Tuning Question: Why tune for speed first, why not accuracy?

[dizzums]

well, all nodes aside, ultimate accuracy is less important than a predictable trajectory to me .. may be fine for paper targets but in the real world after an ornery critter a 'guess' is usually a miss ... needs to be pretty fast and 'acceptably' accurate ..i consider 1" acceptable for a dead on hold killzone myself ..

 

[ddnzf]

I have tuned my fx maverick .22 sniper several times over the course of the last month or so. Same maverick, same equipment, same NSA 24.8 in .218.

I have had 3 tunes all with the regulator around the same , which is around 125 - 130 bar. None of the two previous tunes can be replicated, probably because I can not get back to the same regulator pressure again. That is surprising to me, every tune gives me a little different speed.

I started at 950 and slowly increased speed to get the accuracy I want. Why 950? I wanted a flat trajectory. So a speed is only a guide. I’ll take whatever speed gives the best accuracy.

 

[jps2486]

Oh, but it's the American way-faster, more powerful! You're on the right track, brother.

 

[hussn32]

Yes 800-900 is the perfect accuracy zone. But from a hunting perspective sometimes you need more speed, especially with a larger caliber airgun. And at longer ranges. I have had critters move or take flight as soon as my gun would fire. Other than certain condition’s like this , 800-900fps is perfect and accurate.

 

[douger]

i also think new tecnology alows pellets to fly better at higher fps per say older tecnology

 

[Ghostranger169]

Revoman,
I agree in principle with methodology behind what you're saying(let accuracy be your guide instead of numbers on reg gauges, chrono, or HS tensioners; all of which MAY or MAY NOT be accurate. Or instead of just MAXXING everything out BEFORE you even start shooting).
There are a lot of less experienced airgunners and/or those who are new to tuning on the forum who have posted frustration about not being able to get their airgun to do what they THINK it should do. So, I would add these steps before yours.
To have a better chance at being happy with your purchase:
Step 1: Figure out what your objective is and define it. I.e.- "I want a hunting/pesting rig that will be able to hit a ... size kill zone at ... distance and will have enough power to dispatch game/pest in an ethical manner" OR "I want a ... yard target shooting rig that will score high enough to possibly win at my local club" OR "I want a rig to competitively shoot PRS style matches" OR "I want a rig that will hit what I aim at most of the time at .... distance(or ... distances) OR "I want a Hunter Class field target rig" OR ....
Step 2: Research your purchase options. The airgun world(forum members, retailers, youtubers, internet, etc...)is full of helpful people that will share information to get you in the ballpark, if you just ask. Is there evidence of many others having success using whatever you are thinking about buying for the purpose that you want to use it? If so, what ammo are they using, and at what speed? What accessories? Optics? Etc...
Step 3: Contact retailer/seller and ask about expected performance desires to make sure you're not waaay off base(like expecting to win a EBR or RMAC 100 benchrest with a .177 Marauder).
THEN move on to the steps you mentioned above. BUT if you have knowledge of what you're trying to accomplish, then you may want to START your accuracy testing with reg and hammerspring settings already in an APPROPRIATE RANGE(meaning, for example,- if you're trying to get accuracy out of high caliber or heavy slugs, you probably don't want your reg set really low with the hammerspring just tapping it, which is the way it may come from the factory).
Just my .02

 

[Nsboost]

I have tuned my fx maverick .22 sniper several times over the course of the last month or so. Same maverick, same equipment, same NSA 24.8 in .218.

I have had 3 tunes all with the regulator around the same , which is around 125 - 130 bar. None of the two previous tunes can be replicated, probably because I can not get back to the same regulator pressure again. That is surprising to me, every tune gives me a little different speed.

I started at 950 and slowly increased speed to get the accuracy I want. Why 950? I wanted a flat trajectory. So a speed is only a guide. I’ll take whatever speed gives the best accuracy.

I agree a flat flight path is highly desirable in a lot of instances. You have to think about the arc of the projectile on the way to your target/game. A slow projectile is going to have a big arc and a lot of drop. There’s plenty of instances that you potentially hit something that’s higher than your target as the projectile is on a perfect flight path to your target. You also have to think about how the projectile will impact. Say pellet moving at 800fps at 100y is coming DOWN into the target, not straight at it. A sunstantialy heavier slug moving at 980-1020fps is on a much flatter flight path. It’s all about the use case

Lot of opinions here seem to be based on pellets. Pellets and slugs are completely different worlds. A pellet is stabilized by the skirt. A pellet is much lighter. A pellet (ime.. as I live in a VERY windy place) is much more prone to wind drift. I have a ton of fun with low speed pellets to 100y in low to no wind circumstances (indoor range).

But outside, in 10-20mph breezes, shooting targets 100-200y… a fast moving slug is far more consistent and kills are far more humane than any pellet of the same caliber.

The original question still is weird to me? Don’t mean to rock the boat saying that lol. I believe everyone is tuning for accuracy. Nobody wants the projectile to just go wherever. And just like he said in his “response” to me… I don’t have a single friend that waste ammo and time dialing in on the knee of the curve of a fps before knowing the results of said fps are good.

I don’t see it any differently than precision shooters in the powder world doing load development to find their accuracy node.

I guess what I said above would be the answer to the op question. People might be aiming for a given speed with a given weight and BC because of the benefits of it. So if they want a high bc slug moving at high speed for those benefits, they ain’t gunna just load up the projectile and find the node at 800fps. That’s not what they want. They want to find that node at higher speeds.. so they set the rifle up in the middle of its adjustability in the area they HOPE to find a accuracy node at. And adjust till they find it.


Just like politics, cars/trucks, tool brands, clothing choice, and whatever.. everyone has a different use case with different goals. Your way isn’t the correct way. My way isnt the correct way. The correct way is whatever works and meets the end goal of the user. It really doesn’t matter if they guy shooting next to you does it differently if the end result is the same (accuracy wise.. because that is the one thing that we all have in common.. we want accuracy!). Lol

 

[Leatherman]

Since Nsboost isn't getting it, let me try this....
1.) Receive a rifle from the factory, shoot it, leaving the chronograph in the box.
2.) Shoot it to see if it's as accurate as anticipated at the range required and using the projectile of choice.
3.) If it is, then you're good. If not make an adjustment and shoot again. Repeat as necessary the entire time not using the chronograph.
4.) Once the accuracy is attained, then crack out the chronograph to see what speed has been settled upon by the rifle, projectile and range required.
5.) Then bump the regulator pressure slightly to elevate the speed and use the finer tuning adjustments to drop back to the accuracy velocity as established.
Make a little more sense?
mike

I agree with what you said and in my experience you cant say I’m only going to shoot JSB pellets , in so in so weight for example because they are the best or because they shoot well in another gun?. Every gun is different and the gun will tell you what brand , size and weight and speed is best Through it. I have several brands of PCP rifles that shoot best with different brands and weights of pellets or slugs. I read posts from new airgun shooters that are disappointed in the accuracy they are getting using a particular brand of pellets but don’t want to try other brands either because they figure there isn’t any reason to try or don’t want to spend the money to experiment. that is why as you stated if you do not get the accuracy you want don’t blame the gun but change the ammo. I learned this from my Powder Burners days. You try different bullets in a desired weight range to see which performs best, then fine tune with powders and loads and velocity And faster is usually not the best. Benefits of this may also find more than one brand shoots as well and gives you options when shortages happen.

 

[Scotchmo]

Punching paper at a fixed distance depends less on a flat trajectory, so higher velocities may not be beneficial. But in other circumstances, flatter trajectories can trump absolute precision. Even though my Hunter Division FT rifle might be more precise at 880fps, I choose to set it for 930fps. Now my range estimates can be off by 3yds, and I still have a good chance of hitting the far targets. At 880fps, that’s almost a guaranteed miss.

 

[Revoman]

I appreciate all of the valued input. I have tried the 'normal' set the wheel at MAX and adjust the speed until it maxes out, then drops. While it seems to work okay, it still made me wonder where to start within the 'usual' pellet FPS range of 880-920 once that was done.
Therefore, my statement intention was; Let the pellet choose the speed by starting perhaps on the low end and work up instead of "choosing" any FPS in between. Many state that they have good results at 960FPS with RD's for example, which adds another layer to the already muddied "This works in my gun." syndrome.
When working with a single pellet brand/weight, it's going to like a specific speed. There is no way to know what this is until the work is done, but guessing at a FPS first makes little sense to me.
Working from a low FPS using the same pellet combination and raising the FPS incrementally does make sense to me.
Perhaps I'm not making myself clear, thus the confusion.
Nsboost; I simply spoke to your thread only because if you didn't get my intent, then I explained it incorrectly. No other reason intended.
mike