New 22 mrod, bad groups.

[Brewerja]

So i picked up a refurbed .22 mrod about 2 weeks ago and just finaly got to group it again. I have tried the degreasing with googone and smoothing it with mag polish but this baby just WILL NOT GROUP!!! I work at a range on camp pendleton so i set myself up a few targets at 20 yds and my groups are a half dollar or larger!! So far iv tried JSB RS 13.4gr, JSB exact 15gr, JSB JUMBO 18.1, logan penetrators, cphps and benji discovery 14.3gr. The best i couldget was a quater with half of them flyers. Im at a loss here, did i just get a bad run of barrels on mine? I have heard that these things really need 5.55mm or 5.6mm pellets to really shine. My benji trail XL will send jsb 18gr through the same hole all day at 25yds. I know this is the dark sidebut, does that mean i have to use "the force" to will the pellet into the bulls eye? Lol, perhaps im missing something? I tried grouping both with and without the shroud. The POI changes significantly but the groups randomness doesnt change. I need some help, what do i do next?

[Brewerja]

I forgot to mention that most of the groups were about 3" and i will post pics of my hideous groups tonight

[JFS737]

I got mine used... was an older one and had the "old" barrels... The newer ones supposedly have different barrels.  Well, I ordered 2 and put one on.  It is MUCH better.  Likes JSB 15.9 and 18.1 (testing Kodiaks tomorrow), and will shoot nicely.  I get .3-1.1 inch groups at 50 yards, mostly about .6 or so from a benchrest.  I still get fliers and that's bothering me, so I'll be working on it.  Fliers open up my normally good .6 groups and make them 1.1 's !   

I highly recommend spending the $24 or so, or if you call Crosman and complain they may send you one.  Also, make sure your baffles are .280" for the pellet opening (as I recall), ensure the barrel shroud is centered in the barrel and chrony the gun to make sure it's shooting properly (decent max spread). 

My first barrel was just like yours, a couple in a group then a couple shotgun style. 

Good luck,
John

[MustangMike]

if you need a barrel id contact mellonair.com and see about getting a mrod barrel through him. he recrowns every barrel he sells so you get a new barrel with a good crown and its only like 30 bucks for his barrels... think that includes shipping as well

[barcabarca]

Hey, I don't know if you saw my post, but my groups at 25 yards were around 2" or so.  This was at 2800+ PSI.  They shrunk to below 1" when the pressure was between 2600 and 2200.   I am still not sure why this is, but I am trying to see if it is just a problem with having too much pressure for the rifle\pellet combination.  I am still trying to understand why this is...I am going to try heavier pellets soon to see if they can make a difference.    Maybe you have the incorrect pressure in the tube Are you filling to 2500 psi or more

[Gixxer340]

I can't believe how badly mine will throw pellets it doesn't like. With JSB 18.1 I get 3" groups at 20 yards. But with H&N Baracudas the same gun will produce 1 hole group at 30 yards. Not saying this is your issue as well just giving you my experience as a new Marauder owner. Mine also seems to do ok with predators and Crow Magnums but not nearly as good as the Baracuda's. I also tried Rabbit magnums and got like 7-8" groups at 30 yards. Not exactly sure cause I didn't even measure them they were so bad. So, maybe you just need to find the pellet(s) that it likes. I have heard that they can be pellet finicky at times.

[aack73]

i have heard others report good results with h&n ftt. not sure what size but worth a try.

[captwoody]

Do you have a chrony? mine wont shoot Groups unless it is below 900fps.I have mine shooting sub dime groups at 25 now just takes time in pellet selection. i am not a pro but i live in murrieta 30 miles from the base and i have a huge pellet selection Pm me if you would like and in a couple of hours we can trouble shoot it first before doing barrel changes.This is my way of paying forward the help guys here gave me and its fun to shoot so its not like work. I am a fireman so i have a pretty flexable schedule

heres my range, and i have all the air and tools needed-woody

[Brewerja]

Hey woody, yeah i have a chrony at the range. When i first got it, it chronod at 840 @ 3000 psi and worked its way up to 915 by 2200 psi. I havnt tried to adjust anything yet as far as hammer or velocity screw or anything. I was waiting to get some kind of group out of it before i mess with things.  Its a dang scatter gun!!! And if i can only shoot super huge and expensive h&n FTT to make it group, i should probably just return this dang thing. I may take you up on the offer captwoody, but i have finals this week, i will send you a pm. I am pretty frustrated with this barrel. I wonder how crosman let this sneak past them? Also, are there any other things i need to check to ensure the accuracy is up to par? Any other possible parts that may be out of tolerance or need some TLC? I tore the gun down and cleaned and lubed everything and i couldnt find any jaggys or burrs on it so... I give up. Lol. I will call crosman on monday. Is there a way i can be sure they dont send me another junk barrel froms a bucket full of junker barrels? Like do i request a certain lot number or run/ series? If these new barrels are anywhere near what my titan and Trail XL are, i think i will be a happy dude. haha. I will get in touch with ya woody. Thanks man.

[jonnnyboy]

A few things I checked before working on my Mrod barrel was:

1.  Make sure the shroud is centered and not touching.
2.  Remove the baffles and make sure they are not clipping.
3.  Check that the shroud is screwed in securely and that the o-ring between the barrel and the baffles is in place.

These were simple things that have caused some Mrod owners problems.  Maybe that will help.  I hope you get it figured out.  Let us know what you find.

joe

[captwoody]

I have a barrel polish set up i do that really has helped my gun. plus pellet selection changes when you make adjustments so variables are huge with these guns but when you get time this is what i can help with.
check crown-fix if needed
polish barrel-swab and mothers mag polish
center shroud and make sure screws are tight but not overtightened
ensure scope is level and tight
adjust pellets to 850-890 fps
un hook lawyer spring-put trigger to about 1.5 lbs
test 20-30 types of pellets 5 shot groups pick top 3 to work with
decide what fps you want to shoot and retest top 3
i am fairly confident by this time we would have groups much smaller than you would have now and this take about2-4 hours dependin on what we encounter and would give us an idea which direction to go if further improvement is needed. good luck with school woody

[Markez]

You may want to check if the pellet is getting damage from the clip. do you have a singal shot tray?


Mark

[Jay]

Mark has a good point try single loading it, you can load one with just your finger's if no tray(I know you can if I can with my short stubby finger's). Also check your breech 0-ring inside barrel as it can cause flyer's.

[Brewerja]

yeah, sorry i forgot to include that i was using the single shot tray. suprisingly, that thing is plastic!!! i thought it was aluminum, i should have known better, lol. I tried both with the shot tray and the clips. i did notice that the bolt seems to cycle much smoother with the single shot tray, but i did not note any change in POI from using clips vs the shot tray. i will look again at the oring inside of the barrel, however, when i i cycle the bolt on an empty chamber, it feels tight and i didnt notice any obvious gaps or inconsistancies in the fitment. I was hoping that, the marauder, being crosmans prize piece next to the rogue would be a little better quality controlled. I am disappointed but expected something to be wrong with it since i bought a refurb. It looks like i know why this one was sent back to the factory! I am trying to keep a positive attitude towards these fine pieces of machinery and crosman/benji but its extremely frustrating to spend hard earned money on a gun that claims superior accuracy but fails to deliver t over and over again. ohh wel, i will keep messing with it and hopefully the new barrel and or the barrel polishing will solve things. we shall see. thanks for the help guys! 

[Brewerja]

Just called crosman about the fudged up barrel i have on my M-rod, i got lucky and got Kim on the phone. Long story short, i got a free barrel and O-ring complements of Kim over at crosman!! I cant wait to get the part in and install it. I am like a little kid on Christmas waiting for my barrel to get here!!!

[captwoody]

before you install, polish the bore with bore polish or mothers mag polish this helps immensely,polish the lead,and transfer port. and of course crown. also it is easiar to push pellet through with dowel checking for tightness with barrel out.this will elimiate trouble shooting steps later-woody