New Sheridan 2260MB: Here's my groups. What do you recommend next?

[WilsonLR]

Wilson:Just waiting...you already know which way the rear sight has to move to make it shoot left. But with that set up (good test), would be more of a pivot than a side-slide.

Never a fan of the slot in the fill cap...if finger strength won't seal it, then you need a new seal.

Yeah that model 99 Peep had to slide left and pivot a little for it to shoot straight. I put everything back and shot a group compensating with the buckhorn so if an Iguana shows up, I know I can shoot an inch group.

I only use finger tight. I didn't see your post until I started a new thread about the problem. Thanks for all the help. Which seal do I need to replace?

[WilsonLR]

Is this what I need?

[WilsonLR]

UPDATE: Something went wrong at the time I added that peep sight using the rear sight screw. I don't know if the 1/4" longer screw I used wasn't tight enough or somehow misaligned something slightly. Or maybe I didn't crew the CO2 cap enough and ruined the Valve Seal G397-012. I have another thread on that problem.

Moving forward on this thread, thanks for all the help on the iron sights. I found a deal on a Leapers UTG 4x32 AO True Hunter scope on Optics Planet. Unfortunately the only model remaining had the wrong rings so some BKL rings were an add on for a total $76 shipped. I'm excited to experience a scope with decent turrets and learn how to use mildots. A fixed scope with 15yds-infinity AO suites my backyard plinking/Iguana range perfectly. FWIW, Optics Planet has one left:
https://www.opticsplanet.com/leapers-utg-4x32-1in-ao-true-hunter-riflescope.html

As far as the gun shooting right 3" at 10 yards, can I loosen the tube side of the barrel band and twist it slightly to correct this?  I'd wait till after I properly mount the scope. If the problem persists, is the band adjustment a valid "fix" or a dummy noob mistake?

[Ribbonstone]

EDIT at bottom.

Not saying you have to buy from here....just wanted the picture. You could hunt up the parts numbers and order from Crosman (phone orders...and they pretty much deal in parts numbers).

https://www.@#$%^.com/Seal-and-Valve-Stem-Kit-for-Crosman-2240-and-1740-p/2240sealvalvestemkit.htm

Think middle part(the valve stem) is the part leaking down the barrel.

Looking at the picture,the "peach"colored sealsare what the 12gr.nise is pushed into to deal.
The big o-ring goes between the two halves of the valve body.
Medium0-rings seal the transfer port.
Little o-rings are bolt probe.

I'll look around on-line. They used the same valve in the 2240 as the 2260, they interchange.


Not too picky about scopes....simple inexpensive ones generally work better than complicated inexpensive ones....I've used that scope and have no complaints.  Several rifles do use 4X scopes,it's really a pretty good match to the rifle.
-----------------

Read 2nd thread at last:

OK...tube got cold...yep, that's likely the peach color seal.   MAking a substitute is a whole lot of trouble, so I'd buy the reseal kit (I'd still want a spare valve stem).   For that matter, could get a complete 2240/2260 valve (they are the same) if the price was reasonable (haven't checked in awhile).

[WilsonLR]

Great timing @ribbonstone.  I decided it was likely the peach valve face seal. I just now have a shopping cart at "archerairgun" with a replacement valve and seal kit so I have a quick fix if/when the valve stem goes. That seal kit also has the TP seal so if/when ...  Looking at Alliance next. Thanks again for all the help.


Now, what about the barrel band adjustment tweak for the shooting right problem?

[Ribbonstone]

Take the band off then try gently moving the barrel and see if it wants to just stay wherever you move it or if it want's the spring back to it's original place.

Part of that is how the breech end is tightened down....but for goodness sake don't strip the little front breech screw (And as you're going to have to take apart the rifle to get to the seal you need to change, don't do anything now you'll have to re-do later?).

Generally, would rather have the barrel in it's neutral spot, then put on the barrel band, and just deal with a scope adjustment.....forcing it into a stressed alignment hasn't worked out all that well.

[WilsonLR]

Awesome. Will do.  I added a stainless steel breech screw to my cart at alliance. Getting a valve and seal kit.

[Back_Roads]

UPDATE:

Moving forward on this thread, thanks for all the help on the iron sights. I found a deal on a Leapers UTG 4x32 AO True Hunter scope on Optics Planet. Unfortunately the only model remaining had the wrong rings so some BKL rings were an add on for a total $76 shipped. I'm excited to experience a scope with decent turrets and learn how to use mildots. A fixed scope with 15yds-infinity AO suites my backyard plinking/Iguana range perfectly. FWIW, Optics Planet has one left:
https://www.opticsplanet.com/leapers-utg-4x32-1in-ao-true-hunter-riflescope.html

As far as the gun shooting right 3" at 10 yards, can I loosen the tube side of the barrel band and twist it slightly to correct this?  I'd wait till after I properly mount the scope. If the problem persists, is the band adjustment a valid "fix" or a dummy noob mistake?

Here is something old school to help with the mildots, great handy slide rule, that gives you accurate range estimates using your scope and the charts.
 

 And yes I would center the scope , if new should be close enough, shoot and adjust the Barrel Band to get on POA. then fine tune with turrets.

[lefteyeshot]

I have a 2260MB. Got old eyes also. Never shot it with open sights. You really need to scope it.

[WilsonLR]

Scope shipped today. Magazine arrived and I tried it out. Totally obscures the iron sights. You have to go to a higher rear and front sight, red dot or scope.

The magazine works like a charm.

[WilsonLR]

Scope arrived but the rings I ordered were for a 30mm scope so I am waiting for an exchange. Opticsplanet is great that way. As easy to return and exchange as Amazon.

In the meantime, I installed a power adjuster and a Pro-Top valve seal to replace the brain dead Crosman face seal. The Pro-top pierces the the canister when you tighten the top instead of waiting till you cock and shoot. The later is problematic when you don't tighten enough and the seal blows or vice versa, tighten too much and the seal is damaged. IMHO the 2260 is fundamentally flawed that way. Pro-Top should be standard.

I now have a working gun. The 2260MB iron sights are useless. The gun fires 2-3" right at 10 yards and there is no windage adjustment.  At least the Crosman 2260LE comes with a rear better sight at the cost of a plastic breech.

[lefteyeshot]

What is that magazine and where did you get it?

[WilsonLR]

That is a GRAVmag 9s. It only supports specific pellets. I got the Croosman bersion that has an extra tube for Crosman pellets. It comes from the UK but you gotta grab one while they are available. Works like a charm. FIts under Standard/Medium rings.

https://www.airgun-parts-shop.co.uk/collections/all-crosman-products

[Ribbonstone]

Did get the old protop sealed....a little toughter than the orginal,so I have to screw down a bit harder,but it works. Used what I think is a Discovery valve stem.

Still looking for a little bit more "squishy"seal material.

Never did polish it...cleaned it,but the dull oxidized brass from years of being in storage doesn't bother me.

Did shoot a bit faster than the orginal...likly due to less clutterand the smaller valve stem.  Which is NOT what I wanted,but  adjusted the spring tension a bit and it got back to the energy level I was looking for.
You would not have been thrilled with the plastic breech and the clamp on scope mount that that required. That plastic breech works well enough with the issue rear sights of the time,but consider that the barrel is just pushed into the plastic breech,NOT secured with set screws,just the metal transfer port interlocking the barrel in place.



Considering th shape of the feeding systemof that mag...it's likely to be a bit pellet picky.....keep an open mind testing, likely there is something that will both feed and shoot well.

[WilsonLR]

I think the Sheridan 2260MB should have come with usable open sights. You pay more but is usable out of the box. The sights from the LE would have been fine. Or a rear sight with windage. Or a gun that shoots straight.

Anyway, is the advantage of the Discovery valve stem that its smaller and therefore allows more air to be used in the valve per shot?

These are the approved pellets for the standard GRAVmag magazine tube:
JSB Exact Jumbo Diabolo (15.89)
Air Arms Diabolo Field
RWS Super H Point
Webley VMX
H&N Baracuda Hunter
Weihrauch FT Exact

For $5 more you get a "Crosman Tube" which supports these:
Crosman Premier 14.3gr
Crosman Premier Hollow Point 14.3gr
Crosman Premier Ultra Magnum 14.3gr
Webley Accupell

[HYspd]

why are you going nuts with all the after market producers that resell crosman parts?


go to crosman's web site and look at the exploded views and parts lists and call them to place an order, they have the lowest prices for the parts that they make...


order a cheap bottom of the line kt2400 from the custom shop and you'll get open access to order everthing they offer there too...


the REAL question STILL hasn't even been considered....why does the barrel shoot so far right?


look on this site for info on how to clean, check and crown an airgun barrel....use a dowel to push some pellets through the barrel to check for smooth passage (requires some easy disassembly to get the barrel off)...

and welcome to what we call the Lego Gun series...aka the crosman 22xx and 13xx platform based airguns that range form the 1377 and 2240 at the low end up to the Fortitude rifle and Marauder pistol at the higher side

[Ribbonstone]

Could well be a jacked up barrel....but they do sell them with what is basically 1/2 fixed sights (elevtion,m but no windage)....and put a plastic front sight that hides the muzzle/crown.

If the barrel were off, one good roll on a clean glass table top would pretty well show if the barrel was seriously bent.

Couple of pushed though pellets could confrim if there is a bugger on the barrel port.

A crtical visual and a stright edge (or a dead straight 3 foot rod/dowel)  would give clues to the alignement (often foced cock-eyed by the barrel band).  If you don't have that, a string and a weight (plum bob).

Evidently, he's going to scope it....which is what most of us would do....which might solve all his problems.MIght solve none of them.

Figured we'd deal with them after that point.



ProTop does worek....it also limits the ability to hot rod a 2260.  Whatever gas gets into the valve has to move though that tiny-tiny hole in the middle of the piering nipple. Willpoke a good sized hole in a 12gr.,but it'sthe little hole in the middle of that fixed nipple that passes the co2 along.

Really no problem...can't cycle the bolt fast enought to NOT have the vlave get filled between shots.

[HYspd]

2260 rear sight is adjustable (cough) for windage....you just have push firmly, pry on or take a hammer to it...

your milage may vary, but it worked for me....

ans while nearly everything i own has  scope on it, i'm begining to think open sights are less hold sensitive in the eye relief and cheek weld areas...

i don't group well with open siights, but in practical situations, i hit what i am aiming for with far less deliberation...


that said, come on y'all help me lead this guy down the rabblt hole...hehehahahehe...(counting my 13xx and 22xx series airguns, all modified by me...7....8...9....oh and this pile of parts will be....)....you won't believe what my 2260MB looks like now...

[Ribbonstone]

Don't really like leaning/rotationally challenged, sights.

But were it mine, it would get the sight bald cut off to a stump....an adjustable leaf spring sight low temp. silver soldered onto the stump...and would "clciky-clicky" my way to zero.

[fivestar45]

I think the Sheridan 2260MB should have come with usable open sights. You pay more but is usable out of the box. The sights from the LE would have been fine. Or a rear sight with windage. Or a gun that shoots straight.

Anyway, is the advantage of the Discovery valve stem that its smaller and therefore allows more air to be used in the valve per shot?

These are the approved pellets for the standard GRAVmag magazine tube:
JSB Exact Jumbo Diabolo (15.89)
Air Arms Diabolo Field
RWS Super H Point
Webley VMX
H&N Baracuda Hunter
Weihrauch FT Exact

For $5 more you get a "Crosman Tube" which supports these:
Crosman Premier 14.3gr
Crosman Premier Hollow Point 14.3gr
Crosman Premier Ultra Magnum 14.3gr
Webley Accupell

The Disco valve stem is not so much smaller, but rather harder than the OEM 22xx co2 stem. The advantage is it lifts easier, and quicker with less force. So you can get more power with less striker spring pressure. Also works very well with a lighter striker.
The downside is that it does not always give a good seal with the OEM brass 22xx valve body, unless you lap it in. I always recommend using the higher quality Disco valve body, and stem mated to the Pro-Top.