Aaaaaaand the BC of the LYMAN 257420 bullet is……….
.129
At least at my velocities and altitude it is.
Got seriously BORED cause of all the rain and snow and cold and caught a slight break. Still overcast and cold but at least the rain stopped for a while. I went to a local mountain range and quickly set up my chrony and video camera and loaded a 74 gr Lyman 257420 bullet in the TD257 and blasted one downrange. Well, OK, 3 downrange till i got a good reading on my Chrony.
While my TD normally shoots at 900 fps from a 3200 psi fill, today in the 50 degree weather, i could only manage 890 FPS at the muzzle from her. At 55 yards away, the bullet zipped over the chrony at 841 fps which translates to a .129 BC.
So there you guys go. RC, RJ, DOUG, and anyone else interested in a 257 of any type, you’ve got your BC for the LYMAN 257420 Bullet.
I also checked my numbers against G7 Ballistics program and via Handloads.com and they both concurred with the BC i got.
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Any further and that ole man is gonna need a ATV to get back and forth from the target.
I know his WALKER has got to be worn out by now… 😆
Based upon pictures of his young beautiful bride…I’ll have to disagree with you on that one, otherwise she would have left him in the dust a long time ago 😎 😆
Yeah 80,
Any further and that ole man is gonna need a ATV to get back and forth from the target.
I know his WALKER has got to be worn out by now… 😆
Yes sir! It gives CLICKS, MOA, MILS, INCHES. And its FREE to download and use. Just gotta be on the internet. Its for PB’s but it does already have some cast bullets stored from LYMAN, RCBS, Lee and others. They have a very extensive bullet database. As long as you have all the info including Corialis, spin drift and temp and range and humidity, it will put you precisely on target. And these guys know there long range shit. LOL,,,,,Just take a look at their guns and their videos. 700-1500 yard grizzly, moose, coyote, elk kills is nothing for them…lol!
Here ya go: http://www.gseven.com/ballistic-program
Yeah and we know that in the not too distant future Charlie will have to factor in “Corialis” as he extends his reach. 😆
RC,
Yes sir! It gives CLICKS, MOA, MILS, INCHES. And its FREE to download and use. Just gotta be on the internet. Its for PB’s but it does already have some cast bullets stored from LYMAN, RCBS, Lee and others. They have a very extensive bullet database. As long as you have all the info including Corialis, spin drift and temp and range and humidity, it will put you precisely on target. And these guys know there long range shit. LOL,,,,,Just take a look at their guns and their videos. 700-1500 yard grizzly, moose, coyote, elk kills is nothing for them…lol!
Here ya go: http://www.gseven.com/ballistic-program
A couple months ago, I thought I had Chairgun figured out as far as entering new bullets and BC into the pellet base for my 25 caliber cast bullets.
But range testing has proven otherwise.
Going from 40 yards to 285 yards I am always 6 MOA down at 285 using the Chairgun data.
If I plug this new BC into Handloads.com, it is right on the money for my adjustment from 40 to 285 yards, which is 36 MOA.
But if I plug the same BC into Chairgun, I get 30 MOA.
I like to use Chairgun because iI can use it without being on the internet, meaning down on my range, but mostly because it gives MOA for my Hollands reticle.
I have not tried G7, does it give MOA?
RC
80G,
Yeah, as usual, the 1st 2 shots missed the 2nd photo eye therefore giving me a ERROR 2 message (GOD, I SO HATE THAT MESSAGE). I then went downrange and changed out the target and centered the chrony a little better and BLAAAAAAAAM, i got my reading (841 fps). YES, SHOOTING OVER A CHRONY IS “SCARY” while its 50+ yards away….. 😆 Especially if its your only one and you live by the use of it. But, it did survive this outing/shooting. And yes, i did plenty of sight in before hand to put myself at ease….lol! So far, I’ve found out the BC #’s this way with the JSB Kings and now these 257 bullets.
Here ya go:
http://youtu.be/z2ArxjpKypY
Butcher,
I hear ya too. That’s why i use G7. It seems a little more precise in which it should be cause its a long range trajectory program. But, the “MISSING FACTOR” is exactly why i chonyied the bullets near and far. The BC number that i got was NOT in Hand loads data base. But once i got the number, Hand loads pulled up the same trajectory info as G7. G7 did have the BC number that i got already stored in its data base. I don’t even know what profile that little bullet would be considered anyways. That’s another factor missing from the equation. Lee is the only mold company so far that actually list all the BC’s for ALL their bullets. Wish Lyman, Ideal, RCBS, Hoch, Saeco and other did the same thing.
Sure is neat watching all this super-long range, ultra-powered .25 testing unfold in the “pioneering stages” with these .25 rifles you guys been getting lately.
must have missed it, it was late and I was past my bed time 😳
I was using .137 that I got off of Handloads.com for a 72 grainer, but I did notice about a 6 inch error at 285 yards.
Thanks.
RC
One thing I have often wondered about when using the handloads.com calculator is how much of an affect the “missing factor” in the calculator is, that factor being “muzzle rise” (especially at our relatively moderate muzzle velocities).
He posted it took three shots to get a reading…..
Sure is neat watching all this super-long range, ultra-powered .25 testing unfold in the “pioneering stages” with these .25 rifles you guys been getting lately.
Cedric, in prison, what you asked RJ to do to you is called: “tossing your salad”.
Tell me, how many Chronies were destroyed in the discovery of this BC ? Okay, if none destroyed, how many shots till you made a registered pass over the sensors? I have a hard time at the muzzle let alone 55 yards away 😮
And Pork a Pig at the same time!!! 😆 😆 😆 😆
Couldn’t resist! 😀
Mike
Shit RC
I can play the banjo and drink a soda.
Only thing I would correct here is that RJ being from South Carolina, he would probably have a preferrence for making you squeal like a pig.
In a Deliverance sort of way. 😆
Hell who knows he could probably play the Banjo at the same time.
RC
RJ,
You guys are welcomed EXCEPT RJ. he can French Kiss my asshole…lol!
Knife,
That’s a good question. Those bullets while being pistol bullets are pretty accurate. But i’m sure they are just a little less that what the 257420 bullets are. Wouldn’t be suprised if they are in the .07-.09 range. But that’s just me taking a wild guess cause they are pistol bullets. And yeah Knife, at 250-300 yards, my retained energy is still more than the Wolverine 30. So the energy and bc is there and the all out accuracy isn’t too far off. More “NEW” results coming soon!
RC,
Yeah, i too was using about .14 bc that i got off handload and it did not concure with my mildots. G7 program actually ALREADY had the number in its data base and has the weight at 67 grs and not 65 like Lyman. But of course, thats just a difference of alloys. Also, the one thing on our side is that the bullet we cast are 7+ grs HEAVIER than whats listed so we carry energy better while still keeping the 65-67 gr BC #. .129 concurs with my mildots at various ranges. You and RJ though might get even better BC’s cause you guys are shooting much faster than i am. Once Doug finishes my new and improved valve/bottle, i will have more speed and will have to recheck my BC. But i used G7 and printed me a MOA chart out to 300 yards and i’m soooooo ready to go try it out. RIGHT NOW!!!!!…lol! In my next vid, i’m gonna try and hit some pretty small stuff waaaay out there….loL!
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Cedric,
I have a ATV, but I don’t use it for painting the target, but I did use it to haul that 3x4x3/16th inch plate down and to set it up on the fence.
I find that walking up that hill as fast as I can from painting the target is great exercise.
Here is some pictures of the tired old Polaris 6×6. I have hauled in so many deer, elk and bear with this thing, not to mention hauling groceries and kids to the house during the spring breakup. I have had it since 1995.
It almost killed me the last time I went antelope hunting.
Its great to ride, but I like riding momma better and again thats better exercise. 😛
RC
