Anyone regularly keep track of these? If so, here are a few data points.

.270 Win. (Sporterized VZ-24 Mauser, 22" bbl.)

Federal 150-gr. Nos. Part. List 2850 fps (24"); chrono 2743 fps. (But very accurate.)

Rem. 150-gr. Nos. Part. List 2850 fps (24"); chrono 2866 fps.

.30-06 (pre-'64 M70, 24" bbl.)

Federal 180-gr. Nos. Part. List 2700 fps (24"); chrono 2487 fps. (Extremely accurate in this rifle.)

.30-06, Interarms Mark X Mauser (24")

Remington Premier 180-gr. Partition. List 2700 fps; chrono 2559 fps.

Win. 180 Power Point. List 2700 fps; chrono 2577 fps.

Federal 180 Hi-Shok. List 2700 fps; chrono 2595 fps.

Hornady Light Magnum 180 BTSP. List 2880 fps; chrono 2664 fps. (Reasonably accurate in this rifle but the recoil difference was noticeable.)

All velocities for 5-shot groups, taken by Chrony Beta 12 ft. from muzzle.

John

[This message has been edited by John Frazer (edited 06-25-2001).]

[This message has been edited by John Frazer (edited 06-25-2001).]

Factory data are ballpark range of velocities. Different brass, primer, powder, seating depth, lot, barrel, chamber length, neck size, ambient temperature, humidity . . . these will all affect velocity.

To provide an accurate measure of your chrono velocity you should provide highest/lowest of a fair sized sample and then calculate standard deviation.

Oh, it's a nit-picky game we're playing here . . .

------------------
PowderBurns Black Powder / Muzzle Loading Forum:

www.hotboards.com/plus/plus.mirage?who=powderburns

What you found has pretty much mirrored my experience. Most factory rounds run around 100-200 fps below claimed velocity though I did have one that exceeded claims, 140 gr. remington core lock 7mm stw went 3440 vs. 3350 claimed.

I agree with Boltman. Most factory loads are enough below claimed velocity to make some real-world difference in performance. On the other hand, you'll occasionally find a lot which is right up there: 90 grain 6mm/.244 Rem in a 721 with a 26" bbl; .257 Roberts 100 grain (which isn't hard to do since the factory claim is so conservative to begin with). .30/06, 7mm Remington, and .264 Win Mag seem to be big "offenders" in missing factory velocities by wide margins, while most Weatherby factory ammo is reasonably close to published velocity.

I think that it's fair to say that handloads loaded up to factory "advertised" velocities in .308 will equal or exceed factory .30-06 in most instances. By the same token, .30-06 handloaded to a reasonable working maximum pressure will come close to equaling most factory .300 Win Mag loads. Can the animal tell the difference? Usually not, but knowing your ammo is actually performing to expectations can give the hunter a psycological edge.

Yet another reason I need to invest in a chronograph.