Posted: 11/24/2006 9:08:25 AM EDT
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Steve, I am looking at purchasing a 20"A4 varmint upper. My question is regarding the twist rate of 1 in 8. I mainly shoot 55 grian V-MAx bullets. Is the twist rate too fast for this wieght or would I run the chance of the bulet blowing up due to too fast a rotation. Thanks. |
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55gr is at the low end of what you should use in a 1:8 twist barrel. Even amongst 55gr bullets, a longer bullet will be better off than a shorter one. I haven't gotten any negative feedback on over-rotation of 55gr through the 1:8 varmint, so my best my advice would be to go ahead and try it. Steve/RRA |
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I shoot 55Gr Noslers Well below max charge of Benchmark and at this elevation I run at 3380fps. ~(24in barrel) with .25 CtoC . You can get the 55Gr to go faster but you loose accuracy. JMO~I have shot the 55 V-Max and ((I)) have found that Noslers were more accurate (for me). I have shoot 40grs and with 1:8 I would stear clear. For varmint hunting here in Wyoming...eh...with the wind I still use 55gr up to 260yrds (will go farther but gusty wind are had to figure)so then I use my .270 with a 110gr V-Max and very lightly charged with varget and they screem out to 500-600yrds with lots of energy. wind what wind? I might add the weight diff is neglegable from 18" to 24" dont let that be your deciding factor. Git one or two...have fun and be safe. |
| Thanks for teh replies. I am having trouble between the 20 or the 24" model. As far as wieght is concerned my bolt rifles are heavier than this new rifle will ever be. Plus with my fat a** I need the work out. I normally shoot off of tall bipods. I was thinking about a butt stock wieght. I have shot my uncles 20" heavy barrel and I thought the butt end of the rifle was too light, causing me to move the rifle too much for long shots. |
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I have not shot any 50grs bullets. So I can not say from experience how accurate they will be for punching paper but if I had to guess… based on the 55grs Nosler that I shoot. I think that they would shoot fine thru. 1:8 twist, as factory load are concerned . As far as the barrel wear. The longer (heaver) the bullet the more wear. The shorter (lighter) the less wear. The wear of the barrel is due to the friction of the bullet traveling down the barrel (the longer the bullet the more friction). For shooting Paper and varmints I use the 55gr Nosler ballistic tips with a little less than Max load with very impressive results with my RRA 24” Varmint. A bullet weight that is loaded with a charge that is matched to your barrel for accuracy NOT speed is best for punching paper . I guess what I am alluding to is that you should find a good round (be it a factory or hand load) that has your desired accuracy and stick with it, learn its ballistic and use it for varmint hunting as well. Sorry so verbose. hope this helped. |