Pump to CO2 conversion

[JMJinNC]

I have a 1377-based carbine that I built for my son. LW barrel, custom stock, etc. Here's a video of him shooting it:

https://vimeo.com/334783635

I'm considering replacing the compression tube assembly with a CO2 unit (from a 2240, for instance). This way he does not have to pump it, just cock, load and shoot. The compression tube seals are due for replacement, so now is the time to do the modifications, since I have to tear it down anyway.

Any thoughts on going this route?

I saw this on eBay, wondering if it's a deal or not, since it sems almost the same cost as a 2240.

https://www.ebay.com/itm/290962552054

I would have to fill the hammer to be compatible with me 1701P trigger, make a new trigger frame strap, and make a hammer spring adjuster, but that is a given whether I go with a full 2240 or the eBay "kit".

Thanks all.

JMJinNC

[CraigH]

Seems expensive, but then 2240's have probably increased in price.   And you have the steel breech and barrel.

Since the 13xx is a longer chassis, I would consider using a 2250 gas tube.  Makes it 1.6 inches longer and a place for a forearm.   And that gives the (future or present) option of making an extended valve.

I would make an SSG device instead of a hammer spring adjuster - will substantially increase shot count.

[mudduck48]

Need something to do? Then go for it, or just buy a 2240.

Crosman 2240 Bolt Action CO2-Powered .22 Pistol

https://www.amazon.com/Crosman-2240-Action-Pellet-Pistol/dp/B00069PQFY/ref=sr_1_1?crid=OOSYL6SIICYZ&keywords=crosman%2B2240&qid=1682078753&sprefix=crosman%2B%2Caps%2C176&sr=8-1&th=1

[JMJinNC]

Mudduck. Great find. Thanks! 

CraigH, I'll price out the 2250 tube. Found a 2250/2400 kit on eBay as well, same price.

JMJinNC

[CraigH]

Mudduck. Great find. Thanks! 

CraigH, I'll price out the 2250 tube. If it's longer, is the valve longer or the end-cap to take up the extra length?

JMJinNC

2240/2250/2260 models use the same valve, end caps are different - 2250 end cap is Crosman part number 2250-008.

The difference in length is 1.6 inches.

[CraigH]

The tube is 2250-009.

The valve is 2250-003.    (By implication, the 2250 pre-dates the 2240)

[JMJinNC]

Got it. Thx!

[CraigH]

BTW, it has been posted that the Custom Shop is operating again.

If you are a CCS customer (have purchased a CCS gun), you may be able to buy an unstamped 2400 gas tube.

[JMJinNC]

I bought a 2260 tube & internals set off eBay. Other than my custom breech hold-down strap, this should be a drop-in conversion with a nice long tube to mount a forestock.

I'll just have to make a hammer spring adjuster and fill in the hammer groove. Easy.

Jmj

[Rezarf]

JMJinNC: How do you fill the hammer groove? JB Weld? How do you get it smooth and circular?

[CraigH]

This topic describes the hammer fill during a grip frame conversion:

https://www.crosman-air-pistol-owners-forum.com/board/index.php/topic,4561.msg45155.html#msg45155

Carl filled the hammer with JB Weld, turned it on the lathe, and coated the epoxy with super glue - IIRC.

Easier to get a 1701/2220 or Challenger hammer.

[JMJinNC]

JMJinNC: How do you fill the hammer groove? JB Weld? How do you get it smooth and circular?

I use "high strength" JB Weld, but I mix in some stainless steel filings in the area where the sear drags to increase wear resistance.

Smoothing is easy on the lathe, followed by polishing.

I think I actually have a fluted hammer in my parts box. Amazing the stuff you collect over the years.

JMJinNC