6GT project/range report

[Clancy]

I don’t take many gun pictures, so this is as good as y’all are going to get.

Beanland, TL3, Krieger 23.5” Rem Varmint 1:7.5

Manners EH6A hunting stock

Tungsten Cerakote

NF NX8

 

[RickB]

RL15 falls between Varget and H4350 for burn rate.

The Hodgdon burn rate chart places Rel 15 just a little bit faster than Varget, although burn rates may occasionally vary a little bit from one cartridge.

 

[Laurie]

The Hodgdon burn rate chart places Rel 15 just a little bit faster than Varget, although burn rates may occasionally vary a little bit from one cartridge.

The problem with burn rate charts, general unreliability and uselessness aside, is any two rarely agree. Nevertheless, Re15 has usually been shown as slower burning than VarGet pretty well across the board from the time of the latter's introduction some quarter century ago. I gave up even glancing at Hodgdon's chart a long time ago. If I use a burn rate chart, I prefer this German one from LHS which fits better with actual experience and results.

 

[RickB]

Thanks for a different source. I will take a look at it and compare some pas loads.

My current use of burning rates is looking for something to substitute for Hodgdon Benchmark which is unavailable. I am going to try some Vihtavouri N133 this coming week. I’ll see how close it comes to some shared load data.


Cheers!

The problem with burn rate charts, general unreliability and uselessness aside, is any two rarely agree. Nevertheless, Re15 has usually been shown as slower burning than VarGet pretty well across the board from the time of the latter's introduction some quarter century ago. I gave up even glancing at Hodgdon's chart a long time ago. If I use a burn rate chart, I prefer this German one from LHS which fits better with actual experience and results.

View attachment 1355597

 

[Raptor]

Does anyone know or have the actual round count for barrel life of the 6GTs??? Thanks guys!!

 

[DDRH65PRC]

Does anyone know or have the actual round count for barrel life of the 6GTs??? Thanks guys!!

Dunno yet, at ~2100 rnds
Using H4350 @ ~2900fps
Bartlein 400MODBB bbl

Had a proof bbl throw fliers @ ~1600rnds, but running it hot around 3025fps.
I think this bbl needs a deep cleaning with some bore paste. Bbl has been pulled for now.

2nd Proof bbl (might be a Benchmark bbl) is still shooting @ ~1600rnds (2880fps). Bbl needs a deep cleaning too.

Velocity and heat kills bbls

 

[Raptor]

Dunno yet, at ~2100 rnds
Using H4350 @ ~2900fps
Bartlein 400MODBB bbl

Had a proof bbl throw fliers @ ~1600rnds, but running it hot around 3025fps.
I think this bbl needs a deep cleaning with some bore paste. Bbl has been pulled for now.

2nd Proof bbl is still shooting @ ~1600rnds (2880fps). Bbl needs a deep cleaning too.

Velocity and heat kills bbls

So, it really is not all that much better on barrel life than a 6xc or a 6 Creedmoor??? I pulled my 6 Creedmoor at 1600 or so. I started getting the "Unexplained" fliers at 600yds. Do the Dashers do better?? I want to go back to a 6mm but with my 6.5s I am getting around 2400 and more with a set back. With my RPR I can't have them set back so that is why I would like the idea of getting more accurate rounds down range..

 

[DDRH65PRC]

I only experienced that with one bbl. A good scrubbing may bring back accuracy.

Dasher should do better, less case capacity. Keep velocity below 2900fps and bbls will last longer. Just guessing here but should be able to get at least 3500-4000rds through a 400BB bbl for 6GT.

 

[Fuj]

I only experienced that with one bbl. A good scrubbing may bring back accuracy.

If you have not already, and with that amount of round count, I'd
get it re-crowned. I normally like to cut off at least 1/2' then crown.

 

[RAG]

It's quite funny you said that about the 40 degree shoulder ,I have been running what I call I 6 / 47 40 degree shoulder .100 thousands short since about 2012 in 600 and 1000yd benchrest.
I make my case's out of 6.5x47 lapua brass.

Interesting. I just came across this. I've been conceptualizing something similar. I was thinking about a .100 GT short with 40 deg shoulder, or .200 short from the 6x47L. Really, I'd like to end up with Dasher capacity, or thereabouts. And I'd like to have a longer neck...as I'm working with my first Dasher now, and the short Dasher neck bothers me, for a couple reasons. I'm leaning towards a neck in the vicinity of .35", maybe even up to .4".

Did you ever try .150 or .200 short (from the 6x47L)?

Thanks!

 

[DHuffman]

Interesting. I just came across this. I've been conceptualizing something similar. I was thinking about a .100 GT short with 40 deg shoulder, or .200 short from the 6x47L. Really, I'd like to end up with Dasher capacity, or thereabouts. And I'd like to have a longer neck...as I'm working with my first Dasher now, and the short Dasher neck bothers me, for a couple reasons. I'm leaning towards a neck in the vicinity of .35", maybe even up to .4".

Did you ever try .150 or .200 short (from the 6x47L)?

Thanks!

You're not going to get an answer from Stan, he's passed on.

 

[RAG]

You're not going to get an answer from Stan, he's passed on.

Sorry to hear, but thank you for letting me know

 

[Clancy]

Interesting. I just came across this. I've been conceptualizing something similar. I was thinking about a .100 GT short with 40 deg shoulder, or .200 short from the 6x47L. Really, I'd like to end up with Dasher capacity, or thereabouts. And I'd like to have a longer neck...as I'm working with my first Dasher now, and the short Dasher neck bothers me, for a couple reasons. I'm leaning towards a neck in the vicinity of .35", maybe even up to .4".

Did you ever try .150 or .200 short (from the 6x47L)?

Thanks!

What is the intended purpose? I love my GT, but if I didn’t need a lot of brass it wouldn’t bug me at all to shoot some norma dasher cases once with a light load to set the pockets.

 

[RAG]

What is the intended purpose? I love my GT, but if I didn’t need a lot of brass it wouldn’t bug me at all to shoot some norma dasher cases once with a light load to set the pockets.

Right. Intended purpose is punching paper and long range varmints with mid-weights (87s and 88s). But I'm not sure I'd want to play with Norma brass, as I like to run them hard! Love the concept of the Shiraz/Norma brass though...and I'd even like to see neck just a touch longer to test my theory about extending throat live with a longer neck.

I'd like to run a little less capacity than the GT too. But I'm wondering...how's that Alpha GT brass shaping up anyhow (I've not yet had the time to read up on it)...because it would be awfully easy to form a long neck dasher, or even something in-between the GT and Dasher, from Alpha GT brass...

 

[Clancy]

Right. Intended purpose is punching paper and long range varmints with mid-weights (87s and 88s). But I'm not sure I'd want to play with Norma brass, as I like to run them hard! Love the concept of the Shiraz/Norma brass though...and I'd even like to see neck just a touch longer to test my theory about extending throat live with a longer neck.

I'd like to run a little less capacity than the GT too. But I'm wondering...how's that Alpha GT brass shaping up anyhow (I've not yet had the time to read up on it)...because it would be awfully easy to form a long neck dasher, or even something in-between the GT and Dasher, from Alpha GT brass...

It’s tougher than a cockroach. I love to experiment too, but there’s so little room between the GT and Dasher I’d just pick one or the other, you could always have a GT reamer ran in short though, I suppose. Much cheaper getting dies made that way.

I’ll add the the 88s have easily outshot the groups I posted above from the 108s. Lots of low to mid .2s and pretty well every 3 shot group is in the mid .1s

 

[Jimmy76]

Any thoughts or experience on loading a 6mmGT with a 6mm 70gr SIerra BlitzKing for varmint hunting? Sierra data shows 48.3 of H4350 as max (6 Creedmoor data). I have a 26” Bartlein 1:7.5 MTU contour chambered in 6mmGT.
Thanks, Jim

 

[Clancy]

Any thoughts or experience on loading a 6mmGT with a 6mm 70gr SIerra BlitzKing for varmint hunting? Sierra data shows 48.3 of H4350 as max (6 Creedmoor data). I have a 26” Bartlein 1:7.5 MTU contour chambered in 6mmGT.
Thanks, Jim

Not sure why you referenced Creedmoor data, but that would be a no no.

Have a look at N135 and H4895 for the 70s in 6 GT. N135 is pretty easy to get right now.

 

[SmokinJoe]

Clancy, I have had similar thoughts, a 6 GT AI so to speak. You should get the efficiency of the Dasher along with the benefits of a longer neck.

 

[LVLAaron]

Some anecdotal data - I have two 6GT's - One in a PRS looking gun (28 inch M24 barrel) One in an F-Open gun (Bat M, 28 inch 1.25 straight barrel) - Both like 34.1 varget and berger 105's - The open gun won a very competitive F-class match.

I hate to admit it but I love 6mm for midrange.

 

[SmokinJoe]

I guess I spoke out of ignorance. After looking over the entire thread it appears that the 6GT has the 40* shoulder. Wish there was a Dasher in the picture for comparison.