52gr ELD-M twist rate - reality check needed

[JustinP]

Gents

Have a 223AI in a 14” twist that won’t stabilise any projectiles north of 50gr. I haven’t actually measured the twist rate to confirm but suspect it is a little slower than that.

I’m pulling the barrel and will be replacing with either a 12” or 9” twist. I intend to utilise the 52gr ELD-M for varmint shooting out to 500m (on a good day). My calculations put the 52gr at just under a 1.5 on Miller stability scale coming out of a 12” and 2.4 in a 9”. Muzzle velocity 3600ish.

Not keen on over-spinning these but think the 12” may be a tad slow? Am leaning towards the 9” but happy to be schooled.

Cheers, Justin

 

[Zero333]

I shoot 52 smk in a 9" twist 223rem 20"bbl

No problems. Shoots good.

 

[Shawnba67]

Calculate the bullet rpms.
MVx720÷twist rate.
most of the new high bc stuff i shoot wants to be about 288k rpm.( The couple i checked came out right at 288rpm for optimum stability)
3600x720÷9=288000rpm
3600x720÷12=216000rpm
I know which one i would buy, but the br crowd love to be spinning just enough.

 

[Evlshnngns]

My Savage 12fv 223 has a 9 twist, does well with 52-69gr. Got lucky. Before that I gambled on an r700 varmint with a 12 twist, just for the 52's, turned out to be a stinker. A 12 twist 223ai should launch the slippery 53 vmax as well.

 

[JustinP]

Thanks gentlemen. Greatly appreciated. @Shawnba67 - thanks for the twist rate formula. Didn’t know that one before today. I’ll be going 9” twist.

 

[NCVarhtr]

I have a few .223 AI rifles and shoot the 53 Gr V-Max and some of the 62 Gr bullets. the 10" twist works perfect for me. Complete stabilization but not over spun.

 

[SSL]

My .22-250 has a 1-14" twist and loves the 52-grain ELD-M (and before them, the A-MAX). Best bullet I have found for it. I sampled a few of my friend's 53-grain VMAX out of curiosity with very poor results...just like Hornady advises. I'm guessing that the velocity of my loads (3,850 fps) makes the difference in the ELD-Ms working well. Of course, if as you suspect, your barrel is even slower than 1-14" it would really make a difference.

 

[B23]

My 223AI loves the 53gr Vmax and has a 22in. Hart 1-9tw barrel. The 53gr Vmax is a fair bit slicker bullet than is the 52 ELD-M, which I'm not so sure just isn't the old 52gr A-max but with a new name. If the new 52gr ELD-M is the old 52gr Amax, they always shot very well in the 14tw 22-250's I shot them in.

I wouldn't worry to much about over spinning any bullet in a 223AI with a 9tw and it would be my first choice.

 

[JustinP]

Always thought it odd that the 53 V-Max had a higher BC than the 52 A-Max (now ELD-M). You’d think it was the other way around given the ‘usual’ varmint vs match bullet design scenario.

Couldn’t get the 53 V-Max to stabilise in my 14”-ish barrel for love nor money. They’d go ok at 100 and then go completely haywire shortly afterwards. Simply not moving or spinning fast enough..

 

[Brady W]

According to the calculations that we did here if you were going to run the 52s, which on one chart I found are .710 length, the minimum at 3000 fps is 14.336 twist, and 15.232 twist at 3400 fps. In order to get more stability, as noted, you would have to push them faster.

If that's not the correct length let me know and I can run the numbers again.

I agree with what was said above - I would make mine a 9 twist, then you'd be good up to a 75 grain bullet. If you wanted to shoot lighter, I guess you could go for a 1-12.

Good luck,

Brady W
Bartlein Barrels

 

[moorepower]

My 1-12 Rem 700 will shoot both 52 Amax and 53 Vmax. IF I was building a .223 it would be a 1-9. I love the 1-12 as it lets me shoot the 50SX which I think is the most explosive bullet I have ever shot.

 

[JustinP]

According to the calculations that we did here if you were going to run the 52s, which on one chart I found are .710 length, the minimum at 3000 fps is 14.336 twist, and 15.232 twist at 3400 fps. In order to get more stability, as noted, you would have to push them faster.

If that's not the correct length let me know and I can run the numbers again.

I agree with what was said above - I would make mine a 9 twist, then you'd be good up to a 75 grain bullet. If you wanted to shoot lighter, I guess you could go for a 1-12.

Good luck,

Brady W
Bartlein Barrels

Thanks Brady - appreciated.

I was working off a .796 length for the 52 ELD-M, per the JBM Ballistics bullet length library: https://www.jbmballistics.com/ballistics/lengths/lengths.shtml#Hornady

Looks like this bullet is about .004 shorter (or thereabouts) than the old 52 A-Max, if the JBM data holds true

That all stated, the 9” twist is still the one...

Cheers, Justin

 

[B23]

Per QL the 52gr ELD-M is .769 long with a G1 BC of .247, the old 52gr A-max was .797 w/G1 BC .247, and the 53gr Vmax is .829 w/G1 BC .290

If you're going to spin on a 9tw, I'd skip right past the 52 grainers and go right to the 53gr Vmax.

 

[moorepower]

Per QL the 52gr ELD-M is .769 long with a G1 BC of .247, the old 52gr A-max was .797 w/G1 BC .247, and the 53gr Vmax is .829 w/G1 BC .290

If you're going to spin on a 9tw, I'd skip right past the 52 grainers and go right to the 53gr Vmax.

I have a close friend at hornady, and the only difference is the heat shield tip. I do agree with the 53Vmax being the way to go, and that's what I use in both of my 1-12's and a 1-9 with very good success