• Watch Out for Scammers!

    We've now added a color code for all accounts. Orange accounts are new members, Blue are full members, and Green are Supporters. If you get a message about a sale from an orange account, make sure you pay attention before sending any money!

Range Report 20" barrel Speed question

tepeter1

Private
Full Member
Minuteman
Jan 13, 2007
72
0
MS
Does 45.8gr of Varget equate to an averag speed of 2787 pushing 155 Berger VLD's? I have a lot more data, but my new bartlein 20" barrel just seems ridiculously fast. Any input will be appreciated.

Yes caliber would be appropriate .308. I did use a competition electronics chronograph to get that average speed. I was conducting an OCW test yesterday. 47.0 and 47.3 averaged 2858 and 2859 respecively. This was virgin lapua brass with Federal LR primers. I was using a beam scale to measure all of my loads, but I may have screwed up because I measured 2996 once in my 46.7 load and recoil was more intense (I new that round had some power before I even looked at the chrono). I stopped at 47.30 and was getting some carbon pushing from the primers, but no sticky bolt lift or other signs of overpressure. all of my increases in velocity were consistently corresponding to powder inceases, it just seems awfully fast. 44.0 grains averaged 2685 for 13 shots.

I am definately not complaining, jsut curious. I see no need to push the brass or rifle any harder if the velocity is already this good out of this short barrel.

The barrel is a standard bore, but the chamber is cut specifically for lapua brass and berger 155's. Thanks for the replies.
 
Re: 20" barrel Speed question

You would need a chronograph, or calc by your bullet drop. Every rifle is different. There is no answer that anyone else can give you because it would be for their rifle. You could use JBM if you have all the conditions, and recorded drop. The further out the better hope that helps.
 
Re: 20" barrel Speed question

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: tepeter1</div><div class="ubbcode-body">Does 45.8gr of Varget equate to an averag speed of 2787 pushing 155 Berger VLD's? I have a lot more data, but my new bartlein 20" barrel just seems ridiculously fast. Any input will be appreciated</div></div>
QL says yup. 2742fps and just into overpressure with a 8% compressed load.
 
Re: 20" barrel Speed question

That sounds well within the realm of possibility. I get 2650 fps out of a 20" barrel using 45.5 gr. Varget behind a heavier 165 gr. Accubond. Still, it's nice to actually measure with a decent chronograph.
 
Re: 20" barrel Speed question

I have found QL to be pretty close on all my loads. When I shot my 530+ yards shots I used the QL velocity because I forgot my chrono and luckily I had QL numbers. So I would say The Mechanic is pretty close as to what the OP will get.
 
Re: 20" barrel Speed question

My 21" rock creek will run at 2850 with its prefered 155 scenar loading using 8208 and 20" stock remington tactical, same load 2725, FWIW.

In my testing 8208 usally will be a little slower FPS (25-50)wise than varget before pressure rears its ugly head with 155-175 grain bullets.
 
Re: 20" barrel Speed question

I think your chronograph readings are accurate. When I reach pressure signs in my 18" 1 in 11 Broughton with suppressor I am just over 2800 fps. Same components as your load with slightly more Varget.
I wouldn't be surprised if you find a good accuracy node between 2800 and 2860. The OCW will tell you.
Keep us posted.
 
Re: 20" barrel Speed question

Running a LTR at 2580 with 44.5 of varget behind 175 SMK. Chronographed.
 
Re: 20" barrel Speed question

I have the SPS Tactical 20" with same reading but with weather at about 65-70*

How accurate are you with that load.(I just recently shot a .217 and a .319 with the same load) I'm really happy with it.
 
Re: 20" barrel Speed question

Winxp. Load runs a consistent 1/2 moa in 30-70 temps to 550yrds and closer to 1 moa at 850.