Some MRod input needed please

[barcabarca]

I have a Marauder that was a .177 that I converted to a .22.      I like the power, but the results when shooting are strange to me...below are two images.

First one is 10 shots,  with the fill at 2800+ , it averages 900fps  w\CPHP.
Second, 10 shots, with the fill at 2500+. The last pellet chrony's at 855fps
Both are with 14.3gr CPHP out of the tin. 

Why is there such a huge difference in the accuracy\grouping of the pellets.   These are 10 shot groups using a seated bi-pod position from a laser measured 26 yards. 37 degrees, very small gusts of wind, in a protected shooting area.  The first group is almost 2"    The second group is a nice group of 7 and a nice group of 3 next to it. under an inch.

I'd like to maximize the FPE for hunting Racoon size animas at 25-50 yards.  Id like it to have the same size group at 50 yards and more as the 26 yard group.   

Any insights would be helpful..

Thank you...

[gene_sc]

Did you remember to change the baffles to .22 size when you did the conversion?

[MustangMike]

Maybe ur mrod's sweet spot is where the pressure is when it starts grouping tight.. shoot untill shots start dropping and that's ur refill point..

[barcabarca]

oooohhh its always the obvious stuff isn't it.  Can I use a drill press and just open up the size of the holes, or do I have to purchase new ones to be sure

Thanks sir!!!

[RatRacer]

Also, if you have not changed the factory settings, .177 & .22 mrods are tuned for a ~2500 fill.

[daveshoot]

An insightful question by Gene!

You would want to inspect condition of your current remaining baffles, first... not sure they would still be in shape to bore out. I'm sure you could order new ones.

[eddielee70]

.177 and .22 baffles are the same.  .22cal barrel like 5.55mm H&N ftt, 5.53mm H&N match barracudas.  try those and you should get tighter group.

[JFS737]

Hi,
    My .22 won't shoot CPHP's for diddly.  It does like JSB 15.9 and even more so the JSB 18.1,  I haven't shot the Kodiak/Barracudas yet but soon. 


Regards,
John