Taipan Veteran .22 Tuning

[Mink]

Hi all,

I recently got a Taipan Vet Long .22 and am in the process of tuning it for max precision with JSB 18.1s. Talon Tunes sent a chrono string with 18.1s and the mean velocity was around 985 fps. At 50 yards with little to no wind I’m getting .75” to 1.5” groups prone off a bipod and rear bag. I think the gun should be able to do better than this as the trigger is so nice and I’m being conscious of having a consistent hold/follow thru. 


My hypothesis is that 985 is a little hot and would like to get it down around 900 for better stability (and shot count). The only issue is I don’t have a chrono so I’m left to guess how much to adjust the HST to get to this number. 


- Can anyone give an approximate number of turns of the stock HST wheel to drop ~85 fps. Should I be adjusting on the order of full turns, quarter turns, etc?

- I have been trying the old “turn it down and see what the group does” method but I am a little uneasy about bringing the speed too low. 

- What kind of precision should I be expecting from this rifle at 50 yards anyway? What would you deem acceptable/good?

- Finally, if anyone has any tips or other general advice for tuning a .22 Long, be sure to drop that in the replies!



Thanks!

 

[RENVAL]

I would do 1/4 turns, shoot 3 shots and check speed and go from there. 


Renz

 

[mmahoney]

I'd estimate one full turn being about 100 fps. I'd adjust it in 1/8 turn increments especially once you get below 900 fps. I tune my Long to shoot betwen 840 - 900 fps for best accuracy with 860 to 880 usually the money spot. In no wind conditions,you shouldn't have any trouble getting sub 1/2 inch groups. Don't worry about setting the velocity too low. You won't hurt anything.

 

[elh0102]

My Veteran is a .22 Standard. I currently have it shooting the 18 at about 890, and it is very accurate at that level. I'm not sure it will average half-inch groups at 50 yards, but darn close. I agree, your tune seems a bit hot. Barrels are different. My Red Wolf loves the 18 at about 915, and my HW100 shoots best at around 850. Renz' advice is good, quarter turns until you find the sweet spot. Given where you are now, I would probably start with a half turn, but as my wife says, I'm usually wrong. 

 

[RobR]

Are situations are identical.. Purchased the same gun at the same speed though mine grouped decent I thought what little I shot it before dialing it down to 890. Groups tightened up significantly, quieter, and better shot count. Same settings and I was shooting the Griffin cup base LDC 16 grain slugs at 927 with tighter groups yet. Really happy with this setup

 

[Peskådot671]

Not too sure what altitude Talon Tunes is at but if yours is any different, the numbers will be off. I guess you'll have to tune by your groupings adjusting the HST down little by little. Maybe you could use Strelok Pro or Chairgun and validate your holdovers based on the chrony string from Talon Tunes after entering your parameters. Just rambling. 

 

[Enkey]

Hi Mink

When I don't have the chronograph I use this app and if you enter the data correctly it gives you a reading with very little margin for error with the chronograph



regards

Enkey 

 

[RobR]

I re read your post and apologize for overlooking your question. Not sure how much help I’ll be as I’m going off memory and not sure how consistent one gun is to another. I want to say you’re going to be about 3/4 of a revolution ccw. If you’re just looking to tighten up your groups the proof is on the paper. I cleaned my barrel after not that many rounds and it took quite a few pulls to come clean. Might be one less variable to eliminate when you don’t have numbers for every shot.

 

[elh0102]

I overlooked part of your question regarding accuracy to be expected. I always strive for half-inch groups at 50 yards with a precision PCP rifle. I'm not sure all of mine will meet that as an average, but under good conditions, I think they might. You will read many reports of much smaller groups, and indeed I've shot many of them too. But, as an honest average, I think that is outstanding performance. With the rifle in good tune and the barrel in good shape, I think you should see similar results. Regarding cleaning a new barrel, opinions abound. Since you have started shooting your rifle, I would recommend continuing the tuning process and see what accuracy you get. If you don't see 1/2" to 5/8" groups at the lower velocity, then cleaning is a good idea. If pull-through patches don't yield the desired accuracy, then I would take off the barrel and get it really clean with a rod and brush, followed by mild polishing with JB paste. I recently bought an HW100, and accuracy was only mediocre, with pull-through cleaning not helping a lot. One good brush cleaning and polishing improved it a lot, and it has needed no more than pull-through cleaning since. Good luck with the Veteran, it's a great rifle. 

 

[octavius]

I had to lowered pressure on the regulator a bit. I tighten the brass screw for 5 dots. Accuracy is better now I had big deviation from begin of the pressure. Now I have 890fps for 18gr. jsb.

 

[sdel2]

If you want to be shure you must have chrono.

Regards

 

[octavius]

yes, chrono is a must but obviously is good to know also regulation pressure. But in my case I don't know.