Air Arms Reduced Power AA Prosport

[pjstreng]

Got back into Airguns this past year having retired and needing another hobby. Picked up a .177 FAC Prosport, mounted a 4-16 UTG scope, and proceeded to test out a few pellets that I knew it would like.

I decided to zero it for 50 yards and had the best results with JSB 8.4s. I knew I got a pretty good rifle as there was very little spring buzz and was easily shooting under 2 inch ten shot groups at 50 yards. Didn’t need to adjust the trigger as it was pretty good from the factory. Shot it about every other day for a couple months and was quite pleased with it. Even after a reasonable break in, I was still getting an almost imperceptible amount of spring buzz and vibration.

I had often read that Prosports are at their best under 12 fps, so I ordered a reduced power spring. It took me all of about 20 minutes to change out springs. The resulting cocking effort was significantly smoother, the buzz disappeared, and I was now getting that sought after bank vault closing thunk on each shot.

Even better than the satisfying improvement of gun’s shot cycle, I am getting a boost in accuracy. I routinely get under 1.5 inch ten shot groups now, and on dead calm days and no caffeine I can do 1 inch groups at 50 yards. I’m not sure I could do much better with a PCP.

 

[bustachip]

Got back into Airguns this past year having retired and needing another hobby. Picked up a .177 FAC Prosport, mounted a 4-16 UTG scope, and proceeded to test out a few pellets that I knew it would like.

I decided to zero it for 50 yards and had the best results with JSB 8.4s. I knew I got a pretty good rifle as there was very little spring buzz and was easily shooting under 2 inch ten shot groups at 50 yards. Didn’t need to adjust the trigger as it was pretty good from the factory. Shot it about every other day for a couple months and was quite pleased with it. Even after a reasonable break in, I was still getting an almost imperceptible amount of spring buzz and vibration.

I had often read that Prosports are at their best under 12 fps, so I ordered a reduced power spring. It took me all of about 20 minutes to change out springs. The resulting cocking effort was significantly smoother, the buzz disappeared, and I was now getting that sought after bank vault closing thunk on each shot.

Even better than the satisfying improvement of gun’s shot cycle, I am getting a boost in accuracy. I routinely get under 1.5 inch ten shot groups now, and on dead calm days and no caffeine I can do 1 inch groups at 50 yards. I’m not sure I could do much better with a PCP.

Sounds like a good rifle, with practice and the right pellet it will do better. Try the QYS 8.48 domed pellet. In my prosport it shoots better than the JSB's, so it's worth a try. It just depends on how they fit in your barrel.

Here's the best I've done with mine at 40 yards shooting off of cross sticks and a little stool. These are only 5-shot groups, but 10 wouldn't have been much bigger, shot with the QYS 8.48 pellet. The red dots are a 1/4" diameter for reference.

1.0" at 50 yards is great accuracy for sure. But still, there might be a better pellet yet? I haven't really tested it off a bench resting on bags yet, just shooting sticks. The prosport and the 97K are my favorite piston guns.

Have fun.

 

[EMrider]

Got back into Airguns this past year having retired and needing another hobby. Picked up a .177 FAC Prosport, mounted a 4-16 UTG scope, and proceeded to test out a few pellets that I knew it would like.

I decided to zero it for 50 yards and had the best results with JSB 8.4s. I knew I got a pretty good rifle as there was very little spring buzz and was easily shooting under 2 inch ten shot groups at 50 yards. Didn’t need to adjust the trigger as it was pretty good from the factory. Shot it about every other day for a couple months and was quite pleased with it. Even after a reasonable break in, I was still getting an almost imperceptible amount of spring buzz and vibration.

I had often read that Prosports are at their best under 12 fps, so I ordered a reduced power spring. It took me all of about 20 minutes to change out springs. The resulting cocking effort was significantly smoother, the buzz disappeared, and I was now getting that sought after bank vault closing thunk on each shot.

Even better than the satisfying improvement of gun’s shot cycle, I am getting a boost in accuracy. I routinely get under 1.5 inch ten shot groups now, and on dead calm days and no caffeine I can do 1 inch groups at 50 yards. I’m not sure I could do much better with a PCP.

Glad that you are enjoying your PS .

Mine is also in .177 and tuned to about 11.5-12fpe. It is my most accurate spring gun and a real pleasure to shoot. Aside from accuracy and cocking effort, another benefit of tuning to 12fpe is reduced stress on the cocking arm linkage. Mine has remained tight and never given me any trouble.
R

 

[pjstreng]

I’ve shot a couple of truly amazing five shot groups with it. Some have been right at .5 inch at 50 yards. But those are rare.

I think the ten shot groups give me a better idea of what its true accuracy (and mine) is.

 

[stewie]

Good move. MY PS in .22 was my first air rifle a decade ago, and it was, like yours, great out of the box. But after a year or so I started experimenting with various springs and kits; I ended up with a hybrid consisting of an ARH 4600 spring (if I'm remembering right), a Vortek seal, and a Motorhead custom spring guide and tophat. I'm coming in now at around 12 fps, and the rifle's accuracy is amazing. My own accuracy is less impressive. BTW, fantastic wood on that rifle.

 

[bustachip]

Good move. MY PS in .22 was my first air rifle a decade ago, and it was, like yours, great out of the box. But after a year or so I started experimenting with various springs and kits; I ended up with a hybrid consisting of an ARH 4600 spring (if I'm remembering right), a Vortek seal, and a Motorhead custom spring guide and tophat. I'm coming in now at around 12 fps, and the rifle's accuracy is amazing. My own accuracy is less impressive. BTW, fantastic wood on that rifle.

I have that QX4600 spring in my 97K, It's a great spring. He offers other springs that are very close to the same these days.

 

[Sawney Bean]

My TX in .177 was much the same. At 17 fpe it shot well but required real finesse to shoot. Installed a Vortek 12 fpe kit and now at 12.5 fpe it's simply a tack driver. Sub 1" groups at 50 yards are the norm now.

I've been coveting a ProSport in .22 for years now and if I get one I'll probably tune it to around 12 fpe too. Hard to say though as the ProSport is more of a sporting rifle than a target gun and my HW95 handles 16 fpe just fine and is nearly as accurate at that power level as my TX at 12 fpe., so if I could get a tune for one that was both more powerful yet not plagued by hold sensitivity then that's the way I'd go.

 

[bustachip]

Got back into Airguns this past year having retired and needing another hobby. Picked up a .177 FAC Prosport, mounted a 4-16 UTG scope, and proceeded to test out a few pellets that I knew it would like.

I decided to zero it for 50 yards and had the best results with JSB 8.4s. I knew I got a pretty good rifle as there was very little spring buzz and was easily shooting under 2 inch ten shot groups at 50 yards. Didn’t need to adjust the trigger as it was pretty good from the factory. Shot it about every other day for a couple months and was quite pleased with it. Even after a reasonable break in, I was still getting an almost imperceptible amount of spring buzz and vibration.

I had often read that Prosports are at their best under 12 fps, so I ordered a reduced power spring. It took me all of about 20 minutes to change out springs. The resulting cocking effort was significantly smoother, the buzz disappeared, and I was now getting that sought after bank vault closing thunk on each shot.

Even better than the satisfying improvement of gun’s shot cycle, I am getting a boost in accuracy. I routinely get under 1.5 inch ten shot groups now, and on dead calm days and no caffeine I can do 1 inch groups at 50 yards. I’m not sure I could do much better with a PCP.

My .177 prosport is shooting at 15 ftlb with the QYS 8.48, accuracy is good, but a little stiff on the cocking.

 

[stewie]

I have that QX4600 spring in my 97K, It's a great spring. He offers other springs that are very close to the same these days.

Yes, I was looking for a back up for the QX4600 at ARH a couple of years ago, but it was no longer available. Two other springs were recommended so I ordered them and have them on hand. That QX is perfecto, no doubt.

 

[bustachip]

Yes, I was looking for a back up for the QX4600 at ARH a couple of years ago, but it was no longer available. Two other springs were recommended so I ordered them and have them on hand. That QX is perfecto, no doubt.

I need to try the lower power spring in my prosport at some point, I'm sure it would be nice and smooth. I like JM springs.

 

[maxtrouble]

I installed this kit in my Pro Sport. Very nice cocking and shooting cycle now. Right at 12 fpe.

TX200/HC/Prosport MAXI PRO Tuning Kit – Tinbum Tuning

www.airrifletuning.com

 

[BrazosbyNemo]

You did the right thing. Spring rifles are great and as accurate as any PCP out there. You just need to set them up for 12fpe or less. That doesn’t mean you won’t have a learning curve or need a good rifle. The ProSport is a great rifle and tuned to 12fpe is even better. Power don’t mean crap if you can’t shoot it accurately. Good job.

 

[Sawney Bean]

You did the right thing. Spring rifles are great and as accurate as any PCP out there. You just need to set them up for 12fpe or less. That doesn’t mean you won’t have a learning curve or need a good rifle. The ProSport is a great rifle and tuned to 12fpe is even better. Power don’t mean crap if you can’t shoot it accurately. Good job.

I don't think there's anything particularly magical about 12 fpe, but I do think that the TX200/Prosport were designed to shoot optimally at that power level. My HW95 is extremely accurate at 16 fpe and my R7 is a tackdriver at 7 fpe.

My Gamo Magnum isn't tackdriving accurate, but it will shoot 2" groups pretty consistently at 50 yards, which is pretty darn good IMO for a cheap 27 fpe rifle. I used to have a Beeman Kodiak that shot about 4" groups at that range and was hold sensitive to the Nth degree.

My best guess is that spring piston accuracy is probably about 75% determined by how optimally balanced the bore, stroke, piston, spring and transfer port are at a particular power level and maybe 25% how powerful the gun actually is.

And this is only in regards to power vs accuracy. Obviously there are other critical factors like barrels and pellets as well.

 

[BrazosbyNemo]

I don't think there's anything particularly magical about 12 fpe, but I do think that the TX200/Prosport were designed to shoot optimally at that power level. My HW95 is extremely accurate at 16 fpe and my R7 is a tackdriver at 7 fpe.

My Gamo Magnum isn't tackdriving accurate, but it will shoot 2" groups pretty consistently at 50 yards, which is pretty darn good IMO for a cheap 27 fpe rifle. I used to have a Beeman Kodiak that shot about 4" groups at that range and was hold sensitive to the Nth degree.

My best guess is that spring piston accuracy is probably about 75% determined by how optimally balanced the bore, stroke, piston, spring and transfer port are at a particular power level and maybe 25% how powerful the gun actually is.

And this is only in regards to power vs accuracy. Obviously there are other critical factors like barrels and pellets as well.

It’s not the power. It’s being able to handle it. 12fpe or less is doable.

 

[PaulK62]

I had often read that Prosports are at their best under 12 fps, so I ordered a reduced power spring.

Where did you get your spring from?

 

[pjstreng]

Where did you get your spring from?

Pyramyd Air. It’s an Air Arms OEM spring.