EVOL .22 Paradigm Slug Tuning

[Bladebum]

Well my buddy made me 5 different weight slugs and they did great over the chronograph. All produced a standard deviation of 4 fps. Velocity ranged from 970-945 fps for weights from 25 grains too 27.5 grains.

50 yards the groups were literally a single hole and shocking......though at 100 yards, like bladebum mentioned above.......was like a shotgun again. NOTHING I did helped the slugs in any weight with any velocity.

Again went back to the Fx 25.4 grain pellets and made a single hole at 50 yards, and opened up a little bit at 100 but still all within the black of a 10m airgun target. So good enough for the NRL22 match this Sunday.

I will hopefully have some video coming of the shoot as well as some pictures. Will be fun to see how the rifle does in the cold.


I will say that I had a failure with the rifle today. I took the rifle and left it in my truck all day, from 0445 - 1430 at a temp of around 15°. Brought the rifle to the shooting tube and checking the tank pressure noticed my cover for the gauge fell off! Easy fix as I found it in the rifle case and will glue back on. From a full fill at 0445 this morning at 3000 psi, the pressure when I started shooting was just over 2000 psi. Started. Shooting right away WITHOUT warming anything up, and at 50 yards it was a single hole still.

Tom this thing is a TANK and has no problem in the cold so far. I will be locating some critters to shoot soon as well, and will be getting a report about rhat as well.

It can definitely be a fickle beast to shoot slugs sometimes, I know you've been chasing it for a bit but keep trying!

I noticed your cast slugs were .218, how many 217 size have you tried? With my barrel, I can almost guarantee when a new slug will shoot or not based on the force needed to go into the chamber. Anything more than "slightly snug" and they won't shoot, smooth and easy is always better in my experience. For whatever reason, NSA slugs fit very tight even at 2165 head size and likely why they won't shoot for me

Also, you mentioned speeds but at whst reg pressure? Reg pressure being right is more important than a particular speed.

If you've ever messed with reloading with powder burners you know how small of a change can make drastic improvements. Half a grain of powder up or down, bullet seating depth .010" in either direction, things like that. Imagine your reg pressure being the powder burn rate (very important) and your hammer spring adjustment being the amount of powder. Make sure the head size is right, adjust that reg up and find the knee of the curve.

 

[Woogie_man]

The slugs that were made are 217. Just noticed the picture shows 218! Will talk to my buddy and see if the die upside down is a different diameter or something.

Regulator pressure is still around 2250 psi.

Reloading yup I do a ton of that, and yes there are a ton of similarities between the two. I enjoy the tuning part and am having fun doing it. When I get frustrated I go fly my airplane, and I haven't flown in a while.

 

[Airgun-hobbyist]

Woogie_man, try that hollow design with a rebated boat tail base. Shortening the shank (bearing surface) and getting the centrifugal force and center of gravity towards the outside and back may help bring those slugs over apogee at longer ranges with that pellet rifling. These are my renderings of a modified hybrid slug, free for all to use.

 

[Woogie_man]

I will give that a try and see id it is possible with the dies available. I do keep looking at getting a larger lathe again to not only make some fun parts, but to attempt a die set as well.

 

[CTAirgunner]

Going from ambient indoor temp to 15* will do a ton to pressure in a tank. As far as your slug tuning goes, whats your next step? I only ask because you have far more patience than I.

 

[Woogie_man]

Notes
Bullet : 25.4 gr

Shot count: 10
Low: 967
Hi: 972
Avg: 969
STD Dev: 2
Spread: 5

2023-11-27 14:25:23,972,FPS,53.3,FT Lbs,
2023-11-27 14:25:28,967,FPS,52.8,FT Lbs,l
2023-11-27 14:25:33,967,FPS,52.8,FT Lbs,
2023-11-27 14:25:37,970,FPS,53.0,FT Lbs,
2023-11-27 14:25:41,967,FPS,52.8,FT Lbs,
2023-11-27 14:25:46,970,FPS,53.0,FT Lbs,
2023-11-27 14:25:51,967,FPS,52.8,FT Lbs,
2023-11-27 14:25:56,970,FPS,53.0,FT Lbs,
2023-11-27 14:26:00,972,FPS,53.3,FT Lbs,
2023-11-27 14:26:06,967,FPS,52.8,FT Lbs,

Forgot the chronograph numbers for the 1st shots.

 

[Woogie_man]

Going from ambient indoor temp to 15* will do a ton to pressure in a tank. As far as your slug tuning goes, whats your next step? I only ask because you have far more patience than I.

Will keep playing and see what happens. At 50 yards they are great, but the cost difference doesn't make sense to shoot slugs over pellets.

I can keep looking and see what I can't find for boat tail styled slugs. This type of thing is fun so I enjoy it. This is much cheaper than reloading for my long range powder guns.

 

[CTAirgunner]

Will keep playing and see what happens. At 50 yards they are great, but the cost difference doesn't make sense to shoot slugs over pellets.

I can keep looking and see what I can't find for boat tail styled slugs. This type of thing is fun so I enjoy it. This is much cheaper than reloading for my long range powder guns.

It is rare that a slug will fly well when it doesn't jive with the SF calculators, at least I have found but there are some mystical cases where they do! Have you tried messing with the SF calculators to narrow it down some? I remember testing slugs in my alpha wolf .22 and they grouped excellent at 50 but they sounded completely different "WHIZZING" through the air and after 50 accuracy just went to hell.

 

[Bladebum]

Will keep playing and see what happens. At 50 yards they are great, but the cost difference doesn't make sense to shoot slugs over pellets.

I can keep looking and see what I can't find for boat tail styled slugs. This type of thing is fun so I enjoy it. This is much cheaper than reloading for my long range powder guns.

I am optimistic that you can get slugs to shoot because basically we have the same gun, you just have 3" more barrel. The twist rate in our barrels is also considerably faster than say an FX superior liner which is 1:24 and those shoot light to mid weight slugs well.

If I had a hunch, it'd be that harmonics are off from slightly too long dwell time. Bump that reg to 2300 and see if it tightens things up.

Also, I haven't seen but what size groups are you getting?

 

[Woogie_man]

I am optimistic that you can get slugs to shoot because basically we have the same gun, you just have 3" more barrel. The twist rate in our barrels is also considerably faster than say an FX superior liner which is 1:24 and those shoot light to mid weight slugs well.

If I had a hunch, it'd be that harmonics are off from slightly too long dwell time. Bump that reg to 2300 and see if it tightens things up.

Also, I haven't seen but what size groups are you getting?

Let me check the reg again and see where it is at. The groups at 50 were basically a single hole, but for the 100 yard...take a target and randomly poke holes in it....and that's the groupings. Lol


Oh I am not giving up yet. Have more to try for sure. The one that did suprise me was thr Jacelin 40 grain slugs during my first test. The gun was shooting them great to about 60 yards, and then fell short. I was only able to push them around 750-800 fps from what I can remember. Would be curious to bump the regulator up and see if those slugs will shoot.

Hopefully the next couple of days I will play with the stability calculator and see what happens. There is a sweet spot there for sure I know it, just need to stick with it and find it. I have ALL winter to play with tuning in the indoor range.

 

[American Air Arms]

I suggest a solid nose with a moderate meplat and a gas check type base. I don't know what dies you have access to but if you have those options it think you will have success.

Only in 30 cal have I seen the 2 step bullets perform well.

 

[Woogie_man]

I will see wha the dies are able to do and I will give them a shot!

That is why you as a business owner are awesome Tom! You are on the forums here helping out and willing to give advice about the guns.

 

[Woogie_man]

Yup the dose are 218!! I must have heard wrong about the size or wrote it down wrong.

 

[Airgun-hobbyist]

Yup the dose are 218!! I must have heard wrong about the size or wrote it down wrong.

It's better to have an oversized set of dies rather than smaller. Running the oversized slugs through a sizing die is way cheaper than buying multiple sets of swaging dies to get to the correct size. Plus, the same set of oversized swaging dies can be used for multiple gun barrel's and a specific sizing die can be made for each barrel based on size and accuracy.

 

[Woogie_man]

It's better to have an oversized set of dies rather than smaller. Running the oversized slugs through a sizing die is way cheaper than buying multiple sets of swaging dies to get to the correct size. Plus, the same set of oversized swaging dies can be used for multiple gun barrel's and a specific sizing die can be made for each barrel based on size and accuracy.

That is my thought exactly, and honestly they ran really smooth. None of them are hard to push into the breech.

 

[pan60]

@Woogie_man what the news if any.
have you got this lasered in yet?

 

[Woogie_man]

I have tired a few more and had the same results. I am going to work on getting a tune for the 18.1 pellets. Seeing as I have quite a few tins, around two cased worth, of the ammo.

 

[CTAirgunner]

I have tired a few more and had the same results. I am going to work on getting a tune for the 18.1 pellets. Seeing as I have quite a few tins, around two cased worth, of the ammo.

The 18.13 , you can get a ton of shots, I had my original HPS which was 3 inches longer in barrel and tube size getting 130 shots with the reg at 1250 psi lmao

 

[Woogie_man]

Dang! Was playing with the reg last night and have it around 2000-2100. May have to remove the adjuster nut and really drop the reg pressure! Will have a ton of shots, like you said CT, plinking and general hunting

 

[pan60]

i assume my new gun will come set up for the 25 gr but i might be interested in changing down the road for the 18 gr pellets
i have maybe close to 20 tins of the 25 gr not sure i have been adding a few to every oder i make so they have not all showed up. i will use them up first off or at least a % of them