I hope you or some others find food for thought here but it is a long read.
Michael, the FX Elite feeds the air into the "bolt" which then feeds it directly to the end of the barrel, ie., the pellet skirt. This is the same system as the Steyr (you had one remember... "I found the Steyr I once owned ") ... and other high end Olympic rifles.
You may have read this report I wrote a bit over a year ago:
http://www.network54.com/Forum/79537/thread/1394256650/Barrel+rotation+-+indexing+and+possible+effect+on+POI+of+different+pellets
Follow up study: 55 yards test/ 50 metres shooting one each of four different pellets with the barrel indexed in that 6:00 o'clock position.
The pellets were my favourites: JSB Kings 25.5 gr, Benjamin domes 27.9 gr, Predator Polymags 26 gr and Kodiak/Baracudas 31 gr.
The first group top left shot in a very light right to left air drift shows the first three of those clustered with the heaviest Kodiak dropping low but still pretty much in line. The second group (lowest) is 5 Kodiaks showing their lower POI. The breeze was switching. The third group is one of each pellet with just the Kodiak aimed a little high according to group two. The breeze was then gentle from the left. Four very different pellets grouping tightly. Velocity varied from 880 fps for the Kings to around 820 fps for the Kodiaks which have the highest BC.
Here is an indexed target shot with the Benchmarh 3 groove .22 barrel on the FX Elite.
Shot with 360 degree, 90 degree, 180 degree and 270 degree rotations at 15 yards. This is bay far the tightest rotation group I have shot with my various barrels. It is short and thick!
Another test of consistency with the four different pelle: tsame FX rifle and BSA barrel after indexing.
After sighting in at 50 yd and painting out; 12 shots with four different .25 cal pellets, 3 shots each pellet, left to right Predators 5 mm/ 0.20"; Benjamins 5 mm/ 0.20" ; Baracudas 6 mm/ 0.24"(aimed with a slight holdover to compensate for weight and lower velocity); JSB KIngs 4 mm/ 0.16". The coin on the pig is US dime.
That Elite system allows infinite indexing. The Royale system can be barrel indexed up to a point I think by using slightly different "O" rings between the brass thimble abd barrel, or thin shims there placed. I have done this with an ST barrel on my old FX/RWS Excalibre/Tarantula/ FX 2000. Fiddle around and you may be able to work out a system there. Or perhaps ask Dan Brown if he could make you four thimbles of slightly different lenghts and match them to some different "O" rings?
With limited experience I am a believer in barrel indexing for two reasons. I think it can help in getting a barrel to shoot to the same vertical line with different GOOD pellets and that only leaves holdover or sight clicking to deal with rather than also having to care about lateral spray. Secondly I think it may improve group size. The preferred indexed position is either where the indexed groups impact at 6:00 o'clock or at 12:OO 0'clock, with 12:00 being preferred if maximum vertical scope adjustment range is a factor. Otherwise pick the best group position.
Kind regards, Harry.
Michael, the FX Elite feeds the air into the "bolt" which then feeds it directly to the end of the barrel, ie., the pellet skirt. This is the same system as the Steyr (you had one remember... "I found the Steyr I once owned ") ... and other high end Olympic rifles.
You may have read this report I wrote a bit over a year ago:
http://www.network54.com/Forum/79537/thread/1394256650/Barrel+rotation+-+indexing+and+possible+effect+on+POI+of+different+pellets
Follow up study: 55 yards test/ 50 metres shooting one each of four different pellets with the barrel indexed in that 6:00 o'clock position.
The pellets were my favourites: JSB Kings 25.5 gr, Benjamin domes 27.9 gr, Predator Polymags 26 gr and Kodiak/Baracudas 31 gr.
The first group top left shot in a very light right to left air drift shows the first three of those clustered with the heaviest Kodiak dropping low but still pretty much in line. The second group (lowest) is 5 Kodiaks showing their lower POI. The breeze was switching. The third group is one of each pellet with just the Kodiak aimed a little high according to group two. The breeze was then gentle from the left. Four very different pellets grouping tightly. Velocity varied from 880 fps for the Kings to around 820 fps for the Kodiaks which have the highest BC.
Here is an indexed target shot with the Benchmarh 3 groove .22 barrel on the FX Elite.
Shot with 360 degree, 90 degree, 180 degree and 270 degree rotations at 15 yards. This is bay far the tightest rotation group I have shot with my various barrels. It is short and thick!
Another test of consistency with the four different pelle: tsame FX rifle and BSA barrel after indexing.
After sighting in at 50 yd and painting out; 12 shots with four different .25 cal pellets, 3 shots each pellet, left to right Predators 5 mm/ 0.20"; Benjamins 5 mm/ 0.20" ; Baracudas 6 mm/ 0.24"(aimed with a slight holdover to compensate for weight and lower velocity); JSB KIngs 4 mm/ 0.16". The coin on the pig is US dime.
That Elite system allows infinite indexing. The Royale system can be barrel indexed up to a point I think by using slightly different "O" rings between the brass thimble abd barrel, or thin shims there placed. I have done this with an ST barrel on my old FX/RWS Excalibre/Tarantula/ FX 2000. Fiddle around and you may be able to work out a system there. Or perhaps ask Dan Brown if he could make you four thimbles of slightly different lenghts and match them to some different "O" rings?
With limited experience I am a believer in barrel indexing for two reasons. I think it can help in getting a barrel to shoot to the same vertical line with different GOOD pellets and that only leaves holdover or sight clicking to deal with rather than also having to care about lateral spray. Secondly I think it may improve group size. The preferred indexed position is either where the indexed groups impact at 6:00 o'clock or at 12:OO 0'clock, with 12:00 being preferred if maximum vertical scope adjustment range is a factor. Otherwise pick the best group position.
Kind regards, Harry.
