.358 Ballistic Coefficient help

[vancelw]

Does anyone know the ballistic coefficient of a Remington Core Lokt .358 bullet weighing 250 grains and having a round nose (not pointed soft point). I'm searching and still haven't found it.

Thanks

[3leggedturtle]

Hope this helps. The Hornady 250gr RN has a BC of .271 how does it compare to the R-P 250 RN.

[Tycer]

You've got some 250s? Really? No help on BC. You'll have to shoot them at 10 and 100 over a chrony.

[vancelw]

That sounds closer....

The Rem Core Lokt 250 gr PSP has a BC of .409. I liked the results the computer gave me on that

Let me try it....

It only dropped my MPBR 18 yards using the more correct data.

Tycer...I want my information NOW I guess I could set up the chrony tomorrow. I'm kinda lazy nowadays. The new generation must be rubbing off on me.

(I have 3 full boxes )

[Tycer]

The Hornady 250 RNs are .271
Woodleigh's are .300

[vancelw]

I ran the numbers through Ballistic Explorer using .271 BC and 2350 fps muzzle.
I'll get it on paper at 25 and then shoot it at 100 and verify at 200 if the wind will die down a little tomorrow. If I have time I'll use the Ohler 35P to see what it's really running.

I tried looking in my other reloading books but Hornady is one of the few listing RN bullets. When I use these up I will probably reload with Hornady 200 grs.

I may even post pictures if I can hit anything

[Cast Bullet Hunter]

If the bullet you are asking about is fairly recent, since 1989 or so, there is an excellent chance that those bullets are Hornady. Remington used the 250 Hornady RN in factory .35 Whelen ammunition for at least several years after introduction of the cartridge as a production round instead of a wildcat.

Regardless, use Tycer's figure of .271, small differences in BC at reasonable ranges, 300 yds. and less, make so little difference as to be completely insignificant. Here is an example from LFD:

Load; 250 RN @ 2400 FPS (.35 Whelen factory velocity), 200 yd. zero
BC .260;
100 yds, +3.29"
300 yds, -14.90"

BC .280;
100 yds, +3.21"
300 yds, -13.62"

The difference in trajectory is only .08" @ 100 yds and 1.28" @ 300 yds.

Can you honestly say either you, or your rifle, shoots well enough to even be able to tell the difference? At 300 yds the difference is only 3 1/2 times the diameter of the bullet, or just about the length of the bullet! Can you shoot less than 3" groups at 300 yards?

[vancelw]

Well, yeah I can...from the bench. But you are correct...I only need the BC to run the path numbers to get me close. I verify all impact points at 100 and 200 meters. Then I have to trust my data for the farther distances until I can test it in the field. Up until 6 or 8 years ago, 80% of my deer and antelope were taken at 200 yards or more. I think my average (until I quit recording such things) was over 180 yards over dozens and dozens of animals. Now I tend to hunt without a scope and use my leverguns quite a bit. MY shots are 15 to 160 yards now. The 160 yard one taking me by surprise as I didn't realize it was that far until after the successful shot and I lasered it. Buck fever.

This rifle will probably not be that accurate. It is a Remington 750 Woodsmaster in .35 Whelen I bought off of the cousin of a friend because they knew I like "different" things. They were right. With it were 3 boxes of Remington Core Lokt R35WH2 ammo, 250 gr RN. Judging by the box I'm guessing early to mid 80s ammo? I'm sure it's close enough in shape to the Hornady to use a similar BC. The only thing that would surprise me about it actually being a Hornady bullet would be that it is in Core Lokt ammunition. Would Remington use someone else's bullet and call it a Core Lokt? Hmmmm.

I had an "extra" Leupold VX-III 2.5-8 scope in the safe and I put it on the Rem 750 using a DNZ one piece scope mount. I'm going to fire it this afternoon and see how brutal it is off of the bench. I may not be able to hunt with it this year since my mobility is reduced

[vancelw]

Well, I have a problem to diagnose....

Can't get the scope adjusted high enough to hit the target. Scope base only goes on one way, so..... I may have to see if I can measure and see if the barrel is bent or installed crooked.????

One a good note....recoil is zilch With the 750s gas porting and factory installed Limbsaver buttplate....nada. I'm impressed.

Now If I can just get it to hit. I guess it will have to wait until I'm back from Montana and use it on some Texas hogs instead of mule deer.

[44shooter]

My first bet is the scope mount. Could it be backwards? I don't know the mounting pattern on those rifles. Just asking. I would say maybe the receiver holes aren't straight, but that would cause windage issues instead of elevation.

[vancelw]

My first bet is the scope mount. Could it be backwards? I don't know the mounting pattern on those rifles. Just asking. I would say maybe the receiver holes aren't straight, but that would cause windage issues instead of elevation.

My first guess was that the mount might be backwards, but I checked the height and it's the same. I also remembered it does only mount one way.

I did a little surfing via Google and found this to be a not uncommon problem with 750s. The way the barrel mounts tends to point some of them downward! So the iron sights work since they are on the barrel. Now I know why I got such a deal on this rifle and it was in such good shape except for the scratches on the receiver (probably from several different scopes and mounts being tried.)
I could order some Burris scope rings and a different base to "fix" the problem, but I'm going to see if Remington will help.

*holding breath*

So...I won't be hunting with this soon unless I use the iron sights. I guess it wouldn't hurt since those 250 grainers keep me close to my target. When I reload I'm going with e pointed bullet so if I get the barrel fixed by then that would be great.

[Sixgun]

Vance,
Just shim the scope and put the shims in the same manner that you would adjust open sights so in your case try a .010 shim under the rear part of the scope and the same, but over the front scope.--------6

[vancelw]

I would have to shim it a LOT.

I'm about to go on a hunt and just don't have time to get it ready before I go. Unless I use the iron sights. I will probably wait to get back and see if Remington offers to fix it. If they don't, I'll try shimming.

Where do you get shims? I guess I could contact DNZ and see which ones they recommend.

[3leggedturtle]

Beverage cans, electrical tape (not for rings), plastic milk jugs or pop bottles.

[hayabusa]

Brass shim stock at automotive parts stores & machine shops. Different thickness available.

hayabusa

[Sixgun]

t does not take a lot of shimming to have a change of impact. If your good with a file/sanding you can also lower the front mount.

A bud of mine does a lot of the 1,000 yard shooting and he mounts his scopes with mounts that have a 20 degree rise so his settings will reach out there. Once again, instead of filing/grinding, you can make a thin shim for the rear mount to give it a bit of rise.------------6

[vancelw]

It's going to take a LOT of shimming to jury-rig this. I had the elevation maxed out and was still hitting the target 6 to 8 inches below point of aim at 20 yards, which should be my first line of sight crossing. Maybe as much as 5/32 based on other reports I've read.
I'm not even going to attempt to diagnose the degree of angle at this time as I simply won't be able to do anything about it for a couple of weeks.

I could rig it, but I'm going to see if Remington will do the right thing. I paid good money for a DNZ one-piece scope and shims will only add fail points. The scope and mount are rock solid and I want the rifle to be, too.

If the rifle didn't feel so sweet shooting it, it would find a new home and I'd wash my hands of it. The felt recoil out of this .35 Whelen is less than my .45 Colt rifle.

[Sixgun]

Ok, I see your point in doing the job right. It make one feel better about his gun.

I too, do not like to brother rig it, unless it's not an important rifle.....say.....for shooting pigeons out of the barn.

Here I go again...you say 8" or so at 20 with the elevation all the way up? Mmmmmmm.......about an 1/8" will do it! Good luck! ----6

[vancelw]

But then I'm still maxed out on elevation, right? Like I said if Remington doesn't help make it right I'll rig it with shim and never buy a new Remington branded product ever.

1/8 to 5/32 is what most say they had to adjust.

[Tycer]

Good article on BC:

http://arxiv.org/pdf/0705.0389.pdf

[Tycer]

Response to a query to the author of above article included this link.
http://www.jbmballistics.com/cgi-bin/jbmbcv-5.1.cgi

[vancelw]

Leupold's website claims that .001" shim equals roughly 1 MOA. That would mean I only need .040 to .050 of adjustment, about half or a third as much as I was expecting (like I said, I haven't done any analyzing or measuring yet).

I've sent queries to Remington and to DNZ Products asking for advise. The light recoil of this rifle is amazing. I might not get a Mule deer with it this year but if I can get it pointing straight some hogs better watch out if I have 4 in the mag and 1 in the pipe.