.22 Marauder Gen 2 with Marmot Militia Barrel shot string

[StarlingChaser]

I don`t post very often but I thought some others might like to see my final setup and shot string info. First I have a .22 Marauder Gen 2 synthetic rifle with a Marmot Militia barrel. Other than that it is stock. I had a setup that worked pretty well but today I took the time to try many setups. I made over 500 shots and cleaned the barrel every couple hundred shots or so to get to the results I wanted. I use JSB 18.1 pellets. I also oil my pellets as recommended for this barrel. I started at 2900 PSI and shot # 30 was down to about 2050 PSI.
My final setup: Hammer Spring set at max tension.
                      Hammer throw is set at 7 turns in (backed all the way out then turned 7
                      turns in)
                      Metering screw backed out 3 turns

1. 892 fps
2. 900
3. 903
4. 893
5. 904
6. 895
7. 896
8. 900
9. 908
10. 897
11. 895
12. 902
13. 916
14. 901
15. error
16. 908
17. 907
18. 914
19. 913
20. 918
21. 911
22. 907
23. 909
24. 901
25. 910
26. 904
27. error
28. 896
29. 890
30. 891

2.84% deviation between high and low.

This group gives me a 1/2" group at 34 yds. with most shots inside 3/8". All guns require their own fine tuning but this worked for me and hopefully may help someone else with a similar setup. It is kinda odd but most of the 1st shots were on the low side of the 1/2". The center of the string was dead on and the last part of this string was on the high side of the 1/2". I could duplicate this over and over. I am still looking at a max of 1/4" off dead center so I am very happy with the results. I can do 3/8" raged holes all day long if I shoot between 2700 and 2400 psi. All this was done with a bench and bench rest. Happy shooting!

[Christopher]

Sounds like you got it shooting pretty good. How long is the barrel? Is it the stock 20" or did you go longer?

Thanks,
Chris

[Trigger_Finger]

Looks very good for a non-regulated rifle.  Have you compared the shot string to the original barrel?  I have the Gen 2  stock settings Marauder.22 which can hit pellet on pellet at 20 yards but I never bothered or procrastinated doing Chrony. Now you've got me curious as to what my shot strings are.

[moorepower]

You would be very happy with Travis's Twinn spring system. More shots, tighter string. I have one on a .25 and love it.

[kbstingwing]

Looks like you have it dialed in pretty well, for a stock Synrod (except barrel).

[StarlingChaser]

Yes the barrel is stock length. As for the original barrel, it shot so bad I never got that far with it. The best I could do with it was about a 2" circle at 34 yds. so I replaced it right away. The MM barrel is worth every penny!
I am not familiar with the Travis Twin Spring. I will have to look it up. This was my 1st PCP. I was going to get my feet wet with this gun and upgrade to an FX or something later when I was more familiar and had accumulated air tanks, fill assemblies, etc. but I get the same groups as many others at different ranges with this barrel so I really don`t need to. I would like to have a .25 also though.  . Right now the gun is a better shot than I am without the bench rest. I can do a 1" circle at 34 yds. with 20 shots and a tripod with just a couple outside the circle. At 54 I am not as steady as I used to be but I will keep practicing.

[kbstingwing]

I had the same problem with my Mrod .22, bad Barrel, 3" groups at 20 yards,  , had Jim at MM do up a LW barrel I sent him and now it's dead on, better than 1/4" at 20 yards, actually about 1/4" at 50 yards, I was using my Caldwell deadshot tripod when I did those shots, I'm just a year younger than you and it's getting harder to keep the gun still in a prone or standing position these days.

[triggertreat]

I don`t post very often but I thought some others might like to see my final setup and shot string info. First I have a .22 Marauder Gen 2 synthetic rifle with a Marmot Militia barrel. Other than that it is stock. I had a setup that worked pretty well but today I took the time to try many setups. I made over 500 shots and cleaned the barrel every couple hundred shots or so to get to the results I wanted. I use JSB 18.1 pellets. I also oil my pellets as recommended for this barrel. I started at 2900 PSI and shot # 30 was down to about 2050 PSI.
My final setup: Hammer Spring set at max tension.
                      Hammer throw is set at 7 turns in (backed all the way out then turned 7
                      turns in)
                      Metering screw backed out 3 turns

1. 892 fps
2. 900
3. 903
4. 893
5. 904
6. 895
7. 896
8. 900
9. 908
10. 897
11. 895
12. 902
13. 916
14. 901
15. error
16. 908
17. 907
18. 914
19. 913
20. 918
21. 911
22. 907
23. 909
24. 901
25. 910
26. 904
27. error
28. 896
29. 890
30. 891

2.84% deviation between high and low.

This group gives me a 1/2" group at 34 yds. with most shots inside 3/8". All guns require their own fine tuning but this worked for me and hopefully may help someone else with a similar setup. It is kinda odd but most of the 1st shots were on the low side of the 1/2". The center of the string was dead on and the last part of this string was on the high side of the 1/2". I could duplicate this over and over. I am still looking at a max of 1/4" off dead center so I am very happy with the results. I can do 3/8" raged holes all day long if I shoot between 2700 and 2400 psi. All this was done with a bench and bench rest. Happy shooting!

That's a very good stock power tune you have going on there averaging 32.83 FPE and with only a 3% ES (28 FPS).  Good efficiency too.  Haven't seen many good stock tunes like that for awhile now.  You are setup for a great hunt with that tune.


The varying POI shifts are most likely due to the 28 FPS spread, dirty barrel, unsorted pellets, or a combination and possibly the high velocity you've selected.  You may try backing off a little on the speed and see if the POI is a little more stable.  The critters wont know the difference especially at 35 yards with a small drop in energy.  I'm popping squirrels in the head at 50 yards with a 30 FPE tune and they drop instantly.


Thanks for posting your tune.  It's the kind I like to see!

[AlanMcD]

That is a great result from a stock tune.  You should be very pleased, and I would not go messing around with it unless that is a goal/hobby unto itself. 

I have had a Gen I .22 for about 6 years.  It shot pretty good with the stock barrel, but I tried several others (0.47" button rifled LW, 0.63" Poly LW, and MM Hammer Forged) all as part of experimenting, learning, and pursuing a "one-holer."  I can say that it ALWAYS had POI shifts across a full 20 (or more) shot string with all barrels even after pillar bedding the action in a laminated Boyd's stock.  I could get the gun to put the middle ten shots at the sweet spot of the string very tight (often ~0.5" ten shot group) at 50 yards with the right barrel/pellet combination (but not the stock barrel), but not more than the ten shots.  The only thing that got rid of the shifts was regulating the gun - that made it simply disappear . . . .

I can say that the POI shifts were not from the spread in ES - I firmly believe they were from harmonics in the barrel breech system.  The regulator made the shot conditions stable (while on the reg) and thus the shifting ended. I know it was not the speed differences, as I would test 5 shot groups across a 20 shot string, and the first 5 were having a different average POI than the last 5, even though they had the same speed profile.

Interestingly, a bought a .22 Daystate Air Ranger a little over a year ago to explore one of the higher end guns, and guess what - no shifting POI!  I do get some drop with large changes in speed if I shoot long shot strings (with a 500cc tank, I get ~30 shots under 2% ES even at high power), but when it happens everything is vertical and predicable the way we would expect it to be.  Why?  I attribute it to the full diameter barrel to breech interface, a much thicker breech made from a titanium alloy (MUCH stiffer), and a 6 bolt attachment system including two under the mag/tray slot which is the weakest point in the breach (although it is much beefier here than the Marauder breech anyways).  That gun is a tack driver, and I now finally have my "one-holer" (at least when shooting single shot) . . .

So with that in mind, if you decide to get rid of the changing POI, the quickest way to do it would be to just regulate the gun.  But with what you describe, I would just shoot it and enjoy it!

[StarlingChaser]

Thanks triggertreat. For what I do I can live with the .5 @ 35 yds.

AllenMcD I was thinking the same thing, maybe not to the exact cause but that it was in the guns characteristics that was causing the move in POI. I can have the same FPS at shot #5 and # 25 and shot #5 will always be low and shot # 25 will always be high as long as I start at the same PSI fill every time. Like you said If I sight my scope to a specific 10 shot group I can do 3/8 holes all day long with most of the 10 in 1/4". My fix for this when it is possible is to start at 2600 PSI, sight the scope in first 5 shots and just top of the tank at 2800 and refill at 2300. If I don`t have quick access to my fill tank I can still go fro 2900 to 2100 with a good average shot. Starlings don`t know what shot I am on, lol.

[AlanMcD]

You have the system down - that is what I did until I got the regulator installed.  With it (and a modified valve and lightweight hammer) it could shoot 40 JSB 18.1s at 900 fps, and the POI only wandered a bit on the last few.

But even before the reg went in it was a very reliable shooter with the better barrels in it.  Enjoy!

[StarlingChaser]

40 shots at 900 is pretty impressive. What regulator did you put in it?

[AlanMcD]

It is a Huub regulator that I bought from AirgunExporters when they first came out.  I hogged out the plenum near the gauge block for a few more CCs of plenum space, and of course I modified the valve to make it higher flowing with guidance from Motorhead (Scott).

There are many more choices now, of course, but I am pretty happy with it.

[StarlingChaser]

Thanks for the info.

[RAJOD]

Yes the barrel is stock length. As for the original barrel, it shot so bad I never got that far with it. The best I could do with it was about a 2" circle at 34 yds. so I replaced it right away. The MM barrel is worth every penny!
I am not familiar with the Travis Twin Spring. I will have to look it up. This was my 1st PCP. I was going to get my feet wet with this gun and upgrade to an FX or something later when I was more familiar and had accumulated air tanks, fill assemblies, etc. but I get the same groups as many others at different ranges with this barrel so I really don`t need to. I would like to have a .25 also though.  . Right now the gun is a better shot than I am without the bench rest. I can do a 1" circle at 34 yds. with 20 shots and a tripod with just a couple outside the circle. At 54 I am not as steady as I used to be but I will keep practicing.

Really nice shot string! 

How much was that extra Barrel?

I thought Gen 2 Maurader .22 had better barrels, more like the 199.00 Maximus.     That is sad that the factory one shot that poorly you would think it would be at least as good as the Maximus.

Right now you have a winner though, nice job!

[StarlingChaser]

The Gen 2 has a good barrel in .177 and .25. Crosman does not make these barrels. They do make the .22. I paid 200.00 for the barrel. Some people have gotten good barrels in .22 The Marmot Militia barrel is made to a supper tight tolerance that was designed around the JSB 18.1. It is thicker and MUCH harder. I doubt that even a good .22 original barrel can compare to the MM barrel but if they did we would have to pay more for the gun to start with. I just look at it as if I had to pay 700.00 for really good gun. As far as the groups, They have really tightened up today. I finished my tin of pellets except for a few dozen. I opened a new tin and the skirts are so much thicker and fit tighter when loaded in the barrel. I have seen Ted of Ted`s Holdover talk about this in a video but this is the 1st time I saw it for myself. I took a pic, hope it shows it. Anyway the thicker skirt pellets fit tighter and shoot tighter groups. The left is thicker and the right is thinner.

[RAJOD]

The Gen 2 has a good barrel in .177 and .25. Crosman does not make these barrels. They do make the .22. I paid 200.00 for the barrel. Some people have gotten good barrels in .22 The Marmot Militia barrel is made to a supper tight tolerance that was designed around the JSB 18.1. It is thicker and MUCH harder. I doubt that even a good .22 original barrel can compare to the MM barrel but if they did we would have to pay more for the gun to start with. I just look at it as if I had to pay 700.00 for really good gun. As far as the groups, They have really tightened up today. I finished my tin of pellets except for a few dozen. I opened a new tin and the skirts are so much thicker and fit tighter when loaded in the barrel. I have seen Ted of Ted`s Holdover talk about this in a video but this is the 1st time I saw it for myself. I took a pic, hope it shows it. Anyway the thicker skirt pellets fit tighter and shoot tighter groups. The left is thicker and the right is thinner.

I don't doubt that new barrel is great.  But it seems the Maximus .22 barrels are not the same as the Maurader G2. 
Mine actually shoots pretty good for its price.   Just wondering why crosman is not using that barrel and instead one that has been plagued with issues since the get go.