What is a stock 1377 shooting Crosman Premiers at?

[byhsu]

I don't have a Chrono, but I am guessing that the quoted 600fps on the box is probably with really light pellets.  The Crosman Premiers weigh in at 7.9gr and I am wondering what I can expect.  I tried a search function but couldn't come up with much information on stock performance for the 1377.

Thanks

[breakfastchef]

Low 500's at 10 pumps.

[byhsu]

So if i add a FT Piston + FT Valve, Discovery Hammer Spring, Long probe bolt and 16.5" barrel, at 10 pumps i might get low 600's fps with 7.9gr premiers?

[ceejay]

I got 660fps with those mods and 7.8g magnums using the stock barrel and 10 pumps.
Also re-angled the valve exhaust and TP.

[pirouge]

 here's Tom Gaylord's findings on a new stock 1377c  using 7.9 cr hp
3-345
4-393
5-424
6-451
7-469
8-484
9-499
10-515
11-520
12-515   
  my 1377 carbine shoots most accurate at 5 pumps @ 25' and eliminates starlings @  10m with 10 pumps

[AZAG]

Here is a link to testing that I did on a stock 1377 with a variety of pellets.

http://www.crosman-air-pistol-owners-forum.com/board/index.php?topic=4327.msg46625#msg46625

[pirouge]

its what I thought, low. I have a mac1 16" prep'd barrel on mine, I'm looking into a flat piston now hoping to get a honest 600fps with 7.9 chp's,  thats enough for my needs of vermin control and target shooting at 10m.