Need help ( I think)

[beekeeper]

OK to start at the beginning I have been shooting Rifles since my early teens ( no I will not tell how long ago that was)
I have been shooting cast in said rifles since long before the internet.
As I approach extreme old age I spend a lot of time reading web sites about shooting and shooting cast in particular.
Most articles have someone shooting 1 inch groups at 50 yards.
As one of my shooting partners said " heck I can throw a rock that far"
I start out at 100 yards and stop at 485.!
I can hold a 1inch 5 shot group at 100 but at 485 it is in the neighborhood of 8 inches.
Still probably a kill shot but cannot do it all of the time.
Weather seems to play a large part in it as loads developed in the summer shoot shotgun patterns in cold weather.
I will readily acknowledge it is not the rifle!!
It is not the shooting bench or accessories.
I have been using IMR 4198 which has been a temperature stable powder for me for years.
I do not weigh each bullet and do a bell curve of them and only shoot certain ones and throw the rest back in the pot. Never thought 1 grain difference would make that much difference.

So I have to make a decision to stop shooting cast and start shooting jacketed or try to find out why I am so inconsistent at my preferred distance of 485 yards.
I figured 2015 should be the year to do this as there aren't that many more left.

Can you tell I am a little frustrated??

Will accept help and or advice from anyone.


beekeeper

[62chevy]

A man with your experience should be able to get it done. That said I'm not sure what shooting jacketed would tell you, you already know the rifle is accurate. The problem as I see it is the boolit you cast accurate and I can't answer that one as I've not shot cast in a rifle yet. What I've read over the last 2 years is cast has a distance limit but they also said you can't go faster than the speed of sound too.

[RBHarter]

A lot of folks are shooting long range ,like 1000 yd comp with cast. I just spent some time with Tim Malcolm in Conway AR ,he has a rifle, cartridge and cast bullet shooting practically 1 hole at 300 fps. So that takes care of all the speed limits and other just plain silly cast bullet myths.

I have experienced the same thing with several different powders in several different cartridges. You may have any number of things ,some of which you may have already changed.

If you are shooting heavies, 225-250 gr in 8mm,200-225 30 cal (US) etc ,you may be running out of stability at long range in the cold (and more dense air).

[Ranch Dog]

I think for shooting at this type of distance with cast bullets you have to get into custom molds which means you must become versed into what goes into the design of such. If you are shooting a modern bolt gun, it is a pretty good assumption that it is cut to the SAAMI spec but you still are going to need a very specific bullet to provide the accuracy performance down range.