TMK. I know on another thread I started IMR has a powder that works really well too. But they all said Varget at 25g+ was amazing.... I just can’t get it to fit?

 

[Codiekfx400]

Hodgdon Benchmark will run those 55 vmaxes really well at 25 grains.

 

[Steel head]

Get a old retired electric toothbrush and hold it against the outside of the brass after charging the powder. If you want max velocity switch to Benchmark or 8208xbr.

this!
CFE223,and W748 are excellent with 69’s as well as BM and 8208.
Not a big fan of varget for AR loads, too bulky.

 

[quikcolin]

Honestly, upto date, nothing touches CFE223... it has out performed everything I’ve tested in a 223 format

 

[AIAW]

This is for .223, set to an COAL of 2.260”. Or were you asking what the length of the bullet is?

Sorry should have mentioned this is for an AR15. I have measured off the lands, but the mag won’t allow for longer than 2.260.

Just a FYI: If it's an AR then it's most likely a 5.56 chamber, not a .223 (unless it a Wylde). Different freebore between the two, among other differences. My response was based on my thinking it was a bolt-gun.

 

[NighthawkCG]

Honestly, upto date, nothing touches CFE223... it has out performed everything I’ve tested in a 223 format

I found CFE to work well, but shooting in a wide temp range, I thought it seemed a bit temp sensitive. May not have noticed it without chrono, but the differences were larger than I thought. I haven't really used it to load in bulk or shoot at long distance for that reason. That being said, it is not one of the 'extreme' powders so it is likely to show more sensitivity than others. YMMV.

 

[Nimothy]

I compress the shit out of 308 loads with varget and phenomenal consistency and accuracy. I know it’s a different caliber and I also run a little stiffer neck tension on those. But I’m a believer that varget loves compression. It’s a small shot group size and it’s a 18” rifle so I know it’s not super fast but here ya go!

 

[quikcolin]

Just a FYI: If it's an AR then it's most likely a 5.56 chamber, not a .223 (unless it a Wylde). Different freebore between the two, among other differences. My response was based on my thinking it was a bolt-gun.

Yeah it’s a .223 Wylde barrel

 

[AIAW]

Yeah it’s a .223 Wylde barrel

Good choice ?

 

[Ryridesmotox]

Go bat to the standard SMKs. I was using tipped bullets for a while thinking I wanted/needed the extra ballistics, but I had to seat off the lands a good deal further. Not to mention, some seating plugs can deform the meplat, plus I've gotten a box of them with weird deformed meplats anyway. I dunno, just a thought anyway, I like the 69smks in my AR... 1:8 twist 223wyld 18 incher. It shoots them as good as I can muster my ability.

 

[Snuby642]

The crunch of powder being compressed still makes me grit my teeth.

My books are accross town at the moment but, only 1 grain between listed minimum and max?

My sons 308 likes varget and running node before max is about .9gr under hornadys conservative max.
Vibration of the cases has the crunch down to a small amount with a 0.045 jump. (Testing that asap)

Our 5.56 ar's didn't like varget and went to cfe223 which seems to like full case just short of compressed so far.

Something seems off with a measurement some place.
That looks like too much compression by my eyesight.