Would a heavier pellet save a scope from breaking....
Posted: Fri Feb 16, 2007 2:59 pm
....on a spring-piston air-rifle.
That is what we are going to find out.
I had mounted a new Bushnell Banner 4-12x40 on my HW97K which does an average of 910 ft./sec. (Pran, not 950 ft./sec. as posted in error earlier) with 8.64 grain H&N Field and Target Trophy. The scope must have been on the rifle for approximately 1 1/2 years and I have probably shot about 2,000 to 2,500 pellets since it was installed. Could be even double that but definitely not more.
Some months back the recoil knackered the scope and I have sent it to the U.S. for repairs. In the meanwhile I have asked Navdeep to get me another scope - a Bushnell Trophy 3-9x40. This is not the right scope for this rifle but I just couldn't stretch my budget to buy something more appropriate at the time of purchase.
Now, if I don't want this scope broken as well, I have two options open to me:
1) Reduce the power and hence the peculiar whiplash recoil springers generate by using a weaker main-spring or reduce the number of pre-load washers.
OR
2) Use a heavier pellet. In this case, the H&N Baracuda Match weighing in at 10.65 grains. 2 grains heavier than the rifle's usual diet.
I have decided to go with option # 2, even if it costs me another scope. I am a curious sod by nature.... The theory behind option no. 2 is that a heavier pellet will cause slightly lesser piston slam which can damage inappropriate optics.
I have two new tins of Baras totalling 1000 pellets and have decided to give them a go. Will order more when I get the opportunity.
So the bore has been cleaned and ten pellets chrono'd to get an average velocity of 816.60 ft./sec. (as opposed to 910 ft./sec. with the H&N FTTs) and a muzzle energy of 15.77 ft.lbs..
I will now try it for groups and if these pellets prove to be accurate then I will continue with the experimenting.
For the interim, I have mounted a Bushnell Lite-site scope which I have reparallaxed for airgun ranges.
If these pellets prove to be accurate and prevent the scope from going tits-up then there will be a hidden advantage to it. My HW80K does just over 800 ft./sec., so the holdovers for both rifles should be more or less the same.
More later.
Mack The Knife
That is what we are going to find out.
I had mounted a new Bushnell Banner 4-12x40 on my HW97K which does an average of 910 ft./sec. (Pran, not 950 ft./sec. as posted in error earlier) with 8.64 grain H&N Field and Target Trophy. The scope must have been on the rifle for approximately 1 1/2 years and I have probably shot about 2,000 to 2,500 pellets since it was installed. Could be even double that but definitely not more.
Some months back the recoil knackered the scope and I have sent it to the U.S. for repairs. In the meanwhile I have asked Navdeep to get me another scope - a Bushnell Trophy 3-9x40. This is not the right scope for this rifle but I just couldn't stretch my budget to buy something more appropriate at the time of purchase.
Now, if I don't want this scope broken as well, I have two options open to me:
1) Reduce the power and hence the peculiar whiplash recoil springers generate by using a weaker main-spring or reduce the number of pre-load washers.
OR
2) Use a heavier pellet. In this case, the H&N Baracuda Match weighing in at 10.65 grains. 2 grains heavier than the rifle's usual diet.
I have decided to go with option # 2, even if it costs me another scope. I am a curious sod by nature.... The theory behind option no. 2 is that a heavier pellet will cause slightly lesser piston slam which can damage inappropriate optics.
I have two new tins of Baras totalling 1000 pellets and have decided to give them a go. Will order more when I get the opportunity.
So the bore has been cleaned and ten pellets chrono'd to get an average velocity of 816.60 ft./sec. (as opposed to 910 ft./sec. with the H&N FTTs) and a muzzle energy of 15.77 ft.lbs..
I will now try it for groups and if these pellets prove to be accurate then I will continue with the experimenting.
For the interim, I have mounted a Bushnell Lite-site scope which I have reparallaxed for airgun ranges.
If these pellets prove to be accurate and prevent the scope from going tits-up then there will be a hidden advantage to it. My HW80K does just over 800 ft./sec., so the holdovers for both rifles should be more or less the same.
More later.
Mack The Knife
.