Hornady SX Speed Limit?

R

RiverRider

New member
I have looked around at Hornady's website and have found no official word as to the velocity limitations on the 50-Grain SX. I'm considering using them in my old 77V which I believe has a 1:14 twist, but if I have to keep them under 3600 or 3700 fps, I'll just save the time and expense of the whole notion. Any first-hand experience out there?
 
I was thinking it was 3400 but you'd have to try it in YOUR rifle to find out. They might go faster in YOUR rifle than somebody else's. Do a simple ladder test, starting low, working up shooting 1 shot at a time in 1/2 gr increments until they go to pieces. Easy as pie and should only take 4-5 shots to know if it'll do it.
 
Originally Posted By: RiverRiderI have looked around at Hornady's website and have found no official word as to the velocity limitations on the 50-Grain SX. I'm considering using them in my old 77V which I believe has a 1:14 twist, but if I have to keep them under 3600 or 3700 fps, I'll just save the time and expense of the whole notion. Any first-hand experience out there?

I am pretty sure it is 3600, if your shooting a 22-250 don't bother. Been there done that.

Kind of cool though to watch them throw the jackets off for about 2 shots.
smile.gif


Get youself some v-max or Nosler BT and don't look back.
 
Yes, the V-Max works very well and I have a decent stock of BTs on hand. I have a real abundance of SXs though. They work well in my .223 so that's probably going to be the rifle that launches 'em if I can't push them to 3800 fps.
 
The limiting factor is the RPM not the speed.
In a 14" twist barrel there should be no problem loading them as fast as possible.

Jack
 
Jack is correct, velocity means nothing(almost). RPM is what destroys bullets.
That said, IIRC when I called them years ago, they told me the RPM limit was around 250,000 rpm. Obviously barrel smoothness plays a part in this...
12 or 14 twist is common in most(except Savage, & AR's) for 22-cal rifles.
 
I shot the 55 grain SX for years in a Ruger #1 .22-250 and a cousin shot them in a .220 Swift. Both were 1 in 14 barrels and they were loaded full power. Never had a problem. I tried them in a 1 in 9 .223 and they came apart, so twist is more of a factor than speed. They would come apart if they hit a weed in front of a groundhog though.
 
Thanks for all the responses. I guess I'll give it a try and see. I'm getting about 3900 with 50-grain V-Maxes and quite good accuracy when I do my part. I suppose it's possible the SXs could do even better. Ya never really know til ya try!
 
I tried the 50g sx's out of my savage predator hunter which is 1-12 twist. I had these loaded to shoot right around 3600 fps. I had some that didn't make it to the target, and others that were key holing. Switched to v-max's and all's well.
 
I used to shoot these out of a Savage 112J 222 Rem. They were deadly and accurate on groundhogs. I believe the twist on that gun was 1/12 never any trouble with them coming apart.
 
The Hornady SX and Sierra Blitz (NOT BlitzKings) were meant to be [designed] for circ. 3500 FPS maximum; both types are great groundhog killers at .222 and .223 velocities.

Both have worked great in those two calibers for me, are very accurate, and I still use them.
 
During the p.dog wars, I would shoot them in a custom 22 PPC at 3550 with a Hart barrel installed. At some point, the barrel would get hot and the bullet would start going POOF out in front of the muzzle, also if I kept the barrel cool, at some point the bullets would just disappear from barrel fouling.

Smoothness of your barrel and perhaps the throat in the chamber is of a major issue...trial and error will be fun to play with.
 
I looked all over Hornady's website and the only thing I found that even approaches answering the question was this:
Hornady Bullet Guide

V-MAX™ and Traditional Varmint
Rapid, explosive expansion.
Recommended muzzle velocity range: 2000 to 4000+ fps

"And traditional varmint" means SX to me.

I also submitted the question to them through one of the "contact us" inquiry forms.

No matter what the answer is, I realize that what should work in my rifle may not...I'll probably just have to try the SXs. I have some Ballistic Tips to try also and I expect them to be the top performer.
 
I used to shoot the 50's out or my bolt 223's with 12 & 14 twist and they worked great. My buddy tried them out of his AR and they came apart. Jack's right, it's not so much the velocity as it is the faster twist rifling.
 
Ducksoup:

Yes, the twist is an issue along with the velocity...the jackets are quite frangible...when those bullets debuted (70's?) sporting ARs did not exist much or perhaps at all.

But, in the 70s shooters knew the twist on a sporting .223 bolt action was 1x14 or 1x12 and Hornady and Sierra likely saw no need to mention twist.

Today, AR shooters want Vmax' or Nosler BTs anyway, and not the SX or Blitz.
 
The Sx's were some of the first that I reloaded for one of my 22-250 Savages with 1 in 12 twists. I also had to keep them under 3400 fps (chrono'd)to keep them from throwing thier jackets or tumbling.
 
FPS is MEANINGLESS WITHOUT A TWIST RATING FOR THAT SPEED!!!

Call them, but my notes from loading say around 230,000-250,000 RPM.

Since everyone keeps referencing speed, here is how you figure this out:

MV X 720/Twist Rate = RPM

so 3600fps * 720 / 9 twist = 288,000 RPM
 
Back
Top