GTA

All Springer/NP/PCP Air Gun Discussion General => American/U.S. Air Gun Gates => Crosman-Benjamin Air Gun Gate => Topic started by: Flyboy on June 16, 2013, 07:25:47 AM

Title: My Custom Ratty
Post by: Flyboy on June 16, 2013, 07:25:47 AM
I thought I would start a new topic for this, as now it deserves it!

Well here it is, my custom Crosman 2250B Ratcatcher. I call it the 'Varminter' or 'Verminator'.

How can I ever go back to springers now!?

:: MODS DONE ::

REMOVED: Front and rear open sights.
ADDED: Black Steel Breech (with brass extended hollow probe, black steel bolt handle and brass end cap) [GMAC Custom Parts, UK]
ADDED: Power Adjuster (Blued steel, made by Crosman) [SD Custom Design, UK]
ADDED: Custom Allen Headed Re-Bolt Kit (Black) [SD Custom Design, UK]
ADDED: (*^% adaptor (1/2 inch UNF male thread) [SD Custom Design, UK]
ADDED: Delrin spacers (for trigger blade and sear) [SD Custom Design, UK]
ADDED: Hawke Sport Dot 30mm (Red Dot Sight) [Local Airgun Store, UK]
ADDED: Deben Whisper 180 (*^% (nearly a whopping 8" in length) [Local Country Sports Shop, UK]

:: MODS TO-DO ::

MOD: Polish and lube trigger and sear? [DONE]
ADD: Longer barrel? [DONE]
ADD: Brass trigger blade? [DONE]
ADD: Brass safety bar? [DONE]
ADD: Lighter (or adjustable) trigger/sear spring? [DONE]
ADD: Heavier hammer spring? [DONE]
ADD: High flow valve? [DONE]

:: NOTES ::

I would have also removed the barrel band so I could free float the barrel but it didn't look right as the foregrip has a space cut out to accommodate the barrel band.

The (*^% is absolutely awesome. Indoors, where sound echoes the most, I'd say that it reduces the muzzle report by up to a very respectable 75%. Outdoors, where sound is absorbed more, I'd say that it reduces muzzle report by up to a staggering 90%.

:: PICS ::

Attached image filenames are self-explanatory (sorry for poor quality)...
Title: Re: My Custom Ratty
Post by: Flyboy on June 16, 2013, 07:29:36 AM
This is a special kit I made up just for the Ratty... the 'Rat Box'?

I got a small screw box with compartments, in this instance a Draper Organiser with Tote Tray.

Contents (current)...

Allen keys (for Red Dot sight mounts, power adjuster and (*^% adapter) [x2]
Bisley Silicone Gun Oil (30ml) [x1]
Blu Tack (bit of, for loose Red Dot sight turret) [x1]
Cotton Buds [x6]
Kitchen Towel (folded sheet) [x1]
LR44 cell batteries (spare for Red Dot sight) [x2]
Marksman Air Rifle Pellets (.22, domed) [x50-100]
Marksman Pointed Pellets (.22, pointed) [x50-100]
Muzzle end cap (screw on, for (*^% adapter) [x1]
Prometheus Pellets (.22) [x25-50]
Umarex 12g CO2 capsules [x3]

Could also include...

Allen keys (for Pro-Blox, other) [x?]
Front open sight [x1]
Lens cloth (for Red Dot sight) [x1]
Mini Screwdriver (flat-head) [x1]
Pro-Blox (for backup) [x2]
Rear open sight (and screw) [x1]
Screws (spare) [x?]
Seals (spare) [x?]
Springs (spare) [x?]
Tissue Paper [x?]

I take this wherever me and the Ratty go, as being a CO2 gun it needs a few more items to have handy... such as CO2 cartridges and silicone lube.

Find images attached (contents shown are from the first version and have since been updated)...
Title: Re: My Custom Ratty
Post by: Wheelman88 on June 16, 2013, 10:59:45 AM
Nice looking rig.Good luck with your addiction! ;D ;D ;D
Title: Re: My Custom Ratty
Post by: chuckinohio on June 16, 2013, 11:36:55 AM
  That's a day and night difference in appearance, and also apparently in performance.

  Really a neat looking set up!!
Title: Re: My Custom Ratty
Post by: venxxxxx on June 16, 2013, 08:55:29 PM
All rats beware! ;D
Title: Re: My Custom Ratty
Post by: Flyboy on June 17, 2013, 06:43:05 AM
Did a few 'home-tuned' mods last night, inspired by suggestions in my other topic (thanks to 'lillysdad621').

Long story short...

* I tried to trim the original trigger/sear spring to make the trigger pull lighter... and cut it too short... FUBAR'd it. I ended up trimming the replacement hammer spring that came with my power adjuster and cut it just right. This spring has more coils, thinner coils. I also added a spent .22LR casing to the spring, acting as a kind of guide rod and a smoother relationship with the sear. Fully lubed, of course. Can't tell too much if the trigger pull is smoother or lighter, but I'd like to think it is!

* The original hammer spring is actually longer and feels like it's got more tension than the replacement that comes with the power adjuster. So, I replaced the mod spring with the original one. I also stretched it slightly by hand. As a kind of personalization rather than an actual performance improvement, I also replaced the plastic guide rod that comes with the power adjuster spring, with another spent .22LR casing. These .22 casings really fit snug down these hammer springs! Can't really tell if there's a power increase, but again, I'd like to think there is!

* To finish off, all pivot points and contact edges fully lubed regarding the trigger and sear... and a nice coating for the hammer spring and new guide rod!

* The finish on the heads of the foregrip screws had gotten a bit chipped from where I had removed them a few times during strip-downs, and there were no replacements in my custom re-bolt kit, so I gave the originals a coat of gloss black model paint. Like new!
Title: Re: My Custom Ratty
Post by: Flyboy on June 23, 2013, 01:23:52 PM
A new batch of mods have been fitted...

ADDED: Adjustable spring sear trigger Mk2A kit (Mk2A 1/4" brass curved trigger, 3mm stainless steel trigger sear and spring with brass adjuster) [GMAC Custom Parts, UK]
ADDED: Brass Safety Bar [GMAC Custom Parts, UK]
ADDED: Power Hammer Spring with Brass Guide (until problems occurred, see other topic...) [GMAC Custom Parts, UK]
ADDED: Transfer port top seal (plus a dash of silicone oil) [GMAC Custom Parts, UK]

REMOVED: Power Hammer Spring with Brass Guide [GMAC Custom Parts, UK]
ADDED: Home-tuned Hammer Spring (with delrin hammer spring guide)
Title: Re: My Custom Ratty
Post by: F7FTIGERCAT on June 24, 2013, 04:05:58 PM
WELL DONE!   Gary   :D

Looks great and the kit will keep you shooting, in the out back ;D


Ed   8)



Kill all the rats you can they work for the gov'ment   >:(      ???
Title: Re: My Custom Ratty
Post by: Flyboy on July 24, 2013, 06:58:01 AM
Latest additions...

ADDED: Hammer Spring (longer) [GTA's very own 'cherokeesteve', USA]
ADDED: Custom Breech Screw (further modded by me) [GTA's very own 'cherokeesteve', USA]
ADDED: Boss 12-gram CO2 Valve [Crooked Barn, USA]

I also coated all internal parts with silicone oil, coated external blued parts with airgun oil, and applied a roughly 2cm piece of PTFE thread seal tape (doubled over lengthways) to the transfer port (sealing the unit with the recently added transfer port seal).
Title: Re: My Custom Ratty
Post by: AHCampbell on July 24, 2013, 01:55:28 PM
I'd love a 22, 23, or 24-something to play with/mod.  Unfortuantely, I'm between jobs, and working for family for good pay, but low hours.  Gonna have one modded as much as yours some day, though.  Good luck with it.
Title: Re: My Custom Ratty
Post by: cherokeesteve on July 24, 2013, 09:26:09 PM
Awesome job, Now go show the rats what it can  do!
Title: Re: My Custom Ratty
Post by: BillK on July 24, 2013, 10:47:04 PM
Sounds like a wonderful & fun project gun.  Looks great too.
How many shots do you get with the Boss valve?  I've been thinking about one of those.
Will your power adjuster stretch the number of shots?
Title: Re: My Custom Ratty
Post by: Flyboy on July 26, 2013, 06:46:55 AM
I'd love a 22, 23, or 24-something to play with/mod.  Unfortunately, I'm between jobs, and working for family for good pay, but low hours.  Gonna have one modded as much as yours some day, though.  Good luck with it.

Well I'll be honest and say that I have done rather a lot of mods in a short space of time. You can obviously mod it at your own pace. Also, I have learnt that some of the mods could have been done a lot cheaper. As you are in the U.S., you'll have a good selection of hardware stores where you can get such things as hammer springs, seals and screws a lot cheaper than what these custom shops are charging.

Awesome job, Now go show the rats what it can  do!

I'd love to, but (un)fortunately we don't get many rats about here. I'm hoping that the colder winter months will bring them out looking for food. I've done a bit of birding with it so far, but not with the Boss Valve fitted.

Sounds like a wonderful & fun project gun.  Looks great too.
How many shots do you get with the Boss valve?  I've been thinking about one of those.
Will your power adjuster stretch the number of shots?

I haven't done too much to it externally, for all intents and purposes it's just a Ratty with a Red Dot sight and sound mod fitted. Other minor exterior changes include a brass trigger and safety bar. I've mostly upgraded internals. I've only done one test so far, but as stated by Jim at Crooked Barn, you get 18 full-power shots per CO2 cartridge with the Boss Valve fitted (might be a couple more without the other mods I've got on the gun). The shots after the 18th drop off very quickly, getting only 3 or so completely... but they are pretty much unusable as the 19th shot drops about 4 or 5 inches at just 15 yds... then the 20th and 21st shots are just no-shows. I haven't tested the power adjuster with the new valve yet, but I do have it screwed in as far as it will go. I don't honestly think now that I have the gun cranked up with power that releasing tension on the hammer spring will really have any effect, you might get an extra shot but I'd think that's being a bit ambitious.
Title: Re: My Custom Ratty
Post by: Flyboy on July 27, 2013, 01:49:20 PM
Killed my first wood pigeon today with the Ratty! The Boss Valve sure took care of it. I shot it in the neck out of the bedroom window into the garden about 15 yds away.
Title: Re: My Custom Ratty
Post by: cherokeesteve on July 27, 2013, 04:45:54 PM
One shot, one kill, great job!
Title: Re: My Custom Ratty
Post by: JamesRA on July 29, 2013, 11:18:54 AM
I love old Ratties!  Have you Chronied it?  Love to know.

I have a bone stock Ratty - no mods whatsoever and get 535fps and 35 shots @ 85F, slow firing.  I believe that many or all fps-related parts are the same as the 2240.  Valves have the same part #.  Barrels are the same except for length which then makes the transfer ports/gas path the same.  Stock hammer springs are identical.

Observation:
2240 = 455fps (Spec and Chrony)      2250 = 535fps (Chrony)  Increase in muzzle velocity due solely to longer barrel.

Thoughts:
If you're not beating the pants off of a bone-stock 2250 you are wasting gas using the stock Rat barrel.

Example:  Modified 2240 with the 24" barrel and some flavor of a power valve (i.e. has telltale angled exhaust port) but has standard valve spring vs. clearly stiffer spring.  I've seen both flavors and both have a 1/8" longer stem. (Why?)  Has a small section of flexible tube as the transfer element vs. metal.  "Different", nonstandard hammer spring.  Getting 630fps and 15 good shots on a warm 85F day.

So how does yours compare?  Very curious.

Jim

Title: Re: My Custom Ratty
Post by: Flyboy on July 31, 2013, 06:22:37 AM
I love old Ratties!  Have you Chronied it?  Love to know.

I have a bone stock Ratty - no mods whatsoever and get 535fps and 35 shots @ 85F, slow firing.  I believe that many or all fps-related parts are the same as the 2240.  Valves have the same part #.  Barrels are the same except for length which then makes the transfer ports/gas path the same.  Stock hammer springs are identical.

Observation:
2240 = 455fps (Spec and Chrony)      2250 = 535fps (Chrony)  Increase in muzzle velocity due solely to longer barrel.

Thoughts:
If you're not beating the pants off of a bone-stock 2250 you are wasting gas using the stock Rat barrel.

Example:  Modified 2240 with the 24" barrel and some flavor of a power valve (i.e. has telltale angled exhaust port) but has standard valve spring vs. clearly stiffer spring.  I've seen both flavors and both have a 1/8" longer stem. (Why?)  Has a small section of flexible tube as the transfer element vs. metal.  "Different", nonstandard hammer spring.  Getting 630fps and 15 good shots on a warm 85F day.

So how does yours compare?  Very curious.

Jim

I don't have a chrony, or know anyone that has... so no, I haven't chrony'd it. I'm guessing it's somewhere between 10-11 ft. lbs. Looking at what other people say, you get about 11.4 ft. lbs. when you've got all my mods PLUS a longer barrel. I don't have a longer barrel, so I'm knocking a tad off that power ratio to get my estimate.

Details about shot count per CO2 cartridge can be seen in another of my posts above.
Title: Re: My Custom Ratty
Post by: Flyboy on August 14, 2013, 06:06:20 AM
Yet more mods to come...  :D
Title: Re: My Custom Ratty
Post by: Flyboy on September 08, 2013, 11:24:25 AM
The last of the mods have now been added...

REMOVED: Crosman Power Adjuster
ADDED: Realtree Camo Stock and Fore Stock [GMAC Custom Parts, UK]
ADDED: 19" .22 barrel (crowned) [Crooked Barn, USA]
ADDED: Brass Power Adjuster for Crosman 22XX [GMAC Custom Parts, UK]
ADDED: Simmons 4x32 scope [A mate's old air rifle]
ADDED: Laser Sight & Universal Mounting System [GMAC Custom Parts, UK]

Find pics attached below (filenames are self-explanatory)...
Title: Re: My Custom Ratty
Post by: Flyboy on September 08, 2013, 12:20:08 PM
Here's the group I got after I set the scope up.

5 x shots of Marksman Air Rifle Pellets (.22, domed); 20 yds; slight breeze; semi-rested position. I used a 1p coin to show size of the group. Note the one flyer!
Title: Re: My Custom Ratty
Post by: cherokeesteve on September 08, 2013, 03:06:09 PM
The last of the mods have now been added...

REMOVED: Crosman Power Adjuster
ADDED: Realtree Camo Stock and Fore Stock [GMAC Custom Parts, UK]
ADDED: 19" .22 barrel (crowned) [Crooked Barn, USA]
ADDED: Brass Power Adjuster for Crosman 22XX [GMAC Custom Parts, UK]
ADDED: Simmons 4x32 scope [A mate's old air rifle]
ADDED: Laser Sight & Universal Mounting System [GMAC Custom Parts, UK]

Find pics attached below (filenames are self-explanatory)...


Looks great! Love the camo.
Title: Re: My Custom Ratty
Post by: Flyboy on October 01, 2013, 08:24:16 AM
ADDED: Three coats of spray-on paint lacquer to the Realtree-camo stock.