Crosmods breech tip #2

Started by airriflenut, September 14, 2012, 02:57:25 AM

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airriflenut

Another thing I have run into with my Crosmods breech, the transfer tube actually.  That flat rubber seal that is standard on the Crosman 1377 (maybe the 2240 as well but I don't own one to verify) fits onthe Crosmods transfer tube...but then it wont fit into the transfer hole of the main tube.  Vaseline and a lot of swearing would not make it fit. 

I tried a smaller rubber ring similar to the Crosman from an eyeglass repair kit and it fit...but 4 shots later I noticed I could see the pellets in flight and they had a trajectory of a cinder block, I could feel a burst of air hit my finger under the trigger as well.  After a tear down it was obvious that rubber ring couldn't handle the pressures developed.  This is when I couldn't get the barrel out mentioned in the previous post.

The fix was simple.  I put a #005 o-ring (the same size used for .22 bolt seals) directly on top of the valve transfer port, mounted the breech carefully as to not strip out that damn 4-48 screw since I was making a compression fit.  Oh, almost forgot, on the other end of the Crosmods transfer tube I put a #003 o-ring (same size as a .177 bolt seal) actually around that small collar on the tube.  It is a VERY tight fit but it seals the transfer tube to the barrel transfer port very, very well.

Once it was put back together the pellets appeared to impact the target faster and harder than they ever have.  I'd give anything for a chrony so I could document all of my work.
Sterling

Nuts about airguns and just nuts in general...but I'm medicated.

1377x

#1
http://www.catsdomain.com/chrono/

another thing you can for thinner square o-rings is
take a look at the stock crosman transfer port sleeve gasket(the square o-ring that goes under the transfer port sleeve)
you will see a line through the center all the way around
take a brand new razor blade and cut along that line.now you have two square o-rings to use as top seals or whatever they are needed for
closed mouths dont get fed

Davio

Quote from: 1377x on September 14, 2012, 05:48:21 AM
http://www.catsdomain.com/chrono/

another thing you can for thinner square o-rings is
take a look at the stock crosman transfer port sleeve gasket(the square o-ring that goes under the transfer port sleeve)
you will see a line through the center all the way around
take a brand new razor blade and cut along that line.now you have two square o-rings to use as top seals or whatever they are needed for

Ed, I really WANT to like this.  It would be too cool to grab and go.  But BBB rates the company an "F" and then this video:
http://video.ezinemark.com/precision-shots-chronograph-my-review-of-this-on-line-sale-item-458cef3bb50.html

Of course, I gotta cut them some slack since the stupey on the video basically shot his chrony with his bad aim self... then blamed it on the plastic construction.  If I shoot the face off my chrony it will be my fault I'd say.  ;)
Silence is golden. Duct Tape is silver. Gravy is brown.

2400KT bulk fed repeater .22
2260 .22 w/ steel breech
2250XE .22
Benjamin Discovery .22
Benjamin Marauder .25
Crosman 1077 WOOD .177
Crosman 1077 BLACK .177
Benjamin NP Trail .177
Crosman 2240 Camo .22
Crosman 2240 polished .22
Crosman 2300KT .22
Dan Wesson 8" .177
Crosman Vigilante .177
Hatsan A44PA .25
Hatsan A44W .25
Sheridan 2260
Benjamin Trail NP XL .25
Benjamin Titan NP .22
Benjamin Marauder Pistol .22
Benjamin 392 .22
Sheridan C9 PB 50th Anniversary .20
Crosman 1701-P .177

1377x

its not made in china just the cover is
the internals are said to be made by texas instruments
i think they had an issue getting cases a while back thats why it took so long for them to ship out
the bbb was mostly going off of complaints about shipping.most of our vendors for ag parts tales 2-8 weeks
like with every thing else some broke during shipping nothing new there
poor customer service nothing new there happens with reputable companies also
a few members here have them matched up with a shooting chrony they were right on with each other
even fired a .22magnum through it no problem
there is a thread over on gta about them.i wouldnt hesitate to get one if i had the money for one
as much as the guy in the video messed with the thing im surprised it worked at all
im looking at combro's they are cool also
http://www.chronoscopes.com/
i just need something i can transport and works with less than optimal lighting.the ps2 fits the bill
closed mouths dont get fed

Davio

#4
That chronoscope looks pretty good. If they'd shove a laser into the alignment tool to double as a bore sight I'd go for it already.  ;D

Okay... hijack over.
Silence is golden. Duct Tape is silver. Gravy is brown.

2400KT bulk fed repeater .22
2260 .22 w/ steel breech
2250XE .22
Benjamin Discovery .22
Benjamin Marauder .25
Crosman 1077 WOOD .177
Crosman 1077 BLACK .177
Benjamin NP Trail .177
Crosman 2240 Camo .22
Crosman 2240 polished .22
Crosman 2300KT .22
Dan Wesson 8" .177
Crosman Vigilante .177
Hatsan A44PA .25
Hatsan A44W .25
Sheridan 2260
Benjamin Trail NP XL .25
Benjamin Titan NP .22
Benjamin Marauder Pistol .22
Benjamin 392 .22
Sheridan C9 PB 50th Anniversary .20
Crosman 1701-P .177