Gun is performing well(great numbers at 10 pumps)

[ham484]

this is my setup
1377
Airgun smith flattop valve and piston with custom work
14.5" barrel
crosman steel breech
melon air solid roll pin kit
melon air long prob bolt
Heavier hammer spring
Power adjuster
lighter sear spring
all contact points polished

The last thing i added was the long prob and it sure makes a difference i get more FPS and consistent shoots(I was averaging 651 before the long bolt now i average 693)

i did a string and here are the results

1-697.5
2-690.2
3-697.4
4-697.2
5-691.0
6-697.1
7-691.2
8-694.5
9-695.4
10-684.7  where did he come from

AV 693        FPE 8.4     7.9 Grain crosman pointed pellet

I must say i am very satisfied with the end results.

Next thing is a metal barrel band if i can get the balls to spend 42 bucks for one(i think that's to expensive) Yes a know these are custom but man i'm all about saving a buck.

[sbcrockett]

wow, nice numbers and thanks for reporting back! I wish I had a chrony...

[ham484]

When i first brought this gun and found this forum i told somebody that i was going for 700FPS @10 pumps. They said if a get a 24" barrel it can be done. Well i am nearing my goal. I think i may polish the hammer and report back.

[breakfastchef]

Numbers look excellent. You are pretty close to maxing out the 1377 platform.

[sbcrockett]

very nice, ham. you've road-mapped what I hope to do w/ my 1377. hopefully, i'll get my 16inch barrel and muzzle brake next week. then to start thinking of the valve and piston and where to buy them...

[ham484]

keep us posted,i know i can squeeze out a few more fps at 10 pumps just don't know where at this length.
Suggestions Will be appreciated.

[Cross Pistol Packer]

Very good numbers for a 1377 still in pistol form,if you go down the carbine route 19inch barrel +
close to 800fps can be had with 7.9grain pellet

Just re read your post,and see you are sticking to 10 pumps,for 800fps 15 pumps needed.
Ray.

[ham484]

well thats the plan,i got 746 with 15 pumps. Soon ill start a .22

[Crosshairs]

Wow nice numbers good job. 
                              Mike 

[1377x]

those are very good numbers
there really is much you can do to inprove those numbers with out a risk of affecting the consistency
get closer to the chrony im sure you will pass 700fps then.
i had a polished hammer in my 13xx it didnt make a difference
do you know what size your hammer spring is? can you get a part number to look up the size of it?

[ham484]

no i dont ,i brought a sear spring and the guy gave it to me free with my order. I never asked him. I am using it now and @ 20 pumps it dumps all the air

[1377x]

if you have a caliper you can measure the wire size
if the gun is hard to cock then the spring might be to heavy
its been noted to heavy of a spring will damage your valve
the heaviest wire spring i used is .041 which is on the heavy side a disco spring is the happy medium i found so far valve shows no sign of damage
my 2289 pooped out yesterday probably from debris in the tube.i saw it there but hated to take the gun apart now i have to

[ham484]

i have a caliper but its not digital,its not hard to cock i use a power adjuster and backed it out for cocking adjustment. 
i need to get a digital caliper

[1377x]

for a metal barrel band you can use a phase one 760 bb
thats what im using for a metal bb

[ham484]

nice pumper, where can i find one @?
do you have a crosman part number,