Getting the Maximus out of my Discoveries.

[JamesD.]

Why? Because I've had them since the start (original .177, 3rd .22) & with all I have in them I'd not get it back. Plus they are great shooters. What do I want improved? One thing. Efficiency. How to get it? 4 ways. I need you guys to tell me what'll work best.

I can hear my hammer bounce at 2000psi be I use power adjuster or leave it at a set point. So, do I get a 24-26" barrel? Heavier poppet spring? Regulator or HDD? Out of those 4, what will increase efficiency the most or do I need a regulator or Steve in NC HDD, other product (lighter hammer, etc?) 

 

[nervoustrig]

The biggest single improvement is likely to be with a debounce device and careful tuning. Beyond that, I would strongly recommend combining a regulator with a debounce device. Great shot count and tuning is a breeze provided you can adjust hammer spring preload. 

 

[John "spysir" Blount]

"24-26" barrel" thought the discovery has a 24.5" barre? You can gain 10-15fps ( w/no other change) per inch of barrel

You say you have a lot invested in them, marauder trigger group? Or really, striker/hammer with adjustable pip ? If adjustable just use the bstaley oring trick, works a charm IF you can adjust hammer stroke length.



Heavier poppet spring would make it worse.

A regulator and slight tuning for the reg would be the ticket.

A well tuned discovery should get 30 good shots. Regulated you should get 30 good shots but it's SO much easier to get there.



Drop an oring and see what it does.



John

 

[nervoustrig]

I agree with most of what was presented here but a heavier poppet spring will indeed tend to improve shot count of an unregulated PCP by way of reducing dwell and extending the usable pressure range. It just won’t be as singularly beneficial as focusing on eliminating hammer bounce.

 

[B3ntong]

Got the Maximus .22 and did the oring mod added a power adjuster to tame the stiff hammer spring. I now get 40 shots @ 18.55fpe peaking at 20.55fpe with 14.3 CPHP. At first I though the pressure gage was broke for I already got about 10 shots and did notice difference in dial reading..kept on shooting until it starts dropping. Noise was considerably more quiet than without the mods.

 

[JamesD.]

Looks like I'll try the BStaley mod. Get a reg eventually for the .177. Thanks.

 

[JamesD.]

And I want to point something out. LW makes 23.8" stock barrels. The Maximus barrel is 2" longer than The Discovery. I was looking at Maximus barrels as they allegedly have better rifling & with a ported Valerie & gauge block or replaced on my .22 those 2 things & a 2" longer barrel can gain youu 50-75fps. If I were to to this, then just get. 26" TJ liners. A longer barrel to a certain point always increases speed on a PCP. If your gun is loud, a longer barrel will gain a lot. A spring gun, 10" max & then slow it. This is why BB"s have 3-4' barrels. Extreme big bores. Not many want long barrels. Bull pups & short is in when efficiency is in long barrels that make ultimate use of all that wasted air.

 

[JamesD.]

http://www.airgunhome.com/agforum/viewtopic.php?t=937

Full info on B-Staley mod for a Discovery. I do mean full info, extensive testing & measurements to the thousandths of inches. Here lies first 3 problems I see.

I own no chronograph any longer. I would need a Challenger hammer or drill & tap an adjustable striker on my Discoveries hammers. Price for Chronograph, Challenger hammers or time to work a striker in both, cost of 4 #113 O-rings in 70 & 90 Durometer? Cheaper & probably more effective to get a regulator.

Am I missing something? Is this a drop in mod or is an externally adjustable striker on face of hammer needed? Also, who makes Discovery regulators? I honestly don't know what a bellvue washer is. Can I make a regulator? Even if I could, no chronograph, reg tester, thus way to set it all to optimum. 

I've tuned these to perfection (I know from when I owned chronograph 7 turns out from maxed is 900fps w/ 7.9 CPHP's & new stock hammer spring. I can go from 400 (13 turns out)-1000 (3 turns out from binded)+fps with this .177 Discovery. A good friend & FFL, machinist, stock, bow, knife, guitar maker crowned the barrel on the Jet, 6 screwed the band & set it harmonically. The 3 screw trigger mod has been improved upon slightly as he made me sears, delrin spacers, washers, metal trigger blade. Just too much to let go plus I like single shot & lightweight rifle even scoped with Bushnell Banner & Trophy Japan era.

I just resealed both rifles. Chamfered while apart. Upgraded to Bill Baldyga's parts. Valve screws, ported better gauge, power adjuster (hammer preload) is nicer than Cothrans old style. I liked Cothrans smaller one but Bill's has 8 has marks to Cothrans 1. When adjusting out as shooting to lessen the hammer strike and each revolution is +/- 0.036" in stroke length, I think I need a prepared mod man/tuner/ as I'm not buying instrumentation, Chronograph, reg tester, etc.

Yeah yeah. Tuned to perfection but want more. I'm just saying I can hit a tennis ball 9-10 times at any given distance to 75 yards through easily 40 shots on 2700psi fill. Rated for 3K+ but valve, hammer, springs work best starting at 2700psi. No, I don't have a chronograph now but sound & impacts at varying distances, drop, splatology tell me tons of info.

So, would you keep on modding or sell both & get ONE new FT Marauder (owned 8 Mrods) because I admit. I'm dying to see how good they are. Regged & LW's? Like a GD but no wait from factory. Almost 1/2 the price also of Greg's. Wish I'd kept my .22 Greg Davis. Did Greg ever recover or did he pass? I've never heard word of.