115gn D-Tacs won't shoot

[rebel107]

Anyone having trouble with 115gn D-Tacs RBT? I've tried H4350 over 2 gns in .2 increments in a 1:7.5 twist barrel 30". speeds are 2750- 2980 and groups are wild, nothing better than 1.75" at 100 yards.
powder charge is from 36.7 to 38.7 in Lapua brass. Is it the RBT and the barrel just doesn't like them?

 

[dstoenner]

I am running 39.2 of h4350 in 6x47 Lapua. My 100 yard groups are running right at .4 in position for F-class. Every group i shot in load development was less than an inch. My barrel is 1:7 McGowen 30” long with velocity right at 2950 with single digits SD

David

 

[linedrive301ft]

I could never get the DTAC's to shoot at 100 yds. Try them at distance and they should do better.

 

[Dusty Stevens]

Is this a 243, 6br, or 6mm/338lm?

Dont force a bullet to shoot. If they wont shoot better than that keep them for the next barrel and try something else.

 

[Dusty Stevens]

I could never get the DTAC's to shoot at 100 yds. Try them at distance and they should do better.

Have you seen a bullet shoot a smaller moa spread at a farther distance? This was a heated topic for many years. I believe my friend alinwa has a standing challenge for anybody that can do it. You could make a lot of money if you can.

 

[urbanrifleman]

Its pretty obvious this is not a bullet problem.

 

[Delfuego]

We have seen the difference in DTAC over the last lot. The original RBT DTAC's were great and a lot of us used them happily. The latest batch from late 2018 - early 2019 did not perform the same. As a result many shooters I know have moved on to different bullets.

 

[Dusty Stevens]

It also goes to show how es doesnt correlate to group size. You may have a broken scope- do you have another you could try?

 

[rebel107]

I am running 39.2 of h4350 in 6x47 Lapua. My 100 yard groups are running right at .4 in position for F-class. Every group i shot in load development was less than an inch. My barrel is 1:7 McGowen 30” long with velocity right at 2950 with single digits SD

David

David, If i ran my loads up to 39.7 the speeds would be well over 3000 fps. Did you use the Rebated Boat Tail projectiles? Barrel is a Benchmark 3 groove.

 

[rebel107]

Is this a 243, 6br, or 6mm/338lm?

Dont force a bullet to shoot. If they wont shoot better than that keep them for the next barrel and try something else.

This is a 6XC chambered for the D-tacs. Benchmark 3 groove 1-7.5T barrel

 

[rebel107]

It also goes to show how es doesnt correlate to group size. You may have a broken scope- do you have another you could try?

Brand new scope first time out. This is my second 6XC as the first one was a tac driver (1-7.75T)but in this barrel all of my pet loads are way too fast. In some of the loads the ES was reasonable but the groups blew out to 2". I'm guessing a 3 groove just doesn't like them?

 

[Dusty Stevens]

Brand new scope first time out. This is my second 6XC as the first one was a tac driver (1-7.75T)but in this barrel all of my pet loads are way too fast. In some of the loads the ES was reasonable but the groups blew out to 2". I'm guessing a 3 groove just doesn't like them?

Sounds like you may need a new barrel. This one may be a dud

 

[dstoenner]

David, If i ran my loads up to 39.7 the speeds would be well over 3000 fps. Did you use the Rebated Boat Tail projectiles? Barrel is a Benchmark 3 groove.

Yes I am shooting the RBT version.

I might add that I have not had the chance to shoot 1000 with them yet. We have had 3 out of 4 matches canceled this year due to rain

David

 

[rebel107]

Yes I am shooting the RBT version.

I might add that I have not had the chance to shoot 1000 with them yet. We have had 3 out of 4 matches canceled this year due to rain

David

Maybe it's just the combination I'm running or as Dusty says, maybe a Dud barrel, I'll try some Sierra 107's, if they don't shoot nothing will.

 

[Farmerboy78]

I run the 105 hybrid and the 112 match burner in my 6xc... using 6 creed srp brass and reformed... great velocity and amazing accuracy in my proof 8 twist... getting 3012fps with that 112gr.

 

[Evan]

I'd not give up on the barrel until you've tried a few different bullets. You may find that barrel really likes Berger 105s, or hornady 108, or 107smk. Folks seem to have more consistent results with the 105 class than the 115 class.

 

[Hoser]

We have seen the difference in DTAC over the last lot. The original RBT DTAC's were great and a lot of us used them happily. The latest batch from late 2018 - early 2019 did not perform the same. As a result many shooters I know have moved on to different bullets.

That is a huge bummer. I was going to order another 5-10K of them. Might just order 500 to test.

 

[Farmerboy78]

That is a huge bummer. I was going to order another 5-10K of them. Might just order 500 to test.

Try the barnes 112gr match burner. I'm using a .624 bc and my buddy uses .625... it's as advertised

 

[Evan]

Have you seen a bullet shoot a smaller moa spread at a farther distance? This was a heated topic for many years. I believe my friend alinwa has a standing challenge for anybody that can do it. You could make a lot of money if you can.

Slightly off topic, but there is a Litz paper: Understanding Long Range Bullets or something like that on the applied ballistics website that talks about how the destabilizing effects (velocity) on the bullet are going away faster than the stabilizing ones (rotation), a.k.a Sg increases as the bullet proceeds downrange. This is all fun theory though, because the reality is that if it groups poorly at 100, it won't group appreciably better at 600 or 1000. Wind and everything else will just start to cover up the lack of raw precision.

 

[Delfuego]

That is a huge bummer. I was going to order another 5-10K of them. Might just order 500 to test.

Ask some of the brothers, they may have some leftovers you can test with.