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View Full Version : 50BMG Come-Up from 100yd Zero..?


a.tinkerer
06-28-2011, 7:45 PM
I'm wondering if anyone here can point to (or provide) actual come-up data from a 100yd zero (or whatever zero is appropriate for given data), either from their rifle/ammunition or from other known rifle/ammunition.

I'm just curious here, hopefully someone has data to share.





Cheers
Tinker

killshot44
06-28-2011, 7:55 PM
Need to know velocity and bullet weight. And what distance(s)?

50BMGBOB
06-28-2011, 8:06 PM
About 27-30moa (depending on your load) to get to 1,000 yards from a 100 yard zero. Are you going to come out to the FCSA match in Aug?

CSACANNONEER
06-28-2011, 8:20 PM
Bob,

If he doesn't show on Friday, you should just head over to his ranch and drag him to the match. He really needs to get that McMillan out to play with it's siblings. And, he really needs to meet Rolly, Randy, Doug, the Fikes and any other local 50 shooters I've forgotten.

a.tinkerer
06-29-2011, 11:25 PM
Killshot- I can just shoot and track my own loads here, I have positions past 1000yds here off my front porch but I haven't committed to a bullet yet for the handloads.
I'm interested in hearing what others have recorded with their rifles, with factory or surplus or custom ammunition.

As for you other two geeks, I might make it out there to the range in August. It just depends on whether or not I'm in the area that weekend. It pretty much depends on wether or not I have work out of town right then.
Bob I live very near the range - but I won't likely be set up to compete for that weekend. If I go it'll be a meet/greet/etc
I'll check in with y'all if I plan to make it over to the range.


So, if anyone has come-up data to share I'm still interested in seeing it.








Cheers
Tinker

bcrich
06-30-2011, 8:06 AM
When I first got into reloading for the .50 Greg was my go to guy and have to give him props for his madd skillz! I never shot any surplus past 500yds (groups kinda sucked) so I settled on 213g of H-50 and a 750g Amax in WCC cases. I have never shot these through a chrony but from a 200yd zero it takes 25-26min of elevation to reach 1kyds!

CK_32
06-30-2011, 8:36 AM
Jbm ballistics calc.. Google it. Thing is amazing and free

50BMGBOB
06-30-2011, 9:21 PM
I am hoping to make it there myself. Lot's of other things going on so I am not sure yet. If I do, my son wants to shoot the match for the first time (he's 14) so I'll be the proud dad shooting an AR50 from the ground.

CSACANNONEER
06-30-2011, 9:42 PM
I am hoping to make it there myself. Lot's of other things going on so I am not sure yet. If I do, my son wants to shoot the match for the first time (he's 14) so I'll be the proud dad shooting an AR50 from the ground.

If he does, I want pictures of him shooting and his targets! Also, if he's going to shoot, get with Rolly and have him order a first place Junior shooter plaque (you should pay for it instead of using match fees). That's what I did when Blake shot his first match and Mike S. was match dirrector. That way, your son/my favorite target puller, is sure to get in all the match pictures!

Don29palms
06-30-2011, 9:50 PM
Look at www.handloads.com ballistic calculator.

a.tinkerer
06-30-2011, 10:17 PM
Don, CK32-- I'm not looking for a ballistic calculator, I'm interested to hear what the *actual data* is from anyone who wants to share what they're getting from their particular ammunition, and what that ammunition is.
Thanks for the links anyway!

It's more of a 'how is your gear doing, let's see the data' kind of question, not a 'how do I find out what my bullet will do at (given)FPSmv

Cannoneer, I had a ten year old seventy pound kid running the big rifle yesterday morning.



Cheers
Tinker

brando
06-30-2011, 10:25 PM
Don, CK32-- I'm not looking for a ballistic calculator, I'm interested to hear what the *actual data* is from anyone who wants to share what they're getting from their particular ammunition, and what that ammunition is.

Wait...you do realize that the science of ballistics is well understood and that the libraries and models these calculators use are very effective at predicting a host of parameters over range (velocity, drop, energy, etc), right?

Someone else's DOPE may not jibe with your rifle. Environmental conditional differences alone can be enough to throw them off, but barrel length will affect velocity on the same load used between different rifles and when you're shooting far (which most .50BMG shooters do) those little difference add up exponentially.

Still, if you want someone else's DOPE on a .50BMG, I suggest you join the FCSA and ask on their forum. The top .50BMG shooters in the world post there.

a.tinkerer
06-30-2011, 10:47 PM
yes brando I know that someone elses data does not equal field work with my own rifle.
I really do know that.


do you have any data to post on this thread?

brando
06-30-2011, 10:53 PM
Just checking, because it seemed like an odd request.

50BMGBOB
07-01-2011, 1:33 AM
Took mine out today a switching from 1000 yards with match loads to 200 yards with ball was exactly 30 moa.

If he does, I want pictures of him shooting and his targets! Also, if he's going to shoot, get with Rolly and have him order a first place Junior shooter plaque (you should pay for it instead of using match fees). That's what I did when Blake shot his first match and Mike S. was match dirrector. That way, your son/my favorite target puller, is sure to get in all the match pictures!

If I make it you can bet there will be pics. I was about to call Rolly when a family issue came up. Now I am waiting to see how that goes. If we don't make Aug, then I will take him in April sense he isn't allowed to shoot my gun in Coalinga. I may have to buy a 510DTC for him to shoot. I was already thinking of a plaque, remember how we used a pic from a Reno match for the first years match in Coalinga? Well I might just be ordering a new brass plate just in case we do make it sense it is probably to late to add it to the normal awards order.

a.tinkerer
07-01-2011, 9:55 AM
Brando-


I've owned and shot too many rifles to remember. Quite a few of them have been big bores and double rifles, which for many reasons (often excused as voodoo...) tend to defy conventional logic around the efforts of load development and field use.

I'm looking for more of the 'how is that thing shooting' kind of information than the 'how is my rifle supposed to shoot' information.
I know it's my job to find out how my rifle shoots.
My sense here is that these big rifles are more in the 'Agricultural Equipment' category than the 'Smoke and Mirrors' category -- which is a good thing.
I've been running rangefinders, anemometer/thermo/hygrometers, and ballistic calculators for a long time.
I just haven't given much attention to the BMG-class precision rifles.

My interest is growing.

:thumbsup:






Cheers
Tinker

a.tinkerer
07-01-2011, 10:13 AM
Bob-


Here's a friend's 10yr old son.

http://farm6.static.flickr.com/5278/5891529226_aacfae1667.jpg

Perhaps he'll end up being a partner in competition for your boy some time in the future.

On your match loads, what bullet/load/etc are you running?





Cheers
Tinker

50BMGBOB
07-02-2011, 5:36 PM
My rifle is a stock AR50. I shoot Amax's over 223.0grs of H50BMG and a CCI #35 primer.

a.tinkerer
07-02-2011, 9:04 PM
Bob thanks for the note.
I have 40 of the newer AMax bullets and a pound of the same powder you're using. Haven't handloaded anything with them yet though.

I got the McMillan out today to test drive on one of our 1000yd positions here on the hill while using the JBM calculator that CK_32 offered.
I thought I'd get the chronograph out and provide data to this thread from the morning/evening shoot - but as to be expected when I want to run it with a big rifle it wouldn't recognize the start screen. Grrr... No big deal really, but I thought it'd be nice to run that particular calculator against my actual scope settings for comparison.

I'm blasting through some Mitchell's ammunition, guessing velocity I ran the JBM software suggested above here in the thread and ended up with a .8moa difference between my settings and their suggestion.
I might fiddle with the chronograph in the morning and see if I can actually put some real data in my own thread!
As it goes, 22moa(actual) from my 100yd zero up a 5degree line of sight gets me hits at 1000yd
That would pan out to about 2900fps with the box ammunition if the JBM software data and my velocity guess was correct.





Cheers
Tinker

CSACANNONEER
07-02-2011, 9:07 PM
My rifle is a stock AR50. I shoot Amax's over 223.0grs of H50BMG and a CCI #35 primer.

This was the exact same load I use for my AR50. Then, while staying up too late and loading for an upcoming match, I caught myself throwing a 232 grain charge. While it is still within the safe range, it would have sucked if I had actually completed the round and shot it in the match. So, I changed my loads to 222.0grs. In AR50s, both loads seem to be very common among match shooters. I've shot a few .6moa (sub 7" groups) with these loads and my AR50 and, I've pulled targets for Bob when he has shot exactly 7" groups to 7 1/2" groups with his. I'm not bragging or saying that I can out shoot Bob. In fact, he always posts better scores than me and has even been able to shoot a 50 4X off the ground. Only one person has ever shot a 50 5X and she will always hold the world record for being the first to do it. BTW, I don't think I've ever shot more than 4 Xs over the course of all six targets in one class.

CSACANNONEER
07-02-2011, 9:12 PM
Tinker,

First, to chonograph 50s, make sure the unit is 15 feet or so from the muzzle. If you have a longer cable, use it. Secondly, a trick I've heard of is to put a sharpie ring around the bullet. Apparently, it helps the chronograph recognize the bullet.

a.tinkerer
07-02-2011, 9:26 PM
Cannoneer-

Sharpie!
Sounds like a great little trick, and I'll try it.
This chronograph is home to a nasty little troll who from time to time interrupts the communication between my screens and the unit brain.
I think he's just jealous.
:D




Cheers
Tinker

50BMGBOB
07-03-2011, 1:19 AM
Sharpie works good sometimes. If I was around the house I would look up my fps. Great pic of your young shooter. I love seeing young and new shooters get to shoot.

Donít let CSACannoneer fool you, he usually out shoots me but I look better!

a.tinkerer
07-03-2011, 9:08 AM
Sharpie seemed to do the trick.
Actually verified function with the .22 first then went ahead with the marked bullet cartridge.


Measured distance from muzzle to screens is 15ft as yesterday, corrected MV is 2792.
I picked around looking for data on that Mitchell's ammunition, and from what I saw (somewhere...) BC.620 at 682gr for the bullet.
I'd be thrilled to hear confirmation or correction on that if you know otherwise.

The JBM calculator suggests 24.6MOA drop, the scope says 21MOA up.
As noted earlier, this particular shot is on an incline - which I corrected from the earlier figure of 5degrees to 3.1 degrees for this morning's data. Also fwiw the humidity and temperature are different now from what they were last night too, but for the sake of conversation the prescribed adjustment from the calculator and the actual scope adjustment do have a bit of spread between them.
Thought I'd share that - and that's the kind of information I thought would come out of this discussion. Calculator data doesn't always equal anecdotal data for whatever reason.


Also, Bob - I'd very much appreciate seeing whatever velocity data you have on whatever loads you have recorded.
Thanks for that.



Cheers
Tinker

a.tinkerer
07-04-2011, 12:58 PM
Bob-


Sharpie. Sometimes. Yep.
I cleaned up the Mitchell brass in the RCBS dies, touched up the necks in the file-trim die and loaded a set of cartridges to see how the H50BMG works out in this rifle.
Loaded to 5.725 (about .015 off the lands) 222gr shoots to MOA on an imorovised rest.
Today the chronograph didn't want to recognize the start screen with the big black-stripe bullets.

:shrug:

I'll call this a fairly good start anyway, getting the brass back through the dies and back into the file-trim die shows about .002" stretch which gives me the sense that 222gr of this powder with the AMax isn't pushing the limits. That's in 95degree sunshine and the rifle was much hotter than that with no shade on the bench.
Also, as I'm on the initial learning curve with this priming system I ended up with three different primer seating depths.
I might machine an adapter for the priming rig to run it in my big Lee cast press and also set up the lockring for the priming punch with a setscrew.
It'll be good to have a set-and-go arrangement for that little bugger.
My gut tells me that with minor neck-turning, proper primer seating, and my proper bench-rest (no showboat heavy rifle rest rig here yet...) set up to go I might do better on the target.

:thumbsup:




Cheers
Tinker

50BMGBOB
07-04-2011, 1:36 PM
I'm still looking for my notes, it has been a while sense I chrono my 50. I found my 7mm & 223 though. Remember chrono's are looking for the shadow. Some like lots of light, others prefer less. Think of the angle of light too. Was it diffent the day it worked from when it didn't? Which model chrono do you have? Does it have a diffuser across the top?

a.tinkerer
07-04-2011, 4:30 PM
Bob-


The chronograph is a Pact Professional.
I had the diffusers on, but the angle of light could have been an issue.
I don't think that there's a chrono out there that gives data 100% of the time, this one tends to be snitty from time to time. This morning was one of those "the .22 that you don't care about is OK, the big rifle data you want is a no-go..." times.
No biggie, I'll get the data for this rifle and load soon enough.




Cheers
Tinker

50BMGBOB
07-04-2011, 5:17 PM
I don't think that there's a chrono out there that gives data 100% of the time, this one tends to be snitty from time to time.

That is so true. I know one guy that on really bright days has to put his chrono in the shade to get good reading. I have a Oheler(sp?) 35P that does really good. I get an occasional bad read but so far I have always been able to get it to read most, if not all of my rounds.

I may have to rechrono my 50 soon. I can't find my old data. I also like to double check when I get new powder to make sure it matches the old stuff and I have 3 new 8lbs jugs to check. I can also fire a few of the ball I was shooting as it is different from what I had before.

a.tinkerer
07-05-2011, 9:07 AM
Yeeeaap.
Another good sit with the rifle at the bench - no chrono data for the big rifle.
The .22 no problem, the .50 - nah.

Will be calling PACT today to see if they can help with things.





Cheers
Tinker