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Bullet dropping more than it should do round 2


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Ok,

 

This afternoon I reloaded some 58 grain vmaxs with heads which a mate had.

 

Then I went to the range, and shot the vmaxs at 250, with the scope set as it was (.75" high at 100)

 

I also shot my 95 grain sst's and rws 96 grain cone points ( factory load) , please see the attachment below on the data which I recorded.

 

post-14252-0-56081700-1472490366_thumb.png

 

as you can see the 58 grain vmax is doing 3630 fps on average and drops a total of 2.25", this is far more like the number that strelok was calculating ( the difference is likely to me my as at 250 the wobble is about .5-.75")

 

Both the sst and the rws follow almost exactly the strelok calculated drops (as now do my mates batch of vmax's), therefore my conclusion is that the current batch of vmax bullets are not performing to standard and are more like a bullet with a bc of .15 rather than .25.

 

And I will be contacting hornady regarding this issue.

 

Austin

 

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Austin,

I'd gently advise another look at your data,before you contact Hornady.

The table gives results at 200,not 250-or at least is headed 200

The rifle is alleged .75high at 100,but isn't for the heavier bullets...given all the poi etc...some uncertainty here?

 

BUT crucially,you did NOT shoot it inthis session at 100y-so we do not know where the 100POI was.....so not much can be concluded with any confidence.

A BC of .15 would be quite difficult to achieve in a 58 vmax looking bullet.

Here AGAIN,is Hornady's load data for their commercial SAAMI load 24"barrel,58 vmax moly,BC .252:

 

MV 3750 100y +.8 ; 200y 0 ; 300y -5.0

 

I can see that this is not reconcilable with what you say strelok gives,but your lack of accuarte data means it can't be checked.

 

I'd certainly want to tidy up your presentation-AND include 100 as well as 200 poi real data for the 58g before contacting Hornady.

 

Be prepared for a Hornady comment that strelok is not their engine of choice,and they use the 'new'

Hornady ''4 DOF" ballistic engine (no BC used).....

 

and best of luck with that (see separate discussion on current post on this site!! :-)

 

g

 

Read Litz too on '4DOF'-he knows his stuff,and also has a respected Ballistic Solver......(Applied Ballistic site). At the very least,this suggests there is no one universal Perfect Ballistic Solver,esp one that is tolerant of somewhat approximate input-how could there be-and thay don't all agree to first decimal even.

 

"Uni" lesson from all this is that no one system is immune from criticism,and that only very good data helps resolve competing opinions. Three decimal places is not "the accurate truth",if the input lacks validity and reliability-and no ballistics program can answer those two-the shooter can check,but it needs to be meticulous.

 

FWIW,here is Hornady's published data for their 95SST Interlock @2950,BC.355:

 

100y +1.7 ; 200y 0 ;300y -7.5 (the Black Hills Hornady 95gSST load is identical)

 

Hornady 95SSTLM @3100 BC .355 is 100y +1.4: 200y ) ; 300y -6.7

 

and very similar loadings (Win,Rem,Fed) for 95 g (2950-3100 fps;BCs .35-.4) all come in at 100y 1.5; 200 0 ;300y 6.6,within +/_ .1 ; as ever,small MV and/or BC differences don't have much effect sub 300y

 

 

Take care,hold your fire until you shoot some more.

gbal

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Gbal,

 

Thats my cock up about the heading, that should be 250!

 

And yes I didn't shoot at 100, yet the bullet is doing pretty much the same speed, so poi should be conserved.

This can easily be checked, and I would say that it would be about right on the poi at 100 being around .75" but only testing will show if it is or not.

 

I'll do some reading into this 4 DOF calculator.

 

Thanks

 

Austin

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Gbal,

Thats my cock up about the heading, that should be 250!

And yes I didn't shoot at 100, yet the bullet is doing pretty much the same speed, so poi should be conserved.

This can easily be checked, and I would say that it would be about right on the poi at 100 being around .75" but only testing will show if it is or not.

I'll do some reading into this 4 DOF calculator.

Thanks

Austin

OK,no probs.

I'm sorry-I didn't give the reference for 4DOF....so onlya Beta minus for me for that essay,academic standards are worthwhile---allowing the reader to check for themselves properly.

 

A brief 4 DOF 'news item' is on the excellent site "Accurate Shooter"-one of the recent (about a week?) Daily Bulletin items,and that gives the Hornady source-which has some hype (Hornady earlier were pushing a new thermally improved ballistic tip,having 'found' the older ones were a bit like a drop nosed Concorde coming in to land...hmmmm.....since old man and real shooter Joyce Hornady went to the range in the sky,I suspect the marketing boys have new ...err... freedoms (maybe more than 4).

g

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I've been following the two threads with interest . Personaly I make my own table once I've established a proper 5 shot group at 200yards I then take it out in 50yard groups. This is time consuming and not every one has the land to do this to 600yards but for my stalking rifle in 308 and 243 I've found a simple range card works.

As a side note I'm running in a new 22-250 for foxing with NV it was looking very good until I shot it yesterday when the group was wide open at 100yards!

After checking every thing on the rifle then blaming my self as I'm suffering with two slipped discs in my back it finally dawned on me to try another box of Horndays 50g. Well straight away things were tight at 100 and at 200y 3 holes with in a quater of an inch.

Why it took me so long to just try another box I don't know but the next job will be to use the data from the factory rounds to build my home loads.

When shooting at Bisly I refer to my notes every time for elevation at 600y to 1000y as weather and wind can effect elevation and notes on paper are easily read and understood. Still learning and this thread has been most informative.

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Dont get carried away with the "New Hornady 4DOF" There is nothing new about it!

 

Its a big marketing hype and publicity stunt, nothing new, 4DOF something that has been around for years as well as 3DOF and 6DOF and Hornady being rather naughty suggesting that they come up with the idea!

 

http://appliedballisticsllc.com/Truth%20In%20Performance/Hornady4DOF.pdf

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