.25 slug liner
- Thread starter jfrench64
- Start date
Glem.Chally - Thanks Nathan, it is nice to be praised by a great Tinker like you. And you know I didn't even think about the EunJin 35.8 round nose or 43 grain pointed pellets...of all people I should have thought of those because during my Sumatra era I shot thousands of them! And as a matter of fact there was one brand of pellets that shot better than any other in my Sumatra's even at max power, and that was the Benjamin Domed 27.8 grain! I hope one of you guys try them in a .25 slug liner. In a couple days I will be returning this Crown to its owner, who was gracious enough to let me tinker with his gun so that I could see what makes it tick...so I won't be able to do any more experiments with it after today.
Tomiboy: The weight I used was from my old .25 Wildcat Original than weighed 175.6 grains...I just cut it down with my Dremel cut-off blade a little at a time until I got it where I wanted it. Then I chucked it up in my Makita and beveled the head and tip of the shaft on a piece of 400 paper taped to my glass top desk. You guys don't have to ask Ernest to make you hammer weights because you can make your own. Just order a hammer weight from the .25 Wildcat that weighs 175.6 grains and then cut it down to whatever size you want; or get a 200 grain weight from a .30 Wildcat, or a weight from a .25 Streamline...just call Newman or Summer at FXUSA and tell them you want to buy some hammer weights. The price is $5.00 each.
Bob_O: Thanks Bob, your video on how to adjust the D5 screw in the D4 hammer adjuster block was invaluable and instrumental in me attempting this whole modification. After watching it several times I thought about the new Gen 3 Extra High Pressure regs from Huma, and remembered that I have a friend that just got a new Crown...When I followed your video and removed the set screw in the hammer spring guide and removed it and the hammer spring I was flabbergasted to discover there was no hammer weight in there!!!
So I called my friend to tell him this and get his permission to do surgery on his gun and he laughed and told me that Ernest had already made a video on "Hammer Weight Mod", and gave me permission to proceed. After watching Ernest's video though, I thought that leaving a nub of the spring guide rod was a better idea than cutting it off and drilling a hole for the spring to ride in. I don't have a drill press and I would have had to just free hand it with my Makita, and I thought that if I screw it up God only knows when I could get a replacement part and how long my buddy's gun would be out of service.
For those who may wonder why I wanted to add a hammer weight to a Crown, the reason is that after installing the Gen 3 Extra High Pressure Regulator and turning it up to 160 bar I couldn't get anymore velocity from the 34's...and it was the same for 170, 180, 190, and 200 bar! That's when it dawned on me that all that extra pressure was holding the valve pin closed and that the weight-less hammer wasn't hitting with enough force to open the valve pin. At first I tried a softer valve pin spring but that only helped a little...so then after watching Ernest's video and re-watching Bob's a couple times I sallied forth.
To those interested in an FX Crown I would like to say that this has to be the easiest air rifle in the whole world to work on yourself! You could do your own power tune on one in an hour! And it is light and shoulders and points perfectly! I would dearly love to own one myself someday with the light synthetic stock.
And Bob, I want you to know what an inspiration your YouTube video was to me. It is a big part of the reason for me coming back here to share some of my little discovery's, which is the reason I ever joined in the first place. I think I have things in a better perspective now.
All the best, Chuck
You got those numbers with a 600mm barrel? Yeah i was meaning the 43gr eunjins, try a few
Upvote 0
G
Guest
Guest
Yes Nathan the Crown I have been tinkering with is just a standard .25 caliber with a 600 mm barrel. To accomplish this was as easy as eating apple pie...these Crown's have to be one of the easiest airguns in the whole world to work on. Here is all I did:
1) I installed one of the new Gen 3 Impact/Crown Extra High Pressure Regulators - 140-195 Bar Model.
2) I installed a 90 grain hammer weight that I cut down from one I had leftover from my old Wildcat .25 (after trimming off some of the spring guide rod to prevent binding).
3) I removed the hammer spring adjuster (D4 on the parts diagram) and adjusted the grub screw (D5) about 3 mm out so that it just touches the cam on the Power Adjuster (D2), so that the word MAX is at the 12:00 position.
4) Then I turned the reg up to 160 Bar and shot over my chronograph with the Power Adjuster set on the 3, 4, 5, & MAX positions. Then I turned the reg up to 170 bar and shot over my chrono at the 3,4,5, & MAX; and then at 180 Bar, and then at 190 bar, and then at 200 Bar. Setting the reg up to 190 and 200 Bar did not increase the velocity above the 180 Bar setting...I'm thinking that the 90 grain weight just could not fully overcome the pressure on the valve pin with the reg set at 190 and at 200 Bar.
I am guessing that I would have had to use a much heavier hammer weight and much lighter valve pin spring to get anything out of the 190 or 200 Bar reg setting. So I stopped and dumped all the air out of the gun and reset the reg to 160 Bar to begin accuracy testing the 34 MKI through the slug liner, where I stopped and left it at 180 Bar for now. I reached my goal of getting the 34 MKI's through the slug liner up above 1000 ft/s... now I will leave it up to one of you guys to install a heavier hammer weight and see what you can get out of setting the reg up to say 195 Bar!
The whole process was Easy Peasy!
P.s. The .25 Wildcat hammer weights average 175.6 grains each, and only cost $5.00 a piece... so you don't have to get anyone to make them for you. Just buy some and cut them down to whatever weight you desire to experiment with.
The bottom line is that this .25 Crown is now shooting at the same 78 ft lbs of energy as an FX Boss .30 or FX Wildcat .30. And it has plenty of accuracy and shots from the 250 Bar factory recommended fill up for hunting any small game in North America. The best part of it is that this .25 caliber ammo costs half as much as the .30 caliber ammo does!
1) I installed one of the new Gen 3 Impact/Crown Extra High Pressure Regulators - 140-195 Bar Model.
2) I installed a 90 grain hammer weight that I cut down from one I had leftover from my old Wildcat .25 (after trimming off some of the spring guide rod to prevent binding).
3) I removed the hammer spring adjuster (D4 on the parts diagram) and adjusted the grub screw (D5) about 3 mm out so that it just touches the cam on the Power Adjuster (D2), so that the word MAX is at the 12:00 position.
4) Then I turned the reg up to 160 Bar and shot over my chronograph with the Power Adjuster set on the 3, 4, 5, & MAX positions. Then I turned the reg up to 170 bar and shot over my chrono at the 3,4,5, & MAX; and then at 180 Bar, and then at 190 bar, and then at 200 Bar. Setting the reg up to 190 and 200 Bar did not increase the velocity above the 180 Bar setting...I'm thinking that the 90 grain weight just could not fully overcome the pressure on the valve pin with the reg set at 190 and at 200 Bar.
I am guessing that I would have had to use a much heavier hammer weight and much lighter valve pin spring to get anything out of the 190 or 200 Bar reg setting. So I stopped and dumped all the air out of the gun and reset the reg to 160 Bar to begin accuracy testing the 34 MKI through the slug liner, where I stopped and left it at 180 Bar for now. I reached my goal of getting the 34 MKI's through the slug liner up above 1000 ft/s... now I will leave it up to one of you guys to install a heavier hammer weight and see what you can get out of setting the reg up to say 195 Bar!
The whole process was Easy Peasy!
P.s. The .25 Wildcat hammer weights average 175.6 grains each, and only cost $5.00 a piece... so you don't have to get anyone to make them for you. Just buy some and cut them down to whatever weight you desire to experiment with.
The bottom line is that this .25 Crown is now shooting at the same 78 ft lbs of energy as an FX Boss .30 or FX Wildcat .30. And it has plenty of accuracy and shots from the 250 Bar factory recommended fill up for hunting any small game in North America. The best part of it is that this .25 caliber ammo costs half as much as the .30 caliber ammo does!
Upvote 0
That is crazy power CHUCK!!
When I made that video, it was to help people get MAX on the hammer wheel after they tuned the gun for max velocity.
I was wondering if it would be useful to anyone and I'm glad it helped!!
When I made that video, it was to help people get MAX on the hammer wheel after they tuned the gun for max velocity.
I was wondering if it would be useful to anyone and I'm glad it helped!!
Upvote 0
Very nice job, according to Ernest 100 gn hammer weight (6.5 grams) will open the valve fully @ 200 bar, elongating the ports also help (pin and brass) On the impact I went from 920 to 945 fps just doing that (on the mk2 @ 145 bar). I think the crown (not 100% sure) uses the same pin and brass ports than the impact on the barrels.
Now I wonder, do those liners shoot slugs?
Now I wonder, do those liners shoot slugs?
Upvote 0
G
Guest
Guest
Haha! Well Bob you definitely helped me tune that gun to max power just not the max power you were thinking of!
Bob I think you should install one of the New Gen 3 extra high pressure regs and a 100 grain Hammer weight to your Crown 22 caliber and see what velocity you can get those slugs up to! I'm thinking about 1100 feet per second will be just right ...
I can already see Nathan's wheels turning ...
Edosan I am leaving it up to you guys to figure out the rest because I have to return my buddy's gun that he was gracious enough to let me play with for a while
Bob I think you should install one of the New Gen 3 extra high pressure regs and a 100 grain Hammer weight to your Crown 22 caliber and see what velocity you can get those slugs up to! I'm thinking about 1100 feet per second will be just right ...
I can already see Nathan's wheels turning ...
Edosan I am leaving it up to you guys to figure out the rest because I have to return my buddy's gun that he was gracious enough to let me play with for a while
Upvote 0
G
Guest
Guest
Bob, here is the answer to your shot count conundrum...just put one of these in your backpack and leave it tethered to your gun while you are out hunting!
https://www.airgunsofarizona.com/air-cylinders/omega-18-cu.-ft.-4500-psi-portable-air-tank/
https://www.airgunsofarizona.com/air-cylinders/omega-18-cu.-ft.-4500-psi-portable-air-tank/
Upvote 0
G
Guest
Guest
Drumsnguns, Check with Joel at Palm Beach Airguns for slug liners... he may be able to help you.
Upvote 0
G
Guest
Guest
Jorgo,
The 34 grain MKI shot into one small hole at 50 yards out of the pellet liner (A liner) with the velocity set at 890 ft/s... but when I turned up the power any higher than 900 ft/s they became less accurate. So that's when I wondered if they would do any better in the slug liner at higher velocity...and it turns out that the faster I pushed them the better they liked it! It was one of those Eureka Moments that every tinker lives for. I increased the power until with the reg set at 180 Bar I was getting an average of 1015 ft/s and 1/2" groups at 50 yards!
Every small game hunters dream come true, because with such a flat trajectory the Point Blank Range is from 18 yards to 60 yards. For those that don't understand, it means that from 18 yards all the way out to 60 yards your point of impact (POI) will not be more than 1/2" below or above your point of aim (POA). So that from 18-60 all you have to do is put the cross hairs on what you want to hit and squeeze the trigger. You will either be dead on or a 1/2" high or low, but you will not have to even think about dialing in the shot or trying to figure out which holdover on your reticle to use...just point and shoot. Every hunter knows that many times you only have a split second to shoot when you see your game or it is gone, and will also tell you never to take your eyes off your game because odds are that when you look back it will have disappeared.
I am hoping that Bob or one of you other guys with the .22 slug liner will do this power upgrade for fun to see how fast you can get slugs or redesigned JSB's to shoot accurately. I would love to see 1100+ ft/s...as long as you stay sub sonic. Not just for the additional power mind you...but to achieve the flattest trajectory possible so as to achieve a Point Blank Range of say from 15 yards out to 75 yards. Now that kind of a PBR would definitely make it all worthwhile to any hunter I would think.
The 34 grain MKI shot into one small hole at 50 yards out of the pellet liner (A liner) with the velocity set at 890 ft/s... but when I turned up the power any higher than 900 ft/s they became less accurate. So that's when I wondered if they would do any better in the slug liner at higher velocity...and it turns out that the faster I pushed them the better they liked it! It was one of those Eureka Moments that every tinker lives for. I increased the power until with the reg set at 180 Bar I was getting an average of 1015 ft/s and 1/2" groups at 50 yards!
Every small game hunters dream come true, because with such a flat trajectory the Point Blank Range is from 18 yards to 60 yards. For those that don't understand, it means that from 18 yards all the way out to 60 yards your point of impact (POI) will not be more than 1/2" below or above your point of aim (POA). So that from 18-60 all you have to do is put the cross hairs on what you want to hit and squeeze the trigger. You will either be dead on or a 1/2" high or low, but you will not have to even think about dialing in the shot or trying to figure out which holdover on your reticle to use...just point and shoot. Every hunter knows that many times you only have a split second to shoot when you see your game or it is gone, and will also tell you never to take your eyes off your game because odds are that when you look back it will have disappeared.
I am hoping that Bob or one of you other guys with the .22 slug liner will do this power upgrade for fun to see how fast you can get slugs or redesigned JSB's to shoot accurately. I would love to see 1100+ ft/s...as long as you stay sub sonic. Not just for the additional power mind you...but to achieve the flattest trajectory possible so as to achieve a Point Blank Range of say from 15 yards out to 75 yards. Now that kind of a PBR would definitely make it all worthwhile to any hunter I would think.
Upvote 0
Very good stuff Chuck. Your tinkering is way above mine . mine is just trying different pellets , barrels and speeds with a stock impact . it's truly amazing how much power your making . thanks for sharing all your findings with us .
Upvote 0
G
Guest
Guest
Thanks you are most welcome. It's just a lot of fun to me to figure out what makes these tick and then see if I can get a little more horsepower out of it and a little more accuracy.
Upvote 0
I had really been interested in the Slug Liner for my Gen 1 .25 Impact but not sure now. I don't really hunt more than I pest but it's always fun with a new toy.
Question....can the Impact hammer be modified like the Crown or is it a totally different animal?
I'd have to get the high pressure Huma reg but if I can't get past 160 (without extra weight)....then it won't benefit me to get this liner.
Anyway, I'm just thinking outloud...feel free to chime in.
KP/NC
Question....can the Impact hammer be modified like the Crown or is it a totally different animal?
I'd have to get the high pressure Huma reg but if I can't get past 160 (without extra weight)....then it won't benefit me to get this liner.
Anyway, I'm just thinking outloud...feel free to chime in.
KP/NC
Upvote 0
Is a bit different, in the impact you need a 3mm center hole in the hammer weight for the rod.
Upvote 0
This makes me want to modify my 30 crown! I'm wondering if I can be modified to shoot the 51 grain JSBs at some where north of 900 FPS, say 940 FPS for 100 FPE, and then dialed down to shoot the 44s at a lower speed and conserve some air? That would be the best of both worlds.
Upvote 0