Range Report Are these worth their salt?

[GearboxRacquetball]

A friend has the ballistic card for the 168gr .308 using Federal GMM ammo he obtained from Sniper central. Aside from the actual atmospheric conditions present when actually firing, which would obviously be different from what is calculated on the laminated cards, could these be acceptable in terms of the degree of accuracy and obtaining <span style="font-style: italic">semi-accurate</span> initial "dope" for this bullet brand and weight? Your thoughts? I'm thinking, no because bbl length would have to be determined, for one hitch with using these ballistic cards, and every rifle shoots, or excells with different loads. Just a friendly discussion with one of my shootin' buddies who thinks that these cards are "golden" considering the absence of a chrony to obtain his own individual results..

 

[The Mechanic]

Re: Are these worth their salt?

Should get you in the ball park at closer distances. As stated before there are so many variable to account for at longer ranges ENV data and MV is paramount.

 

[BOLTRIPPER]

Re: Are these worth their salt?

they make very nice book marks...................

 

[GearboxRacquetball]

Re: Are these worth their salt?

! Yeah, a waterproof bookmark.. Can't wait to show him these responses, he was dead set on using the above mentioned caliber/weight specific card for an upcoming distance shoot between the two of us..

 

[BLAWTON]

Re: Are these worth their salt?

Thats why most people get a ballistic programs and do up the charts. That way you know its right for you charge and rifle.

 

[The Mechanic]

Re: Are these worth their salt?

So tell me why would you show him these responses before a competition?????

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: splatroll</div><div class="ubbcode-body">

! Yeah, a waterproof bookmark.. Can't wait to show him these responses, he was dead set on using the above mentioned caliber/weight specific card for an upcoming distance shoot between the two of us..</div></div>

 

[GearboxRacquetball]

Re: Are these worth their salt?

Ha, only because we're good friends and I want to help him learn the craft. JBM seems to be getting good reviews for establishing dope for virtually any factory loads, not to mention handloads. I'll probably inform him of using an online resource like that..

 

[The Mechanic]

Re: Are these worth their salt?

Won't do you any good without accurate muzzle velocity.

 

[Victor N TN]

Re: Are these worth their salt?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: The Mechanic</div><div class="ubbcode-body">Should get you in the ball park at closer distances. As stated before there are so many variable to account for at longer ranges ENV data and MV is paramount. </div></div>

+1...

Maybe somewhere to start. But you really need to make your own figures farther out. Very seldom are "factory" drop sheets dead on for long distance. And then only if you're going to shoot those factory loads.

 

[GearboxRacquetball]

Re: Are these worth their salt?

Would you all recommend the JBM ballistic calculator then?

 

[LoneWolfUSMC]

Re: Are these worth their salt?

Yes....for initial soft dope. You need to shoot to get hard dope. I have sucessfully shot long range with JBM cards, but I adjusted on the fly. So if I had to add elevation versus the dope on the card at close range, I added a
little more as I went out. You probably won't be getting first round hits with it, but it should be close enough for a spotter to get him on.

 

[GearboxRacquetball]

Re: Are these worth their salt?

I'll maybe get him going with the JBM, but will also check out NF as well. I've only got limited experience with these shooting aids as well, so it'll be a little bit of a learning curve for me as well, especially past 500 yds. I've got a 20 inch bbl, and he's got a 26 inch bbl, so it'll be interesting to see the drop in velocity going from his to mine at distance.

 

[The Mechanic]

Re: Are these worth their salt?

You REALLY need to chrono them! Some powders will give a big difference with longer barrels others will give much less difference based on burn rates. You can not get accurate predictions without muzzle velocity. Otherwise you are just guessing. You will really just end up walking the rounds into the target. Not much prediction there.

 

[GearboxRacquetball]

Re: Are these worth their salt?

I agree. I think that is probably why he went with the ballistic cards from supersniper that were initially specific to his preferred round (FGMM) with the exact bullet weight. He will no doubt be shooting this factory load until I continue to talk about the benefits of reloading with a quality press to him. Maybe together we can go in on a chrony. I'll have to search on how to obtain the info. for some of the variables needed on the JBM calc. to ensure accurate #'s..

 

[Greg Langelius *]

Re: Are these worth their salt?

MV is an issue. I wouldn' count on them to get a first shot 'kill', and maybe not even to get on paper way, way out. But they can be of considerable help in getting a round close enough for a spotter to feed you corrections.

I use the JBM and Pejsa spreadsheets to get me into the ballpark. I wouldn't count on any calc top get me an X first shot. Such shots, for me, are purest luck; and except for one genuinely shocking personal coincidence, are the stuff of imagination. Basically; I've found that when I shoot a X for a first spotter in a match, it's an "Aw, crap" moment, and it's all sliding straight downhill from there.

PS ... And this is not a good thing...

Greg