2240XL pellet choice

[badduck]

Hi,new to air guns so i have a lot to learn,I have a 2240XL I see a lot of people use 14 gr pellets if I use the lighter pellets a ten shot target looks like a shotgun pattern this is at 25 yards, but I switched to 17.75 gr and it does a lot better groups.Is it me or does this gun just like the heavy pellets. It's stock maybe 100 shots threw it.

[ThatFella]

I feel like I'm having exactly the opposite result.  I have probably 4-500 shots through mine, though it's the standard 2240, not the XL, and all of that has been off hand.  Feel like I need a decent rest before I get too judgy on the pellets.  Most of my shooting has been with Crosman premier hollow points, the 14.3 gr.  Dirt cheap and readily available always score points with me.     I also picked up a variety pack of JSB diabolos that has four diff weights- a 13.5 (or 8? I forget..) a 15.5-ish, 18.something, and some big ol' 25 gr honkies.  Pistol seemed to really like the 13's and pretty consistently sent the fatties high/right.  There is noticeably more recoil with the heavy pellets so *maybe* that had an effect... dunno yet.  Also, all of my shooting has been in the 5-15yd range.

At any rate, trying new ammo is fun and I wish more variety packs like that were available.  There are some but few and far between. 

[badduck]

As you said jsb pellets have been recommended to me by others so I'm going to order the sample pack and see.

[RScott]

Here are my results with a modified 2240.  I too got good results with pellets around 16 grains.  But weight was not the only determinant.  Results vary by pellet type/shape as well as weight.
(Sorry for the poor formatting of the copy/paste of my spreadsheet table)

Crosman 2240 speed, accuracy, and sound levels                        
   Steel breech (purchased Crosman 2240XL)                     
   18" barrel from Alliance Hobby                     
   Boss Max valve, stiffer hammer spring, and hollow bolt probe from Alchemy AirWerks, 3.9mm transfer port from Alliance Hobby; uses about 1 gram CO2 per shot                     
   Bulk CO2 set-up:  fed from 250 gram / 9 ounce cylinder; powerlet eliminator from Alliance Hobby                     
   Falx moderator from Silent Thunder                     
                     
   Crosman 1399 stock                     
Speed measured with Competition Electronics ProChrono DLX                        
Accuracy is max center-to-center distance of 3 shots, from 30 feet, inches                        
                  
Session 2: Simple Caldwell stand; 75 degrees; 60% humidity; overcast; at least 20 seconds between shots                  
Barrel length   Valve   Moderator   Hammer spring   Pellets   Grain   FPS   5-shot accuracy, 10 yards (CTC, inches)   Comments
18   Boss Max   Falx   Boss Max   Gamo Red Fire   15.4   560   0.20   Loading alignment helped by seeing red tip
18   Boss Max   TKO   Boss Max   AA Field 16   16   590   0.23   584 FPS with AV 1100 psi air tank
18   Boss Max   Falx   Boss Max   Skenco Newboy Heavy Weight   26.2   478   0.28   Oxidized; difficult to close bolt
18   Boss Max   Falx   Boss Max   Predator Polymag   16   556   0.28   Loading alignment helped by seeing red tip
18   Boss Max   TKO   Boss Max   H&N FT Trophy Green   9.56   695   0.31   
18   Boss Max   Falx   Boss Max   JSB Match Exact - Ultra Shock Heavy   25.39   474   0.31   
18   Boss Max   Falx   Boss Max   JSB Match Exact - Jumbo Monster   25.39   469   0.31   Easy to load
18   Boss Max   Falx   Boss Max   H&N Terminator   16.36   559   0.31   Very firm bolt fit
18   Boss Max   Falx   Boss Max   H&N Baracuda Hunter   18.21   538   0.35   Large hollow in tip
18   Boss Max   Falx   Boss Max   JSB Match Exact - Beast   34   428   0.43   2 out of 7 would not allow bolt closure
18   Boss Max   TKO   Boss Max   JSB Monster   25.39   494   0.5   484 FPS with AV 1100 psi air tank
18   Boss Max   Falx   Boss Max   JSB Match Exact - Jumbo   15.89   558   0.55   Easy to load
18   Boss Max   Falx   Boss Max   H&N Field Target Trophy Green   9.56   675   0.55   
18   Boss Max   Falx   Boss Max   Crosman Premier dome   14.3   591   0.63   
18   Boss Max   Falx   Boss Max   JSB Match Hades   15.89   567   0.75   
18   Boss Max   Falx   Boss Max   Crosman Premier hollow point   14.3   572   0.83   But 30 shot string was within 24 cm = 0.9 inch
18   Boss Max   Falx   Boss Max   FX Hybrid Slugs   22   495   1.06   Very easy to load
18   Boss Max   Falx   Boss Max   H&N Baracuda Hunter Extreme   18.52         Not tested

[Rezarf]

Here are my results with a modified 2240. 

The data look like a lot of fun - I reconstructed the table in Excel so I could examine it. Have you considered repeat testing at 20 yards to see how they fall out? Piques my curiosity, especially the tight group with the gamo pellets - never would have thought they'd be  that accurate. Thanks for sharing!