New Syn Mrod .25 - Let the mods Begin

[Rdsail]

Thank you for the complement.

For starters, I think I got very lucky finding this combination of ports on the first try. I started conservative and I was going to open the ports more as I saw fit. But I stopped after that turn out.

I have not tried heavier pellets on this tune. The heaviest I have on had are HN cudas (31g). When the weather gets better I'll have to try them. I was gaining about 2fpe from the JSB's to the cudas. I would expect to see at least the same increase. It would be nice to see more. Although the accuracy of the Cudas is not that great. That is why I'm sticking with the JSBs.

It would be interring to see hot the gun shoots with heavier pellets.

If I decide to make a more powerful valve I'll have to buy another valve. I'm not touching this one. I learn that the hard way with my disco.

Daniel

[vtmactech]

What software or spreadsheet are you using to make these calculations?

[Rdsail]

it is a spread sheet in excel. It has to be in excel for all the functions to work properly.
Actually a guy from the Yellow started and I grabbed it and added a lot more calculations.\\

here is the link for anyone to use. https://www.dropbox.com/s/0e3i5ljguhce9ww/Mrod25-1-4-14.xlsm

all the yellow fields need to filled out and of course the string number. But before you file them out you need to choose the number of  shots per string and the number of strings also the FPS right under that is for the max of the FPS chart.

[vtmactech]

Thanks.  Why 3 shot strings rather than 5 shot?  Was that the format of the spreadsheet or did you choose that?  Know of an iPad or Android app that does this?

[Rdsail]

You can set it up to 3, 5 or 10. I used 3 to measure the efficiency better through out the curve. this way I can measure more air pressure changes.

[lloyd-ss]

Daniel,
How long was that gun out of the box before you had it all taken apart? 
Lloyd

[Rdsail]

LOL. The partial tare down took 2 days and the full tare down was 7 days after purchase. I could not help myself.

[Norm_m]

OK so I've had a little more patience than Daniel but to get inside of it is really getting hard not to do, especially after reading Daniel's post. The only thing keeping me from jumping right inside is that mine is Serial #1 and do not know if I want to mod it. I've done the foam and black tape to the stock as I could not stand the hollow sound of the synthetic stock and could always get a new factory synthetic if I wanted to bring it back to original.
Possibly once parts are available I could get new parts and mod them and keep the original ones in a safe place, of course that will be impossible for close to a year. I talked to Crosman the other day explaining I was a Authorized Service Center and would it be possible to get a Parts Manual for the new .25 Synthetic Marauder and was told not for about a year as they want all the Synthetic Marauders that have any issues to be sent back to them so they can see if there is something they need to correct in the design.
I guess I could go ahead and do some of the mods as long I do not do anything to the air reservoir that has the serial # then get replacement parts once they are available so I can convert it back to factory specs if needed to do so.

Hmmm now it is getting very difficult to resist! LOL

Norm

[lloyd-ss]

............ mine is Serial #1 ...........................

Norm

NORM !!!     How did you get SN # 1 ?

Lloyd-ss

[lloyd-ss]

LOL. The partial tare down took 2 days and the full tare down was 7 days after purchase. I could not help myself.

Daniel, I totally understand.  It was going to be taken apart sooner or later, so why put off the inevitable? 
Lloyd-ss

[Rdsail]

here is a video of the gun shooting from 40 yards at at metal target. This is for the sound level. The camera is set about 2 feet from the gun. The metal target sound is at least X2 the sound of the gun. Actually hitting the pellet trap with rubber mulch is sounder.

[Rdsail]

Norm,

I don't know if I would modify #1 stock. that is would be a collectable item some day

[Norm_m]

Lloyd basically Crosman announced they were going to sell the 1st 100 .25 caliber Synthetic Marauders made at 12:00 Noon on a  certain date (I cannot remember the date) in November.
So on that date at about 11:30 AM I went to Crosman's website and checked out the new Synthetic Marauders and they were on a countdown to the start of the sale. So I scratched my head to think of a way to get #1 and came up with a plan that I was not sure would work. So I tested the plan on two other items and it sure looked like my strategic plan would work.
So I added a Disco to my Cart then went to my cart and filled out all my info (name, address, phone # etc.) and credit card info, which is the most time consuming part of the checkout process. So it looked like I was 100% ready to submit the order. Now I went back to the new Synthetic Marauder page and waited for 12 noon to come so I could add it to my cart. Once added I then went to my cart deleted the Disco (sure did not need 2 guns) and submitted the order.
Four days later the Marauder arrived and I could not open the box fast enough and the 1st thing I checked was the serial #. When I found the serial E I said WOW NUMBER 1!!!! I would have been happy with any single # serial number but I was sure smiling when I saw the #1.
A little strategy always helps when doing most things.

Norm

[vtmactech]

Lloyd basically Crosman announced they were going to sell the 1st 100 .25 caliber Synthetic Marauders made at 12:00 Noon on a  certain date (I cannot remember the date) in November.
So on that date at about 11:30 AM I went to Crosman's website and checked out the new Synthetic Marauders and they were on a countdown to the start of the sale. So I scratched my head to think of a way to get #1 and came up with a plan that I was not sure would work. So I tested the plan on two other items and it sure looked like my strategic plan would work.
So I added a Disco to my Cart then went to my cart and filled out all my info (name, address, phone # etc.) and credit card info, which is the most time consuming part of the checkout process. So it looked like I was 100% ready to submit the order. Now I went back to the new Synthetic Marauder page and waited for 12 noon to come so I could add it to my cart. Once added I then went to my cart deleted the Disco (sure did not need 2 guns) and submitted the order.
Four days later the Marauder arrived and I could not open the box fast enough and the 1st thing I checked was the serial #. When I found the serial E I said WOW NUMBER 1!!!! I would have been happy with any single # serial number but I was sure smiling when I saw the #1.
A little strategy always helps when doing most things.

Norm

This makes me feel almost normal.  A little strategery goes a long ways, and I thought I over did things...   Kudos to you good sir!!   

[lloyd-ss]

Norm, Great that the planning paid off!
Lloyd

[Rdsail]

I did a test to compared the FPE difference by just changing the pellet weight

I tethered the gun to my scuba tank. The pressure on the thank was 2350-2400. I figure I kept the pressure constant and took the average of 8 shots on each pellet. I figured it would give a good reference. It would have been nice if the tank had the pressure at 2600-2700 psi. This is close to the peak of my shot string anyway.

JSB Kings  25.4g    @ 903   FPE  46
HN Cudas  31.02g  @ 846   FPE  49.3

If I remember correctly (I could not find my notes on the pellets test) when the gun was stock I only got a 2fpe gain between the pellets. But I'm not positive on this.

It is a shame that the Cudas don't group well. Group I got was around 1.5 in compared to .5in with the JSBs. It might be acceptable for hunting. Also the gun in quieter with the cudas

It is actually shooting a little faster than what my chart above but off by 4 fps . If I assume that they are using the same amount of air, the efficiency on at that psi would go up from 1.453  to 1.558. This is a rough estimate but it should be some what close to that.

If I assume that the increase of speed is linear between the two pellets, My gun with the current set up maxes out at 975 with the JSBs (53.6FPE) then the Cudas should somewhere around 910fps which will mean 56.9 FPE. not bad with the size ports that I have.

[lloyd-ss]

Very nice performance for the PSI you were shooting at.

[Rdsail]

I decided to power down to average of about 880 FPS with Kings. The results were not as good. Here are the numbers I got. My efficiency went down and the shot count is the same as at the higher power level. I also did some accuracy testing through out the different pressures and found that the shots down from 1200 psi a very bad shots. It almost looks like the pellet tumble all the way down range even though the speed is good out the muzzle. I wonder if all the extra air creates turbulence for the pellet. This is not as pronounced on the high power setting by it still happens. For best accuracy, I'm filling to 3000 psi and the shooting 2 mags. I Can shot and extra one but the last 2 or 3 shots are not as good.



This is just a picture of a pellet Shot from 40 yards at about 45fpe. It hit a 1/16 steel plate. The plate got a nice dent. I like how you can see the rifling on the skirt and the expanded head.

[MelonFarmer]

Wow. Impressive stuff

[IRONWORKER]

I was just before buying a Rainstorm but after reading this I'm seriously considering a Synrod.... 50+ FPE is awesome!