Home Forums Hunting & Shooting Ask The Gunwriters True muzzle velocity of factory ammo?

Good day! I’m a long time reader from South Africa and decided that it was time to finally register on the fire. Is there perhaps a database that I can be referred to which gives true, tested MV figures of factory ammo? I am specifically interested in the Federal Premium .270win 150gr Partition load (code P270E) which is listed at 2830fps. Thanks for any pointers.

It used to be that MV on a box of ammo was usually pretty optomistic, but anymore, it tends to be a pretty good number for a 24" barreled rifle in my limited experience. I mainly reload and therefore shoot very little factory ammo. The little I have run over a chrony in the last ten years really surprised me how close it was to what it says on the box.

Thanks Miles. I don’t own a chrony and just haven’t got into the reloading thing yet, but I will at some point. I picked up three boxes of the above ammo and was just wondering what the real world MV would be. I think you have a point though as I did once fire a Winchester PP 150gr round through a friends chrony and it read 2834fps. This surprised me as the listed MV is 2850 and I only have a 22.5” barrel (Sako 85). I have no experience with the Federal loads however.

I recently ran two loads, both Federal Premium, over the chrono. Different bullets, but the same weight and same advertised velocity. From a 22" barrel, one was right on what the box said and the other was 100fps slower.

Thanks prm, that's interestng if a little inconsistent. Were any of those two a Partition, and if so, was it the quicker one?

In part, muzzle velocity of ammo depends on the firearm it is fired in. Each firearm is a constellation of variables so muzzle velocity of the same ammo will vary between firearms.

Yep, the only "true" muzzle velocity is the one from each rifle. Looking at a chart of results from other rifles won't tell you that.

Fair enough,thanks.

Anywhere from 25-50 fps difference between individual guns with the same length barrel is normal and I've seen 100+ fps. I've seen 20" barrels shoot faster than 22" barrels. Just because ammo is 100 fps slower than advertised doesn't mean the ammo makers claims are false. It could just be the individual rifle.

I shoot mostly hand loads, but my chronograph usually shows speeds pretty close to what the books say. Same with the few factory loads I've shot over it.

No, they were 200gr Trophy Bonded Tip and 200gr Trophy Copper. The copper was slower. Fired from same rifle on same day, no extreme temps, same magnetospeed chrono. In this example, it matched my experience of getting slower velocities out of E-Tips (a Trophy Copper is nearly identical to a Nosler E-Tip). VERY long bearing surface.

Two other factors in variation from specified velocity:

The Sporting Arms and Ammunition Manufacturers Institude (SAAMI), a group of mostly North American companies, agrees on certain specs for factory ammo, to make sure it works in all rifles. SAAMI's standards allow for plus or minus 90 fps for a particular lot's velocity in a standard test barrel.

Many if not most of the powders used in factory ammunition are not particularly temperature resistant. The factory velocity is standard at 70 degrees Fahrenheit, but will vary some at different temperatures.

So, are we saying that a particular rife, "rifle A", could be a fast shooter and will generally shoot the same factory ammo faster than another rifle "rifle B", with the possibility that these two rifles are the same model from the same manufacturer. I.e you just get some rifles that shoots faster than others? Sure hope I have one of those. Thanks for all the input guys, appreciate it.

I had some 130 Corloks that were at 2,782 fps vs 3,060 on the "box". 22" M70. They still make meat though.

If I might, why do you want to know?

Don't we all. While having a firearm that shoots ammo faster is preferred, it is meaningful mostly for bragging rights.

no experience with a .270. I can tell you the federal high energy 180 grain 30-06 nosler partition was rated at 2880. it clocked 2888 out of my 30-06. a very stout load, and great game bullet.

I've found Federal and Winchester .270 150 grain loads to be spot on with their published velocities. Unfortunately my chrony went haywire before I got to try 280 Rem 140 core lokts. I've been wondering about them ever since.

Been a couple or so years back I got to chrono two rounds of the .280 140gr. Rem PSPCL though a Rem Mnt rifle. Scant notes show 2753fps avg.

Just last week I measured the last 2 140gr Core Lokts I had in an old box in my new M70 FWT. They ran 3008 and 2968.

Two 140gr Federal Fusions ran 2881 and 2874.

Both were advertised at 3000.

Did you find that rifle to have a slow barrel or was that the ammo's fault?