Twist rate too fast
- Thread starter revenger
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I had a different experience with the boat tail bullets, so don’t start using those .250 1-14 TJ’s for pry bars just yet.
I have only been able to shoot at 10 yards with my TJ 1-14 250 barrel, so take this for what it is worth.
In my Troy Hammer ported and restrung Kral Bighorn, NSA 43.5 grain flat base hp’s shoot into a tight one hole group tuned down from 1050 fps to 900 fps.
I also tried the Gtiffin 68 grain and 60 grain both BTHP. With the boattail, I hoped to get a longer projectile without the long bearing surface that the Altaros 67 grain bullets had, thus gaining more velocity to stabilize the longer/heavier bullets. The 68 grain bullets would group tightly until 3 or so shots were fired, then as velocity decreased, from 825 fps to high the 790’s, key holing entered the picture. The 60 grain Griffins at 905 fps shoot the same as thev NSA43.5 grain bullets.
But again this was at 10 yards, but at that range the NSA and Griffin 60 grai bullets shot as well or better than my 3 .22’s that are for 10 yard shooting ever have, and those 3 rifles shoot little bug hole groups. I hope to get out to my sons range this month and stretch the Bighorn out further.
The top group was fired with my newly installed 1” od x .75 “ barrel shroud coming loose, the results were better after retightening it as seen in the two lower groups.
Regards,
Roachcreek
I have only been able to shoot at 10 yards with my TJ 1-14 250 barrel, so take this for what it is worth.
In my Troy Hammer ported and restrung Kral Bighorn, NSA 43.5 grain flat base hp’s shoot into a tight one hole group tuned down from 1050 fps to 900 fps.
I also tried the Gtiffin 68 grain and 60 grain both BTHP. With the boattail, I hoped to get a longer projectile without the long bearing surface that the Altaros 67 grain bullets had, thus gaining more velocity to stabilize the longer/heavier bullets. The 68 grain bullets would group tightly until 3 or so shots were fired, then as velocity decreased, from 825 fps to high the 790’s, key holing entered the picture. The 60 grain Griffins at 905 fps shoot the same as thev NSA43.5 grain bullets.
But again this was at 10 yards, but at that range the NSA and Griffin 60 grai bullets shot as well or better than my 3 .22’s that are for 10 yard shooting ever have, and those 3 rifles shoot little bug hole groups. I hope to get out to my sons range this month and stretch the Bighorn out further.
The top group was fired with my newly installed 1” od x .75 “ barrel shroud coming loose, the results were better after retightening it as seen in the two lower groups.
Regards,
Roachcreek
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This is a question that has been talked about many times with no simple answers. We long for it...but it eludes us. Carry on in hope, as it feeds us all in our common quest to find the "magic tune and twist" for our precious ones.
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I have a 24.75" (if I remember right) .25 acp barrel in my condor.
I'm shooting AVS .253 48g slugs and getting consistent 3/8" to 1/2" groups at 60 yds (thought it was 50 yds until I actually measured it, nice surprise
)I'm shooting around 950 fps for 96 fpe with 2700 or so psi.
The main thing that improved the accuracy was the maddog stock, made a world of difference with the condor.
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Roachcreek, I tried several boattail slugs, from the 50's to the high 60's grain, just couldn't get them to group as well at 60 yds as the dish or cup base hollow points I use.
It did take a while though for me to find the right size and weight for accuracy. The 48g .253 are perfect for anything I shoot at, not too light, not too heavy, just right for the 50 yd shots I stay at.
It did take a while though for me to find the right size and weight for accuracy. The 48g .253 are perfect for anything I shoot at, not too light, not too heavy, just right for the 50 yd shots I stay at.
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Well like I wrote, it is only 10 yards so far. Having said that the 43.5 NSA are very consistent at 900 fps range, more testing of the 60 grain Griffins need to be done.
Thanks for the info.
RC
Thanks for the info.
RC
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Experimenting with caliber, weight and
AirForce Condor SS Review | Field Ethos
Here’s an interesting discussion of
shooting with a 900 dollar pre-charged
pneumatic rifle.
AirForce Condor SS Review | Field Ethos
By Jeff Johnston I’m not one of those guys who claim airguns are good for everything from dragonflies to Cape buffalo. (Those guys tend to have two things in common: They all have poopty outdoor TV shows and they are all sponsored by airgun companies.) Rather, I stick to the timeless words of...
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