Over pumping 140/1400

[Kallysan]

Figured I would ask before my nephew asks me.  Does anyone knows what kind of +fps you get from pumping a 140/1400 past 8 pumps?  I think I remember 8 as the recommended  pumps. I am sure he is going to ask.

[avator]

Nope... If max recommended ain't enough I go get something that is..... JMHO.

[Kallysan]

Yeah, but he is the inquisitive type.  How​, why, what if, are some of his favorite words.

[Trophyhunter49]

  8 is the recommended  pumps.

[Trophyhunter49]

  You'll just have yo tell him that's the way it is!

[avator]

Sounds like some 1 on 1 lessons are in order before you turn him loose. The range on that 1400 will be surprising. He'll need to know about pass thru and what lies downrange. Besides the velocity, the .22 is going to carry energy downrange. I'm sure you know all this. Just a friendly 
I wouldn't back off of a 50yd. heart and lung shot with one. And that's with open sights.

[Kallysan]

Sounds like some 1 on 1 lessons are in order before you turn him loose. The range on that 1400 will be surprising. He'll need to know about pass thru and what lies downrange. Besides the velocity, the .22 is going to carry energy downrange. I'm sure you know all this. Just a friendly 
I wouldn't back off of a 50yd. heart and lung shot with one. And that's with open sights.

He's fifteen, been hunting with PBs since he was 12.  Good kid, he just likes to know everything lol.  If I tell him 8 pumps, he will stay at 8 pumps but still want to know what if.  (Can't have the Uncle say hmm IDK  lol) . He wants to squirrel hunt with air next season.  So I found him a nice 1400

[avator]

Good job !!!

[Kallysan]

  8 is the recommended  pumps.

Just found the owners manual online

https://support.crosman.com/hc/en-us/article_attachments/201590310/C1400-OM.pdf

Lists 610fps at 10 pumps.  Always thought it was 8

[avator]

I thought it was 10.... no matter.. never needed 10.

[Mackado]

Yes, the manual for the CR140 recommends from 6 to 8 strokes to avoid bending the pump arm lever, I did a chrony test on my newly sealed 140 and it shoots at 715 to 728 FPS on 10 strokes with 14.5 RWS, reaching 10 strokes on my 140 is very hard to do, so I use max of 6-7 strokes. Don't have numbers for my 1400 yet since I'm still working on it.

When researching a couple of years back before joining here I found this old post with info on this subject, member reached 20 strokes with his rebuilt 140 using a pump piston mod, and created a very interesting graph, here's the link.

http://www.gatewaytoairguns.org/GTA/index.php?topic=18193.0

[Kallysan]

I thought it was 10.... no matter.. never needed 10.

Just checked the 140 OM it says 8. Never knew they upped it for the 1400

[Kallysan]

Yes, the manual for the CR140 recommends from 6 to 8 strokes to avoid bending the pump arm lever, I did a chrony test on my newly sealed 140 and it shoots at 715 to 728 FPS on 10 strokes with 14.5 RWS, reaching 10 strokes on my 140 is very hard to do, so I use max of 6-7 strokes. Don't have numbers for my 1400 yet since I'm still working on it.

When researching a couple of years back before joining here I found this old post with info on this subject, member reached 20 strokes with his rebuilt 140 using a pump piston mod, and created a very interesting graph, here's the link.

http://www.gatewaytoairguns.org/GTA/index.php?topic=18193.0

Thanks for the link.  Leave it to Bob to figure it out lol.  That's the piston I ordered.

[Mackado]

Thanks for the link.  Leave it to Bob to figure it out lol.  That's the piston I ordered.

I resealed this 140 with a mac1 kit that includes the piston mod, but the original factory cup looked good and decided to leave it until testing, after picking up a chrony decided to keep the original cup, and I'll be using the leftover piston on a second 140 that shoots like100 FPS weaker after resealing without replacing the cup.

[BrushPopper]

As a kid, I thought  "Good lord, what IS this howitzer?!" (Loud!)

I'd charge it heavy, and load 5 .22 lead balls behind a felt cleaning pellet. Walking around stock tanks, with a headlight after dark, that load would starch big bullfrogs like a thunderbolt.

6-8 pumps should be plenty for limb-chickens, at reasonable ranges.

BP

[Trophyhunter49]

I thought it was 10.... no matter.. never needed 10.

Just checked the 140 OM it says 8. Never knew they upped it for the 1400

  I have a phase I 1400 and 8 is max on it. Its all I can do to get the 8th pump in. 6 pumps is all i ever shoot in it.

[45flint]

You need to emphasis with him that with each pump less and less power is added.  After 8 pumps, the increase per pump is so small that it is really not worth the effort.  And quickly it levels off to nothing.

[TerryM]

  My 140 shoots well over 600 fps with eight pumps, upper 600s with ten.  Trigger is atrocious with ten.  I left the original pump cup in this one.