A customer asked me to mount and zero a scope. Then shoot both kinds of ammo, to see which one the rifle liked the best. And asked that I chronograph the ammo. Test barrels are 24". This rifle has a 22" barrel. 2" of shorter barrel would reduce the MV by 50 fps at most.

I don't doubt it at all. Everything in marketing is optimistic.

Yep, not surprised.

Would be interesting to check again on a hot afternoon in August to see how temperature sensitive the ammo is.

The response I received from Hornady Support when asking about the load and my intention to use it in my Winchester Model 70 with a Leupold CDS scope...

Thank you for reaching out. The velocity on the box is from a 24" SAAMI spec barrel which is an industry standard. My recommendation would be to shoot your rifle on a chronograph to get the most accurate velocity data. Traditionally you will see about 25-50 FPS of velocity loss per 1" of barrel loss.

From MGM going from 27" down to 13" in 1" increments. There is an actual mv increase on some shorter lengths.
https://matchgrademachine.com/velocity-testing-thompson-center-barrels/

Hornady lied.

20 to 25 fps per inch is the real numbers.

I chopped my 7-08 McWhorter/hart barrel from 24 to 18" and added a suppressor. JG's numbers are very close to what I chrono'ed post chop.

Hornady.....the same company that brought us the melting tip farce, and an owner who demanded his employees get the unproven and deadly jab to keep their jobs. Screw them.

I can’t say this shocks me. Factory ammo is almost always materially lower than advertised.

I have found this to be the case as well. My last box of Hornady 300 PRC 225 eldm averaged 70 fps slower than the box velocity of a weak 2810 FPS. It had an ES of 42 fps.

I would be willing to bet that all their test chambers are SAAMI minimum speck to ensure safe ammo in all production guns (except Christensen of course) which is also netting them their velocity gains. They’re stated velocity is probably what they are getting.

I am not surprised. Anyone that has a chronograph and reloads knows velocity claims on factory ammunition is oftentimes ambitious. Published reloading data from most bullet manufacturers are very often quite ambitious as well though. High quality tight test barrels are usually the culprit. I have seen many bolt actions where the chamber was flexed enough during firing to cause a sticky blot lift by an overly optimistic reloader trying to match the advertised data published by a bullet manufacturer. Some to the extent of needing to step down on the bolt with a foot to extract the case and still not achieve the bullet manufacturers advertised velocity. Bullet manufacturers seem to play free and lose when it comes to velocity claims with their products.

Years ago I loaded for 2 identical Remington 700 in 7mmSTW with 26 inch barrels one had a very tight chamber, the other one had a very generously chamber. the tighter chamber was consistently 200fps faster with the same loads. Got them to the same velocity but accuracy was below that in that rifle/powder combination. The fast barrel beat the factory load box listed velocity by I think it was about 50fps. It has been close to 20 years.

I have a 17 Remington that is 200fps faster than what is one the box consistently.

Both rifles that are much 150 to 200fps faster than listed for loads and yes faster than factory loads list have very tight chambers. basically with them full length size the case on an RCBS FL die or the Redding die for the 17 and all you size is the neck a few thousandths.

Chamber/barrel internal dimensions can make a big difference.

The last box of Winchester ammo that I checked produced an average velocity of 2756 fps, which is 96 fps below the 2850 fps value given on the box. The Standard Deviation for a three shot group came out to be just under 15 fps, which I consider quite good for factory ammo. In any case, the velocity falls within the guidelines given earlier by Hornady for a 22-inch barrel.

When you think about it, the velocities given by ammo manufacturers are likely meant to offer consumers a relative number for purposes of comparison, somewhat like treadwear ratings on tires. However, much like tire ratings where testing criteria often varies, based on what I've read in some of the blogs, manufacturers don't always use the same test setup or barrel lengths when testing their ammo, nor do they include this number on their boxes. Not sure what guidelines SAAMI places on manufacturers to list for their ammo, or even if the organization is any position to do so.

Every rifle is a rule unto itself. Something I’ve seen first hand: Two identical rifles may shoot the same lot of ammunition, reloads or factory, an average velocity that differs over 100 fps between the two. Same make. Same caliber. Same specs. When somebody boasts about factory ammunition shooting right at the velocity printed on the box, it is out house luck.

This is true. Still, just like treadwear values, the velocity values given by manufacturers offer the consumer something they can use to make better purchase decisions.

just shoot through a damm chrono

Perhaps we should shift the discussion to who makes the most accurate chronograph and why. Personally, I'm not convinced spending a lot more gets you a much greater level of accuracy.

Not even 1 in 100 riflemen that only shoot factory ammunition own a chronograph.

Ive said many times how little I know about this stuff but I find this amazing. I do not doubt Smokey one little bit but the 100 fps swing is interesting.

No chronograph, no problem. Zero at 100. Then zero at 500 (or 400 or 600). Note the elevation used to get you there. Use a ballistic calculator to work backwards and determine your velocity.

Much like the cost of borescopes, the price of chronographs has dropped to the point where hunters might add one to their tool bag as easily as they might a set of torque screwdrivers. I mean, how often does a hunter need these? I purchased a chronograph simply to send Leupold a more realistic velocity value to use when creating my free, customized elevation turret (which I'll likely never use). Now that I own one, I can see it coming in handy to compare the Standard Deviation of different brands of factory ammo to see which ones perform best.

I have to believe relatively inexpensive chronographs are also becoming increasingly common with bow hunters looking for greater accuracy and performance from their equipment. Simply put, they take at least some of the guess work and trial and error out of the equation for both those who shoot a rifle and/or a bow.

Serious question for you guys that are dogging the manufacturer. What MV should they print on the box? They obviously cannot test every chamber/barrel combo on the planet.

They should print the truth.

I've spotted thousands of shots of factory ammo. 95% of the time, what is on the box is no where near what is the truth. 100 fps or greater, as a lie, should be criminal! There are three metroplex SWAT Sniper teams that use my range. They have to use factory ammo. They go through this same trouble every time they switch lot numbers. Re-zero, get all new DOPE. Even though the box was always labeled the same. One team saw over 200 fps less than what was printed on the box.

I've measured some of the fired brass. They are not running sloppy chambers. Rifles made by GA Precision as an example.

But, manufacturers trump up their velocities, almost always. And some bullet manufacturers trump up their Ballistic Coefficient.

I didn't have the chance to warn you. There are people who take someone else's brass, powder, primers, and bullets and make hundreds of rounds (at best) in a month or two, and yet somehow believe they know more than those who produce thousands of rounds in a single day.