Author Topic: Pellet tests, and the importance of head size.  (Read 2303 times)

Offline greyskullnz

  • GTA Donations
  • ******
  • Posts: 14
Pellet tests, and the importance of head size.
« on: August 08, 2009, 07:00:07 PM »
Finally able to get out in the fine weather to do some tests on the Chinese pellet sampler I got my hands on. (http://henan.ccpit.org/shangpinku/wenhua/zhengzhouqiangyuan/default.htm)

Conditions were:

SteyrLG110 FT 12 ft/lbs .177 cal

10-30am
5 mph to none wind, rising and falling but quartering from Left.

10 shots each target.

55 yards distance for both pellet types tested.
Sitting position, on a bean bag, unrested.

I chose to test these pellets against known performing pellets in my barrel, and also in circumstances that would not be out of the norm for a FT match. ie: with a slight quartering wind. I wanted to see what effect the wind would have on the pellets out at long range.

Just out of interest, the outer of the 7 ring on this target is equivalent to a 40mm FT kill zone. Anything inside that is hit.

I had an idea that due to the only head size being available at 4.50mm, they would not be optimum for the Steyr barrel. What I wanted to find out was how much wind effect these pellets were going to take, as they were bound to be precessing and nutating. (well that was my hypothesis) As it turned out the pellets were slapping the target side on as can be seen.

Results for the Chinese 4.50mm pellets below.



I expected poor precision, not because they are poorly made pellets, but because of the poor fit to the barrel.

Interesting results regarding the amount of wind they took, and that was because they were not flying in a stable flight trajectory, they were spiralling. Rather than poor manufacturing, I suggest that they were getting a blast from the muzzle and were already unstable at the crown due to poor head size fit. Not the pellets' fault. But it does beg the question why make only one head size and expect shooters to use them?

They were Impacting 3.5" lower than the FX 4.52mm pellets, which the steyr was zero'd for. This again because of poor sealing in the bore due to incorrect head diameter.


Below is the 10 shot group using JSB made pellets (FX brand) with a head diameter matched to the Steyr barrel.




Unlike the Chinese pellets I was able to shoot the wind, as the first two shots went left, and subsequent 8 shots I was able to dope for the centre. Impacts from the Chinese pellets were so unpredictable I could not dope the wind at all.

Again, 55 yards, sitting position unrested. Shot about half an hour after the first group. Wind was about the same strength but shifted , quartering from the right.



I reckon that the Company making these pellets needs to look hard at whether they really want to make pellets for top International competitors, and if so, they need to take all factors into account such as barrel/pellet fit. One size does definitely not fit all, particularly at 55 yards.

Other than that, they are of a reasonable quality and finish. If I had something that shot 4.5mm heads, I would not have a problem using them. But as it stands they represent a poor choice for top level competitive FT shooting.

Some real R&D required on the Chinese made Domed head pellets before they are up to the standard of what we already have. IMHO.

cheers
GS