I was wondering if anyone has had a bit of experience using a 15 twist maddco barrel?
I shoot 13.5 twist traditionally so 15 twist is a bit of a mystery.
The Barrel is a heavy tapered and pretty long in length.
Any advice would be appreciated.
cheers Chris
Hello Chris,
Yes, I have one of those 15 twist Maddco's. They shoot pretty good as long as you observe a couple of details.
Best to use 65 grain bullets - I use Berger BT's. Have shot 67 Elf's as well. Don't go heavier than that.
Secondly,and this is important. Do not shoot the 15 twist if the temperature is below about 14 degrees. Sully got caught out with one of these in Perth years ago first detail of the morning. I got caught out in Portland with a 15 and it was about 10 degrees. Bullets went everywhere! Later in the day it shot dots again.
I don't really know why this happens but it does. Try it on one of those cold Silverdale mornings and see for yourself.
Cheers
Brendan
Thanks Brendan
I am interested to know if you think it’s atmospheric or the fact the barrel is cold.
I personally have noticed that My parallel Barrels tend to shoot better when they are warmer rather than cold. Is this something people have experienced or is just me .
I was planning on shooting Canberra Club shoot on Saturday and they have forecast 3 degrees in the morning and top of 17 . If all goes to hell I can’t say I wasn’t warned.
I am using 66 rooster flat base, so hopefully that might curve the trend.
Better to find out in a casual Club match than a Serious comp
Hi Chris,
Thought I would add my 2 cents as well. I am relatively new to CF's but I have read alot in the last couple of years about bullets stability, there are always comments about stability being an issue as temps drop. Another thing as Canberra can be dam cold overnight so don't leave your ammo out in the car, take it inside where its a bit warmer. Eg Motel room. I have shot Rimfire at Canberra for many years and the cold (worst was -7c overnight once) definately effects the ammo performance. Some brands are affected more\less then others but we notice things get weird the lower the temps. Seen the same at Silverdale on those cold, clear still mornings.
With CF some powders are more sensitive then others but I bet you would see a change in velocity if you drop 20c deg, the difference might mean your tune is now off a bit.
Good shooting.
Dave Dundas
Fly Shooter
