Rod, First I always add a disclaimer that way works for me may not work for you.
Like you stated I apply over 25 years of gunsmithing along with nearly twice that in shooting to Airgun tinkering.
Airguns and a PCP's in particular don't always react the same as a powder burner. The principle is the same but their reactions are a little different.
Let's talk about your stock issue first. Normally with a powder burner if you had an issue with that movement, you would automatically do an aluminum bedding or a glass bedding to correct the issue. Along with free-floating the barrel, and making sure you have a good crown should eliminate any accuracy issues.
With a crawl having the framework attached to the bridge I would definitely do something to stop the movement. I'm not sure bedding would be the best solution nor the easiest. For me having some experience with channeling out blanks for rifles I would look for a solution of getting a better fit with the wood. That would require some in letting and fitting which isn't too hard but it would need to be pretty tight. Harmonics with a PCP would not really be an issue unless precise target shooting like Benchrest and even FT...hunting you have a larger margin of error then trying to hit a pin head size 10 zone on a BR card....
My friend Jimmy Fussell on The Forum AKA Camp Fussell, had an FX Royal 400 and .22 caliber. I had the exact same gun in the synthetic model. He had an issue with the POA moving around, mine was lights out perfect.
He asked me to take the gun and take a look at it. I prescribe to the K.I.S.S. principal. Keep it simple stupid!
The first thing I checked was to make sure the barrel was seated securely. After that I checked the stock fit and I found a little left to right movement inside the wooden stock. Not uncommon as most of these guns I use a single stock screw to hold them together. Not a lot of movement just a tiny bit. So I remove the stock and took pieces of masking tape on either side of the breach. Two thin pieces of that tape on either side stopped the movement there was no vertical movement with it taken down period took the gun outside and placed hole in hole at 30 yards without any difficulty. That tiny bit of lateral movement related to a good bit of movement at distance.
Usually with loose left to rt movement will show as lateral POI shift. Bouncing up, over , back the other way of the POA, indicates a more severe cause, mostly loose barrel screws...
See? Simple. Most cures come this way. Most of these guns and especially the high-end guns are so precise, sometimes only a little teeny bit of an issue can throw it way off.
Adventure to say, if you can get the gun seated into the stock tightly weather using tape, routing out a little bit of wood with a chisel, etc, you would be able to firmly mount the stock and eliminate a lot of your problem with POA right there.
You could ck to see how much the stock is causing the bad grouping, by leaving the stock off and shoot the gun off a bag from a bench. The Cauldwell Tack Driver bag works great. It won't matter that the actuator lever is at the bottom...
Then try going through your pellets again to see which ones groups the best. I have been using air arms 25.4 grain with unbelievable results. The Diablo pellet definitely is the way to go for accuracy . Some people prefer a raptor or one of the expanding pellets and they are right, they will have more down range impact. But for me I only take headshots on small animals when hunting. I always try for the one-shot kill.
With your dirty Barrel that would definitely be an issue. Most likely The quality control when Kral rifles leave turkey may not be the best. First thing I always do with a new rifle especially powder burners, is to give it a good thorough cleaning. A lot of times there is some metal chippings from the Machining that's left in the barrel. Nothing major and easily fixed by cleaning.
Now with my competition Steyr it does not like pellets straight out of the box, even if they're washed first. Most Steyr's and people that use the Steyr's that I know of. lubricate their pellets with a lubricant like slick 50 One Lube. The barrel stay cleaner longer, and it slightly slows To pellet but increases the best grouping.
Pellet speed can effect your grouping too. Most air Gunners know that the speed claim you see on the boxes of the Gamos and some of the other rifles at big box stores, are not real world. the claim 1100 feet per second is not right. Most of those guns will not do that without PBA ammo and are slower with lead. But it emphasizes a point with air gun pellets.
Once you exceed a certain speed usually around just under 900 feet per second, your accuracy falls way off. This is because at that Speed. Most pellet start to tumble and lose their aerodynamics.
In field Target, it's a well-known fact that the 12 foot pounds of energy guns are inherently more accurate than the same exact gun shooting at 20 FPE. Decidedly more affected by wind but still more accurate
inherently.
So with this point in mind check your speeds and back it off or increase of a little bit according to what your pellet does best. With the Kral, I did not do it with the adjustable power setting. All it is, is a port size adjustment. It basically increases or decreases the size of the port. I preferred it to be wide open and set, as the adjustability is to quirky, not having any dentint to stop it at a particular opening size.
I preferred to use the hammer spring tension to increase or decrease and found that the best was that about 35 - 36 FPE. That gave me the best accuracy out of the gun .
Okay let's talk pellets. My gun prefers, and most of my guns prefer, air arms over the JSB's. Not that they're too far off of each other, it's just the air arms seem to group a bit tighter than has JSB's. I chose 25.4 grain Air Arms pellets. You may want to try others and even CP's as they have a harder blend in material.
Now for another issue Old Corps and I found. If you tilt the gun back while loading a pellet into the mag, it can slip back into the breach and jam the mag. The magazine looks like the FX mag, but it is no FX!
It holds the pellets too loose for my liking... !!! With a mag rifle, field target and bench rest guys don't use a mag. Using a single shot tray allows precise placement into the lead-in of the barrel. Magazines have too many problems with proper placement... They are not aligned perfect, the pellet can be pushed in slightly crooked, it can mishape the skirt. A myriad of issues.
I bought a used and broke Evanix Blizzard from a friend. The cocking lever also pushes the arm to rotate the mag to the next pellet. I removed the arm as it was gouging the side plate from a guide screw not staying in the hammer. I rotated the mag by my finger waiting for the new side plate and hammer to arrive from Korea. Since my finger did not touch the mag after clicking it to the next dentint on the gun. The mag automatically seated itself perfectly in line for the pellet. The gun went from grouping 1" to a 1/2" at 30 yards, to grouping one ragged hole at 30 yds. It was a. 22 and I left the lever out when it arrived. I sold the gun and the new owner had the option of me putting it in or leaving it out. I told him I could guide him installing it on the phone. He loved the accuracy and left it out. Besides after doing it 20 times you could nearly rotate it as fast.
Hope I gave you some ideas to try Rod...Good luck and keep us posted...
Like you stated I apply over 25 years of gunsmithing along with nearly twice that in shooting to Airgun tinkering.
Airguns and a PCP's in particular don't always react the same as a powder burner. The principle is the same but their reactions are a little different.
Let's talk about your stock issue first. Normally with a powder burner if you had an issue with that movement, you would automatically do an aluminum bedding or a glass bedding to correct the issue. Along with free-floating the barrel, and making sure you have a good crown should eliminate any accuracy issues.
With a crawl having the framework attached to the bridge I would definitely do something to stop the movement. I'm not sure bedding would be the best solution nor the easiest. For me having some experience with channeling out blanks for rifles I would look for a solution of getting a better fit with the wood. That would require some in letting and fitting which isn't too hard but it would need to be pretty tight. Harmonics with a PCP would not really be an issue unless precise target shooting like Benchrest and even FT...hunting you have a larger margin of error then trying to hit a pin head size 10 zone on a BR card....
My friend Jimmy Fussell on The Forum AKA Camp Fussell, had an FX Royal 400 and .22 caliber. I had the exact same gun in the synthetic model. He had an issue with the POA moving around, mine was lights out perfect.
He asked me to take the gun and take a look at it. I prescribe to the K.I.S.S. principal. Keep it simple stupid!
The first thing I checked was to make sure the barrel was seated securely. After that I checked the stock fit and I found a little left to right movement inside the wooden stock. Not uncommon as most of these guns I use a single stock screw to hold them together. Not a lot of movement just a tiny bit. So I remove the stock and took pieces of masking tape on either side of the breach. Two thin pieces of that tape on either side stopped the movement there was no vertical movement with it taken down period took the gun outside and placed hole in hole at 30 yards without any difficulty. That tiny bit of lateral movement related to a good bit of movement at distance.
Usually with loose left to rt movement will show as lateral POI shift. Bouncing up, over , back the other way of the POA, indicates a more severe cause, mostly loose barrel screws...
See? Simple. Most cures come this way. Most of these guns and especially the high-end guns are so precise, sometimes only a little teeny bit of an issue can throw it way off.
Adventure to say, if you can get the gun seated into the stock tightly weather using tape, routing out a little bit of wood with a chisel, etc, you would be able to firmly mount the stock and eliminate a lot of your problem with POA right there.
You could ck to see how much the stock is causing the bad grouping, by leaving the stock off and shoot the gun off a bag from a bench. The Cauldwell Tack Driver bag works great. It won't matter that the actuator lever is at the bottom...
Then try going through your pellets again to see which ones groups the best. I have been using air arms 25.4 grain with unbelievable results. The Diablo pellet definitely is the way to go for accuracy . Some people prefer a raptor or one of the expanding pellets and they are right, they will have more down range impact. But for me I only take headshots on small animals when hunting. I always try for the one-shot kill.
With your dirty Barrel that would definitely be an issue. Most likely The quality control when Kral rifles leave turkey may not be the best. First thing I always do with a new rifle especially powder burners, is to give it a good thorough cleaning. A lot of times there is some metal chippings from the Machining that's left in the barrel. Nothing major and easily fixed by cleaning.
Now with my competition Steyr it does not like pellets straight out of the box, even if they're washed first. Most Steyr's and people that use the Steyr's that I know of. lubricate their pellets with a lubricant like slick 50 One Lube. The barrel stay cleaner longer, and it slightly slows To pellet but increases the best grouping.
Pellet speed can effect your grouping too. Most air Gunners know that the speed claim you see on the boxes of the Gamos and some of the other rifles at big box stores, are not real world. the claim 1100 feet per second is not right. Most of those guns will not do that without PBA ammo and are slower with lead. But it emphasizes a point with air gun pellets.
Once you exceed a certain speed usually around just under 900 feet per second, your accuracy falls way off. This is because at that Speed. Most pellet start to tumble and lose their aerodynamics.
In field Target, it's a well-known fact that the 12 foot pounds of energy guns are inherently more accurate than the same exact gun shooting at 20 FPE. Decidedly more affected by wind but still more accurate
inherently.
So with this point in mind check your speeds and back it off or increase of a little bit according to what your pellet does best. With the Kral, I did not do it with the adjustable power setting. All it is, is a port size adjustment. It basically increases or decreases the size of the port. I preferred it to be wide open and set, as the adjustability is to quirky, not having any dentint to stop it at a particular opening size.
I preferred to use the hammer spring tension to increase or decrease and found that the best was that about 35 - 36 FPE. That gave me the best accuracy out of the gun .
Okay let's talk pellets. My gun prefers, and most of my guns prefer, air arms over the JSB's. Not that they're too far off of each other, it's just the air arms seem to group a bit tighter than has JSB's. I chose 25.4 grain Air Arms pellets. You may want to try others and even CP's as they have a harder blend in material.
Now for another issue Old Corps and I found. If you tilt the gun back while loading a pellet into the mag, it can slip back into the breach and jam the mag. The magazine looks like the FX mag, but it is no FX!
It holds the pellets too loose for my liking... !!! With a mag rifle, field target and bench rest guys don't use a mag. Using a single shot tray allows precise placement into the lead-in of the barrel. Magazines have too many problems with proper placement... They are not aligned perfect, the pellet can be pushed in slightly crooked, it can mishape the skirt. A myriad of issues.
I bought a used and broke Evanix Blizzard from a friend. The cocking lever also pushes the arm to rotate the mag to the next pellet. I removed the arm as it was gouging the side plate from a guide screw not staying in the hammer. I rotated the mag by my finger waiting for the new side plate and hammer to arrive from Korea. Since my finger did not touch the mag after clicking it to the next dentint on the gun. The mag automatically seated itself perfectly in line for the pellet. The gun went from grouping 1" to a 1/2" at 30 yards, to grouping one ragged hole at 30 yds. It was a. 22 and I left the lever out when it arrived. I sold the gun and the new owner had the option of me putting it in or leaving it out. I told him I could guide him installing it on the phone. He loved the accuracy and left it out. Besides after doing it 20 times you could nearly rotate it as fast.
Hope I gave you some ideas to try Rod...Good luck and keep us posted...
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