Nosler 40 gr. B-Tip and 20 Practical
- Thread starter willyp19
- Start date
a better question may be what twist is your barrel your trying to shoot the 40 NBT in?
SDH
SDH
Willy, I've been well served with 11 twist barrels for the 40's, 12 twist for the 32- 35 grain range and 9 twist for 50's on up..
SDH
SDH
willy i've followed this idea from my smallest 20's (20Killer bee)
up to my largest
20 x 47 Lapua improved.
SDH
SDH
10 will definitely work without question. Have you tried berger 40's in your 11 twist?
SDH
SDH
The 40 grain Nosler shoots in a number of my 12" twist barrels, it's not the most accurate but neither is in a 9" twist. I think the 40gr V-Max gave the 12" twist a bum rap, as it seems to be hard to stabilize period. Some rifles shoot the 40 V-Max well at 100 or 200 yards but I've yet to see them group well further.
The 39gr BK, 35&40gr Berger will shoot well in a 12" twist, can't tell any difference in a 11" but I wouldn't want a 10" twist due to my experience with a 9". More bullet stress, pressure for no gain unless you've got the horsepower to push a 55 grain bullet and the 20 Practical doesn't. I prefer a cutrifled Bartlien or Krieger 12 twist myself but have factory bbls, Hart, PacNor and Shilen button rifled in 12" twist that do great with the 39gr.
The 39gr BK, 35&40gr Berger will shoot well in a 12" twist, can't tell any difference in a 11" but I wouldn't want a 10" twist due to my experience with a 9". More bullet stress, pressure for no gain unless you've got the horsepower to push a 55 grain bullet and the 20 Practical doesn't. I prefer a cutrifled Bartlien or Krieger 12 twist myself but have factory bbls, Hart, PacNor and Shilen button rifled in 12" twist that do great with the 39gr.
I'm partial to 24" or shorter barrels unless you plan to be shooting from a bench. most of my shooting is done from the field and prefer shorter barrels. My calling rifle in 20 Duster has a 22" barrel on it.
SDH
SDH
Mine is a 1-12, but I only plan to shoot 32's and 35's. To me the 20 practical shines with the 32's. I have a 1-10 Shilen in my .204 for the 40 grain V-max. I would really like to know the actual psi in the smaller 20's, TAC and practical that are seeing the 3700-3900 with the .223 based rounds. At sane pressures the practical will only see 3500- 3600 fps.
I shoot a 24" lilja 3 groove 1-11 twist 20 Tac and it shoots both 40 gr V-max's and 39 Blitzkings well. I suspect that the better the chambering job and the straighter the ammo, the more likely a marginal twist will shoot well, perhaps explaining the varied results reported. Start right, end right.
At sane pressures the practical will only see 3500- 3600 fps. Pat, I too would like to know the pressure, as I load the 39's to 3950 myself. The win brass I load will only take about 4 loadings at this speed, before the primer pockets get loose. The older WCC cases I have are perhaps made of sterner stuff, and so stand the pressures longer. I would never consider using newer LC cases as they are close to peanut butter in consistency. I believe that Todd Kinder recommended using IMI brass when pushing these smaller 20 cal. cases just for this reason.
Adam
At sane pressures the practical will only see 3500- 3600 fps. Pat, I too would like to know the pressure, as I load the 39's to 3950 myself. The win brass I load will only take about 4 loadings at this speed, before the primer pockets get loose. The older WCC cases I have are perhaps made of sterner stuff, and so stand the pressures longer. I would never consider using newer LC cases as they are close to peanut butter in consistency. I believe that Todd Kinder recommended using IMI brass when pushing these smaller 20 cal. cases just for this reason.
Adam
If I wanted a .20 40 grain V-max at 4k+ I think I would use a 20br.
Odd, I load my 39gr SBK's to 3760fps in rem brass with r10x and got a good 6 loads out of them before I threw them in favour of lapua brass. They were still fine to reload more. Now ive gone back to rems after the extraction problem with lapua brass and still shooting these cases perfectly fine. 23.6gr r10x, CCI BR primers and 39gr SBK's jumped 15 thou gets 3760 avg for 5 shots.
What is the H2O capacity of the Laupa compared to the Rem. Just because you can extract and load and reload 6 times does not mean that you are not pushing 70k psi. I have a relative working in one of major ballistic labs and he has relayed on several occasions to me the normal signs most use are not reliable and alot of these loads that are "safe in my gun" are WAY over 65K psi. You can't push loads with a .223 case up to and over book max loads of the .204 and not be way over what the case was designed for. I know it is done all the time, but that does no mean it is within any design limits.
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