serious mac1 BENCHREST shooter wanted

alegazmoz said:
Andy.
Fitted the adjustable to the MPR. The POI dropped on the vertical by 12mm.
Wound the cone all the way home, shooting free-hand indoors, rezeroed and experienced the normal pattern of rotation expected.
6mm adjustment took the groups sub 6mm, another 0.25mm saw the rotation lost and pellet on pellet, largest hole diameter 5mm.
Guinea-pigged Graham on a rifle he's never shot before and he slotted 8 into the same hole ......... freehand!!
Evidently he's ordered one in brass and gone shopping at Air Arms.
:)
Click to expand...

Well having marked hundreds of S400 shot cards I know that the rotation is there and my own used to display it, you know my views. I don't doubt they do something just don't know whether they strip air. Your own cards have certainly straightened out with much less rotation displayed in the past.

Although to be fair the RT is jetting 80bar as opposed to 150bar. Maybe that is why it needs nothing?

Maybe putting a rifle with a stripper in Robins new torture device might glean something (that sentence just sounds wrong).

Andy
 
Simmmo said:
Well having marked hundreds of S400 shot cards I know that the rotation is there and my own used to display it, you know my views. I don't doubt they do something just don't know whether they strip air. Your own cards have certainly straightened out with much less rotation displayed in the past.
Although to be fair the RT is jetting 80bar as opposed to 150bar. Maybe that is why it needs nothing?

Maybe putting a rifle with a stripper in Robins new torture device might glean something (that sentence just sounds wrong). Andy
Click to expand...

That's 'cos I play the forecast the POI game ..... :cool:

....... I've seen that thing, it's a bit scarey. :eek:

I've made overtures in respect of the fore-stock plate.
If it's a no go, then i'll get it milled in the village.

:D
 
Its good to be in the village.

Monkey,

Another thread kicked to death.
 
Larry, need your experience and help

First question:
On my Mac1 in .177 what is the normal fps range in variation for maybe 20 shots full up? I know chronographs have variations etc. but on an average what has your tests and experiences exhibited?

Second question:
What is the warning signs that a valve is going south?

Third question;
What can be done to enhance valve function ie obtaining a smaller velocity spread?

Respectfully, Frank
 
velocity spread

I now use around 15-20fps a spread for my guns. I find its pretty critical to use best quality sorted pellets and a precise way of aiming the gun over the chrony to get really consistent reading, and that haphazard chrony checking can double the velocity reading spread.

My FT rifle gets a 15fps spread over around 45-50 shots. I polish the sides of the hammer, connecting rod, spring guide, and the spring itself, and use a special thin, stable oil on the hammer spring to maintain decent velocity spread. It shoots 19fpe with 10.5 pellets. My benchrest gun has a wider spread of around 20fps over 40 shots, is set right now for 900fps/18.1 gr pellets. At 25yds, my FT rifle is slightly more accurate, while at 50yds, in wind, the .22 has a slight edge.

If you have a really old valve, the seal at the head tends to flatten, thus increasing its footprint a few thousandths of an inch ... this reduces velocity a bit. Leaving the gun fully charged for a few years causes this. The valve head can be chucked up and sanded down a few thou to restore it. If you don't feed it dirt thru the filling, nothing else seems to go bad over time due to wear that I've seen over the years.
 
thank you

Most rewarding to get REAL answers. YOU ARE MOST KIND.
The air is very dead today so it is back into the building for more 65 yd tuning
 
serious mac1 benchrest shooters wanted

Boy Howdy-finding real answers here for such a backwater sport as airgun benchrest shooting ! you got to be kidding..:D I can,t believe this ! lets git on with something that has some meat to it.:rolleyes: H.B.
 
You must log in or register to reply here.
Back
Top