168gr vs 178gr In a Shorter Barrel

[JAYgs8163]

With a 1/11 twist rate I would be selecting the lighter 168 bullet and push it hard. 168's are magic with Varget for me out of my 10 twist 24" as are the 178's, but the 178's out of my 20" 11 twist didn't perform to my liking at longer ranges.

 

[rustyshackleford]

Just shoot them both and see if the gun prefers one or the other. May make the quandary real simple real quick. If they both shoot great work up a max load with one and you can estimate the velocity with the other using the formula in the attached image. From there plug in the Litz G7 values or go to hornady's page and use the G7 from the BC page. Hornady tells you on that page they use inflated numbers for marketing on their packaging so use the ones on the BC page. That'll tell you what you want to know.

Using RL-15 I got a 195 TMK up to 2550 from a 20 inch barrel so I think you'll get plenty out of a 20 with those bullets

 

[Tyler Kee]

I went through this with my 20" 308 too. 175s+ all the way. Much better BC and every little bit helps in the 308. They drop a bit more, but they do much better in the wind. <400 yards or whatever, run whatever makes you feel good. Beyond that, the 175+ will kill the 168 in the wind.

The way to validate this is to put a real slow 175 load in your calc. FGGM 175 Sierras run ~2650 fps out of my 20" Take it down to 2550 or something. And then see how fast you have to push a 168 to beat it in the wind. It should be about 2700 fps. Energy will be mostly identical. Run it up to 2650 - a real spicy load. You'd have to push the 168 to something absurd to beat it.

Slow is smooth. Smooth is fast. Good luck!

 

[rustyshackleford]

I went through this with my 20" 308 too. 175s+ all the way. Much better BC and every little bit helps in the 308. They drop a bit more, but they do much better in the wind. <400 yards or whatever, run whatever makes you feel good. Beyond that, the 175+ will kill the 168 in the wind.

The way to validate this is to put a real slow 175 load in your calc. FGGM 175 Sierras run ~2650 fps out of my 20" Take it down to 2550 or something. And then see how fast you have to push a 168 to beat it in the wind. It should be about 2700 fps. Energy will be mostly identical. Run it up to 2650 - a real spicy load. You'd have to push the 168 to something absurd to beat it.

Slow is smooth. Smooth is fast. Good luck!

The 168 and 178 ELD's have a far better form factor than the older SMK's. Just look at Sierras own TMK's. The 168 TMK and probably the new 169 smk eat the 175 SMK alive so that comparison doesn't really hold true anymore.

 

[Tyler Kee]

The 168 and 178 ELD's have a far better form factor than the older SMK's. Just look at Sierras own TMK's. The 168 TMK and probably the new 169 smk eat the 175 SMK alive so that comparison doesn't really hold true anymore.

100% agree - the core concept of heavier bullet/better BC at slower MV holds. A 178 ELD is gonna be better in the wind than a 168 ELD unless velocity gets pushed hard.

 

[Idaho Lefty]

Using the 168's is,.. a MOOT Point,.. as he doesn't have any,.. READ Post #7
The 178's,.. should work,.. FINE !
HOPEFULLY, .. RedRanger, HAS,.. a 1-10 Twist Barrel !

 

[Josh06]

So how I'd want to go about this, is test shots over a Chrono, get an average speed, and check to see if I've got the velocity on the bullet at whatever range using a ballistic calculator under various conditions, is that about right?

I've currently got IMR 4064 stockpiled, and with what I'm reading, I actually want a faster burning powder, but that's gonna be a bit difficult. I've got 178 gr ELD-Ms on hand, but not the 168s.

I've got 278 168 A-MAXs to sell/trade.

 

[rustyshackleford]

100% agree - the core concept of heavier bullet/better BC at slower MV holds. A 178 ELD is gonna be better in the wind than a 168 ELD unless velocity gets pushed hard.

Agree most of the time. Some occasions bullet design can make the difference and MFG's do weird things, and sometimes heavier doesn't mean higher BC.

 

[JAYgs8163]

Using the 168's is,.. a MOOT Point,.. as he doesn't have any,.. READ Post #7
The 178's,.. should work,.. FINE !
HOPEFULLY, .. RedRanger, HAS,.. a 1-10 Twist Barrel !

He has a 11 twist. I ran the 178's in my 11 twist 20" Krieger and they didn't stabilize at longer ranges. They run perfect in my 10 twist though. 168s are excellent in my 11 twist.

 

[Idaho Lefty]

See that, now,.. it's on the 1st Line , 1st post !
MISSED IT ! ,.. yikes,.. I'm gettin',.. old !
Time to find some, 168's then ! Josh at, Post 21 HAS,. some,.. A-Maxes !

He has a 11 twist. I ran the 178's in my 11 twist 20" Krieger and they didn't stabilize at longer ranges. They run perfect in my 10 twist though. 168s are excellent in my 11 twist.

 

[xsn10s]

As a side note my 1-12" PSS ran Berger 175gr VLD's really well.

 

[Idaho Lefty]

So how I'd want to go about this, is test shots over a Chrono, get an average speed, and check to see if I've got the velocity on the bullet at whatever range using a ballistic calculator under various conditions, is that about right?

I've currently got IMR 4064 stockpiled, and with what I'm reading, I actually want a faster burning powder, but that's gonna be a bit difficult. I've got 178 gr ELD-Ms on hand, but not the 168s.

On youTube ( Barbour Creek ) You can see, a 140 grain ELD-M's "performance" ( wound channel ) and penetration at, 500 yards,.. Impressive,.. I'd sure Hunt with, them !

 

[Swinehunt74]

I haven't loaded any up yet, I'll be loading and testing this weekend

Load with what you have and see what the gun will do. Start at medium charge from reloading manual, I like Speer. Just go online [for load data] and load to 2.825 OAL. That seems to be the magic length for Hornady bullets. Use what u have and let us know.....

I haven't loaded any up yet, I'll be loading and testing this weekend

 

[RedRanger328]

Hey guys, thanks for the replies!

I think my 41.7gr load might be the ticket, there's an errant shot there because the guys next to me suddenly started rattling off rounds in a mag dump as I was pulling the trigger.

I did 5 groups from 40.5-42 gr and then did single pressure load tests up to 43.2gr. 43.2 was the point I was getting pressure warnings on the brass and a bit flattened primers.

I loaded up another set of groups to test at 41.7 (to confirm), 42.5, and 43.1 just to see if it could shrink.

We forgot the Chrono, so that stinks, but the Hornady book says 41.7 should be pushing about 2550, I think.