7mm Hornady 175ELD-x vs 180ELD-m

[BrienM]

I am curious why the 175 requires an 8.5" twist against the 180 seemingly fine with a 9".. I ran the numbers in strelok and it agrees. The 175gr bullet shows up shorter but i have no experience with either one.. I am looking at them for whitetail deer slugs out to midrange (less than 750yards)
thanks
Brien

 

[clcustom1911]

175 ELDx's run fine and dandy through my 9.5tw Tikka. Stupid accuracy with those bullets out to 600.... first time I made a bunch with a pet load I zero at 100, chrono a couple to get general velocity idea, plug that into my calc. Had steel at 600, make elevation adjustment, take aim, BOOM-TING!

 

[deersniper]

Is the 162amax considered a dinosaur now? Sitting on a pile of black hills loaded with that lol

 

[kyzim311]

What cartridge and elevation? Velocity and air density are also factors in twist rate needed. You will likely be fine with 1:9 for the 175, but the 175 has a thicker jacket so that might be why they recommend a faster twist.

 

[BrienM]

I’m leaning back towards 7mm rem mag. Elevation is 600’ ish

 

[kyzim311]

I’m leaning back towards 7mm rem mag. Elevation is 600’ ish

You should be fine. 1.5 or above is best, but the velocity I used is not breaking any records with 7 rem mag either. This is using Hornady's 4dof calculator on their website, gives stability for any bullet in that library.

 

[BrienM]

I’m not convinced I’ll shoot the hornady. I was more curious why they recommend that much difference in twists between those two slugs.. they have a really good bc though.. the numbers look good. How are the 175eld-x working on whitetail?

 

[Longshot284]

Hornady recommends an 8” twist for the 180 ELD-M. Their recommendations appear to be more of a recommendation for guaranteed dynamic stability at sub-zero temps at 0 ft above sea level not necessarily a recommendation for optimal twist. I’m sure both of them are fine in a 9” twist in the right environment you’d just lose a little BC. For what it’s worth I’ve shot a a whitetail with the 180 and a Muley with the 175. Neither of them super far, sub 400 yds, from a 7 SAUM at 2750fps. Both animals fell in their tracks.
Also of note - Hornady’s 4dof calculates stability based off the exact physical model of the project. Most every other calculator assumes each bullet has the same mass distribution and density. So jacket thickness/taper and polymer tips can cause a slightly inaccurate Sg number with traditional Miller formula calculations.

 

[BrienM]

Thanks for clearing that up... I'm not sure how I missed that!!