223 Projectile, High B.C., Short BTO?

[ericwh]

Just got a 20" Tikka CTR in .223R. 1:8 twist. It has loads of room in the magazine but a short throat. I don't really want to change the throat as I believe that would take me out of "factory" class at local competitions.

I'm looking for a bullet that can stay supersonic to 1000y at 800' elevation and protrudes into the case as little as possible.

What target projectiles should I consider? I was considering the 80gr Sierra MK or Berger VLD but worried about secant ogive and "finnicky seating depth"... Maybe the Berger 82gr Boat Tail [discontinued]?

Any other suggestions? Hopefully something cheaper?

 

[Lawnboi]

My tikka 223 also has a fairly short throat. I’m running 75 eldm at 2.4”, I see no pressure even with a highly compressed load. 2900fps is the most I got out of em, node at 2800

Iv got a bunch of 77tmk to work up next.

I think your going to have a hard time fulfilling your needs without more barrel, or throat modification.

What does that 223 ctr mag allow for coal?

 

[Wrench]

I've not run them into anything at 1000, but I killed two coyotes at 850 with the rdf from my 223ai. Worth a look.

 

[wind gypsy]

My tikka 223 also has a fairly short throat. I’m running 75 eldm at 2.4”, I see no pressure even with a highly compressed load. 2900fps is the most I got out of em, node at 2800

Iv got a bunch of 77tmk to work up next.

I think your going to have a hard time fulfilling your needs without more barrel, or throat modification.

What does that 223 ctr mag allow for coal?

CTR mag allows a little over 2.5”

Bummer about the throat, I was planning on buying one but told myself I’d sell some stuff first..

 

[ericwh]

My tikka 223 also has a fairly short throat. I’m running 75 eldm at 2.4”, I see no pressure even with a highly compressed load. 2900fps is the most I got out of em, node at 2800

Iv got a bunch of 77tmk to work up next.

I think your going to have a hard time fulfilling your needs without more barrel, or throat modification.

What does that 223 ctr mag allow for coal?

What is your CBTO with the 75 ELDM at 2.4"? Or all the dimensions on that 75 eld-m if you could (boat tail, BTO, OAL).

According to one calculator the 77tmk and the 80.5 berger are pretty comparable, and if I get them to 2700fps they will stay supersonic to 1000. But I'm still using G1...

EDIT: I ran the Berger using G7 and it was a little slower but still supersonic at 1000.

 

[ericwh]

Bummer about the throat, I was planning on buying one but told myself I’d sell some stuff first..

Yes. I like the gun, ecstatic I was finally able to get one in left handed, but was bummed by the throat. For 55gr v-max and 77gr SMK, with the current throat, I was looking at seating barely above what I've been using for PMAGS :/

 

[Lawnboi]

What is your CBTO with the 75 ELDM at 2.4"? Or all the dimensions on that 75 eld-m if you could (boat tail, BTO, OAL).

According to one calculator the 77tmk and the 80.5 berger are pretty comparable, and if I get them to 2700fps they will stay supersonic to 1000. But I'm still using G1...

EDIT: I ran the Berger using G7 and it was a little slower but still supersonic at 1000.

Im in the process of moving so it will be a it before I get you any info. The 75 eldm is a long sleek bullet, and that 2.4 was ~10k off the lands

 

[Lawnboi]

What is your CBTO with the 75 ELDM at 2.4"? Or all the dimensions on that 75 eld-m if you could (boat tail, BTO, OAL).

According to one calculator the 77tmk and the 80.5 berger are pretty comparable, and if I get them to 2700fps they will stay supersonic to 1000. But I'm still using G1...

EDIT: I ran the Berger using G7 and it was a little slower but still supersonic at 1000.

Here is the load I ended up with. Don’t have exact bullet measurements as the bullets are packed away. I’m working with 77tmk right now for hunting season.

The 77tmk has a much shorter nose. And much longer bearing surface area. Might be worth a try if you can find some in stock.

 

[Lawnboi]

Left to right. 77tmk .020 off, 75eldm .010 off, 75bthp .020 off

The 77 has a pretty short nose.

I’m fairly compressed with all these rounds at their length. Wish I had a little more throat as Iv got 2.6” in the mag. Iv worked up and not hit pressure with a charge of varget so tight I leave rings on the bullets.

I couldn’t see trying anything longer in this gun, I just don’t think I’ll have enough case left for powder once I seat the bullet to be worth it.

 

[ericwh]

Thanks. I actually just tried non-tipped 77smk as I had some on hand. They were ok. I started getting some primer flow at 24.3gr Varget which was right around 2725 fps. They also sounded noticeably different than the lower charges and put 3 in the same hole.... Velocity was more consistent at 23.7gr though.

I'm hoping I can seat one of the 80gr bullets (or a 75gr eld-m) longer, & with less bearing surface maybe I can get them happy above 2700. Looked at the local store and a fair bit online but couldn't find any 75 eld-m.

 

[ericwh]

Sierra 77 and 80:

 

[Lawnboi]

Thanks. I actually just tried non-tipped 77smk as I had some on hand. They were ok. I started getting some primer flow at 24.3gr Varget which was right around 2725 fps. They also sounded noticeably different than the lower charges and put 3 in the same hole.... Velocity was more consistent at 23.7gr though.

I'm hoping I can seat one of the 80gr bullets (or a 75gr eld-m) longer, & with less bearing surface maybe I can get them happy above 2700. Looked at the local store and a fair bit online but couldn't find any 75 eld-m.

I added a bit more above.

75 eldm have been tough to find, but I think if your gun will shoot them they will give you exactly what you want, decent velocity and a good BC.

If you can’t find eldm, the tmk have been easier to find. And you can find them in 500 packs. I had a few different lots of 75 eld where I had to adjust to maintain the same CBTO, havnt been able to find them in anything but a 100 pack.

I can’t really comment how either does in the transonic range your looking to push them in. I havnt shot them much past 600, after 600 spotting hits and misses becomes pretty tough with those small bullets

 

[ericwh]

Left to right...
Sierra 80gr mk, Sierra 77gr mk, Berger 80.5gr Fullbore target

Bullet base to ogive:
0.555, 0.587, 0.604



The tips on the 77gr Sierra and 80.5gr Berger are mich more open than the 80gr Sierra. The tip on the berger is much more square/uniform/consistent than either of the sierras.

 

[dla]

Just a side note: You can load out to ~2.29" or so using metal mags. I use ASC stainless 5 rounders for hunting.

 

[Lawnboi]

Curious what you get for speed out of the berger

 

[ericwh]

The 80 grains are looking pretty good. This is the Sierra ~.015" off the Tikka CTR lands, next to a Hornady 75gr BTHP loaded to 2.26" overall for PMags.

Now that all manners of hunting seasons are in this may be on hold... but I will update here whenever I get to testing.

 

[ericwh]

So I loaded some test loads with the 80gr smk and they don't fit in my 223 ammo boxes (berry's boxes I think).

Does anyone make an extra tall box that I haven't been able to find?

 

[wind gypsy]

interested to see how the 80 grain SMKs shoot!

 

[ericwh]

Here's what I've got so far. All shot through a suppressor with bipod and rear bag at 100y. ID of the black circle is 1".

Both bullets seated with approx .015" jump.

 

[ericwh]