LGV "Simple Tune" final bliss with the TP

[BTDT]

The muzzle energy has jumped to 11.6 ( I shall keep an eye on it, and may take a washer out if necessary)...

I'd be inclined to set spring preload to give 11.5-6 ft. lb. with 7.88gn JSB pellets (I use Air Arms Express), which should give circa 11.3 ft. lb. with 8.4gn. pellets (JSB Exact, AA Field).

One thing that could nudge the muzzle energy up a little would be the piston seal contracting when very cold, reducing friction, so I'd wait for a frosty morning (won't be long coming now), acclimatise the rifle and then test.

[Vernal]

I'd be inclined to set spring preload to give 11.5-6 ft. lb. with 7.88gn JSB pellets (I use Air Arms Express), which should give circa 11.3 ft. lb. with 8.4gn. pellets (JSB Exact, AA Field).

One thing that could nudge the muzzle energy up a little would be the piston seal contracting when very cold, reducing friction, so I'd wait for a frosty morning (won't be long coming now), acclimatise the rifle and then test.

I am using Exact Express, and will put a few more pellets through it before I check again. Unlike you, I didn't notice any improvement (hard to see how it could improve really) when I tried the 8.4 Express.

[Phil Russell]

Simple question: is it absolutely necessary to use a reamer after drilling? I associate a reamer as ensuring a perfect dimensional diameter to the hole, although I accept it may improve the wall smoothness over that achieved with a HSS drill. I note the 1/8" drill comment above .. this would be nearer to 3.2mm, the diameter oft recommended for the LGU TP; and which I drilled mine to.
Cheers, Phil

[BTDT]

Simple question: is it absolutely necessary to use a reamer after drilling?

Absolutely necessary? No. There will still be a turbulent boundary layer.

Good practice? Yes.

[TonyL]

Very nicely done, Mike

And a big thumbs up to Jim for sharing his huge knowledge so freely and for on-hand support through Mike's little project.

Only one thing to ask now........"Can I have a play at the Halloween Bash please, Mike?"

[Benelli B76]

There was a discussion about the LGV and LGU in April, the transfer port seems to be the main area to improve performance...



17-04-2018, 07:54 AM


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

Baz
Oh to be back plinking on the African plains.....

[Vernal]

Very nicely done, Mike

And a big thumbs up to Jim for sharing his huge knowledge so freely and for on-hand support through Mike's little project.

Only one thing to ask now........"Can I have a play at the Halloween Bash please, Mike?"

Of course you can Tony, but be warned - you are going to want one afterwards.

[the bish]

If spring powered air rifles can be so dramatically improved by a simple modification made by enthusiastic hobbyists, why don't these major manufacturers just take enough care to get things right in the first place?
Better still, why not involve guys like BTDT in their development process?

[TonyL]

Of course you can Tony, but be warned - you are going to want one afterwards.

I think it's a bit late for that, Mike.

Thank you and I shall be counting down the days.