Not Another Marauder Bullpup Question....Marauder to Bulldogish Conversion

[ShadowShot]

I have been looking around again about bullpup options for the marauder. I have seen a few options over the years but none I wanted to spend $400 to $600 on. 

If the basic parts were available, one could get a starter kit and build their own.  It seems that the hardest part to find is the mounts that go around the air tube/barrel with a scope rail.  Not everyone has machine tools to make their own. Does anyone know where just this part of the hardware could be found?

Someone should make one and just call it a starter kit. It would probably be a hot product.  You could get just the kit that mounts onto the air tube and barrel  with the picatinny rail mounted to it. Once you have that on the rifle, you could build your own from there. Any ideas?

[PikeP]

With the emergence of so many cheap air rifles, and alternatives, I see absolutely no reason for anyone to pursue this. There is a good handful of bullpups available on the market that are of equal or lesser cost of entry than the marauder. ~10 Years ago this would have been a novel pursuit, but now, not so much imo.

I used to want to go the bullpup route with my mrod, but I settled with an in between, turning it into a carbine and I couldn't be more satisfied with it for the little effort and cost it took.

[ShadowShot]

Its true it may not for the masses, it is still something I would like to find.  The only way to find it is to put out a request. I have my Marauder 25 cal tuned by Tim Hill with a full upgrade kit. It is a 40 shot hammer. I want to keep this rifle and pup it out.  The carbine in your signature looks very nice. That is an appealing option. Any chance of finding a how to or what's needed list?

Thank you for your input.

[Motorhead]

As I had done near 7 years ago when "PUPS" were just being talked about, EDGUN was the only pup in town ... we built our own.
https://www.gatewaytoairguns.org/GTA/index.php?topic=40431.msg377421#msg377421

[ShadowShot]

Morehead, that's a fine piece of work. I can do most all that is needed to make my special little pup. If I could just find the barrel air tube mounts needed with or for the scope rail. I love your kiss approach.

[oldpro]

 A person could design and build a very inexpensive 3D printed kit. Riser/trigger mount/rail etc etc.

[PikeP]

The most expensive bit with pups is generally the stock. The most difficult, a good trigger and moving forward the cocking as well...no sense moving a trigger half way up the gun and leaving the cocking at the rear bolt, the worse ergonomic design by far. I personally despise a bullpup with rear cocking.

My build was simple. Prod trigger group/frame (moves trigger up around 2" iirc). Then custom fab up your stock, can use ar parts for the butt, or a lee sliding stock like I did, either is fairly inexpensive...and then I formed my fore-end with kydex. Overall cost was roughly 100-150$ all said and done. I was going to build a folding ar stock for the butt end but, can't give up my current sliding stock that has a cheek wield that holds 3 magazines under it, and having that bit of uniqueness others don't is nice.

[FuzzyGrub]

I purchased a MDRL kit when they were first available for a Gen 1 25 Mrod.  Prior to that, looked around for the same hardware you are searching for now.   I had it for a couple years, but it never really grew on me.  It really needs to be a side-lever.  I had severe chicken wing arm.  I didn't like the side to side balance, and for whatever reason (me?), it was not quite as accurate as it was in rifle form.  Sold it shortly after the time the Gen2 Mrods had come out.

To this date, haven't seen any "builder's kit" for any model.   If you just "have" to do it, and understand that motivation,   I'd try finding schematics on as many as the bullpups that you can.  See if there are existing parts you can adapt. 

[ShadowShot]

The post from PikeP has my interest spiked. I like the idea. I've been searching but can't seem to find what I am looking for.

Questions
1. Are the marauder Prod trigger group/frame from crosman a direct drop in replacement to the rifle trigger group? If not, what do I need and where can I find what I need? I have a Gen 1 Rifle.

2. Pike, I like your stock idea. Where can I Find that? When I look up lee slide stocks, I get a long list of old British riffles.

Just on a side note, when I was looking at the parts breakdown of the prod on Crosman for the pistol grip trigger group, I notice the barrel band was way back on the barrel and reservoir. If the prod and riffle have the same barrel shroud and reservoir size, one could get two of them and have the start for a bullpup kit if they so chose.

[FuzzyGrub]

The Prod airtube is much smaller OD, like 7/8".  Shroud diameter is smaller too.  The prod barrel bands are too small to bore out to fit the Mrod tube, as well.

On Mrod G1 the trigger group should bolt-on.  I can't say I've verified it, but have used a number of Mrod Gen 1 trigger assy to replace Prod ones.  You would want to test sear engagement given the thicker Mrod tube.

[ShadowShot]

Seems like I remember this whole conversation about the prod trigger group and the need for some type of adapter plate or spacer to make it work from the old GTA forum.  When we switched over to this forum, all of our post counts started over and I lost heart and didn't post as much here as I did there. Kinda just fell away. Miss the old days, RIP Gene and Charlie. Both were great guys. Miss them both.

Anywho, seems like I remember something about a spacer being needed but that goes back a few years. Ill have to look over there. I just don't have a lot of time for research anymore. Doing the whole church pastor thing kills that time.

[FuzzyGrub]

The spacer (shim) is used when going from Prod to Mrod trigger assy.  ie going to a thinner tube, you might get too much sear drag.   I've had it on some, others not.

In your scenario, it is the opposite and might not have enough sear to hammer engagement, and on a bump may fire.   If it is an issue, might be fixes, as well.   Possibly modifying sear or frame.  Matt has the practical experience here, that I don't. 

[YEMX]

Pretty sure the Prod trigger group needs a new sear, due to the larger tube.  Operationally, the Prod trigger and the Mrod trigger are the same.  The Mrod trigger group already fits, and would be a significantly lower profile than a Prod trigger group... I'd remove the Mrod's safety and make a new trigger blade that would connect w/your bullpup trigger components more solidly.  I feel like most bullpup conversion triggers are bad due to the combination of a bad linkage design, and the trigger interface.  There's also that gauge that's in the way.  After looking at the Rapid-70 bullpup conversion kit parts (I no longer have them, and I didn't take pictures  ), it looks like a lot of RC plane parts were used.  Clevis's and the like. 

I've made the same suggestion of a bullpup kit (sans stock) a few times over the years.  No one's ever made one.  There are no parts kits w/o stock available anywhere. 

Other stock options are:

-  RAI chassis from New England Airguns.  Most expensive option.  You'll HAVE to use a factory trigger blade
-  Modify an airsoft gun's stock- many options here.  Not easy, VERY time consuming
-  Armada stock from Crosman, using just the main chassis (PN: 2264T-001, called the "receiver") is a very cheap and easy option.  Uses AR grips and stocks
-  PikeP's idea

[PikeP]

Two approaches to adapting a prod group to a mrod tube.

1) get a new sear, although the person that used to provide them may not anymore...that man is lloydss.

2) using sand paper on a similar od tube as a marauder tube, and with the guts/sear removed, sand down the trigger group little by little, and test for sear engagement with your hammer until you achieve good contact, then go a tad more.

You do have to drill and tap new mounting screws for the group, or extend the sear cut out in the mrod tube as the prods sear location is a bit different.

The lee sliding stock, I am unsure if lee is still making those, hes a member here. Search for 'marauder compact stock' and you will likely find his posts through-out some forums where you can message him. The alternative as I mentioned is adapting ar style stocks.

Lee also biulds an adapter for the marauder trigger group that allows ar style grips to go on them, but I prefer the prod group as it moves the trigger forward 2 inches and to me, that 2" is worth it.

[FuzzyGrub]

You do have to drill and tap new mounting screws for the group, or extend the sear cut out in the mrod tube as the prods sear location is a bit different.

I highly suspect you have a Gen 2 airtube, which does have to have holes drilled.    The Gen 1 that Paul has, has a different trigger assy, and screw spacing.  It should bolt right up to a Gen 1, otherwise the Mrod G1 trigger wouldn't work on Prods, Discos, Fortitudes, etc.   Sear is still the issue. 

Paul, You can check the screw spacing on your trigger assy.  The two outer screws should be 3 7/16" center to center. 


The gauge and stock lug locations are different between G1 and G2, so the Armada chassis, unfortunately, is not an option.  I believe the RAI chassis were available for G1. 

[YEMX]

Ah- I didn't catch the "Gen1" part...

[ShadowShot]

YEMX,
I think you misunderstood me. It was probably my fault. When I was responding to PikeP, I was responding and intending to say that his carbine option instead of the bullpup caught my attention.  Due to his post I was looking at two different possibilities  of builds, a bullpup option or the carbine option.

After a little more investigating, I think I back firmly with the Bullpup option. I'm like you, I would have thought for sure, someone would have made, or be willing to make, the starter kit for the mrod.

PikeP
I know you said There are a lot of bullpup options on the market now. My situation is, I already have a marauder set up the way I want it. With a full upgrade from Tim Hill, I just want to pup This rifle out. Personal preference I guess. Each have their own. Your point is very legitimate. The new pups are great little guns, but they won't be my marauder.

It's more accurate than I'm able to shoot out to 50 yards, very tight group. I get a 40 shot string with a 3000 psi fill without drop in power until shot 41. Using 25.39 JSB pellets, over the first 40 shots, I get  the following results.

870 fps for a high
852 fps for a low (was within the first 9 shots, never that low again. most all shots were between 860 to 870)
863.75 ave
41 Fp ave
My actual standard deviation was 6.

Thank you all for your kind inputs, keep them rolling. I will continue listening here and searching for a way to build what I'm looking for.

Shadowshot

[YEMX]

No worries- I too would like to bullpup a Mrod...  If you don't want to purchase one (totally understandable- they are PRICEY), you may just have to roll your own...  I'm currently leaning towards putting an Mrod into a P90 shell...  reuse the P90's safety...  I'm interested to see how it turns out, but it won't be built for a while- I have other projects that need building first... 

[ShadowShot]

Check this bullpup build from bulldog parts out.

Skip to around 8:25 if you don't want to hear a long backstory.
I have started looking into it. Parts are very cheap. I see some problems. If you look closely, the barrel is not really free floating, nor is it centered. There are workarounds. It will require just a little more attention. Overall, he did a great job being new to this.

[YEMX]

I just posted on his vid asking if he's going to do a follow up, and show us how he set up the trigger...  I'm going to call Crosman tomorrow to see how much the trigger parts cost.