• 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 198gr Flatline impacts on steel - pic vs lead core bullets

jbailey

Gunny Sergeant
Full Member
Minuteman
Jul 27, 2010
2,286
1,190
Arlington VA
Folks,
Hello and I thought I would share a brief AAR of some shooting yesterday. Felt good to be out on the farm in the beautiful spring weather. No COVID19 there either.

SITUATION:
809yd lane vs steel yote target, 750ft D.A., 3-5mph 3 to 5 o'clock winds.
308 shooting 198gr Flatlines, doing 2780fps at the muzzle w/ very low velocity variation.

Here is the lane. Note this FP is on the side of a wooded hill for about 150 yd and it drops off steeply about 100ft down to a creek, and then goes across 650 yds of pastures, then back into woods for about 100yds. Wind is tough to judge to put it mildly. You can just barely make out a large paper poster I was shooting for groups on. Just past set back in woods is the camo'ed target, the 12" tall, x 24" wide yote from JC Steel : https://jcsteeltargets.configio.com/pd/312/coyote-38-thick?returncom=productlist&source=search
1586198342131.png

On the scope, check out my VCDL "GUNS SAVE LIVES" Sticker from the 2A Richmond Rally! Thank you VCDL for defending our Rights.

RESULTS:

Dead Yote! 3 for 3 impacts. Check out the picture:

1586198943766.png

What I liked about the picture is the nice contrast in splash between Flatlines and lead core bullets.

The Flatlines are circled in red and you can nearly see the machining on the back of the boat tail. You also see 3 impacts from lead core bullets - 130gr Berger Hybrids - but these were at 325 yds. The lead core bullet impacts were just visible to me in my scope (Premier 5-25x) whereas the Flatline impacts were not. But I sure saw the target move on impact and heard it - the 198gr Flatline is still carrying 1900 ft.lbs of energy at this range. Interestingly, the 130gr Berger's at 2950fps 6.5x47L were carrying about the same level of energy when they impacted at 325 yds, so splash energy was about the same for the two impacts.

Fun stuff and I hope you find those impacts comparison interesting.
 
Looks like you've got those Flat lines dialed in well.

Did you send Warner a cut/drop from your barrel or are these just off the shelf 198's?

2780 is cooking pretty good for a 308 with 198's. RL-26?
 
That sounds pretty fast for .308 in that weight, what bbl length are you running? Any pressure signs?
 
  • Like
Reactions: Huskydriver
@357Max and @UpSideDown --

Josh Kunz at PVA built the 308. Josh is also the bulletsmith behind Flatlines. It has his standard 308 chamber, so nothing fancy there. The only things fancy are: (1) its a long action, so you can mag feed really long bullets (using the Magpul 30-06 mags) and (2) its a 9 twist, again to handle the long bullets. Rifle barrel is a long Hawk Hill at 31".

Other stats on the load:

- Using 2000MR per Lowlight's recommendation for 308. 2000MR is temp sensitive but I know the curve well and my Kestrel automatically handles that amazingly well: 20*F in MT or 90*F in VA, the Kestrel has been spot on with the ballistics.
- Flatline's are CNC'ed to have less bearing area than traditional Cu jacket / Pb core bullets. This produces reduced friction going thru barrel. Real world impact: faster MVs all else equal.
- I'm running Lapua Palma brass, so its good stuff there too, tough and able to handle more pressure than the LR primer 308.

This rifle/load combo is what results in the MV.

Negative on pressure signs. I have run the load higher but saw no need to scream it faster, especially since I want it good on even the hottest weather days.

This has a been a 'do something smart with an otherwise stupid idea' quest. Kind of like Don Quixote. Fun every 6 months or so.
 
What's the OAL on the handload?
That looks like a great Quixotic adventure to me, got me thinking about a LA .308 :unsure:
 
What's the OAL on the handload?
That looks like a great Quixotic adventure to me, got me thinking about a LA .308 :unsure:
3.315"
loads from 30-06 Magpul mag smoothly without anything more than a bit of buffing on the feed lips.
 
I always enjoy reading about your .308 and Flatlines. Cool stuff.

I have some 198's that I need to do more work with for my .300NM. I want some N570 for that project though.
 
I always enjoy reading about your .308 and Flatlines. Cool stuff.

I have some 198's that I need to do more work with for my .300NM. I want some N570 for that project though.
What would be interesting is combining that with Theis’s high pressure project.
His projected performance for 308 is impressive
 
31" 308 tube... Making Palma shooting great again eh lol?
 
@Steel head
I'm not aware of Theis's high pressure project. Could you summarize or point me to more info?
thanks
James
He talks about it a bit in the Hoplite Arms thread.
I don’t have the numbers handy but imagine a 308 with basically 300WM speeds with a normal barrel length.