Home Forums Hunting & Shooting Africa Factory Ammo MV Surprise

Have a box of Swift's A-Frame 9.3x62mm factory ammo that I finally got around to capturing some MVs.

Their website says figure on a MV of ~2,400 fps from a 12-twist, 24" barrel. Mine is a 10-twist, 24" barrel.

Cool, I'm thinking I can expect MVs of somewhere's around ~2,350 - ~2,400 fps.

Nope. After first "warming up" the barrel firing 2 handloads (it was 39 degrees out), the 1st A-Frame round: 2,300, and the 2nd A-Frame round: 2,310. I stopped after that.

Either I have a seriously "slow" barrel, or Swift needs to update their website ammo specs page.

I pinged Swift to find out what gives...

I don't think that's uncommon. It's not unusual for factory ammo to chrono quite a bit slower than advertised, although some is pretty close to the listed velocity. I've had reasonable luck with Federal in that regard, although I load most of the ammo I shoot.

Yea, I've had Norma ammo be quite close to spec. I was expecting the same from Swift, but apparently, no cigar.

I'm betting at some point Swift changed their load and didn't get around to updating their website.

We'll see....

Figure the 9.3x62mm, like the 6.5x55mm, to be a "hand-load only" affair.

Once I've harvested enough PPU brass gettin' comfortable w/ the rifle (Ruger African), will start reloading Speer 270 gr. Hot-Cor's.

Followed by Hdy 286 gr. load development, put under 285-6 gr. Orynx and A-Frames.




GR

Not uncommon AT ALL. Recent factory offerings in calibers 375 WIN, 300 Savage, 308 WCF, 3006, etc, have ALL failed to come close to factory specs. The ONLY factory ammo that is up to published specs is Weatherby ammo

So, if I'm getting 3000 fps from leetle bullets in my ,257 Bobby I can advertise 3,400, right?

Arent most test barrels min SAAMI spec'ed? So they always seen to come up with higher speeds?

This is my first experience with factory ammo being a full 100 fps slower from equal length barrels (admittedly, I don't shoot a lot of factory ammo).

Fortunately, this was gift card ammo, so I hadn't laid out the big bucks for this stuff.

Waiting on a reply from Swift...

So you’re 40-100 fps slower than expected, but shooting at 39 deg, and you’re going to make big stink with the manufacturer? Seriously?

Do you write to Hornady, Nosler, Barnes, Hodgdon when your reloads don’t give the exact same velocity as published in the reloading manual?

That's not bad. I chrony'd some factory Hornady (35 Rem and 308 Win) for some friends while at the range, both 200 fps less than advertised.

I seriously doubt any animal you shoot with that ammo will know the difference.

Brian Pearce has often shown factory specs with actual velocity in Rifle or Handloader. Some are slower and some closely match stated velocity. I just checked some Federal 140g Blue box ammo out of my Barrett 6.5x55 with 24" barrel. The box states 2600 fps, but I got 2665 FPS average. This rifle shoots everything very well including these factory loads.

30 are more years ago it was rare to get anywhere near the stated velocity, but it is better these days. You are also using a different rifle than they were.

Not bad, 300 grains at 2300 will still lay a whop on something, takes me 25 inches of barrel and a stiff charge of RL-17 to get 2400 with 320gr woodleighs.

Why am I not shocked.

Thinking about it some more, that 286 grain SAF @ 2,300 MV is probably perfect for Cape Buffalo Cow culling.

Bust through, do the damage, and with a high degree of certainty the bullet won't exit.

What's not to like?

Did Swift reply to you?

Pretty much everything I chrono in 9.3x62 factory ammo is 100 to 200 fps slower than advertised. I think it's a combo of long throats and US companies being worried about old guns.

Nope.

I followed up with a data set for a string of 10 shots. But never heard back.

I know the chrony is correct - well known loads in 6.5 CM, .308, & .30-06 report spot-on.

I figure at some point their online info for nominal MV will just change without notice.

No-problemo....

I've had factory ammo from Norma and Geco actually chrony faster than nominal MV...

In 9.3x62? Or other calibers? Just looked up my notes. Norma 285gr factory loads ran at 2290 fps in my 24" barrel, so only about 75 fps slower than claimed, but still. Definitely possible my barrel has an extra extra long throat, but it seems that most people find that 9.3x62 factory ammo is slow.

Thanks,

I've sent them a couple emails and never heard back either.

Is it going to make a difference on the business end? I think you guys over-think much.

3300fps is no good, but 3500 Is? Really? That's the implication.

Shoot the stuff for drop and group, and that's all you really need.

My opinion is worth what you paid for it- pm me, and I'll send you an address to mail the check.

If +/-200 fps doesn't matter, why don't the ammo companies just advertise the lower and correct velocity?

So you believe in the "news" just as presented? By anyone.

Well, advertised MV does matter for prying money out of the pockets of those who over think it. Advertising always puts a rosy light on the stuff being sold. Expect and allow for it, unless it's too egregious. No one sells stuff by understatement. Usually. It's nice if approaches accuracy tho. As noted, they likely changed something and not the web site. Enough feedback and they probably will.

Plus, are you using the same barrel, throat, twist (not, from your post), etc. they are, under the same conditions?

Or you can load your own for your desired velocity in your rifle, under your conditions. Personally, I load for best (or acceptable, at least) accuracy with the components I am using, at the time I load. I don't own a chronograph, and have never used one. It would be an interesting data point, but that's about it for my use.


One of my scopes says "1 click =1/4" at 100, but in practice, 3 clicks equal an inch at 100. But it is repeatable......I can live with that.

Trust but verify/adapt for your own use?

Sometimes "good enough" is just that. Good luck with your quest.

Hornady Superformance factory 280 Remington ammunition with the 139gr SST loads run 2975 fps out of my 22" barrel. They're rated for 3090 fps.

The only factory ammo that I can recall hit advertised specs was some older 35 Remington 200gr core lokt ammo. It clocked 2150 fps from my short 18" barrel. It's rated for 2080 fps.

Bingo

Quoting las “ are you using the same barrel, throat, twist (not, from your post), etc. they are, under the same conditions? ”

Did the factory test in commercial rifles or in a pressure barrel? Lots of variables; increasing the number of variables increases the range of outcomes and the likelihood of velocities not matching the advertised.

las has listed some excellent solutions which ring true in my experience

“ Shoot the stuff for drop and group, and that's all you really need.

My opinion is worth what you paid for it- pm me, and I'll send you an address to mail the check. smile


Trust but verify/adapt for your own use?

Sometimes "good enough" is just that. Good luck with your quest.“

Is the standard temperatures for ammo manufacturers 59 degrees?. Shooting in temperatures 20 degrees colder than standard would cause a reduction in muzzle velocity. How much I do not know.

Jim

I’ll be surprised when a factory load EVER consistently clocks the speed they claim or higher. I automatically deducts 100fps from published velocities and I’m usually damn close.

I've recently been grabbing MVs of the PPU factory ammo offerings in both 9.3x62mm and .375 H&H. Actuals are surprisingly quite close to the published nominals.

In 9.3 the actual MV was a hair over the published nominal. All these were from a 24" barrel.

I've also experienced this from Norma 6.5 CM and .375 H7H ammo as well.

A 40-50 fps variation is not something to get worked up about.

Have you ever owned two rifles of the same chambering? You’ll find out pretty quick they vary a little and sometimes a lot.