Needing some help with data

[kickinneon]

Im getting ready to make a ballistics card but i dont have access to a chronograph to get the speed of my bullets. So i was wonder if some one could tell me the ball park area of where my bullet speed is with my load data.
.308 26" barrel with a muzzle brake. 1n12 twist
175 smk's
Oal 2.800
46 gr varget Compressed
Cci 210 primer

 

[Gene Poole]

Re: Needing some help with data

Have you used this load before? It looks like it's hot for 175gn SMKs. I use 44.5 gn Varget with 178 A-Max and get about 2680 with a 24 inch 1:12 (but I don't trust my cheap chrono). 44.5 was settled on using OCW. My OCW seemed to show another node at maybe 45.3 gn Varget, but I settled on the lower node at 44.5. I'd think 46 would start to scatter from that node, but might be different in your gun.

Do you have any actual dope? I think it would be easier to back calculate MV from dope at 200, 300, 400, and 500 yd. actual drop. Use Litz G7 data and adjust the MV in the calculations until it matches your dope.

 

[kickinneon]

Re: Needing some help with data

Yes i have shot this load. I started outat 42grains and worked my way up .5 at a time. 46 was the best group of the bounch with a 5 shot group of .462 outside to outside. This is out of a factory remington also.

 

[glocksig40]

Re: Needing some help with data

The load seems hot to me as well. Winter time temperatures can often mask the trouble you will run into when the summer time temperatures come around. Im sure you missed an accuracy node somewhere in your developement. Go backwards and refine your loads in less than .5 grain strings.You can find good load data for this round using Varget here. You dont have to go all the way back down to 42.0 grains to do it. Change the powder charge in .2 or even .1 increments. Thats where you will find the accuracy node and with it you will most likely find a powder charge that will be most accurate. Trying to determing the muzzle velocity for it will not be as easy. As Gene Pool mentioned, shoot it at those distances and use the ballistics calculator to figure the speed. Make sure to take into account the weather during the test as it will be important in figuring out the speed. Best option is spent $200 on a chrono and eliminate the math.
Good Luck

 

[kickinneon]

Re: Needing some help with data

Ive have been shooting this load for over a Year now with no problems. Temp has been anywhere from 0*to 100*s on differnt range trips.

 

[targaflorio]

Re: Needing some help with data

What kind of brass? You are the only person I know who shoots 46 grs.
I get 2700 @44.8 grs 22" barrel 1:11 twist Amax 178, oehler 35p

 

[kickinneon]

Re: Needing some help with data

Using mainly remington and federal brass.

 

[Tripwire]

Re: Needing some help with data

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kickinneon</div><div class="ubbcode-body">Im getting ready to make a ballistics card but i dont have access to a chronograph to get the speed of my bullets.
</div></div>

You could just shoot your drop every 25 yards out to your max range and chart that data.......old school, but it's solid info.

 

[Seth8541]

Re: Needing some help with data

That's a crazy hot load for a .308. I'd be interested to see what kind of velocities your getting. I knoe a pretty accurate node that works for most .308's is around 44gns. You should be able to find a load in that vicinity that shoots well, but if your pushing a 175 with 46gns of Varget without any signs of pressure and its accurate go with it. Just be careful cause that load is smokin hot.

 

[JuniperEyes]

Re: Needing some help with data

I have seen factory Remington .308s that liked 46.? Varget with Win brass and 175 SMK

Velocity is not that high; 2700ish with 26"bbls

They aint exactly Match chambers in the Remmys...

 

[jkonzal]

Re: Needing some help with data

I use 46gr Varget in my 308 loads. 155 A-Max's (I know it's smaller!), 1:12, 26". If you look at the front of the Varget can, it may not be as hot as some think.