Now that it's always dark out . . . attempting to tune Gen 2 Marauder .177

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jdanvers

jdanvers

Member
Jul 7, 2019
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South Central Upstate NY, United States
I purchased the subjected from PA with the lothar walther barrel (synthetic stock, comes with picatinny rails). I *think* (?) it supposedly has a regulator built into it too BUT I'm left to wonder about that as what I see in forums, youtube videos, etc . . . . guys shooting 40 & 50 shot strings with incredible extreme spreads of what . . . 10??

I'm quite new to the sport and still have LOTS to learn. I'm only just now starting into this tune that I'm doing ( in the house, down stairs in the basement, 3/4" thick sheet of plywood and some foam padding to trap / catch pellets - and a wife who is, for the time being, "tolerating" my messing around down there . . . lol ). I've bagged it for the evening but for what it's worth - I've just now got the gun shooting a 10 shot string ( one magazine ) at an average of 846fps with AA10.3's. Yes - shooting over a chrony. Numbers below:

High = 856
Low = 838
Average = 846
ES = 18

This is literally the tightest I've been able to get it so far. Gun setup for what it's worth:

The spring tension preload = 3.1 turns in from all the way out ( backed it out ccw as far as will go - then back in 3.1 cw )
Hammer = backed out as far as will go then turned in cw (to shorten stroke / lighter hit) 8.75 turns
I'm fiddling with the valve metering (choking the gas so to speak) - I "turned that off" by turning it all the way in cw, then backed it off (opened it) 1.5 turns.

I've read that dinking with the latter (valve metering) is not the way to go but, for me, it's resulted in the tightest / flattest string so far. Granted - only 10 shots - quite a short string - but for real - other 10 shot strings from earlier this evening with ES of 40 or more. ( ouch ) :( (( thus my wondering if this thing really does have a regulator in it ))

I've written down the serial number for it - I may e-mail crosman directly and inquire re: if it has one - I suspect that they must be able to look up production runs based on serial number and would likely know if a particular run had "this or that" options built into them - yes?
 
The PA Mrods with the LW barrels and picatinny breeches (.177 & .22) were specially made for PA by Crosman and are NOT regulated. They use the standard Mrod stocks as opposed to the regulated Field and Target Mrods that have a different stock and gauge location. If you have the F/T model than it has a regulator. If it has the standard synrod stock more than likely NOT regulated. IMHO the better gun as you can always add a quality aftermarket regulator. 


Dennis
 
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Thanks guys - I guess I'll just have to degas it and break it down to be absolutely sure - if I get inside of it and there isn't anything else in the tube besides the hammer and the valve well then . . . I reckon I might be in the market for a regulator. ( and I'll have to learn about those too . . . aiy . . lol )

If there is anything good about it always being dark and cold out now . . . . it's time to tune and learn, learn and tune. So - there's that.
 
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As vdwb said: On PA's website you can get a synthetic stocked marauder with a Lothar bbl and pic rail, and it is NOT regulated. On this model they do not list the shot count per fill.

They do carry the field and target model which is regulated and the shot counts are around 80. It only comes in a wood stock.

I once called crossman and asked about the custom shop marauder F&T to see if it comes in a synthetic stock to save weight. She said it did not. Being a little unhappy I asked her if that meant I had to buy an extra synthetic stock just because the custom shop's model won't come with one? She said the reason they only come in wood is because it will not fit in the synthetic stock. They did not have any immediate plans to make one either.
 
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I'm glad to have found this forum. Thanks for the info and assistance guys - this is a great source (you guys) for info and a good knowledge base.

vdwb - will do

JonL - thanks man -- I've heard of the Tim Hill stuff - I'll look into it.

leadfoot - {sigh} ( lol ) live & learn - PA had them on back order and I thought that they were regulated - I waited until they became available and bit as soon as they did . . . . I never saw (read) any distinction between the wood and synthetic stocks re: included reg or not. It ( the distinction) may have been there and my bad for not seeing it -- or it may have not been -- "oversight" on their part or just pure marketing to move / sell product.

I may (probably am going to - lol) monkey around with the "BStaley" o-ring "tune" just for the hell of it now that I'm 99% sure there is no reg in there. I'll verify via vdwb's post above to be 100% sure. The 0-rings are cheap enough and readily available at any hardware store - per the subject - it's always dark out now and nothing else to do, when not @work, but to play and monkey around with it - so why not? See what it does, or doesn't, do. :)
 
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jdanvers,

I have had great luck with the Altaros regulator in a otherwise stock marauder, but it is a .25 cal. It is by far the easiest reg to install and you have your choice of reg set pressure or fill pressure depending on o-ring location. Altaros is one of our forum sponsors and have their regulator on sale right now on eBay for less than $78.00 shipped. They have a YouTube link too. If you are careful you can reuse the o ring, otherwise get yourself some -118 buna 70 o rings. You have the good pieces of the FT/ Custom Shop Mrod (breech and barrel) and the options of wood, wood camo or synthetic and Boyd’s stocks, the best of both worlds. The factory regulated rifle has shot count but is limited in power output. Hill parts are great too. Welcome to the Rabbit Hole, lol. Just remember to not dump too much money into it. Some people regret it and to others it is very rewarding to build and customize Mrods. Have fun, I sure have with my lowly Benjamin Marauders, lol.

Dennis


 
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Rabbit Hole

I started working on my .22 Gen 2 Marauder last year. Polished the inside of the air tube, add a Hill transfer port, Hill hammer and Hill Hammer Spring and this regulator from Lithuania: https://www.ebay.com/itm/Benjamin-Marauder-pcp-pressure-regulator/162104913497?hash=item25be34ae59:g:CpsAAOSwvKha-uSy.

The only way to adjust the Marauder is to degass the gun and take it apart, remove the regulator, adjust and put it all back together.

In the end, I get about 55 shots per fill, shooting the 18.3 grain JSB's at about 840 fps with under a 10 fps spread over the 50 shots. The 15.9 grain JSB's are about 890fps

all in all, was around $150 to do the modifications, but well worth it. Time consuming, but again, well worth it for the consistency and accuracy.

Love the Marauder, easy to work on. Lessons from the Marauder carry forward to any other gun, including the Impact. Great learning and shooting platform.

Oh, and I almost forgot. Tom Holland (YouTube Channel, Field Target Tech) helped me all the way through the modifications. He definitely knows his way around a Marauder.
 
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Saltlake58 -- good stuff.

All - so I went and spent some money on this thing and am from here on out not going to spend any more on it . . . I'll just save and buy . . . some other new gun, 'er - toy. ( lol ) BUT in the meantime - I did get a Tim Hill regulated tune kit per Saltlake's above but I went with Tim's regulator. I've just put it back together today and already the difference in consistency is amazing BUT . . . I'm not getting expected shot count. :(

With a .177 I would expect to get at least 80-90 shots - I just did a 50 shot string across my chrony and was really happy with the consistency up until around shot #30 or so when the numbers started to fall off. They really tanked at #39 as I had clearly come off the reg / running out of air.

The hammer is backed out about 6 turns - so I don't think it's hitting super hard (?)
The spring pre-load ( 1/4" bolt ) is 3 turns in

(Most) of the guys that shoot the field target matches in the summer claim to be running AA 10.3's at around 880fps, which is what I'm attempting to achieve. A match is 60 shots - ideally shot from start to finish without needing to air up. I've got to get better shot count than this - recommendations? Tim's transfer port is quite a bit bigger that the OEM one from Crosman. I'm wondering if maybe *to* big and letting to much air through? I'm thinking about putting the OEM one back in to choke it down and see if I can up the shot count. 

Saltlake's 55 shots with a 22 is outstanding ( in my opinion ) and I'm sure that a .177 should be able to do better than that.

Check this ( hopefully it formats right ) - it's the shot string I just did.

1 876 26 876
2 874 27 876
3 876 28 878
4 878 29 879
5 880 30 875
6 880 31 875
7 879 32 873
8 877 33 869
9 876 34 873
10 878 35 876
11 862 36 875
12 876 37 876
13 877 38 872
14 877 39 861
15 879 40 854
16 878 41 848
17 877 42 841
18 878 43 831
19 880 44 827
20 878 45 814
21 869 46 803
22 869 47 793
23 880 48 783
24 877 49 771
25 876 50 769
 
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Took me a while to get the adjustments right. Luckily I'd purchased a compressor, 'cause I sure needed the air. Probably put 2000 shots over the chrony along the way.

The regulator from Hill is the same one I purchased off eBay so we have the same equipment. The gun is in storage for the moment, so can't check but if memory serves, I ended up at about 1800 PSI on the regulator. After that, it was all trial and error, and probably 2000 shots over the chrony to zero in on the combination.

Parts included the Hill Transfer port, 265 spring, Hill hammer, crosman striker, and the regulator. I kept the original valve.

If you kept the old valve, don't forget to open the transfer port all the way. Once you get to the regulator, preload and hammer spring adjusted to the speed you want plus about 10%, close the transfer port screw until the speed starts to drop. Run a shot string from there.

Goal is to have just enough air to drive the pellet out the end with nothing wasted. That will be most efficient and help accuracy by eliminating the turbulent air behind the pellet. Wish I could help more! Each gun is a touch different, so trial and error it is.

Good luck, I remember having the same experience you are having. 30 shots, then 40, then 35, then 38 then 30, then 40 then 50 and I stopped at that point. It was incredibly frustrating, but keep at it. It's worth it in the end.


 
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