Blain

Not too long ago I received my F1 master chrony chronographer in the mail. Now I have always wanted these so that I could test out how certain shells were performing in my gun, so I could find the true muzzle energy figures. The good news is that the chrony worked, and wonderfully. I was very happy with its performance. The bad news is that the slugs were not up to their factory spec performance, as I feared.

Here are the results; I tested two slug types out of two guns. The chrony was placed at a distance of 2 meters from the guns. Both guns were Remington 870's with 19.5" IC barrels. Only difference between them was one was an express and one was a Police. It should also be noted that the police had shot off a lot more shells since it's cleaning than the express. Thus the police's barrel was dirtier and prob. resulted in the slightly lower velocities between the two.

The two slugs tested were Winchester 2 3/4" 1 ounce rifled slugs, which has a factory velocity of 1,600 fps. The other slugs were 3" brennekes with a factory velocity of 1,502 fps.

Test Results: Listed in the order I shot the shells.

870 Police:

W: 1,466 fps
B: 1,396 fps
W: 1,470 fps
W: 1,447 fps
B: 1,410 fps
W: 1,428 fps
W: 1,439 fps
B: 1,286 fps
W: 1,443 fps
B: 1,327 FPS


870 Express:

W: 1,500 fps
W: 1,506 fps
B: 1,401 fps
W: 1,488 fps

It should again be noted that the 870 Police's barrel was a lot dirtier prior to testing than the 870 express which is a reason why it got slightly lower results. Though on the average my 870 19.5" IC choked shotguns seemed to shoot both slugs at an average of 100 fps below factory specs.

Anyone out there wish to comment on these results or this experiment? Anyone out there with a chrony experience similar problems with their shorter barreled shotguns? Since 100 fps = around a difference in 300+ footpound of energy, this is a big deal. Especially since most slug hunters use shorter barrels such as these. More testing to be conducted this Sunday.



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