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Folks,
David Tubb just sent this report on latest testing of the 6XC necked up to 6.5mm using "Experimental" 123gr Sierra BT bullets. The results are exciting. With moly-coated 123s and Russian primers, David was able to get 3100 FPS from his 26" Schneider barrel.,Note, in my posts I've predicted the 6.5x47 Lapua would be able to push 123gr Scenars at 2950+ FPS. It looks like a 6.5XC can match that and more!)
About the bullets, these were a special "experimental" run from Sierra. David tells us: "the 123s will probably be introduced later in the year." We don't have a BC number yet. For comparison, a Lapua Scenar 123 is rated at .547 BC by Lapua, but David thinks that's a little optimistic.
Testing the 6.5XC -- April 16, 2006
All of the tests were done with one seating length,about .020†jump to the rifleing) Reamer was Henriksen with .296 neck and 1 ½ degree lead,set for a 142 Sierra at 2.800†to touch the rifleing). Reamer is designed to allow using a 142 Sierra and still feed out of the Tubb 2000 magazine box,2.877 inside length). A 142 Sierra when seated at 2.780†length keeps the full diameter of the base of the bullet just in front of the neck shoulder junction of the case.
Maximum OAL 6.5XC case length 1.911â€,48.54mm) trimmed to 1.900â€
OAL of the all loaded rounds were 2.782â€,give or take a couple of thousandths.)
Resize die was a Superior Shooting Systems tool steel die body with interchangeable integral neck shoulder bushings,same one use for the 6XC). A .286 resize bushing and .2625 expander were utilized.
Barrel in all 6.5XC tests was a T2K profiled Schneider 26†8 twist polygonal. All of the bullets were molycoated.
Bullets used were experimental 123 gr Sierras,Looks like a little brother to the 142) and the 142 Sierra Matchking.
All velocities were 5 shots each with the same 5 pieces 6XC brass,neck opened up to 6.5mm) till the maximum load was reached – then I changed to a different 5 pieces of twice fired brass in order to guage brass flow into the ejector.
Note ---Maximum velocity charges were based on brass flow into the ejector plug. This means it is a HOT load. If you do not have an ejector plug in you bolt face you may not see these pressure signs – and probably will go off of the looseness of the primer pocket – with this 6XC brass the primer pocket did not loosen during these tests – so be careful.
All of the 6.5/6XC brass used had been shot with my normal H4350/6XC load a couple of times – could have used new brass but thought this would be more indicative of actual results.
Density altitude for the tests was 4100 ft,+ or – a 100 feet)
Russian primers used in all tests.
All tests were with either Hodgdon’s Varget,lot # 4013) or 4350 powder,lot # 4647)
I did no accuracy tests just chronograph tests.
All barrels lengths were 26†– a longer barrel will usually give slightly more velocity
Experimental Sierra 123 with Varget
Charge Velocity
36 grs 2761 fps
38 grs 2907 fps
39 grs 2980 fps
40 grs 3042 fps
41 grs 3101 fps MAX
Experimental Sierra 123 with H4350
43.5 grs 3025 fps MAX
NOTE: Compressed load – it gave me different seating
lengths based on the powder being crushed
Sierra 142 with Varget
38 grs 2806 fps
39 grs 2853 fps MAX
Sierra 142 with H4350
39 grs 2662 fps
41 grs 2777 fps
42 grs 2829 fps MAX
Just for grins I figured since I had such good luck with the Varget and the 142s in the 6.5XC I would try the Varget with the 115 DTAC in the 6XC. The test rifle was a T2K with a 26†Schneider polygonal ¾ degree lead, loaded round OAL 2.740â€
DTAC 115 with Varget,in 6XC caliber)
37 grs 3003 fps MAX
DTAC 115 with H4350,in 6XC caliber)
39.5 grs 2960 fps - my standard load,NOT A MAX LOAD in my T2K)
It might be a worthwhile endeavor to do further test of Varget in the 6XC for accuracy.
As for the 6.5 XC – Varget is a very good choice of powder,or similar burn rate) for the 123 gr bullet weight,not hardly enough usable case capacity in the 6.5XC for H4350 and the 6.5x47 has slightly less capacity)
I was more impressed by 6.5XC than from my tests,3years back) before. I attribute the increased velocity of the 142 with H4350 to a couple of items. The barrel used before was not a polygonal rifleing configuration and additionally I feel that the better head hardness of current production 6XC brass is probably the main reason for the extra 100 fps when compared to the prior test.
-- David Tubb --
http://www.DavidTubb.com
David Tubb just sent this report on latest testing of the 6XC necked up to 6.5mm using "Experimental" 123gr Sierra BT bullets. The results are exciting. With moly-coated 123s and Russian primers, David was able to get 3100 FPS from his 26" Schneider barrel.,Note, in my posts I've predicted the 6.5x47 Lapua would be able to push 123gr Scenars at 2950+ FPS. It looks like a 6.5XC can match that and more!)
About the bullets, these were a special "experimental" run from Sierra. David tells us: "the 123s will probably be introduced later in the year." We don't have a BC number yet. For comparison, a Lapua Scenar 123 is rated at .547 BC by Lapua, but David thinks that's a little optimistic.
Testing the 6.5XC -- April 16, 2006
All of the tests were done with one seating length,about .020†jump to the rifleing) Reamer was Henriksen with .296 neck and 1 ½ degree lead,set for a 142 Sierra at 2.800†to touch the rifleing). Reamer is designed to allow using a 142 Sierra and still feed out of the Tubb 2000 magazine box,2.877 inside length). A 142 Sierra when seated at 2.780†length keeps the full diameter of the base of the bullet just in front of the neck shoulder junction of the case.
Maximum OAL 6.5XC case length 1.911â€,48.54mm) trimmed to 1.900â€
OAL of the all loaded rounds were 2.782â€,give or take a couple of thousandths.)
Resize die was a Superior Shooting Systems tool steel die body with interchangeable integral neck shoulder bushings,same one use for the 6XC). A .286 resize bushing and .2625 expander were utilized.
Barrel in all 6.5XC tests was a T2K profiled Schneider 26†8 twist polygonal. All of the bullets were molycoated.
Bullets used were experimental 123 gr Sierras,Looks like a little brother to the 142) and the 142 Sierra Matchking.
All velocities were 5 shots each with the same 5 pieces 6XC brass,neck opened up to 6.5mm) till the maximum load was reached – then I changed to a different 5 pieces of twice fired brass in order to guage brass flow into the ejector.
Note ---Maximum velocity charges were based on brass flow into the ejector plug. This means it is a HOT load. If you do not have an ejector plug in you bolt face you may not see these pressure signs – and probably will go off of the looseness of the primer pocket – with this 6XC brass the primer pocket did not loosen during these tests – so be careful.
All of the 6.5/6XC brass used had been shot with my normal H4350/6XC load a couple of times – could have used new brass but thought this would be more indicative of actual results.
Density altitude for the tests was 4100 ft,+ or – a 100 feet)
Russian primers used in all tests.
All tests were with either Hodgdon’s Varget,lot # 4013) or 4350 powder,lot # 4647)
I did no accuracy tests just chronograph tests.
All barrels lengths were 26†– a longer barrel will usually give slightly more velocity
Experimental Sierra 123 with Varget
Charge Velocity
36 grs 2761 fps
38 grs 2907 fps
39 grs 2980 fps
40 grs 3042 fps
41 grs 3101 fps MAX
Experimental Sierra 123 with H4350
43.5 grs 3025 fps MAX
NOTE: Compressed load – it gave me different seating
lengths based on the powder being crushed
Sierra 142 with Varget
38 grs 2806 fps
39 grs 2853 fps MAX
Sierra 142 with H4350
39 grs 2662 fps
41 grs 2777 fps
42 grs 2829 fps MAX
Just for grins I figured since I had such good luck with the Varget and the 142s in the 6.5XC I would try the Varget with the 115 DTAC in the 6XC. The test rifle was a T2K with a 26†Schneider polygonal ¾ degree lead, loaded round OAL 2.740â€
DTAC 115 with Varget,in 6XC caliber)
37 grs 3003 fps MAX
DTAC 115 with H4350,in 6XC caliber)
39.5 grs 2960 fps - my standard load,NOT A MAX LOAD in my T2K)
It might be a worthwhile endeavor to do further test of Varget in the 6XC for accuracy.
As for the 6.5 XC – Varget is a very good choice of powder,or similar burn rate) for the 123 gr bullet weight,not hardly enough usable case capacity in the 6.5XC for H4350 and the 6.5x47 has slightly less capacity)
I was more impressed by 6.5XC than from my tests,3years back) before. I attribute the increased velocity of the 142 with H4350 to a couple of items. The barrel used before was not a polygonal rifleing configuration and additionally I feel that the better head hardness of current production 6XC brass is probably the main reason for the extra 100 fps when compared to the prior test.
-- David Tubb --
http://www.DavidTubb.com
