Help with 103 vtac bullets in 6gt!

[DHuffman]

The whole speed deal for me is dependent on what you're shooting, if it's a 17#+ bench rig on a rest and bags then sure step on it.

If it's a PRS type rig shooting steel there's a lot to be said for low recoil and minimal muzzle jump for spotting your shots. Like i said those two guns of ours will shoot inthe .2s regularly, the .1s occasionally and even a rare group or two down in the high .0s on paper at 150 & 200 yards when verifying loads or tuning back into the optimum seating window.

I'll take that accuracy all day long for a few more clicks on the scope.

 

[Lone Hunter]

Don’t know if you saw this section or not but it is in the Bulletin Section and has data on the 6GT.

6GT project/range report

As a lot of you have already heard and seen, George Gardner of GA Precision and Tom Jacobs (2x 600yd/1000yd Benchrest Shooter of the Year) have developed a new round called the 6GT. Some basic info on the 6GT: Brass can be formed from: 6.5x47L 35 degree shoulder for better feeding. No...

forum.accurateshooter.com

 

[Brentwinkey]

So before you wear your barrel out, after all this work have you not tried in the lands?

Ive tried as close as 10 thou off...its a prs/mag feed gun so im not comfortable being in the lands

 

[Brentwinkey]

I thought the same thing.
Seems like the easiest and simplest thing to try first.
Then give up on that powder. RL16 is a great powder, but if it won't work
try H4350

Would you go h4350 or varget? Have roughly 10-12lbs of varget but only 2lb of 4350. Thanks

 

[DHuffman]

Dave,
I have ZERO experience with the Tiger, but I have a boat-load of expericace with RL-16 and 103's in a dasher.
35gr will get you to the 2990-3013 node depending on lot and that is a full case with little pressure. 36.1 will get me to the next node in my rifles but is painfully slow with a LONG drop tube.

CW
edit to add
1800 rounds was easy with the 35 gr charge.

I've always heard the RL 16 was best up around pressure? I don't know asking. If so I'd think a full case or a near pressure GT load would be plenty north of 3100 maybe 3200 again I don't know.

Would you go h4350 or varget? Have roughly 10-12lbs of varget but only 2lb of 4350. Thanks

The cartridge was designed around Varget as I understand it. If I had 12# I'd try it.

 

[Ranger188]

You can buy H4350 now.
Yes RL16 is a great powder and will give a bit more speed without pressure
compared to H4350, but if it won't shoot, doesn't matter how much you have.
Try backing off on the charge a little bit and try going towards the lands with the RL16.
Quickest and easiest thing to try first. Won't take that many rounds to see
if this will work or not.

 

[DHuffman]

Would you go h4350 or varget? Have roughly 10-12lbs of varget but only 2lb of 4350. Thanks

Before I quit the rl16 though I'd drop down to 2850 and work up at your best seating depth just to see

 

[DHuffman]

Well your no fun. Lol
Barrel makers gotta eat too!!
Yanking on ya bro, I saw your GT targets in the background, you got them shootin small.

I'm thinking about getting a barrel chambered for a bench gun. It tuned ridiculously easy and all off a pair of bags, no rest. Might have shot one or two groups slightly bigger than .5 when it hit the scatter or anti node LOL

 

[WHuff]

Thank you sir

You bet, forgot to mention I’ve been running H4350, Alpha Brass, and BR4 primers.

 

[Bc'z]

I'm thinking about getting a barrel chambered for a bench gun. It tuned ridiculously easy and all off a pair of bags, so rest. Might have shot one or two groups slightly bigger than .5 when it hit the scatter or anti node LOL

Target looked great for a PRS/ Deer killing rifle. It got me interested in what it was making them groups.
I'm thinking OP needs to start at touch with something other than R16.
Sometimes as loaders we need to think outside the box on what we're working with, and how we address the problems were having.

 

[STS]

So far the diagnosis for this issue has been tuning and powder selection. It's quite possible that it's a rifle issue. Bolt to barrel counterbore clearance problems. Bedding issues. Scope issues. I've dealt with rifles with a similar history as this one. The first thing is to check every dimension of the barrel fit, bedding, scope mounts, trigger and bolt handle clearance and barrel float. Make sure there is not something on the rifle that is keeping it from tuning.

 

[Dusty Stevens]

Looks to me like youre missing half the tuning steps. Seat them longer dont just say .010 and go out from there. Youre missing .025+ of seating depth that will work

 

[boltfluter]

What Jeff and Dusty said. I have never pulled a bullet at .010 into the rifling. If nothing, at least it could be a diagnostic tool. Just a thought.
Paul

 

[Gunnut26]

I shot a 1000 103s through my BRA. They shot great only if they were .008 to .010 into the lands.

 

[Evlshnngns]

Update?

 

[Brentwinkey]

Update?

Whatcha looking for? Load info or? I actually sold all my vtac bullets and got away from 6mm for the time being. I will prob revisit 6mm in a yr or 2 after i get my new hunting rig built.

 

[Evlshnngns]

Whatcha looking for? Load info or? I actually sold all my vtac bullets and got away from 6mm for the time being. I will prob revisit 6mm in a yr or 2 after i get my new hunting rig built.

Just curious how it turned out. I have 6gt brass, need to get the rest together.

 

[rogina]

The new Vtacs are very different from the old ones. Mine would not shoot close, or in the lands. I found my jump at .027 off. I know a few guys here who have had the same issue until they started jumping them. Also my vtacs liked a little more neck tension. Was shooting in mid-low 2’s at 600 with 28-30lbs dropped a bushing and now we consistently stay in the mid-high 1’s with good conditions. Also a side note this same load will shoot like a shotgun at 300 yards. This dasher taught me to tune at the distance I shoot at. It’s been finicky the entire time. But finally landed on 32.32grs of varget, with a br4, alpha cases, at a .027 jump. 28” Brux.

My vtacs are 2 years old. Are they old or new?

 

[Brentwinkey]

Just curious how it turned out. I have 6gt brass, need to get the rest together.

I got a good load figured out before i sold the gun and brass. What i found out is the vtac bullets like the .170 freebore vs standard .120 freebore. In my .120 freebore they were super super seating depth sensitive. I had like a 3thou window. It was frustrating. If i get a 6gt again im gonna go .170fb and prob do 115dtac or 108/109eldm maybe. Brent