Caliber / Cartridge for new LR rig

[RockyMtnMT]

If you are going to stay factory chamber and be efficient to 1200+ for elk I think you should stay with 338rum. I would recommend the Defiance action, they are exceptional. Our 260g Hammer Hunter bullet would run about 3100fps with a bc in the mid 7's. We have not completed drop testing with this bullet yet, but initial testing out to 750y, this is what we got. So running these numbers out to 1200y you would still have 1800fps and 1977ft/lbs energy at sea level. This would also give you a 400y point blank range rifle.

Now if you could be talked into a Lapua improved it would run this same bullet at 3400fps. That is what we have run it in. We shot a moose and a wolf with this bullet last fall.

Steve

 

[blacktail 8541]

Thanks for the info. I prefer no wildcats, but if that is the only option to meet my needs I may consider it. Or re evaluate my criteria.

 

[RockyMtnMT]

Thanks for the info. I prefer no wildcats, but if that is the only option to meet my needs I may consider it. Or re evaluate my criteria.

OK, so you really want to know what I think.... If I were you and not wanting to do any fire forming, I would go with the .338 Lapua. It will gain you about 100fps over the RUM. Give you much better brass, and it is shorter than the RUM, per your original post. Since you are going custom you should get a 9 twist barrel that can handle longer bullets. We have a 290g bullet that we have just started working on that would give you fantastic range past 1400y. And you would still not have to mess with fire forming.

Steve

 

[Bart B]

I have a good amount of experience with hard kicking rifles. Used to shoot a 338 win mag as well as currently a 30-338. both with no brake and rifles under 10lbs. I have also shot numerous rifles that were considerably more unpleasant.

I have owned a 338 ultra mag in the past. I purchased it for the action and had to shoot it. 20 rounds in 0ne short session to see what it was like. I had a recoil headache for several hours. The sore shoulder did not show itself till the next day.

Blacktail, in my second paragraph of post #13, I'm not referring to the recoil you mention that hurts your shoulder nor gives you headaches. That happens after the bullet is out of the barrel.

I'm referring to the recoil impulse that you don't feel but moves the bore axis around while the bullet goes through the barrel. That'll change the muzzle axis angle 1 to 2 MOA in different directions depending on how the rifle's held. Nobody holds them exactly the same for each shot. Each shot from a hand held rifle takes off in a different direction. It's all part of the reason no two people use the same zero for a given range, rifle and ammo.

Or do you think the barrel is motionless until the bullet leaves? That's a popular belief.

 

[blacktail 8541]

Bart B. All people can improve on their skills, that is a given. you are taking what I said out of context. I have spent thousands of hours behind rigs in the field and on the range. I have a pretty good handle on long range shooting mechanics and follow through.

Can we please keep this thread on cartridge selection.

 

[Dgd6mm]

OK, so you really want to know what I think.... If I were you and not wanting to do any fire forming, I would go with the .338 Lapua. It will gain you about 100fps over the RUM. Give you much better brass, and it is shorter than the RUM, per your original post. Since you are going custom you should get a 9 twist barrel that can handle longer bullets. We have a 290g bullet that we have just started working on that would give you fantastic range past 1400y. And you would still not have to mess with fire forming.

Steve

Excellent advice, .338 Lapua....gun)

 

[Bart B]

I have a pretty good handle on long range shooting mechanics...

OK. Consider the mechanics of cross winds. What's the cross wind speed at the maximum ordinate above LOS for a .338 Lap Mag zeroed at 1400 yards when it's measured at 1 foot above flat ground for the entire distance at 10 mph?

Can we please keep this thread on cartridge selection.

Depending on the cartridge selected, it will have different amounts of muzzle angle displacement from where it needs to be when the bullet exits depending on the recoil the round produces in the rifle before the bullet leaves. That's a big factor in how accurate the rifle can be shot. And that's a big factor in where the first shot goes down range aiming at anything; big game or golf balls. It's the reason the match winners went to the 6.5x.284 for long range matches fired with hand held rifles against ones shoulder; it's got a lot less barrel time recoil than the big 30 caliber magnums.

 

[red dawg]

An ai used with the right powder to begin with will hold its barrel life as well as a non wildcat I have a 22 6mm ai that has killed more than cancer and still shoots as well as any gun of any friend or mine that i know of

 

[Longrang3r]

If you are wanting to do serious long range hunting on elk out to and past 1000 yards, I don't think it's a question that 338 is the best option to go. Whether that is 338 edge, lapua, or my personal favorite, 338/378, is up to you.

 

[blacktail 8541]

OK. Consider the mechanics of cross winds. What's the cross wind speed at the maximum ordinate above LOS for a .338 Lap Mag zeroed at 1400 yards when it's measured at 1 foot above flat ground for the entire distance at 10 mph?

First of all it is ballistics in this case as you are describing atmospheric conditions. Mechanics as I stated in my post is applied to the physical act of firing the firearm.

The maximum point of arc is determined by the velocity and projectile used. A summing a constant wind velocity across the length of the flight path to target with a 300 grain match king and a 2750 fps velocity taken from jbm ballistic app the drift would be 85.6 inches if zeroed on a calm day or 0 inches if sighted in with a 10 mph 90 degree cross wind. Max apogee would be 195.1 @ 750 wards. or 21.5 in. @ 10 mph

There are a whole slew of variables that are present in shooting @ distance. Wind is very seldom constant. Measured at 1 foot or 20 ft altitude , 10 mph is 10 mph. Altitude barometric pressure,and temp all play a part.

Terrain can cause a 10 mph to be blocked at points and increased at others due to funneling affect.

If you want to discuss this further I will do so in pm.

 

[Bart B]

Mechanics as I stated in my post is applied to the physical act of firing the firearm.

Fine. But a 338 Lap Mag will move the bore axis in a greater angle during barrel time than a .300 Win Mag. That's part of the physics that takes place after the firing pin hits the primer.

And the cross wind speed at the maximum ordinate above LOS for a .338 Lap Mag zeroed at 1400 yards when it's measured at 1 foot above flat ground for the entire distance at 10 mph will be almost twice as fast; 19 mph.

 

[FEENIX]

 

[blacktail 8541]

Fine. But a 338 Lap Mag will move the bore axis in a greater angle during barrel time than a .300 Win Mag. That's part of the physics that takes place after the firing pin hits the primer. No argument here physics are physics
But what has this to do with my OP in this thread?

And the cross wind speed at the maximum ordinate above LOS for a .338 Lap Mag zeroed at 1400 yards when it's measured at 1 foot above flat ground for the entire distance at 10 mph will be almost twice as fast; 19 mph.

Show me a rifle that shoots 1 foot even for 1400 yards and maybe I might care.
Now go try to impress someone else.

 

[sp6x6]

It takes alot of rifle to have some energy at 1400 yrds for hunting .And most that I see on here that are shooting that long,which is few,and I know personal experiances also are using 338 of some type in general or larger