Twist, Freebore for 198gr Flatlines and 200.20x

[XTR]

I’d like to point out to the original poster that the monolithic bullets with super high BCs have been on the market now at least since 2016.

In the intervening 5+ yrs not a single major FTR competitor has won, nor to my knowledge even placed well in a major competition using them. When the 200-20x was released it was in the podium at the next FCNC.

Trust me on this, for those who play to win the problem is not the price. If they could be made to shoot reasonably well at any velocity they would make a 308 shoot inside of the F-open 7s, and if you could make them run at WSM speeds they would be pretty near unbeatable in F open if they coul be made to hold the X ring.

I will go out on a limb here and say that it “aint for lack o tryin”. Good luck.

 

[dk17hmr]

I have a 30" 10T Hawk Hill chambered in 300WSM that shoots pretty decent with 198gr FL at 3000fps but I live at 6200'. I don't shoot that rifle very often anymore but my notes say the last group was 4" at 1000. It puts 208gr amax in the same hole at 100 yards from the bench at 2950fps.

Josh Kunz with Patriot Valley Arms built a 308 to shoot them at extreme distance give him a call and he will tell you what needs to be done to make it work.

 

[XTR]

I've bought them from John and from Warner, and I've spent more than I'm willing to admit to shooting them from a 1:8 with velocities over a MV range of close to 200 FPS. They may work ok for ringing steel in PRS, but to hold the X ring on an F class target for three 20 shot strings a day I have yet to see it. A 4" group is not a 20 shot string with 5" of vertical. When there are 3 to 5 shots per 20 that are ¾ MOA or more high or low you bleed more points than you can make up on wind.

Trust me, they will work on occasion for 5 shots, but even there you will see the flyers. Look at the groups in the image with the calipers. Those flyers show up almost every 5 to 7 shots..

 

[Ned Ludd]

I’d like to point out to the original poster that the monolithic bullets with super high BCs have been on the market now at least since 2016.

In the intervening 5+ yrs not a single major FTR competitor has won, nor to my knowledge even placed well in a major competition using them. When the 200-20x was released it was in the podium at the next FCNC.

Trust me on this, for those who play to win the problem is not the price. If they could be made to shoot reasonably well at any velocity they would make a 308 shoot inside of the F-open 7s, and if you could make them run at WSM speeds they would be pretty near unbeatable in F open if they coul be made to hold the X ring.

I will go out on a limb here and say that it “aint for lack o tryin”. Good luck.

But the price does make the inconsistent vertical even more painful...kinda like putting lemon juice on a paper cut . I put in my fair share of time and money, even going so far as to have a rifle purpose-built to shoot them, with 9-twist barrels for the 180s, and an 8-twist barrel for the 198s. I observed the same phenomena on the target as did XTR. Despite my best efforts, I was unable to rectify the vertical issues, so it was back to lead core bullets for me.

 

[coolbox]

I will not be shooting F class with this. This is for using a 308 to get to 1500mtrs (1644 yards). I will start load development in a couple of weeks. Lets see how that turns out.

 

[XTR]

You need to take a serious look at a stability calculation for the 198s. To get the full benefit of the BC you need a 1:8 twist barrel. They are insanely long. In fact just to measure the BTO on my bullets I had to drill out the base of the adapter that clamps on the caliper and be sure to clamp it with space below so the point could extend through.

If you're spending $1.75+ a bullet a $400 barrel is pretty much lost in the roundoff.

 

[coolbox]

You need to take a serious look at a stability calculation for the 198s. To get the full benefit of the BC you need a 1:8 twist barrel. They are insanely long. In fact just to measure the BTO on my bullets I had to drill out the base of the adapter that clamps on the caliper and be sure to clamp it with space below so the point could extend through.

If you're spending $1.75+ a bullet a $400 barrel is pretty much lost in the roundoff.

My rifle is with an 8T barrel, as well as a spare 9.5t barrel. As explained in an earlier post, I have used 300wm seating die, 308win sleeve, and vld stem. COAL 3.400".

 

[Jdne5b]

But the price does make the inconsistent vertical even more painful...kinda like putting lemon juice on a paper cut . I put in my fair share of time and money, even going so far as to have a rifle purpose-built to shoot them, with 9-twist barrels for the 180s, and an 8-twist barrel for the 198s. I observed the same phenomena on the target as did XTR. Despite my best efforts, I was unable to rectify the vertical issues, so it was back to lead core bullets for me.

If anyone could make them work, it’s Nedd. For my own personal and financially selfish reasons, I’m glad they didn’t work. I remember hearing about them being shot very well at a regional in Mo if I remember correctly, and I was very worried.

 

[XTR]

For my own personal and financially selfish reasons, I’m glad they didn’t work.....

I'm honestly not overly dissapointed that I couldn't get them working either. If someone ever did get them to work the cost of competition would have skyrocketed.

 

[Ned Ludd]

If anyone could make them work, it’s Nedd. For my own personal and financially selfish reasons, I’m glad they didn’t work. I remember hearing about them being shot very well at a regional in Mo if I remember correctly, and I was very worried.

The 180s were shooting pretty well at a Regional in MO. Unfortunately, the idiot behind the rifle was not, so bullet performance was never even close to the limiting source of error. I'm also not sorry the monolithics don't seem to be the advantage in F-TR that their high BCs might lead someone to think they would be.

 

[coolbox]

The 8t barrel is shooting quite decent with 175smk. Holding x ring vertical at 800mtrs for 5 shots. I wouldn't be able to tell if it was 8t or 11t from the results. Barrel has 220 rounds through now, and load development starts this weekend.

 

[coolbox]

I shot two groups of three shots each, at 100mtrs (109 yards) (175smk at 2730 fps)
First group with a folding bipod and a sandbag.
2nd group with seb joypod and edgewood rear bag. Had one ragged hole, under 0.5moa. Not bad I think. Mathematically, its abt 0.4moa group.

.


I tested a ladder for 198 FLs too. Seated at touch (3.400" COAL),
RL15
43gr 2598 fps.
I skipped 43.3 and 43.6
43.9gr 2650 fps
44.2gr 2657 fps
44.5gr 2676 fps (ejector mark)
The 44.5gr shot was 1moa higher. The other 3 are marked in pic below.


I will now test 43.8, 44.0, 44.2 and 44.4 at 100mtrs and 800 mtrs, to reconfirm both velocity flat spot as well as impacts at distance.

I also tested 185 juggernauts, and they successfully made the target at 800mtrs at up to 2700fps, but the velocity flat spot appears at ~2660 fps.

 

[coolbox]

 

[Ned Ludd]

View attachment 1291392

The 198s load long, no doubts there. I even purchased a longer 10" Mitotoyu caliper to make measuring rounds loaded with the 198s a little easier on the hand. Just out of curiosity, what is the ring/groove on the 198 out near the tip? Is it possibly from one of the Tubb nose ring tools, or is Warner now selling them modified that way?

 

[coolbox]

The 198s load long, no doubts there. I even purchased a longer 10" Mitotoyu caliper to make measuring rounds loaded with the 198s a little easier on the hand. Just out of curiosity, what is the ring/groove on the 198 out near the tip? Is it possibly from one of the Tubb nose ring tools, or is Warner now selling them modified that way?

It is the Tubb nose ring mod, available as an option from Warner when ordering.

 

[Ned Ludd]

It is the Tubb nose ring mod, available as an option from Warner when ordering.

Thanks. I'll be interested in hearing how the modified 198s work out for you; best of luck with the project!

 

[coolbox]

Checked impacts at 800mtrs.
I think 44.0gr seems OK. Vertical impact is abt 3", and for all 4 shots (including 44.1gr) is 5". Loaded at touch, 3.400".

 

[coolbox]

I think the 8T experiment has worked out pretty well for me.

I got the 175smk, 185 juggs and 198 flatlines to work well with the 8T barrel.

The 198FL got me 2nd position at 1500mtrs. I was the only 308win, other calibers were 284win, 300wm, 300wsm, 338LM (a few) and one 408CT.
1st position went to 338LM, the 408CT was 3rd. It was more to do with the conditions, and being able to take a faster follow up shot probably helped.

The corrected BC was abt ~.400 G7 out of 308win at 2660 fps.

I also used this as in a PRS type match, and the 185 juggs performed as good as I could shoot them, with an accutac bipod and beanbag.

I did shoot a 3 shot group with 200 hybrids, and it was 0.3 moa at 100mtr. I will do more testing now with these and some 200.20x. If they work out at distance, I will keep shooting this barrel in FTR, and the 198FL in the 1200/1500mtr matches. If the 200h and 200.20x dont shoot good enough (i can get 0.3moa accuracy out of my FTR rifle with 11T barrel), I will slap on the 9.5T barrel for these bullets. However, I have a feeling it may not be necessary, based on initial results. Will update here once done with all this.

 

[coolbox]

I would like to add that the 408CT shooter made a few errors, else the rifle and the shooter were both easily worthy of top position. I got some tough luck myself, could not spot shots on target (holes too small, too much mirage), else I could have been 1st myself. All on all, 1500mtr is doable with a 308 and 198FL. I wouldnt hesitate to do it again.