Some BR questions and troubles i can´t solve it

[Doc_pafumo]

Hi everyone,

I have several questions about Benchrest and also a problem I've already mentioned in the PCP airguns section, but I still haven’t found a solution.
I own an FX Crown with a 700 mm Superlight barrel and I shoot JSB 18 grain pellets at 870–880 fps. Accuracy at 30 meters has always been outstanding. About a month ago, I fine-tuned the rifle to find the plateau-knee area around 875 fps, and the consistency improved a lot, very stable with maximum spread of 4-5 fps.
At the same time, I started shooting at 72 meters outdoors. The target is placed downhill, around 5 or 6 degrees from my shooting position. I don't use wind flags.
The issue I’m seeing is that accuracy at this distance is totally erratic. Sometimes I get 2 or 3 shots almost touching or very close, and then suddenly the POI shifts drastically and the group opens up by 5 or 6 cm—like if the scope had moved.
I've tried many things: I reduced magnification to check for pellet spiraling (didn’t see any), cleaned the barrel, changed the barrel, checked the liner spacer positions, changed the moderator, shot without the moderator, switched from rests to bipods and back, changed shooting tables, checked torque on the stock screws, changed scopes… everything. But the accuracy keeps coming and going unpredictably.
On the other hand, maybe I’m just expecting something that’s not possible with my setup at 72 meters. So I’d like to know: what kind of group is realistically achievable at 72 meters by an enthusiast who’s been into this for about a year?
Any suggestions would be greatly appreciated. I’ve read about the importance of wind flags and I’m already working on that. Many thanks in advance!

 

[cavedweller]

Hi everyone,

I have several questions about Benchrest and also a problem I've already mentioned in the PCP airguns section, but I still haven’t found a solution.
I own an FX Crown with a 700 mm Superlight barrel and I shoot JSB 18 grain pellets at 870–880 fps. Accuracy at 30 meters has always been outstanding. About a month ago, I fine-tuned the rifle to find the plateau-knee area around 875 fps, and the consistency improved a lot—group sizes dropped to a max of 4–5 mm and became very stable.
At the same time, I started shooting at 72 meters outdoors. The target is placed downhill, around 5 or 6 degrees from my shooting position. I don't use wind flags.
The issue I’m seeing is that accuracy at this distance is totally erratic. Sometimes I get 2 or 3 shots almost touching or very close, and then suddenly the POI shifts drastically and the group opens up by 5 or 6 cm—like if the scope had moved.
I've tried many things: I reduced magnification to check for pellet spiraling (didn’t see any), cleaned the barrel, changed the barrel, checked the liner spacer positions, changed the moderator, shot without the moderator, switched from rests to bipods and back, changed shooting tables, checked torque on the stock screws, changed scopes… everything. But the accuracy keeps coming and going unpredictably.
On the other hand, maybe I’m just expecting something that’s not possible with my setup at 72 meters. So I’d like to know: what kind of group is realistically achievable at 72 meters by an enthusiast who’s been into this for about a year?
Any suggestions would be greatly appreciated. I’ve read about the importance of wind flags and I’m already working on that. Many thanks in advance!

WIND - and - Thermal shifts

 

[Aimright]

A 1 MOA group (we are talking appx 2 cm at your 72 meters) or less is certainly achievable if the gun and shooter are capable. Just a 4 mph puff of wind crossing your target at 90 degrees could easily be your culprit - it is likely that you might not even notice it at your bench or see much vegetation movement, so I think you are on the right track getting some wind indicators set up.

 

[Gerry52]

Have you tried the next heavier pellet? The 18gr JSB work very well in so many .22 guns but we have no control over Mother Nature. The 25gr might not be quite as affected as the 18gr. 72 meters should be a piece of cake for your gun. I hunt, no BR stuff but always have to account for wind. The heavier pellets give me more stability, especially @ 75 yards or longer.

 

[Revoman]

^^^^
Agreed, plus, not all pellets are beauties with out of the tin. Many here have had poor experience with that issue....FLYERS!
You may think that measuring and weighing is the answer. While it MIGHT be, it is VERY time consuming and not 100% reliable.
There are many threads here addressing both of these issues.
I am also NOT a BR shooter, but a hunter like Gerry 52, but have shot many targets fine tuning and your description is very common.
It seems that slugs fare better than pellets at longer distances in most cases.

mike