chouchin66
Top Tier member
Soooo glad I missed nasally ejecting coffee, mid laugh, & saving my phone screen, reading that.
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the Daily hi thread
S400 .22 - Strange Hold Sensitivity and Accuracy?
- Thread starter BradleyW
- Start date
nav2022
Member Extraordinaire
I wanna see a video with sound of this infamous bucking bronco S400.
OP, put a video up.
OP, put a video up.
Without wishing to get sucked in, this seems to be a matter of simple physics and subjective perception.
When fired a PCP will move in reaction to two* components:
Striker
When the striker is released it travels forwards under spring force, driving the rest of the gun backwards in reaction. The gun's motion is rearward at first before decelerating and reversing direction when the striker hits the valve - just like a springer but with far lower forces / displacements involved.
Pellet
As the pellet accelerates forward under action from the air behind it, the rifle is driven reward under the same force until the pellet exits the barrel.
*There's also arguably the effect of the muzzle blast acting on the front of the barrel momentarily, but we'll ignore this for the sake of simplicity for now.
These will manifest as both pure rearward travel and a rotation about the gun's centre of mass which can be seen as muzzle rise. Hold / restriant will also affect this behaviour. External factors notwithstanding the magnitude of any displacement will depend directly on the ratio of masses between the rifle's action and whatever it's reacting against (pellet or striker) - i.e. you will get a more pronounced movement with a lighter rifle and heavier striker or pellet. Shorter guns are also more prone to muzzle rise as they have less mass at the front to suppress this.
With most PCPs these effects are so minimal that the shooter will only perceive them when the gun is bench-rested; although the significance of this motion is recognised by the fact that most top-end match guns come with mechanisms to mitigate this and keep the gun as close to static as possible ("stabilisers" or "absorbers").
Ultimately it sounds like the gun in question is behaving exactly as would any other of a similar format and the OP is lost down a hole obsessing over what small amount of movement is present. Is it moving? Yes. Is this having some effect on POI? Yes (although the magniture of which will be very small and possibly eclipsed by other factors). Is this amount of movement objectively large? No - certainly not compared to springers or firearms.
As has been suggested already it looks like some objective point of reference is needed to drag the OP back out of their rabbithole - such as firing someone else's gun of a similar spec or getting someone else to assess the gun.
Finally the groups are another example of the need for managing expectations - those certainly look towards the better end of what I'd expect from a .22 pcp at that range and while it's easy to see that they're not perfect (one single pellet-sized hole) it would be unrealistic to expect this.
When fired a PCP will move in reaction to two* components:
Striker
When the striker is released it travels forwards under spring force, driving the rest of the gun backwards in reaction. The gun's motion is rearward at first before decelerating and reversing direction when the striker hits the valve - just like a springer but with far lower forces / displacements involved.
Pellet
As the pellet accelerates forward under action from the air behind it, the rifle is driven reward under the same force until the pellet exits the barrel.
*There's also arguably the effect of the muzzle blast acting on the front of the barrel momentarily, but we'll ignore this for the sake of simplicity for now.
These will manifest as both pure rearward travel and a rotation about the gun's centre of mass which can be seen as muzzle rise. Hold / restriant will also affect this behaviour. External factors notwithstanding the magnitude of any displacement will depend directly on the ratio of masses between the rifle's action and whatever it's reacting against (pellet or striker) - i.e. you will get a more pronounced movement with a lighter rifle and heavier striker or pellet. Shorter guns are also more prone to muzzle rise as they have less mass at the front to suppress this.
With most PCPs these effects are so minimal that the shooter will only perceive them when the gun is bench-rested; although the significance of this motion is recognised by the fact that most top-end match guns come with mechanisms to mitigate this and keep the gun as close to static as possible ("stabilisers" or "absorbers").
Ultimately it sounds like the gun in question is behaving exactly as would any other of a similar format and the OP is lost down a hole obsessing over what small amount of movement is present. Is it moving? Yes. Is this having some effect on POI? Yes (although the magniture of which will be very small and possibly eclipsed by other factors). Is this amount of movement objectively large? No - certainly not compared to springers or firearms.
As has been suggested already it looks like some objective point of reference is needed to drag the OP back out of their rabbithole - such as firing someone else's gun of a similar spec or getting someone else to assess the gun.
Finally the groups are another example of the need for managing expectations - those certainly look towards the better end of what I'd expect from a .22 pcp at that range and while it's easy to see that they're not perfect (one single pellet-sized hole) it would be unrealistic to expect this.
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not sure a chronograph would show any problems with the gasket on the thermo-coupler Rog, although i suppose it would show any issues with the condensation capacitor and relay switch, it could even be a worn dynotronic pulsation cuff, so probably best to ignore all these daft so called simple checks and look for the real technical issues. trading it in for one of those fx guns might be a trouble free optionBeen watching this for a while now, noticed that there has never been mention of a chrono ?
I would have thought that that would have been one of the first things to check, it’s obviously getting more oomph from somewhere
BradleyW
Proactive member
Regarding questions surrounding chronograph results and consistency, please refer to page 1, post 1. It states "At 140 BAR down to 110 BAR, I see as little as 5fps variation, with many shots being the exact same velocity".
Huge thanks to Cloverleaf for your input. It is highly valued.
Huge thanks to Cloverleaf for your input. It is highly valued.
Varminter
Super member
I hear all this stuff about recoil/ flip/ jump...
Makes ya ( me) wonder how folks that shoot stuff that has a firing pin striking a primer, setting off a controlled explosion, raising a muzzle & sending 20 plus pounds of recoil energy into a shoulder ever manage to get on....
I’ve been reading thinking if a PCP is prone to muzzle flip, hold sensitivity and recoil then they may as well get a springer! It seems to defeat the object of PCP shooting, particularly if they single shot load a PCP like many on here do!
Colesy
Member Extraordinaire
Hi All from the above posts,....do you think it could be a thermocouple on my goose gun, if so, where can i order one please, and will I need any special tools....As regards chronographing,...I did try chronographing it after reading about it on here, but I think I may have placed my chronograph too close to the gun as after I fired it, ( remotely, with the aforementioned bit of string), I couldn't find the chronograph...just disappeared, I know, unbelievable,..I don't understand it....got to be the thermocouple now I think.
Cheers
Chris.
Cheers
Chris.
chouchin66
Top Tier member
Nah, brother , just a low charge in your Flux Capacitor.
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Colesy
Member Extraordinaire
Hi all...update...found a bit of the chronograph...it was in the next field...that's going back for a refund...obviously faulty and not up to the task....I made sure the three and a half inch magnum cartridge had BB in it as I read you can chronograph BB,'s with this chronograph. I'm doing everything right, by the book, and still not having much luck to be honest.
Cheers
Chris.
Cheers
Chris.
Dag
Super member
Rog5
Super member
BradleyW
Proactive member
Between 11.4 - 11.6 FPE (16g AADH, Batch 54, Y2022). Pellets were weighed to ensure consistency. I'll find the shot string results and post them.
Edit:
30 shot string starting from 150 BAR. Ambient temp approx. 25c. Pot size 57mm. Caldwell Chrono with lighting kit used.
567 (Min 11.42 FPE).
568
570
570
570
569
571
572 (Max 11.63 FPE).
571
571
570
569
569
569
569
570
572
569
568
569
570
569
570
569
568
571
568
570
568
567
Edit:
30 shot string starting from 150 BAR. Ambient temp approx. 25c. Pot size 57mm. Caldwell Chrono with lighting kit used.
567 (Min 11.42 FPE).
568
570
570
570
569
571
572 (Max 11.63 FPE).
571
571
570
569
569
569
569
570
572
569
568
569
570
569
570
569
568
571
568
570
568
567
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Wing Commander
Member Extraordinaire
From experience, every rifle has its own peculiarities with hold, balance, etc with getting a shot off in a straight line.
We just have to experiment to find the "secrets".
Are you adding value to this thread or just spamming it now?
Colesy
Member Extraordinaire
Just trying to have a laugh and lighten it up a bit.
Cheers
Chris.
Cheers
Chris.
Appreciate that, we all like a laugh, but the one piss take was enough...no need to ruin the thread by carrying on and on.
Colesy
Member Extraordinaire
Well I do hope I haven't caused any offence to anyone. Didn't realise I was going on and on or ruining the thread but there we are.
Cheers
Chris.
Cheers
Chris.
in all fairness i doubt you've caused offence to anyone chris, as i know your pisstaking, along with mine, is just an attempt to get Bradley back on track so that he can sort, and then enjoy shooting his s400
Bradley says he hasnt used the gun for a couple of years because of the issues, which is a shame as they're a cracking gun, and usually simple enough to set up, although occasionally we do get a ''head scratcher''
these s400 series guns are a reasonably simple design, and these ''head scratcher'' guns nearly always get stripped down several times, have parts replaced or modified, and when that fails, a simple test that should have been done at the start or out of sequence, reveals that the problem turned out to be the simplest of problems
@Rog5 and yourself are in the upper stratosphere for knowledge of the s400 series, and its no coincidence that you've both suggested the 2 basic and simple start points for problem solving these guns. i really hope Bradley realises that, unless he starts at the very beginning with your advice, one step at a time, then he'll be pissing in the wind and probably wont shoot the gun for another 2 years
Colesy
Member Extraordinaire
Hi Pogue. Thankyou, much appreciated. I did try, genuinely, to point Bradley in the right direction, as did you and several others and I would have been more than happy to have carried on through the process of fault finding,checking and set up etc. My,.. obviously not appreciated,..attempt at humour was just that and was intended to entertain whilst making a couple of subtle points and was in no way meant to be offensive or indeed to ruin the thread, I just hope it gave people a smile. I agree that there's not much on an s400 that can't be sorted and, as stated earlier, I sincerely hope Bradley gets his rifle shooting to his satisfaction. By the way, if I was making a list of people who know their way around an s400, I would put you up the top too.
Cheers
Chris.
Cheers
Chris.
try this for an accuracy test Bradley, rather than trying to shoot 1 hole groups on paper. if you can shoot the horizontal row, and then the vertical row @ 25yds then theres nowt up with the guns accuracy. then when you do it with just the matchsticks your gun is as perfect as its going to be, although 20yds might be better for the matches to start with
