Been working on the Bulldog

[wll2506]

Remove the barrel. About 3/4" from the fill nipple there is a setscrew that will bleed the air out of the bottle, then unscrew the bottle,  pull the cocking handle back, drill down through the rear barrel setscrew opening, you can see the air valve through it, then drill the barrel.  Be very careful and square everything up.  Here is a drawing of the gun

https://www.crosman.com/fileuploader/download/download/?d=0&file=custom%2Fupload%2FBPBD3SRT_EVP.PDF

Regards, Tom

I'm going to do this mod, I will drill a .250 hole. just because, because.

I assume you remove the total barrel frame unit out of the gun and then clamp this completed unit down and drill through after removing the top set screw ? Did you run into any problems or things I should watch out for? I plan on getting a .204 drill and use that as a guide and then put in a .250 drill and go from there. I assume the frame is pot metal ?

After removing the stock screws did the frame and barrel come out pretty easily ?

I'm worried about going to far and destroying the gun, if you know what I mean !!!

wll2506

[tkerrigan]

Yes, empty and remove the bottle and the valve stem, then you can look into the air valve and you should notice that the hole you will be drilling is very close the the sealing line of the poppet.  Just make sure you drill straight down and don't go through the seal line.  .250 should work well, I think mine is .275 or so.  If you leave the valve spring out you will gain another 35fps or so.  Regards, Tom

[tkerrigan]

Almost forgot, Just remove the breech end set screw, the other one will keep it lined up.  Regards, Tom

[Randy B]

hey tom i just want to thank you for all the great  info on the bulldog mod.  Awhile back i googled on.  power  tune  a bulldog and it linkes to your post and i read up and got brave and i took the gun apart crossed my fingers and keep reading back and forth on your stuff and making sure i was doing just the way u said i drilled both port and barrel  .275 tightened hammer spring all the way. And man wat a totally difrent gun!!  I love it now and wouldent ever want it stock agin  !  As Matter a fackt  i put the drill bit i used uo in the bulldogs stuff cause the next  one i order will get the same thing done  to it before it even gets shot lol .  now im a member i just want say thanks agin .
 

[tkerrigan]

You're welcome, this is the easiest gun I've ever worked on.  You may have already done this, removing the air valve spring between the air cylinder and the receiver will add another 30 or 40 fps.  That might give problems if filling with a hand pump.  Might have to use shop air to seal the valve then use the pump.  With out the spring, rifle must be aimed up and cocked.  Regards, Tom

[Alexander Arvizu]

Changed up the look, tune (port, valve work, depinger, lcd and carbon fiber shroud). Some chrony testing tomorrow.

[MJP]

Cool, only one observation, bipod mounted to the barrel doesnt work too good.
You are limiting the natural harmonics of the barrel, most of the times it gives erratic grouping.

Marko

[rifle50]

Cool, only one observation, bipod mounted to the barrel doesn't work too good.
You are limiting the natural harmonics of the barrel, most of the times it gives erratic grouping.

Marko

So very true............Carl

[Alexander Arvizu]

Added noise deadner and mover the bipod to the stock.

[FuzzyGrub]

Added noise deadner and mover the bipod to the stock.

Have you noticed any accuracy changes with cutting down the trapezoid shroud/rail?   I'm not a real fan of how the full length trapezoid shroud aligns to the barrel, but wondering how you locked it down for such a short section. 

Yea, this gun needs a serious depinger!  I have a cross-flow depinger from a Mrod that has been opened up and larger O-rings to fit the bulldog, but haven't tried it yet. 

Mine is de-tuned for pellet use 130FPE.  No plans for any big game shooting, but noticed flooding on my creek trails, so the beavers are back.  Maybe it is time for first blood with the BD?    (NYS DEC Permitted)

[Taso1000]

Changed up the look, tune (port, valve work, depinger, lcd and carbon fiber shroud). Some chrony testing tomorrow.

Removing the shroud makes the rifle look so much better!

Taso

[Prouzy]

Changed up the look, tune (port, valve work, depinger, lcd and carbon fiber shroud). Some chrony testing tomorrow.

Removing the shroud makes the rifle look so much better!

Taso

X2! Very nice!

[TheLakeRat]

Hey guys, I have been building alot of parts for the bulldog and am working on a de-pinger now.
Tom, and maybe a few other people, would any one like to test them for me?
Not everyone wants or needs the regulators i built but for the guys that don't the depinger is a big help.

I have 3 test ones printed out and so if anyone wants one please e-mail me at pitbullairguns@gmail.com

[TheLakeRat]

Ok all 3 are spoken for. I'll let y'all know how they did

[Taso1000]

Hey Matt!  Are you working on a standard stock or do you know of anyone who is?

Thanks,

Taso

[TheLakeRat]

No sir, I do not. It's probably something your going to have to have built by a stock builder.

[Taso1000]

No sir, I do not. It's probably something your going to have to have built by a stock builder.

Thank you!

Taso

[FuzzyGrub]

Are you working on a standard stock or do you know of anyone who is?

I have given that idea some thought, but still more than I'd like to tackle.  To make it a rifle would require some sort of trigger mechanism change and a way to mount a stock lug to the action, along with a custom made stock and a rail added to top of receiver.     

[supertech77]

very informative post,will be doing these power mods,as for its looks,it grows on ya,this is my first bull pup type rifle,i really like the feel,shoots great,am still wanting a slayer if they ever get some more made.

[supertech77]

update, did the power mod,s at 9/32 on barrel and valve,left the valve spring out,cleaned and polished all,ran a exact 35 cal threw barrel no damage passing thru the barrel, filled to 200bar,shot 5 slugs thru,without barrel cover, ya it's a lot louder,and stronger,slung some 150 gr led,did not crony it yet,but could tell by the impact and  damage to the bullet she,s right about where i want her,also tightened hammer spring to tight,then backed off 2 turns.once my mega ldc gets here will be able to crony,and will post some spec,s,thanks again all for the info,