Home tune on LGU?

[MrChipShoulder]

I've not shot a springer for years, and certainly not a 'proper' one like this

I ran about 150 shots through it the other evening on a farm I know, target in the field with crap pellets.

Today I got more serious. I set up an 18 yard bench rest shoot in my garden and shot about 200 shots.

I discovered the crap pellets really were crap!
I was able to get a 10mm hole (well under a 5p) with 10 pellets using AA Diabolo Field 8.4g 4.5mm
My PCP (AA S400 MPR FT) was able to put single holes with 10 pellets

I wouldn't say the LGU was hold sensitive, but it did make a difference if you held it firmly. It's like a big dog, it goes where you make it if held firmly. My small daughter (who you will meet at the springer bash) had her first go on the LGU springer with me today. She nearly fell off the chair after the first shot Once she discovered how different it was to shoot from her PCP, she was grouping 10 shots in a 5p Think I may have her hooked on Boing guns now! Her face said it all after a good shot

So it seems the gun is going well, but less recoil is always going to be better. As you say, tread with caution with something that aint broke!

[TonyL]

Much good advice up above.

Personally, I'd be holding back on piston lightening as described for a while......

Lightening the piston will give faster piston acceleration and may result in slightly less primary recoil, but COULD result in more piston bounce (surge) which is much more detrimental to hold sensitivity. The piston on this 25mm bore gun won't be that heavy anyway.

For now, I'd be paying more attention to technique and "get into" the art of springer shooting. This will generally mean employing a looser "hold", letting the gun move around, the whole point being repeatability of hold. If you grip a springer tightly, you cannot guarantee gripping it to the same degree each time.

Also, although you are using high quality pellets, there is no guarantee of absolute accuracy. This was shockingly demonstrated last week at The Bash....HW95 with high quality, JSB Exact 8.44 pellets. Rested. Range approx 15 yards and the groups were about 2" diameter! Yes, really! Before the owner explored other (much more complicated) avenues, fingers crossed I made a bit of a "stab in the dark" suggestion that he tried some other pellets. He had a selection with him. Switching to the same pellet, but a different batch number, group sizes shrank to just slightly larger than single pellet hole. Not sure if it was just a bad batch or just a case of this barrel not liking that particular batch.

[MrChipShoulder]

It is shooting well, so I'll leave it and run it in some more in time for the bash

[Rapidnick]

My experience with the LGU is that it is up there with a tuned HW or Air Arms-they are superb air rifles!. My advice to the OP is persevere and use quality pellets.

[Benelli B76]

Got a new one running nicely by opening the transfer port and reducing spring. Smooth and very accurate rifle.

Baz

[Shed tuner]

Yeah, as Baz said first thing is sort the port - open to around 3.2 if it's at std 2.9mm. Possibly more depending on the below.

Weight the piston - how heavy is it ? Also what cal are you ? .177 tend to bounce more than .22

Also what's the stroke ~88mm IIRC ?

You cant just generalise on "light pistons reduce recoil", it depends on all the variables, otherwise all guns would have ally pistons.

You also need to think about what you want from the gun - do you care about cocking effort too ? or Surge ? Or accuracy ? Or full power ? Or hold sensitivity ? Or sight picture movement ? Or just "recoil" ?

[hmangphilly]

Got a new one running nicely by opening the transfer port and reducing spring. Smooth and very accurate rifle.

Baz

What did you take it out to Baz .?
Is it your gun ?

Got one here that i'm having a fiddle with .

[itsray]

Got a new one running nicely by opening the transfer port and reducing spring. Smooth and very accurate rifle.

Baz

Hi,
I am considering doing the same to my .22 LGU so could you tell me what size you opened the transfer port to and the shortened length of the mainspring.
What are the chrono readings now after the modification?
I have ordered a new cylinder and mainspring just in case I cock it up.
Cheers
Ray

[Barryg]

My experience with the LGU is that it is up there with a tuned HW or Air Arms-they are superb air rifles!. My advice to the OP is persevere and use quality pellets.

Can anyone explain why a LGU is equal to a TX when a TX is better looking has a better trigger a better underlever set up and wins competitions just to mention a few things.
What bit of a LGU is equal to a TX? Is it that they are cheaper

[NickG]

Can anyone explain why a LGU is equal to a TX when a TX is better looking has a better trigger a better underlever set up and wins competitions just to mention a few things.
What bit of a LGU is equal to a TX? Is it that they are cheaper

a stroke similar to the MK 2 TX so are less hold sensitive , ie easier to shoot accurately in standard trim.

[Barryg]

a stroke similar to the MK 2 TX so are less hold sensitive , ie easier to shoot accurately in standard trim.

But mk3s still beat the LGU in competitions but even if you are right that's 1point to the LGU and 100 points to the TX

[Vernal]

It is shooting well, so I'll leave it and run it in some more in time for the bash

Very good thinking. While you are there, you might like to try my Nick G tuned LGU -very quick, no recoil, and pellet on pellet.

[averageplinker]

Hi Sunbeam,

I have the LGV (the break barrel version). I find it very smooth and accurate but note like you that it has some recoil. Some of this is or rather seems to be twist (torque from the spring?). Now it is out of warranty I intend to strip it polish the spring ends and remind to see if that helps.

I am also thinking of adding weight at the muzzle to see if that reduces any muzzle flip. This latter option is a cheap, easy and reversible way to see what happens which might be worth trying on your LGU?
Cheers Rich.

[TonyL]

Hi Sunbeam,

I have the LGV (the break barrel version). I find it very smooth and accurate but note like you that it has some recoil. Some of this is or rather seems to be twist (torque from the spring?). Now it is out of warranty I intend to strip it polish the spring ends and remind to see if that helps.

I am also thinking of adding weight at the muzzle to see if that reduces any muzzle flip. This latter option is a cheap, easy and reversible way to see what happens which might be worth trying on your LGU?
Cheers Rich.

Pure physics dictates that you will always have recoil in a spring (or gas) piston powerplant. However, this can be reduced in many ways, by tweaking the internals and/or increasing weight and altering the weight distribution to give more favourable movement characteristics.

I've mentioned a few times on here of one particular LGV that starkly demonstrated the twist you mention. I also opined at the time that I believe this phenomenon to be more illustrated in guns with rotating pistons. In all fairness, that rifle shot beautifully. Very little perceived recoil and a very quiet action. Shooting at a 20 yards indoor club range with a high mag scope and the twisting effect was very prominent. Certainly not knocking it as it was accurate and forgiving to shoot. Making sure those spring ends are square and true, polished and with the addition of some polished steel washers, or Delrin items, will hopefully reduce this.

[les allam]

Very good thinking. While you are there, you might like to try my Nick G tuned LGU -very quick, no recoil, and pellet on pellet.

I have some nicely tuned guns,but I have tried Vernal's Lgu at the last Bash and it is the mildest fireing springer I have shot yet..
Les..