GTA

All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: condornh on June 10, 2011, 03:58:50 PM

Title: Discovery mods - full list
Post by: condornh on June 10, 2011, 03:58:50 PM
Can someone list out the mods for a Benjamin Discovery, and list whether it is for better accuracy / power or other (comfort, ease of use, etc.)

I'm debating a Discovery over a Marauder.
Title: Re: Discovery mods - full list
Post by: dk1677 on June 10, 2011, 04:07:56 PM
Well you can do the trigger yourself or get a TKO,  same with making a power adjuster or a TKO and a TKO LDC , There is a multi-shot breach also ( can't remember who has that)   hammer mods , the list goes on,others will chime in I am sure
Title: Re: Discovery mods - full list
Post by: rsterne on June 10, 2011, 04:22:52 PM
Please keep in mind that anything you do to increase the power will almost always reduce the shot count.... It may also completely eliminate the "bell-curve" of velocities and give you a gun that shoots the hardest on the first shot and loses velocity with every shot after that.... which is NOT the way to tune a PCP.... While it is possible to tune up a Disco to acheive stock MRod performance (or even higher).... doing so will give you a lot fewer shots than the same power level in an MRod....

Bob
Title: Re: Discovery mods - full list
Post by: JonnyReb on June 10, 2011, 04:26:09 PM
  I really liked the power adjuster mod, $8.00 from Charlie Mellon and now i can adjust as needed to well over 1000fps in .177.  The do it yourself trigger mod was easy and works great. I also had to re crown my barrel, which helped accuracy TREMENDOUSLY. Oh yeah, while your on Charlie Mellons site, pick up a 2nd barrel band for the 2 band mod. I'ts $7.00

  All the mods i needed were $15.00 and some time. I like my disco better than my old Mrod for pest/smallgame hunting and general plinking. The Mrod is hard to beat for thumping targets and/or hunting medium sized game(.25).
Title: Re: Discovery mods - full list
Post by: condornh on June 10, 2011, 06:08:59 PM
Do you have a link to Charlie Mellons site ?
Title: Re: Discovery mods - full list
Post by: condornh on June 10, 2011, 06:20:57 PM
Also would like hear about power mods boosting up to Maruader class, as I shoot a few shots, maybe 5 to 10 as opposed to 30 ?
Title: Re: Discovery mods - full list
Post by: 1377x on June 11, 2011, 10:28:38 AM
Do you have a link to Charlie Mellons site ?
www.mellonair.com (http://www.mellonair.com)
Title: Re: Discovery mods - full list
Post by: rsterne on June 11, 2011, 12:17:20 PM
The simplest and best mod IMO is to replace the hammer spring with one made from 0.040" wire (stock is 0.035").... That will allow the Disco to dump 2000 psi in the same manner as it currently does 1600 psi (ie at the top of the bell-curve).... This means, of course, that in order to rebalance the shot string you have to fill to 2400-2500 psi (ie the top of the yellow zone) and refill at ~1400 psi instead of ~1100.... Crosman don't say in their instructions that this is unsafe, only that you will lose velocity.... which you won't with the heavier hammer spring, you will gain velocity.... Calculations done by many different people tend to show that the weak point in a Disco is the valve mounting screws which should, in theory, fail at ~6500 psi.... It is up to you to decide if you feel safe filling the Disco to more than 2000 psi....

How much difference does the stiffer hammer spring make?.... Basically it bumps the gun up to MRod power.... With NO other changes (not even an RVA) you will gain ~80-100 fps depending on pellet.... which puts the gun up to ~29 FPE.... If you fit an RVA (rear velocity adjuster / power adjuster / hammer spring tensioner) then you can increase the power even further.... up to about 34 FPE with the heavier pellets.... Here are some shot strings with the heavy hammer spring just shy of coil bind and NO other modifications....

(http://i378.photobucket.com/albums/oo221/rsterne/Discovery/WebDiscoHeavyHammer96.jpg)

Note that I only included shots which were within 4% of the maximum velocity for each pellet.... Also note how flat the shot strings are.... If you start hogging out the ports you can get even more power.... HOWEVER, the shot strings will become more curved and therefore shorter.... You will notice that the lighter pellets are travelling too fast (transonic) and the shot strings are also limited by the 2400 psi filll chosen.... This state of tune is at its best using 18 gr. and heavier pellets.... in particular I like the JSB Exact Heavy and the Kodiak/Baracuda.... as both have great BCs and can really let the Disco stretch out its range....

Bob
Title: Re: Discovery mods - full list
Post by: condornh on June 11, 2011, 04:02:39 PM
Great detail Bob - thanks
Title: Re: Discovery mods - full list
Post by: Backyardsniper1 on June 11, 2011, 09:55:55 PM
The Crosmod site has some interesting stuff on it.
Title: Re: Discovery mods - full list
Post by: condornh on June 11, 2011, 10:13:55 PM
Is that www.crosmod.com (http://www.crosmod.com) ?
Title: Re: Discovery mods - full list
Post by: Backyardsniper1 on June 12, 2011, 08:03:31 PM
This is it.
http://www.crosmods.com/guns.html (http://www.crosmods.com/guns.html)
Title: Re: Discovery mods - full list
Post by: gene_sc on June 12, 2011, 08:18:00 PM
Jay Joiner makes a very nice multishot breech. I also like many of the other mods that many others make such as CrosMods. Melon Air, Cothran Machine Shop, Mountain Air and others. You can pic and choose what you want. Virtually let your imagination go wild...:) Best of luck


Well you can do the trigger yourself or get a TKO,  same with making a power adjuster or a TKO and a TKO LDC , There is a multi-shot breach also ( can't remember who has that)   hammer mods , the list goes on,others will chime in I am sure
Title: Re: Discovery mods - full list
Post by: newguyontheblock (Nathan) on June 13, 2011, 12:04:18 PM
tko22.com
qbmags.com
sacramentobee.com

TKO LDC
10 shot mags from qbmags
Rubber band from the bee

i may do the DIY trigger mod soon though
Title: Re: Discovery mods - full list
Post by: gene_sc on June 13, 2011, 11:53:58 PM
Thanks Bob for the graph. Keep helping us poor lost souls..:) I have a Disco .177, Kantana .22 and M-Rod .177. With the M-Rod it has been gone over but no added power. Just accuracy and shot count. I get around 40 shots per 2700 psi fill. I did a trigger mod, the .040 wire power spring and made my own power adjuster on my Disco .177. I get at least 40 shots or more out of a 2200 psi fill. I use the heavy CHP's. The Kantana is completly stock and prolly will never alter it. Shoots dead on.

I recently have purchase a second Disco .22. This one I will replace stock with Kantana stock. The trigger I will replace with the M-Rod trigger I purchased from Crosman. I will also make my own power adjuster and use the .040 wire spring with it also. Will be buying a breech, shroud, barrel hanger and end cap from Crosmods. The stock will be stained with ebony, new breech, shroud will be black with a blue barrel strap and end cap. Not to flashy but just a tad of bling...:) Should make it shoot faster with the purdy stuff on her.... ;D

Hope to have the parts needed from Crosmods within two weeks.
Title: Re: Discovery mods - full list
Post by: sawtoothscream on June 14, 2011, 12:00:19 AM
crosmods stuff looks awsome.   was thinking about buying some aprts from them as well in the future. if my disco i bought ever comes.   
Title: Re: Discovery mods - full list
Post by: SnoValley on June 14, 2011, 02:22:12 AM
Where are you guys finding the .040 springs? are you winding you own?
Title: Re: Discovery mods - full list
Post by: Mark5043 on June 14, 2011, 03:43:47 AM
http://www.trakar.com/products/compression-springs/?part=C0762-102-0445&submitpart=1 (http://www.trakar.com/products/compression-springs/?part=C0762-102-0445&submitpart=1)

# C0762-102-0445: Length = 1.76", OD = 0.305", Wire = 0.040", Coils = 15

"Copied from one of Bob's Posts"
Title: Re: Discovery mods - full list
Post by: gene_sc on June 14, 2011, 10:54:19 AM
Also a good place is McMaster Carr


http://www.mcmaster.com/# (http://www.mcmaster.com/#)
Title: Re: Discovery mods - full list
Post by: jeeperatt1 on June 14, 2011, 01:27:10 PM
Thinking about blinging my .177 Disco up a bit myself.  Keep us posted on the progress of that .22 gene!
Title: Re: Discovery mods - full list
Post by: condornh on June 14, 2011, 05:23:18 PM
sacramentobee.com

Rubber band from the bee
Is there a good link to the Rubber Band and what does it do for the Discovery ?
Title: Re: Discovery mods - full list
Post by: condornh on June 14, 2011, 05:29:15 PM
Where can I get more info on the  RVA (rear velocity adjuster / power adjuster / hammer spring tensioner) ?
Title: Re: Discovery mods - full list
Post by: Flyer91 on June 14, 2011, 07:58:15 PM
I have an M-rod so I hope this doesn't sound like a "get what I got" thing, but by the time you mod a Disco to be 'almost' an M-rod (trigger, increased power tune, 10 shot mag receiver mod, Katana stock and etc.) don't you have spitting distance to the price of a well shopped M-rod (or even more)?

Is it because a fellow can do it as their budget allows, the lighter Disco for lugging out to the field, the enjoyment of tweaking it yourself, or all of the above that have some of you going Disco w/mods over an M-rod?

Also ....... it 'seems' from reading, in .22 the Disco has a better reputation than the .22 M-rods. (??)

I don't mean to  hijack the OP's thread, but these are what comes to my mind when considering my next PCP in .22
Title: Re: Discovery mods - full list
Post by: Flyer91 on June 14, 2011, 08:12:36 PM
I think the rubber band it to hold the Disco bolt down. Evidently it doesn't have the same detent system as the M-rod has to keep the bolt in the firing position.
This is my WAG based on my readings about the Disco.
Title: Re: Discovery mods - full list
Post by: sawtoothscream on June 15, 2011, 01:39:43 AM
I have an M-rod so I hope this doesn't sound like a "get what I got" thing, but by the time you mod a Disco to be 'almost' an M-rod (trigger, increased power tune, 10 shot mag receiver mod, Katana stock and etc.) don't you have spitting distance to the price of a well shopped M-rod (or even more)?

Is it because a fellow can do it as their budget allows, the lighter Disco for lugging out to the field, the enjoyment of tweaking it yourself, or all of the above that have some of you going Disco w/mods over an M-rod?

Also ....... it 'seems' from reading, in .22 the Disco has a better reputation than the .22 M-rods. (??)

I don't mean to  hijack the OP's thread, but these are what comes to my mind when considering my next PCP in .22

its pretty fun modding the guns.  i have a good amount of cash into my 2240 and im still finding parts to buy for it.   

i have a disco coming and ran the numbers on how much it would be after i modded it the way i wanted and it was going to be a $800 gun after all the parts.  so to save the time and money i ordered a .22 m rod also.   still want the katana stock and a trigger replacment for the disco though so i guess i didnt save anything haha
Title: Re: Discovery mods - full list
Post by: Flyer91 on June 15, 2011, 11:58:18 AM
I certainly don't see anything wrong with that.
Personally ..... as I've gotten older I find myself driftting to the  "if it only looks OK, then just make it work the best it economically can" camp.
I think this same philosophy effects the way I look.
I've put on weight and sometimes I don't even comb my graying hair ........
Even though, I do exercise and eat well, but not as much so's I can mac on the babes anymore.
Now it's just survival!!  ;)


 
Title: Re: Discovery mods - full list
Post by: Wingman on June 25, 2011, 08:08:10 PM
Keep it stock and just shoot it like you stole it! Their are other guns that you can get with higher FPS...
Title: Re: Discovery mods - full list
Post by: newguyontheblock (Nathan) on June 25, 2011, 11:57:04 PM
just get a rubberband, rab once around the bolt then around the trigger guard, it holds the bolt down while shooting, some people have noticed air shoot back from the breech.

i did it just out of precaution
Title: Re: Discovery mods - full list
Post by: Benjamin disco on October 29, 2014, 02:13:38 AM
I'd like to buy a spring from this website. But it requires need to spend $30.... Hah ummm ok. not happening. If anyone else knows where I can get a spring with these specs please let me know
Title: Re: Discovery mods - full list
Post by: CptMoonlight on January 17, 2015, 04:35:02 PM
The simplest and best mod IMO is to replace the hammer spring with one made from 0.040" wire (stock is 0.035").... That will allow the Disco to dump 2000 psi in the same manner as it currently does 1600 psi (ie at the top of the bell-curve).... This means, of course, that in order to rebalance the shot string you have to fill to 2400-2500 psi (ie the top of the yellow zone) and refill at ~1400 psi instead of ~1100.... Crosman don't say in their instructions that this is unsafe, only that you will lose velocity.... which you won't with the heavier hammer spring, you will gain velocity.... Calculations done by many different people tend to show that the weak point in a Disco is the valve mounting screws which should, in theory, fail at ~6500 psi.... It is up to you to decide if you feel safe filling the Disco to more than 2000 psi....

How much difference does the stiffer hammer spring make?.... Basically it bumps the gun up to MRod power.... With NO other changes (not even an RVA) you will gain ~80-100 fps depending on pellet.... which puts the gun up to ~29 FPE.... If you fit an RVA (rear velocity adjuster / power adjuster / hammer spring tensioner) then you can increase the power even further.... up to about 34 FPE with the heavier pellets.... Here are some shot strings with the heavy hammer spring just shy of coil bind and NO other modifications....

(http://i378.photobucket.com/albums/oo221/rsterne/Discovery/WebDiscoHeavyHammer96.jpg)

Note that I only included shots which were within 4% of the maximum velocity for each pellet.... Also note how flat the shot strings are.... If you start hogging out the ports you can get even more power.... HOWEVER, the shot strings will become more curved and therefore shorter.... You will notice that the lighter pellets are travelling too fast (transonic) and the shot strings are also limited by the 2400 psi filll chosen.... This state of tune is at its best using 18 gr. and heavier pellets.... in particular I like the JSB Exact Heavy and the Kodiak/Baracuda.... as both have great BCs and can really let the Disco stretch out its range....

Bob

I know this is an old thread, but if you happen by this could you tell me if this mod will affect accuracy? I'm new to air guns and have read boosting power sometimes decreases accuracy.
Title: Re: Discovery mods - full list
Post by: zaphod621 on January 17, 2015, 08:00:29 PM
The rubber band is a cheap looking way of keeping the bolt from coming up during firing. A far better permanent and simple solution is to use a center punch at the "L" in the cocking slot above where it will hold the handle in the down position positively. The breech metal is pretty soft so go easy. Here is a photo that explains it better. A dab or two of cold blue will make the punch mark almost disappear.

(http://i447.photobucket.com/albums/qq194/zaphod621/DiscoveryBoltMod_zps5840af19.jpg)
Title: Re: Discovery mods - full list
Post by: Busta Cap on January 17, 2015, 08:56:35 PM
BNM has a multi-shot breach
Title: Re: Discovery mods - full list
Post by: Benjamin on May 09, 2015, 03:24:45 AM
is there a way to get a multi shot magazine on the discovery without replacing the breech.
Title: Re: Discovery mods - full list
Post by: Pellethuntr on May 09, 2015, 07:22:24 AM
is there a way to get a multi shot magazine on the discovery without replacing the breech.

Not currently and I don't think there ever will be. The receiver would need to be machined lower around the loading port so that the bolt would go through the mag. You would also have to incorporate some sort of lock and mag system. At that point it would be cheaper to by a new breech that uses already available mags.
Title: Re: Discovery mods - full list
Post by: 21grains on February 16, 2019, 06:04:55 PM
Where can I get more info on the  RVA (rear velocity adjuster / power adjuster / hammer spring tensioner) ?

https://www.magnumairpower.com/ (https://www.magnumairpower.com/)