Canadian Airgun Forum

The #1 Community for Airguns in Canada!
It is currently Tue Nov 12, 2019 5:33 am

All times are UTC - 5 hours


The Canadian Airgun Forums are a place for people to discuss and learn about airguns and the airgunning sport in Canada. There are lots of discussions about airguns, airgun accessories, reviews, modification and repair information, airgun events, field target and free classifieds!

 

You need to register before you can post: click the register link to proceed. Before you register, please read the forum rules. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload your own pictures, and access many other special features. Registration is fast, simple, and absolutely free! To start viewing messages, select the forum that you want to visit from the selection below.








Post new topic Reply to topic  [ 8 posts ] 
Author Message
 Post subject: Crosman Optimus
PostPosted: Sun May 13, 2012 8:13 pm 
Offline
User avatar

Joined: Thu Mar 15, 2012 6:38 pm
Posts: 1267
Location: Near London Ontario
Hi Gang!

As a favor for a PAL rated friend, who is a registered hunter, I put a nitro gas spring into a new crosman optimus for him.

Figured I'd take the time to chrony the before and after.

Pre Mod (all in FPS)

435
425
451
437
431

Post Mod

814
812
804
808
812

I had to jimmy a few things because the fit of the gas spring wasn't native to the optimus. I had to put a jig in the piston head to keep the spring centered and lower the ceiling of the piston as well, and fiddle with the other end as well. Had to take it down and put it back together a total of 3 times to get it safe, fire smoothly and consistently every shot. It's got quite the little snap now as it goes off.

I'm really happy with this work, and just thought I would share it! This simple $30 gas spring really put some penetration power into this springer.

I used 7.9 grain crosman premiere hollow point pellets.

That puts this air rifle in at 11.5 foot pounds. Plenty strong to tear down tree rats, when they are in season. I guess there is a season for them, he is a well educated hunter, I'm just a pelican with some molly lube :)

_________________
Airgun Addicted since 2012!


Top
 Profile  
 
 Post subject: Re: Crosman Optimus
PostPosted: Mon Jul 29, 2013 1:43 pm 
Offline
User avatar

Joined: Mon Jul 23, 2012 2:13 am
Posts: 265
Location: Surrey, BC
Hi Chewy, saw your post about converting a optimus into a np. very interesting modification. is your friend's rifle still holding up and shooting the higher fps? my friend wants to quiet his optimus to shoot quietly like an NP. care to share some detail instructions? Thanks.

max115

_________________
AAS510 SL .177
HW100T .22
Diana 34 .22
HW45 Black Star .177
HW97KL .177 (V-mach)
Diana 24 .177
HW97K .22 (JM kit)


Top
 Profile  
 
 Post subject: Re: Crosman Optimus
PostPosted: Thu Aug 15, 2013 6:39 pm 
Offline
Supporting Member 2009
User avatar

Joined: Sun Dec 24, 2006 12:37 am
Posts: 3468
Location: Out There
Something's not right with the numbers- should be closer to 900fps and 15 ft-lbs. check the spacing on your tophat/rod guide.

_________________
www.scopesandammo.com/storefront



Please note: I do not conduct business through Private Messages (PM's) in online forums. Please do not send a 'PM" with a business-related question.


Top
 Profile  
 
 Post subject: Re: Crosman Optimus
PostPosted: Sun Aug 18, 2013 8:59 pm 
Offline
User avatar

Joined: Thu Feb 02, 2012 8:39 pm
Posts: 207
Location: Waterdown, Ontario
Looks like the optimus was a non pal version, under 500 fps. Did you close the bleed hole in the pistion?. By doing so it would boost up the fps to 850 using the spring.

_________________
"If it can be built, it can be taken apart, re-assembling is another story...."
2240
2240 bulked CO2
2260
XT15
Sig Sauer SP2022
BSA Meteor MK5 .177
Webley Alecto .177
P17
HW45 Blackstar .177


Top
 Profile  
 
 Post subject: Re: Crosman Optimus
PostPosted: Sat Aug 24, 2013 7:36 pm 
Offline

Joined: Sat Aug 24, 2013 7:00 pm
Posts: 67
Location: Abbotsford, BC
mes4u2c wrote:
Looks like the optimus was a non pal version, under 500 fps. Did you close the bleed hole in the pistion?. By doing so it would boost up the fps to 850 using the spring.

doing ONLY the bleeder hole plugging puts the fps up around 850?
Ouch!

_________________
Crosman M4-177 w/red dot
Crosman Optimus .177 w/ 3.5-10x36 scope
Benji Classic .22 w/3-9x40 scope
Crosman "vigilante"
Benjamin Trail NP .22 w/3-9x40 Centerpoint


Top
 Profile  
 
 Post subject: Re: Crosman Optimus
PostPosted: Sat Aug 24, 2013 7:43 pm 
Offline

Joined: Sat Sep 08, 2012 3:33 pm
Posts: 484
Location: Montreal
It sounds like chewy used some other gas spring, not crosman's.


Top
 Profile  
 
 Post subject: Re: Crosman Optimus
PostPosted: Sat Aug 24, 2013 8:36 pm 
Offline
User avatar

Joined: Sat Jun 16, 2012 8:09 pm
Posts: 463
Location: Kitchener, On
McBride73 wrote:
mes4u2c wrote:
Looks like the optimus was a non pal version, under 500 fps. Did you close the bleed hole in the pistion?. By doing so it would boost up the fps to 850 using the spring.

doing ONLY the bleeder hole plugging puts the fps up around 850?
Ouch!


Just the bleeder hole mod will net you avg of 780, at least from my experience.

_________________
Benjamin Classic 22
Crosman Optimus .177
ИЖ-38
Crosman 2240


"Boredom sets into the boring mind." - James Hetfield

- Derek


Top
 Profile  
 
 Post subject: Re: Crosman Optimus
PostPosted: Sun Sep 01, 2013 3:14 pm 
Offline

Joined: Sat Aug 24, 2013 7:00 pm
Posts: 67
Location: Abbotsford, BC
that's a pretty big jump for such a simple mod

_________________
Crosman M4-177 w/red dot
Crosman Optimus .177 w/ 3.5-10x36 scope
Benji Classic .22 w/3-9x40 scope
Crosman "vigilante"
Benjamin Trail NP .22 w/3-9x40 Centerpoint


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 8 posts ] 

All times are UTC - 5 hours


Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
News News Site map Site map SitemapIndex SitemapIndex RSS Feed RSS Feed Channel list Channel list

Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group

phpBB SEO