Fx crown plenum

[Rogvi]

I have made (power plenum) for my 30 cal crown

Before i did anything it was shooting 265 ms at 160 bar reg and pw on 5

Now when i added the plenum i get 275ms at 140 bar reg with the 44grains and pw at max.

Haven't tried more hammer weight yet.

And with the 22 jsb knock out same reg pressure and pw am i getting 285ms

Had to cut a little bit out of the stock,but it was worth it

 

[Glem.Chally]

Very cool and creative! Not an easy task to add a plenum on the Crown and make it look good.

Nice gains too, so you drilled the block and threaded it?

 

[Enkey]

Hi Rogvi

A very interesting job, what capacity does the plenum have?

Regards

Enkey 

 

[Long_Gun_Dallas]

The block is threaded there. There is a cap for the mill work there Simple and effective, nice work. 

 

[Raider03]

Great job!

 

[Eamon]

Oh my goodness would I like to have that added to my Crown. Cutting the stock was totally worth it in my onion.

Eamon

 

[JoeKool]

Good idea and modifications!

 

[Mask]

Really a great job. The idea is fantastic. You haven't ruined anything and you can easily go back to the original factory crown. For several months I have been thinking about how to mount a plenum on my crown and you have shown me that it is possible. As other friends of the forum asked you ... what capacity does the plenum have? I am indiscreet .... You could give me the measurements of your plenum ... It would be easier to have it built.

 

[Scotaty]

Impressive, well done.

 

[ackuric]

Nice execution, must be a very small plenum to begin with if that addition helped as much as it did. Wonder what your current total plenum volume is now.

 

[Leatherman]

I’m definitely going to try this. I think we could gain another 1/4’ of length plentum by grinding some off the front of the trigger bar without any problem. 

 

[RabbitBlaster]

Very well done. I have been discussing how to do this as well. What was the volume that you added? Any other details would be great!

 

[darkcharisma]

If i have to guess, that's only adding 3-5cc Max. I would say 3cc. any plenum added is a PLUS even 1cc.

 

[lenweber2]

OK who is going to make these and how much? Good business opportunity here.

 

[Mask]

Unfortunately, the length of the plenum is obligatory .... You cannot make a longer plenum than you did @Rogvi for the reason that there is the trigger assembly that creates a rise. But, as it is already been written, even 1 cc of volume increase makes the difference. Looking at the photographs, the plemun cannot have a capacity greater than 5 cc. Do you think it is better to use brass or steel to do this job?

 

[Mask]

Ahhh @Rogvi..... although I am European, I did not know the Faroe Islands. I inquired where they were located and, looking at the photographs on the web, I must say that they are of an extraordinary beauty. Congratulations on your land !!!

 

[Long_Gun_Dallas]

Think I'll have a go with 2024 t3

 

[Rogvi]

Hi thank you Libellule1.

This was my first prototype and just made it of brass easier to work with.

Going to try to make it out of stainless steel or titanium and make the walls thinner to get more volume.

The brass plenum is giving me 3 ml extra

 

[Rogvi]

Made me a bigger plenum now 

Now i have taken a little bit off the trigger,and i gain 1,5 ml.

Not a plenum you notice so well

Havent tried any shooting yet with the new upgrade.

Not true i did 2 shot quikly with 22 hybrids 

100bar 245

Then the wife called

 

[Mask]

The work is increasingly interesting !!!!

How many mm of the snap group have you filed?

From the photos it is difficult to understand it.

How much longer is the new plenum now?

.. But have you also made it a little thinner as a structure?