Modify Crown mk2 stock for easy access to internal hammer spring adjustment.

[tor47]

I think about way back when when folks drilled out the back of their wildcat MK1 MK2 stocks to access the hammer screw adjustment, and I always wondered why? Set it, locktite the adjustment nut, and call it good.

I have donne that also, on both a bobcat, and a wildcat mk2 But there is a difference of not having acces to any adjustement at all, and having acces to a powerwheel, without taking the stock off.
You can almost take any gun, and set it a a desired speed, with good chrony numbers. But it might not be the most accurate at that setting. The only way to really find out what speed or setting your gun likes, is in the end to test it at a bench. Having to take the stock off, for any minor adjustement, just make the prosses longer.
Regarding the crown, when I used it some years ago, I often swapped between a .177 barrel, and .22, trying out differnt weight pellets. The reg was often adjusted also. Nowadays I do not shoot it to often, as I have other dedicated guns, for each caliber. I have also found out that adjusting reg to often, is also not a good idea, as it can lead to creep.
With addition of the newer 24 step powerwheel which was not available back then, I would probably gotten me one first, before cutting into the stock. I have a similiar powerwheel for my impact, and the need for using the setscrew is not as big as before.
But back then I still think it was a good option for me.
But I do agree if you mainly are gonna use the gun for one caliber, and dont plan to adjust it when you have set it, it probably is better to not cut the stock.

 

[MEC17670]

I have donne that also, on both a bobcat, and a wildcat mk2 But there is a difference of not having acces to any adjustement at all, and having acces to a powerwheel, without taking the stock off.
You can almost take any gun, and set it a a desired speed, with good chrony numbers. But it might not be the most accurate at that setting. The only way to really find out what speed or setting your gun likes, is in the end to test it at a bench. Having to take the stock off, for any minor adjustement, just make the prosses longer.
Regarding the crown, when I used it some years ago, I often swapped between a .177 barrel, and .22, trying out differnt weight pellets. The reg was often adjusted also. Nowadays I do not shoot it to often, as I have other dedicated guns, for each caliber. I have also found out that adjusting reg to often, is also not a good idea, as it can lead to creep.
With addition of the newer 24 step powerwheel which was not available back then, I would probably gotten me one first, before cutting into the stock. I have a similiar powerwheel for my impact, and the need for using the setscrew is not as big as before.
But back then I still think it was a good option for me.
But I do agree if you mainly are gonna use the gun for one caliber, and dont plan to adjust it when you have set it, it probably is better to not cut the stock.

It's a dedicated .25 caliber. I have a .22 600mm barrel. But, I have a good .22 caliber pellet gun. Hw100, FX smooth twist barrel that AZ installed and tuned, with a Dr.Bobs Buddie bottle system install. Loves both 18.1 jsbs and 17 gr Neilson slugs. 78 shot at 32ftlbs. It's a Lazer and loves eating ground squirrels.
How does your .25 like the jsb 34 gr King mk2?

 

[tor47]

To be honest I do have a .25 cal barrel for my impact, but I seldom use it. I mostly shoot my bullpups nowadays, as they are more conveniant to use in the car, so my crown is not that much in use either. .177, and .22 is cal, I use the most.

 

[MEC17670]

 

[fiestaman]

I did this a couple of years ago. It may make your gun less valuable if planning to sell it, as some may not like it. Maybe it would look better without the lip, over the wheel? It personally does not bother me, as the gun feels the same when shooting it.
I think it makes the gun more user friendly when adjusting it. You can reach the internal hammer adujster with an allen key, with the stock on.

View attachment 288424

View attachment 288425

That's an excellent job. Why couldn't fx do this from factory

 

[MEC17670]

Outstanding work!
Dremal ?

 

[tor47]

I drilled many small holes with a drill. Can not remember exactly what I used to cut the material between the holes.Then I straightened the remaining material with some woodworking files, and sand paper. I also remember i used some ballistol, to darken the surface of the cut a litle.

 

[MEC17670]

Great info, thanks.
Have you notice any problems with dust getting inside the spring guide while hunting?

 

[tor47]

Great info, thanks.
Have you notice any problems with dust getting inside the spring guide while hunting?

I use my airguns for bench, and target shooting, so I have not much experiance with that. For my use there has not been any problems with dust.

 

[fiestaman]

Getting to the same place from different directions.
I found for me, going to 23 then adjusting preload so there's no movement up to 24 then backing off a tiny bit. Then go to 21 on the pw and start increasing reg pressure till i get close to the velocity I'm looking for with the heaviest projectile i want to use. I then shoot for groups.
This post was started to find away to fine tune the internal pre-load in an attempt to find that sweet spot where harmonics are balanced, matter of dwell, imo. Equal forces acting opposite but equally, while being able to shot groups. As the Crown is manufactured, love the gun, this is extremely hard to due because you have to take off the stock to tweek that pre-load. Yes, it takes loads of time and help. Lots of help here, the rest is up to you.
Have fun, take good notes and pictures. You'll get just right for you. View attachment 289258

Hi, just curious, when you max out on 23 why do you drop back to 21 to start with.

 

[qball]

Ok Guys,
You talked me into not cutting my stock. Already set the pre-load pretty close to as much as I can with out binding. Loktite it in the last time I was in there.
953 with a 29 gr . slug. Will do unless I fool with the reg pressure again. 44 shots per fill, and carry extra 480 air vessel. 88 shots while hunting should make for a good day. If I need more, I have my larger vessels to fill from.
Those 29gr. Neilson slugs gives me sub moa accuracy when I do my part.
Been a great stock modification post.
Seems we got into different tunes for our Crowns. What do you folks think about the adjustable seating depth pin probe?

Nice!!!

Short answer: DO NOT use ANY pin probes!!!


Long answer: You NEED the adjustable pin probe IF you have to use a pin probe!!!! Not because seating depth makes that big of difference, it doesn’t…..not in my testing at least. BUT it does make a difference on feeding issues with slugs in mags. You need it short enough so it doesn’t jam thanks to the carrier jump ahead and blocks the fat part of the probe from chambering the slugs, this is especially problematic with factory mag and you might not be able to make it short enough to work with the factory mag as factory mag carrier thing is very thin. For flawless slug mag performance you need yo figured out the minimum seating or shortest the pin can be so the slugs clears the slug port AND find a mag that works like the ones @Elis5173 makes which has a thicker carrier.


OR just open up the pellet probe with dremel and never have any problem at all with any mag, you are not losing more than 5fps so not even worth the trouble honestly!

 

[qball]

not from my experience. I ran my reg up to 150 and had no issue opening the valve with stock hammer and spring.

From my testing factory hammer CAN go up to 150 bars BUT you won’t get a power curve or dropping of power when there is too much hammer. The max reg pressure where I see the power curve is actually under 140 bars, so if you want MAX power 140 is about where you want to be with factory hammer. If you want more power or higher than 145 bars think you need the tungsten hammer weight but tuning will be a little harder with shorter barrels.


At 150 bars with factory there is PLENTY of power and VERY efficient!!! This is why I usually leave mine at 150, with a longer barrel you can’t over power the reg and make tuning a breeze! Or easy to get good efficiency AND accuracy AND shot count with any barrel length…….ok 380 won’t be as easy but night and day easier than lower reg pressure.

 

[MEC17670]

I use my airguns for bench, and target shooting, so I have not much experiance with that. For my use there has not been any problems with dust.

Thanks for the reply and shared knowledge.

 

[pumpmonster]

Hey Guys and Gals,
For all those FX Crown lovers out there, we all know how much a pain in the rear end it is to fine tune the internal hammer preload while tuning for accuracy. In and out of the stock multiple times so each fine adjustment can be grouped.
Got an idea about resolving this inconvenience. Why not cut a small tuning slot in the stock, in my case synthetic, that allows access to the adjustment screw. I can't see any reason that it would hurt the structural integrity of the stock by doing so. The slot would not have to be to wide and it could be made long enough , depending on how you have your gun set-up, to make those super fine adjustments.
Has anyone out there done this before?
Your thoughts?
Thanks Mike

hi mec; i did it to my Daystate huntsman regal xl stock took my time and it came out beautiful. Next thing for me to do is find a little plug to put in the hole so it looks really factory. Sure beats taking off stock every time. If i ever sell it i'm sure the next person will love it.

 

[MEC17670]

hi mec; i did it to my Daystate huntsman regal xl stock took my time and it came out beautiful. Next thing for me to do is find a little plug to put in the hole so it looks really factory. Sure beats taking off stock every time. If i ever sell it i'm sure the next person will love it.

Glad you did it right. Got a pic of your handy work?
No need to do it , I got the Crown shooting lights out now. 33gr zan at 970fps. 1/3 " 5 shot groups at 57 yards.

 

[pumpmonster]

Glad you did it right. Got a pic of your handy work?
No need to do it , I got the Crown shooting lights out now. 33gr zan at 970fps. 1/3 " 5 shot groups at 57 yards.

That is some awesome shooting. i will never see that. i'm just not that good. Not trying to put myself down i guess age has something to do with it. When i think i'm doing well that's when things seem to go wrong. like right now. i was just shooting and i thought everything was fine scope set hitting my target next thing you know pellet starts clipping for no reason. so i try another moderator then works fine for a while then again starts clipping on that one also. talk about frustrating. If you have any idea's i'm all ears believe me. hope to hear from you thank MEC

 

[MEC17670]

That is some awesome shooting. i will never see that. i'm just not that good. Not trying to put myself down i guess age has something to do with it. When i think i'm doing well that's when things seem to go wrong. like right now. i was just shooting and i thought everything was fine scope set hitting my target next thing you know pellet starts clipping for no reason. so i try another moderator then works fine for a while then again starts clipping on that one also. talk about frustrating. If you have any idea's i'm all ears believe me. hope to hear from you thank MEC

I'm a young 72. Those groups were shot off the bench. Not bad but would like 1 ragged hole.
A short period ago I heard a strange noise as I shot, wtf? Turned out my moderator had come loose from the harmonics I suspect. Tighten it back up and volia no more sound. I'm lucky with the horsepower this gun is producing , I didn't damage my rig.
Your barrel might be moving , I had that happen to me. Do you have a shroud on your gun, sorry not familiar with your gun. Maybe a rough spot in your bore that as it leads up catches extra lead.
Don't know.
Tell me about your gun, new , used? Chrony results, pellet type, weight. Caliber, etc. I'm sure someone in the forum will come up with a solution, but we need some info on it. Might be as simple as it doesn't like the pellets your feeding it.

 

[pumpmonster]

I'm a young 72. Those groups were shot off the bench. Not bad but would like 1 ragged hole.
A short period ago I heard a strange noise as I shot, wtf? Turned out my moderator had come loose from the harmonics I suspect. Tighten it back up and volia no more sound. I'm lucky with the horsepower this gun is producing , I didn't damage my rig.
Your barrel might be moving , I had that happen to me. Do you have a shroud on your gun, sorry not familiar with your gun. Maybe a rough spot in your bore that as it leads up catches extra lead.
Don't know.
Tell me about your gun, new , used? Chrony results, pellet type, weight. Caliber, etc. I'm sure someone in the forum will come up with a solution, but we need some info on it. Might be as simple as it doesn't like the pellets your feeding it.

you got me by a couple years. but my eyes are really not too good. last time i went to the eye dr. he said I had cataracts. I would love 1 ragged hole. My moderator also comes loose but i am always checking it. No sir: my barrel is real snug all the time. I really keep an eye on that also. Barrel stays clean always not that I clean it because it's dirty. I just like to clean it about every 2000 pellets. Yes sir: I do have a shroud. Everything is pretty much brand new. I have tried different moderators also; that's what puzzles me. Chorny is about 870fps---with 18.13 gr. JSB pellets---15.89gr. JSB pellets---.22 cal. When it was brand new, I didn't seem to have that problem. As soon as i put any moderator on it seems to put pellets all over the place. I don't know about you but that just Erks me. If you come up with anything i am all ears. thank you MEC

 

[Long_Gun_Dallas]

That is some awesome shooting. i will never see that. i'm just not that good. Not trying to put myself down i guess age has something to do with it. When i think i'm doing well that's when things seem to go wrong. like right now. i was just shooting and i thought everything was fine scope set hitting my target next thing you know pellet starts clipping for no reason. so i try another moderator then works fine for a while then again starts clipping on that one also. talk about frustrating. If you have any idea's i'm all ears believe me. hope to hear from you thank MEC

Sounds like a shroud alignement issue. I'd degass the gun, shine a light thru the breech, and find ways to either tighten, or realign the shroud, maybe add a barrel band if there is not one. Or shim the existing one if it is not tight.... many fixes for this issue.

Light thru breech will allow you to see down the bore and you will be able to see if it is out of alignment

 

[pumpmonster]

Sounds like a shroud alignement issue. I'd degass the gun, shine a light thru the breech, and find ways to either tighten, or realign the shroud, maybe add a barrel band if there is not one. Or shim the existing one if it is not tight.... many fixes for this issue.

Light thru breech will allow you to see down the bore and you will be able to see if it is out of alignment

hi long gun dallas; Everything is brand new. I had sent it to AOA and Shane put me a brand new barrel and bore. Shroud is very tight and i do have a barrel band on it. I did what you said about looking down the barrel. the whole thing is new from breech forward. Like said earlier once i put on the moderator it clips---if i keep it off nothing clips crazy isn't it thanks long gun dallas