Q:

Review: Rapid Compact P-Rod bullpup kit

As promised here’s a small review of the compact P-Rod bullpup kit being produced in Spain by our buddy Rapid..

Although I have built my own compact walnut stock for a P-rod I felt the urge for another one.. I figured one in .22 and one in .177 should cover all bases.. :mrgreen:
My first emails to Rapid were to satisfy my curiosity requesting pictures of the trigger set up etc but he did not share this with me.. I ended up placing an order anyway for his “Walnut look” compact kit and he kept me well informed of its build progress and shipping status once sent.

The kit in my opinion is very reasonably priced at $350 USD + postage. With the price you can pick up a Marauder pistol that makes for a very cheap little mid powered multi shot minipup. I will probably keep this one tuned at 13-14ftlbs but the P-rod can be wound up to about 20ftlbs if desired.
Realistically this is a 30-50 yard gun and a great back yard plinker so I dont see any point in tuning it so hot that your shot count crashes..

The package showed up well marked and the kit well packed. No damage and all complete.


The stock is made from Kiln dried (vaporized) European Beech Wood. This timber is stable, resistant to warping, lightweight and easy to work. There are no knots. As I said earlier I ordered the “walnut look” which means this stock has a light walnut coloured stain on it and has been finished with a satin varnish.
The stock is well made and shaped right but could benefit from a little more sanding work before finishing. My stock has a few signs tool burning and “blunt CNC tooling trauma” that tends to chip out some of the grain when tools are dull or the machine speed is to slow. I will fill them back to level with a clear resin and lightly sand the whole stock with 1200 grit paper then give it a coat or two of true oil or similar to satisfy the OCD in me. 😉



Once I had the kit in hand Rapid sent me a word document of instructions to fit it.
After a quick browse through I set to work and stripped the Maurauder pistol. The safety catch needs to be removed and pistol grip requires some major surgery that may not sit well with the guys that buy with “originality or re-sale value” in mind but with all parts including the complete pistol grip available from Crosman at a very reasonable price I soon found myself halfway through the pistol grip with a hacksaw… 😯 I had considered originally milling a new trigger block that was just big enough to retain the trigger components but the hacksaw dulled that urge.


With that job complete I moved onto fitting the small brass gauge extension that drops the gauge low enough to run the trigger linkage “wishbone” parts either side of it.
This is where my first problem came up… the thread on the Marauder gauge and cylinder is 1/8″BSP tapered but the thread on the brass extension is a 1/8″NPT tapered, a non tapered male 1/8″ BSP thread will thread loosely into a female 1/8″NPT but a Male NPT straight thread wont thread into a female BSP. Because the threads on the Marauder are tapered it will allow this extension to be fitted but no matter how much thread tape I put on it I couldn’t get it to seal! I tried 3 different loctite products and even a couple of O rings but it still leaked bad.

I soon worked out that it was bottoming out on the air tube before the “slightly loser” tapered NPT thread could lock up and seal on the female BSP..

I put the part in the lathe and removed about an 1/8″ from above the thread so more of the taper could screw into the cylinder..
With a small amount to thread sealant this did the trick and the “hiss” stopped.

The gauge does sit a little too recessed in its viewing port for my liking which shows a large void and will probably let crap into the trigger parts so I will eventually machine a new extension to bring the gauge almost flush with the stock.

From there I fitted the weaver rail and trigger linkage which as a whole is nicely designed and functions well.


Once the trigger was set up I wasnt happy with the heavy raspy feel to it, I tracked the grittiness down to where the threaded rod runs through the trigger block and washer held under load with the return spring.. the thread rod was grinding up and down the washer which felt and sounded terrible..

…back to the lathe I filed and polished the thread off the accused section and now it runs smooth.

With a bit of fine tuning I now have a very acceptable adjustable trigger. Just dont expect any miracle match triggers from it as it is only as good as the factory P-Rod trigger it mirrors.


The metal parts are well machined and the fit is great, the shroud remains floating within the new front riser mount but it does not have the internal Oring that the factory one has. Again a little more time taken on the polishing before anodising process would leave a better finish at least on the Weaver rail and riser that are visible.

The riser mount and weaver rail are machined from 7075 “alzintok 75”. (Duralumin with alloy aluminium and zinc) and the other parts are 6063-T5 “simagaltok 63”. (alloy: aluminium, magnesium and silicon.) Both materials are up to the job they carry out but the finish on the 7075 parts are a shade of steely blue which often happens when anodizing this harder 7000 series alloy.


Rapid, if you want to get a better finish on these parts you should bead blast them before the anodizing process, this will hide all the machining /de-buring marks and aid a more durable coating also match the matt black finish of the P- rod better.

The last small mod I made was to the rear stock mounting cap screws. The stock is countersunk for the smaller oddball factory dome head screws that hold the plastic pistol grips on but I saw no point in needing a Allen key to remove the front cap screws then a flat head screwdriver to remove the rear screws so I have drilled and tapped the pistol grip frame to 4mm and countersunk the stock with a 5/32″ piloted countersink tool, after a spot of touch up stain I fitted some countersunk cap screws to match the front.




So all in all I think its a great little product and makes a very compact little pup out of a relativity inexpensive pistol.
Well done to you Rapid for an all round nice product that will provide us with loads of fun and nice work on your great follow up service with your sales.
:thumb:

I am yet to sight it and shoot it as I ran out of light while trying to fix the leak but Ill do that tomorrow and group it with a bunch of different pellet to see what diet it prefers. Id imagine it will shoot like every other P-Rod out there and certainly not break any records but If anyone is interested in that I can post a few pics here too..
Here it is all mounted up with some compact Burris 4X glass.



Other BullPups

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Viewing 10 replies - 16 through 25 (of 25 total)

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Hi WingM,
I always read your review carefully and learned a lot from them. Thanks.
I see that Prod only has about 16 good shots.
Do you have any good idea to make the rapid mini to close to Lelya? e.g.
regulated and close to 35 shots? Disco’s double kit and Mkaking mini bullpup for it?

Forgot to ask if SPA will make mini bullpup less than 20″?

I have just turned mine down another few mm so the nut doesnt contact the cylinder at all and added a “liberal” amount of thread sealer… Ill give it 15mins to set and test again..

I was able to procure a 1/8 npt to 1/8 npt extension that is 3000 psi rated, so I’ll see if this stops my leak issue before having to tear it all apart.

For your reference, Crosman use 6061 T6-51 alloy on their guns. It is a slightly lower tensile alloy to your “tooling grade” 7000 series alloy but it has a different mix of alloys so is much easier to anodise and leaves a better matt finish when bead blasted first.

In regards,to your the brass gauge extension, would suggest you look outside of the hydraulic suppliers you have because the bsp to bsp adaptors do exist.. here’s a few I found with a quick search..


http://www.kiowa.co.uk/products/2525-Camozzi-18-x-18-BSP-Male-Female-16mm-Extension-Adaptor-OA-22mm/P00002948/1205

http://www.bestfittings.co.uk/shopdisplayproducts.asp?id=139&cat=1%2F4+BSP+Fittings

There are several ways you could drop the gauge down lower into the stock that would also give the required room for the trigger linkage…
Another way is to use an 1/8″bsp to 1/8″bspT (tapered) coupling into an 1/8″bsp barrel nut:


Either way I think you should be supplying the correct part with the correct threads for the job with your kit to save other customers with less of an engineering background the headache of ongoing leaks. (mine has started leaking again)
You could even supply the same brass extension but with the 1/8″bsp-t male and suggest to your customers they need to buy a new 1/8″NPT gauge.. they are very inexpensive.

As for the finishing work, I totally understand and appreciate the time it takes to have a perfect product, and I think your compromise to keep the customer cost down is very acceptable, however as with all my reviews “I tell it as I see it” so others can judge for themselves if they can live with a few imperfections or attempt slight improvements themselves etc.
Your price and product is good and of above average standards, most of the imperfections would not even be noticed by the untrained eye and in general the fit and finish on my compact pup is very good, again I commend you on this. :thumb:

I have spent the last two days shooting it and Im enjoying it a lot! Its is certainly more fun than a std P-rod in pistol or carbine format and the rearward centre of gravity seems to aid in a steady hold..
The H&N FTT’s at 18ftlbs have proven plenty for smacking the starlings that loiter around my property..

Buy with confidence guys.. right out of the box or with a few small improvements this little pup is a gem.
Rapids service is great and his product is solid.. go buy one..
I know you want one Hoot: :hoot: :mrgreen:

Regarding the pellets:
As Wingman says, the pellets you most like to Prod, are the H & N Field Target Trophy.
My Prod, the pellets that her best shoot are:
– H & N Field Target Trophy 14,66 gr
– JSB Exact Jumbo Express 14,35 gr

Average speed: 744,75 fps
Average power: 17.70 ft-lbs


EXCELLENT REPORT. GOOD TO HEAR COMMENTS, TO IMPROVE EVERY DAY.

Of airguns that I become a bullpup; you just have to make that little modification (cutting the grip) to the Marauder Pistol.
In Marauder Rifle (MROD and SROD) and the Air Arms; doesn’t change anything of the original.

The Marauder Pistol, as it is so small; to do that little modification. But, as you say, it’s no problem; because a grip costs $ 10.38 ( I believe that is very economic).
In addition, it would be impossible to make a nice bullpup; without that little moficación.
In my new project conversion: FX Royale 400 bullpup. Nor modify anything of the original, of the airgun.

As you say; I use high quality aluminum. And get the same anodized, that the pieces Crosman Company, not knowing, that quality aluminum, they using ; is difficult.

On the subject of small marks in some stocks. It’s wood, and as such it is the grain of the wood; will have more or less marks. To leave perfect the stock (like of manufactures); would have to spend many hours sanding each stock. And that would increase the price of the kit.

I THINK THE QUALITY THAT I OFFER (GOOD WOOD, ALUMINUM TOP QUALITY, WELL FINISHED, DESIGN OF THE PIECES COMPLEX AND EXPENSIVE, ALWAYS LISTENING TO CUSTOMER …) FOR THE PRICE OF THE KIT; IS GOOD.


Regarding the extension of the gauge: the hydraulic / pneumatic industry, there are only two types of connection:
• male thread NPT – female thread BSP
• male thread BSP- female thread NPT


It would be perfect, male thread BSP – female thread BSP. But in pneumatic / hydraulic industry, doesn’t exist.
I use liquid Teflon; and extension seal is perfect.

The threaded rod can be improved; but I think the operation is smooth and perfect. True, a little rubbing is heard; but the trigger operates smoothly and perfectly, right?
Lower each threaded rod, will cost of +/- 20. The lathe is expensive..
It would be cheaper if I would order 200 rods; but I do not think many kits he sells.

And I think the trigger system works very well; and continue offering customers a good price of the kit.
But as you commented; I’m looking to improve that.

Regarding the countersink in the timber; for the rear screws. As it used in Europe “metric” and in the Unites States “English thread”; I leave the countersunk made for original screws of the grip. And in “the installation tutorial”, indicated the option to change.

THANK YOU VERY MUCH FOR THE TIPS TO IMPROVE.
I’M ALWAYS LOOKING TO IMPROVE; AND ABOVE ALL, DO GOOD WORKS.

well the weather has turned to crap today with rain and strong wind so I was confined to my 30 yard indoor range..
I left the P-Rod compact tethered to my buddy bottle with the tap open and 2500psi in it to keep the pressure consistent for pellet testing..
I shot groups of 5 of a selection of quality pellets and the results varied.
I am really seeing a patern forming with guns that dont like JSB pellets well almost always shoot the German H&N pellets well.
The H&N FTTs were a clear winner with 1/2″ at 30 yards with the Barracudas a close second. I feel the 21gr Barracudas are a little too heavy for this little pup and the trajectory will suffer even if only out to 50 yards. I will shoot the H&N 14.66 FTTs exclusively in this one and have tuned them to 750fps – 18.3ftlbs.









I shot of a few mags of the FTT’s out to 60 yards on my 4″ gong and they held true to that range so then it was off for a bit of “soft target testing” :mrgreen:

Great review WingMan.
I have a hellacious leak in the gauge area. I suspected that I could possibly have run out of thread before it sealed, but I also resealed & modded my gun while it was apart, to confuse matters. I found out later that the o-rings I used were noted to be sub par on spec measurements. I am going to to tear it all back apart when my proper sized o-ring kit arrives, and address the extension too.
I wonder if a 1/8″ NPT extension should be used?

Thanks. Best review. I’m very interested in your accuracy test.

That’s great wingman. Thanks for that review!!!!!

Why is it that I was thinking that these prod kits rapid is selling used a eletronic trigger????

I like these..

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