6/22-250. loads needed
- Thread starter Austin
- Start date
I had a similar question - what twist rate for varmint loads in a cartridge with very similar capacity, the 6x47Lap.
I am thinking a 75gr bullet is about right for varmint purposes in a 6mm of this capacity. The bullet comparator section of this site gives the ideal twist for the 75gr VMax as 1 in 12". The best twist for the 87gr VMax is given as 1 in 10".
I hear that faster twist,or a bullet that requires it) is not necessarily a good thing, with pressures going higher and a good load less readily found. I am varying away from my original plan of shooting the 105gr AMax to optimize the twist rate for the 75gr VMax. I would interested to hear just much difference twist rate makes to accuracy,provided the bullet is adequately stabilized). For example, if the stated optimum twist rate for 87gr VMax was used and 75gr VMax bullets shot, what might the accuracy penalty be relative to using the stated optimum twist rate for 75gr VMax and shooting that bullet?
I am thinking a 75gr bullet is about right for varmint purposes in a 6mm of this capacity. The bullet comparator section of this site gives the ideal twist for the 75gr VMax as 1 in 12". The best twist for the 87gr VMax is given as 1 in 10".
I hear that faster twist,or a bullet that requires it) is not necessarily a good thing, with pressures going higher and a good load less readily found. I am varying away from my original plan of shooting the 105gr AMax to optimize the twist rate for the 75gr VMax. I would interested to hear just much difference twist rate makes to accuracy,provided the bullet is adequately stabilized). For example, if the stated optimum twist rate for 87gr VMax was used and 75gr VMax bullets shot, what might the accuracy penalty be relative to using the stated optimum twist rate for 75gr VMax and shooting that bullet?
These bullets appear to be loaded into a 6mmBR, and if the 6mm/22-250 has 300fps on the 6mmBR then there is a little figuring to do to get the twist rates for 6mm/22-250. Given twist rate*,vel in 6BR/,vel in 6BR + 300))ghermitage said:
Have a look at these sites...
http://www.the-long-family.com/6mm_22-250.htm
This site also has a primer study using a 6-250!
http://www.the-long-family.com/primer_study.htm
and don't miss this one....
http://www.the-long-family.com/fireforming%206-250AI.htm
The 6XC is so close to this case, you can use Tubbs load data, I did with my 6 250 30 degree Imp case....
http://www.zediker.com/tubb/images/dies/xcdieins6.html
http://www.the-long-family.com/6mm_22-250.htm
This site also has a primer study using a 6-250!
http://www.the-long-family.com/primer_study.htm
and don't miss this one....
http://www.the-long-family.com/fireforming%206-250AI.htm
The 6XC is so close to this case, you can use Tubbs load data, I did with my 6 250 30 degree Imp case....
http://www.zediker.com/tubb/images/dies/xcdieins6.html
Austin:
I have made a number of 800 - 1000 yard hits on sage rats using that 6-250AI with the 107 SMKs. I have about 2000 rounds down the barrel, and the Hawkeye tells me it is still in great shape.
I used Norma brass, expensive, and a bit soft. Still on the original lot of 500, no problems. If I had to do it over again, I'd go with Winchester brass, and sort by weight and neck thickness.
The 6 Dasher I have now will hit the exact muzzle velocity as the 6-250AI with the 107SMK, using only 33 grains RL-15, verses 39 grains H4350 for 6-250AI. In my experience, even though the 6-250AI has more case capacity, you cannot use it effectively as the case still does not have the capacity to reach the next faster accuracy node, at about 3150 FPS. Therefore, the 6 Dasher is the perfect match of capacity to the bore for that weight bullet at that node.
Hope that this helps.
Cheers,
I have made a number of 800 - 1000 yard hits on sage rats using that 6-250AI with the 107 SMKs. I have about 2000 rounds down the barrel, and the Hawkeye tells me it is still in great shape.
I used Norma brass, expensive, and a bit soft. Still on the original lot of 500, no problems. If I had to do it over again, I'd go with Winchester brass, and sort by weight and neck thickness.
The 6 Dasher I have now will hit the exact muzzle velocity as the 6-250AI with the 107SMK, using only 33 grains RL-15, verses 39 grains H4350 for 6-250AI. In my experience, even though the 6-250AI has more case capacity, you cannot use it effectively as the case still does not have the capacity to reach the next faster accuracy node, at about 3150 FPS. Therefore, the 6 Dasher is the perfect match of capacity to the bore for that weight bullet at that node.
Hope that this helps.
Cheers,
What are the differences between the two barrels?techshooter said:
ghermitage:
The 6-250AI is a 27" Kreiger #17 profile 1 in 8" twist, with brake. The 6 Dasher is a 30" Broughton 5C with a straight 1.25" cylinder contour, no brake. The accuracy load for both rifles are right at the 3050 to 3080 FPS range with the 105/107 bullets.
The 6-250AI is a 27" Kreiger #17 profile 1 in 8" twist, with brake. The 6 Dasher is a 30" Broughton 5C with a straight 1.25" cylinder contour, no brake. The accuracy load for both rifles are right at the 3050 to 3080 FPS range with the 105/107 bullets.
Ackman
Gold $$ Contributor
Austin said:
The 6-250 is a really good varmint cartridge. I have a 2 of them, both are 12" twist. It'll push lighter bullets, up to about 70gr, at velocity approaching a .243 but with a lot less powder. For varmint shooting, use 55-70gr bullets and that cartridge will make you really happy. Don't even mess with VLD bullets, they'll just drill holes. Put a brake on it and the gun will be a delight to shoot.
Here is a one shot ladder test I did with H-4350, 105 Lapua non-moly,measure .2426" in dia), 210M primers, 308 Lapua brass made into 6-250 brass,holds 48.7g H2O fireformed) trimmed to 1.888" that have .0126" neck thickness .272 NK'd chamber, these loaded are .270", approx 2 thou hold on bullet), seated using a .268 button to just touch the lands at 2.084" base to ogive. Date was Mar 29th, 2006, Temp was -3C,27F), winds was SE17 km,10.5 MPH) RH 60 BarPres 101.55. This was a one shot test to check a new powder lot,faster vs slower that last lot) I got from Higginson. Gaillard 1 in 8 twist Barrel 27 3/4" in length
Grains, FPS
37.3 2950
37.6 3034
38.0 3070
38.2 3090
38.5 3133
38.9 3169 max, No sign of extractor mark
39.2 3184 Consider this MAX+, pressure signs, extractor marks here up..
39.5 3190
39.8 3242
40.3 3246
I'd say the 6-250 has the juice to make it to the next node,3150), but as with your 6 Dasher, yes, you would be max'd out and your brass and barrel would take a beating IMO. Mine likes it around 3070 ish
Grains, FPS
37.3 2950
37.6 3034
38.0 3070
38.2 3090
38.5 3133
38.9 3169 max, No sign of extractor mark
39.2 3184 Consider this MAX+, pressure signs, extractor marks here up..
39.5 3190
39.8 3242
40.3 3246
I'd say the 6-250 has the juice to make it to the next node,3150), but as with your 6 Dasher, yes, you would be max'd out and your brass and barrel would take a beating IMO. Mine likes it around 3070 ish
Austin, I like 1 in 8 twists for VLD's myself 
and it looks like it works good enough with ity bitty 65g FB too!
I went out today and fire formed some 308 URBR brass I had made into 6-250 30 degree Imp cases using N135 under 65g Shilen FB bullets in my 1:8 twist Gaillard barrel lite with WSR primers. Making the brass for a wildcat is all part of the fun and reward once you get it right, IMO. I guess that makes me more of a wildcatter than a shooter, but I do enjoy the later greatly too! It would be too easy to use a 6br or 6.5x47 and I'd have nothing to do in the frozen north in the winter.
Here's the 5 shot ladder velocity test I did today, 45 rounds worth.
Chg ... Vel SD ES
34.1g 3347 45 116
34.5g 3402 19 50
35.1g 3428 13 38
35.5g 3470 06 16
36.0g 3490 12 38
36.5g 3525 06 18
37.0g 3573 15 43
37.5g 3615 12 35
I picked 36g as my fire forming load with these cases, went home, loaded up 48 more, went back out and fire formed them too. I was
, not one single hang fire, even in this cold. I never had one sign of pressure at these velocity's/charges either so I could go up higher yet 
I was not after high velocity, I just wanted to fire form these cases and I have a few boxes of the 65g bullets around and many powders of N135 so I thought I would try it. I know I'm way over spinning these bullets with my 1:8 but for fire forming at point blank, who cares eh
I had a group measure .150" at 100 yds and one at 200 yds went .600" or 1/3 moa,pic below) on this second outing today. I held one of those 200 yds shoots off some since I could not see the group forming and I want to confirm I was printing were I thought I was,I guessed up 1 moa up from 100 yds, aimed and fired at this target) or she would have been at .400" center to center. I was using a 16x scope. Temp -6C or 21F. Wind was on my back, S 13 km or 8 mph.
Now all I have to do is ultrasonic clean the cases and match prep 'em,inside flash holes, uniform primer pockets depths, trim 'em all to the same length, outside neck debur and 30 degree inside chamfer, followed by another ultrasonic cleaning, weight 'em, and sort 'em by weight and do a H2O volume check of a few of them and cull any bad ones) Hoping for a 60 pk here of near perfect cases.
After this, once it warmers up,springtime) I will 1 shot powder ladder test on 10 of these fire formed URBR cases with naked 105g Lapua bullets and H4350 to see how they compare to my Lapua cases I used last year, velocity and group wise, then ladder test again with 4 different powders at 1000yds and 115g Tubbs, pick one of these powders, neck turn the high side of the necks off since they should be twice fired by this time, ultrasonic clean again, then test with 5 different primers to find the lowest ES and best SD and group, pick one of these primers and finally play with neck tension and setting depths. I figure this will take another 120-150 rounds to do these tests and I should have a good LR load worked up on the 115's and be ready for the first real LR club match in May of 2007.
My barrel has 1005 rounds down her right now and I'm hoping for +4000 rounds from her.
Here is the case best I can measure.
and it looks like it works good enough with ity bitty 65g FB too!I went out today and fire formed some 308 URBR brass I had made into 6-250 30 degree Imp cases using N135 under 65g Shilen FB bullets in my 1:8 twist Gaillard barrel lite with WSR primers. Making the brass for a wildcat is all part of the fun and reward once you get it right, IMO. I guess that makes me more of a wildcatter than a shooter, but I do enjoy the later greatly too! It would be too easy to use a 6br or 6.5x47 and I'd have nothing to do in the frozen north in the winter.
Here's the 5 shot ladder velocity test I did today, 45 rounds worth.
Chg ... Vel SD ES
34.1g 3347 45 116
34.5g 3402 19 50
35.1g 3428 13 38
35.5g 3470 06 16
36.0g 3490 12 38
36.5g 3525 06 18
37.0g 3573 15 43
37.5g 3615 12 35
I picked 36g as my fire forming load with these cases, went home, loaded up 48 more, went back out and fire formed them too. I was
, not one single hang fire, even in this cold. I never had one sign of pressure at these velocity's/charges either so I could go up higher yet I was not after high velocity, I just wanted to fire form these cases and I have a few boxes of the 65g bullets around and many powders of N135 so I thought I would try it. I know I'm way over spinning these bullets with my 1:8 but for fire forming at point blank, who cares eh I had a group measure .150" at 100 yds and one at 200 yds went .600" or 1/3 moa,pic below) on this second outing today. I held one of those 200 yds shoots off some since I could not see the group forming and I want to confirm I was printing were I thought I was,I guessed up 1 moa up from 100 yds, aimed and fired at this target) or she would have been at .400" center to center. I was using a 16x scope. Temp -6C or 21F. Wind was on my back, S 13 km or 8 mph.
Now all I have to do is ultrasonic clean the cases and match prep 'em,inside flash holes, uniform primer pockets depths, trim 'em all to the same length, outside neck debur and 30 degree inside chamfer, followed by another ultrasonic cleaning, weight 'em, and sort 'em by weight and do a H2O volume check of a few of them and cull any bad ones)
Hoping for a 60 pk here of near perfect cases. After this, once it warmers up,springtime) I will 1 shot powder ladder test on 10 of these fire formed URBR cases with naked 105g Lapua bullets and H4350 to see how they compare to my Lapua cases I used last year, velocity and group wise, then ladder test again with 4 different powders at 1000yds and 115g Tubbs, pick one of these powders, neck turn the high side of the necks off since they should be twice fired by this time, ultrasonic clean again, then test with 5 different primers to find the lowest ES and best SD and group, pick one of these primers and finally play with neck tension and setting depths. I figure this will take another 120-150 rounds to do these tests and I should have a good LR load worked up on the 115's and be ready for the first real LR club match in May of 2007.
My barrel has 1005 rounds down her right now and I'm hoping for +4000 rounds from her.
Here is the case best I can measure.
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