Factual Observations regarding the OEM breech screw:
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"Jiggly pump arm" is likely not a good description of the problem. I would bet that the pump arm itself is firmly secure to the lever assemble, but that the lever assembly is what has unwanted side to side movement that makes you call it "jiggly". If that is the case, maybe we can improve that situation.
I have been asked about extended probes several times each year for many years. Are they necessary? Do they give any more fps / power?
Extended probes are made to prevent the possibility of pushing a pellet into a barrel with the rear skirt of the pellet not going fully past the barrel port (where the blast of air comes into the barrel). If it does not, then part of the blast will be guided to the front for a millisecond until the pellet moves forward and blocks that path. The real question is "Does that happen?". Most pellet skirt length and inner skirt recess geometry will not let that happen even with a stock length probe. I say most because I have not seen them all. I am certain there are some specialty pellets or homemade cast pellets or even round balls that may present a problem. So the best answer is: Maybe, but very infrequently if at all. The only other way I can see this very rarely happening is if someone has a relatively loose fitting pellet chambered, then has the gun pointed up and possibly a bump + gravity lets the previously cleared skirt drop down to lay partially in the port area. So this would be a very rare occurrence (if at all). The only shooters that I can see actually NEEDING this feature would be serious competitive target and silhouette shooters that require consecutive shots to be as identical as possible. There may also be some OCD folks that can't sleep at night imagining that this is a problem, so they should get an extended probe just so they can get some rest! Do they add fps? I have never scene proof that they add any velocity. Bottom line: It is not a bad thing at all. It is not a required thing. It is possibly a preventive thing for a very infrequent occurance. The aftermarket probes we make are extended just because we may as well add that feature to the ones we make while we are making them. Why not? I cannot think of any scenario where the feature is undesirable or does harm... and the added cost is negligible. Assuming that you already have the breech/barrel removed from the tube/trigger frame...
- Remove the stock transfer port and its gasket from the valve exhaust transfer area. - Place the stainless port inside the Viton sheath. If one end of the Viton sheath is cut less "pretty" than the other, put that side down onto the valve. - Hold the frame/tube upright as if shooting and place the Boss Buddy into the tube transfer opening (on top of the valve). Keep it upright. - Tricky part for some: Lower the breech/barrel port opening directly over the Boss Buddy and hold together tightly with one hand. - Make certain the hammer pin is behind the probe... and especially that the breech screw hole in the breech lines up with the tube breech screw hole. - Install and start the breech screw a few turns. Check that is is going together straight and aligned... a very tiny amount of side to side and front to back moving helps me confirm I am in the right spot. If good... - Tighten the breech screw another turn or so... check again... when you feel good about it, then go ahead and snug up the breech screw (do not over tighten or it will strip out the tiny breech screw head). That's it. Note: With all this going on it feels like you need three hands a couple of times, but go slow and keep the tube held level as if shooting the entire time. I am pleased to announce that we are already in the process of gathering parts and beginning building some guns that have been done before (what hasn't?) but that we sorely miss.
The 1740 (basically a 2240 in .177 caliber) has been gone for awhile, but has in most ways been replaced with the 2300T and 2300KT. All three are / were nice guns. We think our recipe will best them... and at a comparable price. The 2289 / BackPacker / Doomsday Bugout (DBO) has just been discontinued. Word has it that the Crosman Custom Shop will eventually offer a pumper along these lines. Ours will be better and will be cost competitive given what we will add to it. It will be available in both .22 and .177 calibers with some barrel length choices as well. Finally, a small run of Stubby / shorty CO2 8 gram cartridge guns will be made as well. Their tubes, barrels and breeches will be noticeably smaller than a 2240, but they will perform and look fantastic. After we build the run of complete guns, we will begin offering the parts needed for the DIY builders and modders out there. The "Stubby" gun will be first out of the gate in a few weeks, then followed fairly quickly by both the 1740 and the 2289. So, watch for these and let me know what you think. Our Pump RP valve for the 13xx family of Crosman air guns has been very popular due to its performance and the fact that it is Plug & Play (meaning that it simply replaces the stock valve and does not require a flat top adjustable piston).
Feedback from many dozens of customers has been 100% positive. Only two were ever returned: one was due to an alignment issue with the threaded hole not exactly 180 degrees from the exhaust port. Easy fix! The other had a tiny spec of swarf at the check valve. Another easy fix. BUT... there is barely a day that goes by that I do not get questioned by prospective owners because they haven't read this blog I am typing now! LOL Lets start at the beginning. I maintain that the longstanding fully modded flat top valve and its companion flat top adjustable piston is not one mod, but actually two. The flat top of the valve and the mating flat top of the piston has NOTHING to do with the power potential of the valve. The flat topping business is ALL ABOUT making the physical pumping efficiency so that a user can get more air per stroke into the valve. Not a bad thing at all, but it does require BOTH parts (more expense and adjustment required) to get it. I make, sell and use the flat top pair when I want BOTH more efficient pumping and a valve with more power potential. So what if one were to take a bone stock (un-modded) valve and flat top the face of it... then pair it with a flat top adjustable piston? What would we have? It will take less pumps to reach the "sweet spot" (please read earlier blog)... but it will shoot the EXACT SAME fps as the stock valve and piston that took more pumps to reach the sweet spot, The flat top is for pumping efficiency but does nothing to make the valve ultimately more powerful. So we would have to pump less to get the maximum power from the stock valve, but the performance would not be enhanced at all. Let's go the RP direction. What if we leave the piston stock, then take a bone stock valve and modify it to make the pressure chamber slightly larger in volume... and then make the exhaust chamber slightly larger in volume AND angle the port? Now the pressure chamber will hold more volume of air. It will take MORE pumps to bring that larger volume of air even to the same maximum PSI as before the valve was modified, but now when we reach the "sweet spot" ... stop pumping and fire the gun... a larger (and more powerful) volume of air can be released from that larger pressure chamber and exhaust a larger charge to the barrel port for higher fps (and fpe). Yes, we had to pump more times, but we get more powerful performance results. We (and our customer users) have proven that this works very well, costs less, and is easier to accomplish. Other than having to pump more times to reach the sweet spot, is there any downside to this? Maybe, depending on the operator. If someone pumps 20+ times every time they fire... and pumps quickly,,, and shoots many times and often,,, then the stock plastic piston with its rubber cup is going to wear quicker. I have not seen one break. I have not even been able to wear out a piston cup yet. But lets say that this speed demon that shoots an entire tin of pellets every outing... and shoots every time they get a chance... experiences a negative change in the gun's performance after many weeks/months/years (who knows?). What is the downside? Another new stock piston and cup is cheap and easy to replace. The valve, tube and linkage should be fine. Bottom line for me: I have a couple of guns with this valve and I like what it does for me with the way I shoot. If I am plinking or target shooting (90% of the time) I do not pump for maximum velocity. If I am shooting for power / speed then I know I have that capability. When I do pump that many times I do not fiendishly pump because I am not racing to shoot again and I can feel how warm the tube gets when I have done that in the past. For some actual chrony data from one of my customers that has two of these (one in a 1322 and the other in a 1377), please see the "Kind Words" page and the long entry there. Just remember to "Have Fun Shooting"! David G. We modders like to know whether our changes are better or not. Efficiency mods on the 22xx family let us count shots per CO2 cartridge. Easy. Accuracy mods let us compare target groupings. But power mods need something to tell us whether our guns are more powerful (or not) than before or after a modification. That something could be a chronometer (chrony for short). I have one... a really good with with a printer! But it is a PITA to set up and worst of all takes TIME (not usually our friend).
For some time now, my quick down and dirty (but relatively accurate) gauge of power results from my modifications has been the use of a stack of cardboard boxes bundled and turned up facing me. These boxes are folded and take up little room, are portable, and are 15 boxes deep... times two layers per folded box equals 30 layers. This is more than adequate to stop any of the 13xx and 22xx family of guns. All I do is make certain the before and after shots are from the same distance (usually 5 meters in my main shop room). I use the stick on dots to give me a bunch of bulls to shoot at. If in a hurry, a Sharpie marker will give me something to shoot at in a hurry. Because the cardboard is so uniform, repetitive shots from a gun rarely varies more than one or two layers. For example: somebody sends me a 2240 to install a hot valve and port. I take the gun before and shoot five times into the boxes. I get 10 to 13 layers. OK. Then I install the valve and the port and make certain everything is buttoned up tight, then shoot five shots into a different spot of the cardbard boxes. I count layers and find 17 to 19 layers have been penetrated. Sweet. Mission accomplished. Now it is true I do not know the exact fps nor can I calculate the fpe, but I do know what I wanted to know: This man is paying for increased performance and he is fixing to get it. You might say that this is the same as shooting a phone book. No, it's not. I can do a dozen or more sessions with one stack of boxes. I can keep the groupings separate. I can count the depth of penetration much faster (in seconds) and I can get boxes easily for free all year long,,, whereas I only have a few phone books and they read easier without holes blasted all into them. Targets I have a range set up in my back yard that lets me shoot 5, 10 and 20 meters. I have a box filled with Duct Seal that holds two pages of targets at a time. I like that. Above that is a shelf where I can set things to shoot... cans, ice figures, spent CO2 cartridges, mild carton full of water, whatever. i like that, too. Above that I have one of the re-settable spinner contraptions that lets me shoot six times, then shoot the 7th that releases the six so can go again. Hey, what's not to like about that? But my favorite target setup is this: I have taken six metal coffee cans, screwed them into a treated 2x10 in a line horizontally with their tops facing me. I pack tightly full each one of these six cans with the plastic bags that we get everywhere (grocery store, Wally World, Target, convenience store, wherever). Then I put the plastic lid on the front of each one... and finally peel off six of the Birchwood Casey orange adhesive targets and put one on each of the can lids. Let me tell you... the stopping power of this is tremendous. i shoot these with the Disco, the Marauder, and the PCP Hatsans. It only goes about 1/2 way in. Our 13xx and 22xx much less. The cans only get hit on the edge if you are really a bad shot or have a flier, but that edge even takes abuse pretty well. I am using the same six cans I started with three years ago. I drink coffee year around so my supply of lids is ridiculous. The lids do not crack or shatter, so they also take a surprising amount of shots before they get replaced (for free). Thanks for stopping in. Remember to have fun shooting! The saying "your mileage may vary" gets tossed around a lot referring to our guns. I use the phrase myself. Whether bone stock right out of the box or highly modified and tuned, there will almost always be differences from one gun to another.
On the pump guns (1322, 1377, PC77, Backpacker, 760, etc.) so many people want more power, more fps, more fpe. Often right out of the gate I get orders for heavy hammer springs over and over. Hardly ever does anyone ask for a lighter valve spring. But we've been over springs earlier, but I am just making the point that there are certain knee jerk reactions that might not be right for the gun (at least not right away). Some examples: I have had folks with a stock 1377 or 1322 call to order a heavier hammer spring. I ask how they are using the gun (targets, plinking, small yard pests, hunting, etc.). Often I hear primarily targets and plinking but with the occasional bird or squirrel as the target. I ask how many times they are pumping the gun. Lots say not over ten (as Crosman advises), but some say 12 to 15 or more. I ask if they pump max all the time? Or just as needed?. So I ask at ten pumps (or whatever their self-imposed max is) is your valve retaining any pressure after a shot? Most do not know and have never tried to find out. I HAVE to ask this next question! Why are you wanting a heavier spring to release more air if you don't know if you even can?... when it is likely that your gun is dumping all of the charge every single shot! So therein lies what I call the "sweet spot". You pump your gun higher until you reach the point that after a shot, you re-cock without pumping and see if there is anything left in the valve. Lets say on a given gun that is 16 pumps. So if that is the case, then why even pump past 15 pumps? If you target shoot and plink 90% of the time with 6 to 10 pumps, then when you think you need more power you will know that 15 is about all she's got (without further mods). Now there are speed demons out there that will pump the maximum all the time/ every time. If your piston is stock and you do this repetitively and often then you are going to decrease the life of that piston due to the heat and friction this behavior subjects the piston to. During a spirited shooting session of repeated maximum pumping just stop for a second and feel the air tube. Pretty warm, huh? The concern over this is what is behind several mods including "stuffed piston" (reinforced so it will not bend / deform under higher pressures and temperatures... also the pistons made from metals (aluminum, brass) or better plastics (usually delrin) to take the heat and pressure abuse. Some go for Viton o-rings at the piston and the valve outer... because Viton handles higher heat than standard Butyl. So find that sweet spot!... if for no other reason than to not be over-pumping every time and stressing your gun for no gain. Hopefully that will be enough for you. If that sweet spot is not enough for you, then you'll know you need to move on to valve and / or piston mods, spring mods, porting mods, extended probes, etc. etc. It's really hard to tell how many readers we have of this little blog. With 100 to 600 visitors every day I would hope that a few of you out there are reading and finding it at least worth the time it takes to read these little meanderings. I'd really love to hear more of your comments, your take on the subject matter and even a few pointed questions.... or suggestions.
So this reaching out does have a motive! I really love all these air guns. I hope you do, too. I am always thinking of what needs to be better or different or improved. I just bet you fine folks do at least a bit of the same now and again. So, with that said I would like to invite YOU to share what you WISH were available but is NOT (yet). I'll go first with a four of my dearest wishes... just to maybe get the collective synapses firing: 1. The "holy grail" part on my wish list is a metal grip frame plate (now discontinued) for less than half the price of a new gun. It is SO frustrating to me that I can plate or powder coat or polish and clear an entire frame, but there is that little triangle of black plastic to deal with. 2. I wish to have replacement options for all the Crosman plastic parts. High on that list are the pumper (including Backpacker) barrel bands. I do not like to be able to twist the barrel and tube laterally with little effort. For some reason I do not have a problem with Delrin or properly engineered 3D printed plastic (the reason being is they are not bent easily at all... are very strong... take finishes well... yet are not brittle and do not shatter or break easily). Metal is good, but the offerings out there are pretty dang pricey. The Crosman plastic bends and distorts. It Is very tough, but hardly "serious" gun worthy. That is perhaps why the metal breeches are so popular as an upgrade. I am NOT knocking Crosman for using it! I will repeat that I am amazed and thankful that Crosman makes these fine guns for so little of price. I acknowledge that if they made them all metal and wood, then the price would be much higher and we would have less fun transforming them into what we want them to be. 3. I wish for some rear sight options (besides the LPA MIM or the standard rear sight). I know there are more, but they cost MORE than the price of a new gun. The Crosman rear sight is in my opinion a superior design (albeit that non-rigid plastic). Maybe we can improve on that. I also like the rear sight to be mid-gun on the guns we put longer barrels onto. Whether LPA MIM, stock rear or other, the visual resolution is terrible when a long barrel is added and the distance between the two sights (front and rear) is lengthened without changing SOMETHING. How can I hit the spinner at 20 meters if the front blade completely covers it up? The stock Backpacker setup is pretty crude in my opinion. These guns are more accurate than the sighting allows. Maybe its just me!? 4. I wish for some inexpensive yet durable accessory mounting "helpers" that make it really easy to add a bi-pod or torch or laser to our guns without hanging metal adapters (scratch makers) all over our blued metal tubes and barrels. That's four. Your turn. Have fun shooting (and wishing). We're not gonna talk about the season-of-the-year Spring, but the Springs in the 13xx and 22xx families of Crosman pump and CO2 guns. There are only four (4) springs in these guns... or five (5) if you count the BackPackers' quick change carbine stock spring.
Lets list them first along with their location, function and modifications (if any) and comments as needed. 1. The Backpacker Quick Change Spring ... is located within a release pin in the grip / trigger frame hole just below the tube (right next to the rear grip / trigger frame screw that screws up into the tube and rear tube cap). All of the modern 13xx and 22xx grip / trigger frames have these holes (just not the pin/spring), so ALL of these frames have the capability for a carbine stock with no grip screws. Its function (along with its pin) is to provide a catch for the BackPacker carbine stock that is in all ways the same as the 1399 except for its lack of screw holes in the grip frame location. You slide it on as usual, but instead of attachment screws the carbine stock catches on the spring / pin and holds it very tightly in place. It eliminates the small amount of up/down slop that most 1399 carbine stocks seem to have unless one puts some padding in the right spot to make it go away. With the pin/spring in place, to release / remove the carbine stock requires that you simply depress the spring/pin so the carbine stock will slide off. I like this feature, but it simply BEGS for a one-piece set of grips (wraparound?) that can go on just as quickly and make use of this pin/spring as well. We'll save that idea for another day. ;) 2. The Safety Spring is located on top of the safety and safety ball bearing. Its only functions are to keep a small amount of pressure on the safety ball for the safety to behave correctly... and to be lost when it you least need or expect it. Just remember when disassembling the trigger frame from the tube to keep the tube and trigger frame UP as you slowly lift the tube from the frame (or slowly lower the frame from the tube). If you do this upside down then chances are the spring and/or the ball will cease to exist this to 3. The Sear Spring is located behind the grips and between a lower frame base and the bottom of the sear. I have already made a blog entry about this, so lets move right along. 4. The Valve Spring is located inside the valve between the valve pin and the face of the valve. It pushes towards / against the valve release pin to keep the valve in a normally closed state. When the valve opens (gun is fired) this valve spring begins pushing to close the valve just as soon as the energy of the hammer that opened it is spent. The valve spring affords opportunity for behavioral change to your gun as well. A heavier valve spring may be a part of a system that uses less CO2 in a 22xx family gun. A lighter hammer spring may accomplish the same thing. A lighter valve spring may increase the dwell open time enough to add power (and use additional CO2 that might not be put to good use (wasted). A heavier hammer spring may accomplish this same thing. 5. The Hammer Spring is located at the breech end of the tube... just behind the hammer. its purpose in life is to propel the hammer into the valve pin (overcoming the valve spring momentarily) to release the air or CO2 that exhausts from the valve to blow a projectile out of the barrel. Given the fact that the hammer energy comes from the hammer spring, hopefully you can see that there is a bit of tuning opportunity within the give and take of the two springs. Most modders / tuners instinctively go for changes in the hammer spring simply because they are easier to do, more readily available, easier and cheaper to purchase, and perhaps easier to understand what you're doing (or trying to do). The stock hammer spring is a simple spring that is pent up between the hammer and the rear tube cover. When we cock our guns, the hammer slides back (compressing the spring) and is held in a ready to fire state when the sear catches the hammer to hold it in position. To exaggerate to extremes, too weak (or short) of a hammer spring and your CO2 gun may not even fire (or certainly not pierce the new CO2 cartridge you just installed). That's no good! Too heavy (or long) of a hammer spring may prevent your gun from cocking or may waste CO2. There are also Power Adjusters (actually hammer spring tension and stroke adjusters). I am a fan of these since there are times when I wish to shoot for maximum power... and others when I want repeatability and to conserve CO2. Having a Power Adjuster (PA) is like having a pocket full of different hammer springs at your disposal but without having to change them in and out. Crosman has a nicely functional PA. I am not particularly fond of the plastic knob nor the fact that it is only for the 22xx family of CO2 guns. Aside from that, note that any PA you have or use can be further tweaked and modded with changing ITS spring from the one supplied. You will have a range of spring tension either way, but you can shift that range with a lighter or heavier PA hammer spring change. Discussion A few things "spring" to mind before I close this rambling of mine: Many folks know that you can use a 13xx family spring as a stronger spring in the 22xx family guns. And some even know that a 760 spring can be used as a stronger spring in the 13xx family of guns. If doing some serious tuning with a goal / objective in mind, DO NOT be afraid to "tune" a hammer spring by cutting it. Just go slow (because you can't put it back if you take too much). If you do cut a hammer spring, put the cut end into the hammer recess. I have better luck with this than fingers crossed trips to the hardware store. Finally, Spring guides can be a good thing in the hammer spring and in the sear spring if for no other reason that to keep the spring from bending / not being repeatable in its duty cycle. Have Fun Shooting and Happy New Years! |
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