Sorry I'm trying to reinvent the wheel here, but I am soon to receive my custom .243 Win (Kampfeld) with a 1:9 Krieger barrel.
What is my ceiling on bullet weight?
I'm thinking I can run 105 A-MAX bullets at best, but I'm probably going to play it safe with the 90 gr. moly scenar.
Also, why can I push velocity more with moly than with the standard scenar?
Is it a slickness issue? Does a clean pass mean less pressure?
Don't get me wrong...I'm a .5", one hole guy with several rifles...I just don't know a thing about the 243 or moly.
With a 1 in 9 twist you should be able to shoot up to about 118gr bullets with no problems.
As to the molly, it reduces pressure with the same powder charge so normaly you have to
increase the powder charge to increase velocity.
The best thing to do to get more velocity is to keep the barrel very clean.( Fouling will slow
the bullet down and rough the barrel ).
The Custom barrels are a cut above in the velocity department because of bore finish.
The down side to moly coated bullets is that it is hard to remove an may slow the break in
of the barrel. So break it in using standard bullets ( About 20 rounds with a cleaning between
each shot for 10 rounds and then every 3 shots clean ).Take care of that new barrel and it
will take care of you.
Yes, you can use more powder safely. Again safety is the key and walk it up slow. Start at max and go from there. 6mmbr has some good load data for the 6 mm round. I personally like the 243AI.
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i'm with Mag, the 9 twist and 105's are about tops. the 115's are pretty much an 8x thing. i've never tried the 115's with my 9x. have heard from more than one it won't work.
BuffaloBob has a Weatherby and shoots 115's but i think his is an 8x. maybe he'll jump in.
Most of the model 70 winchesters in 243 were 1 in 10 twist and they shot the 100+gr bullets
fine but the 6mm remingtion came out with a 1 in 12 twist an the winchesters spanked there ass
and thats why the 243 became so popular.
A faster twist is recomended but the question was if his barrel would shoot a 105 gr A Max
and I think it will.
All rifles like certain bullets and the only way to find out is to try them.
Most of the people on long range hunting like faster twist and most bench rest shooters like
slower twist. so there is no fast and hard rule about twist rates only recommendations.