6GT project/range report

[Clancy]

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.

It’s a 35

 

[SmokinJoe]

Thanks

 

[Ray123]

I would advise anyone thinking of going with this cartridge to think twice. Choosing a cartridge with Alpha Munitions as the only brass maker might leave you disappointed or worse.

I bought some of their 6xc SRP last year with disastrous results. Not one single piece of Alpha brass that I fired performed as new brass should. All of the cases were very difficult to extract after being fired with a very mild load. Two pieces actually ruptured at the base blasting my face with bits of metal and destroying two bottom metal assemblies. When I switched back to Norma and Petersen brass in the same rifle, barrel, load, and chamber, all of the issues that the Alpha brass displayed disappeared.

In the end I was left with twice the cost of the original brass order in repair costs, and a new respect for safety glasses.

Wow.. that is catastrophic...and I considered the 6 GT build.
But I gave to say I chambered for the 6 dasher instead...and am very pleased with the 6 mm dasher brass from Alpha and purchased 400 rds.
I chambered my own rifle, no neck turn chamber reamer, with a 28" .900" at the muzzle Bartlein 5 R 7.5 twist. I used tbe Alpha brass as a go gauge and the 6 dasher go gauge as a close no-go when I chambered it. I run the crap out of the dasher Alpha brass right from the box. Exampe 107 SMK at 3132 fps, 110 SMK 3085 fps, 115 DTAC at 3020 fps. No loose primer pockets, with nice groups...the best were RL 15 or varget ...trying to find out which one to use was difficult but RL 15 was 3030 fps with 108 bergers and mostly in the 2"s I ran 13, 5 shot groups with the 2 different powders and different bullets to find out. The average for all 13 5 shot groups at 100 yds was .313" which is good for me. And I really like 6 Dasher Alpha brass, no forming hassles, just load and shoot. In my rifle it's accurate and tough...and I have recommended it for dasher shooters. I have used it in every bullet weight I could find from 55s and 58s at over 4000 fps to 115 DTAC , and 115 Nosler RDF. 2 favorites are 108 berger at 3020 fps or 110 SMK at 3050 and 3085 fps.
That is my experience Alpha 6 mm Dasher brass is really good stuff. But with your experience something was definitely wrong, be cautious, careful, and safe when loading. Sometimes starting over with the whole new rifle build...barrel, action, everything new, just in case, for safety,...and thanks for reporting your horrible experience...a heads up to all. Reminds me of the 50BMG that blew up and the guy was damn near killed.

 

[ToddKS]

Two things:

Alpha is not the only option in the 6 GT. GAP offers brass as well that is made for them by Hornady. I have a lot of experience with the GAP brass and have had zero issues.

I also know persons with extensive experience with the Alpha 6 GT brass who have not had any issues with that product as well.

 

[G Love]

Anyone shooting a 1:9T barrel 6mm GT for varmints

I know it's old but yes I am. Works great. 88 Berger FB. Whitetail, Mule Deer, several pigs, Coyotes, and Bobcats so far. No runners. Everything has dumped.

 

[Bottom Fodder]

Thanks for bring it back up, I enjoyed the read

 

[neckturner]

For those watching this thread, you might like to know that Lapua will be producing the brass. So that's at least three sources: Alpha, Hornady, and Lapua.

Reloading Cases | Lapua Brass | 6mm GT

The 6mm GT provides flawless feeding from bolt-action, magazine feed platforms when utilizing the latest high ballistic coefficient 6mm projectiles.

www.lapua.com

 

[Clancy]

@neckturner I’m looking forward to this. I got away from the GT because I had a bad batch of cases from alpha. I’m back in whole heartedly. Already ordered a barrel.

 

[kochie]

Might work perfectly for our Varmint Silhouette matches hereIs is it really better than the 6.5 x 47!?

 

[Infrequent Shooter]

For those watching this thread, you might like to know that Lapua will be producing the brass. So that's at least three sources: Alpha, Hornady, and Lapua.

Reloading Cases | Lapua Brass | 6mm GT

The 6mm GT provides flawless feeding from bolt-action, magazine feed platforms when utilizing the latest high ballistic coefficient 6mm projectiles.

www.lapua.com

big news that Lapua will start making brass

 

[wywindsor]

Apparently lapua's ballisticians see this as a great case to work with. So we shall see how much brass they will build on the first run. I have an axis II with a criterion barrel and a homemade chassis. Started off on George's recommendation. 200 rds at 33gr varget. Now at 34 gr. Guns has shot under .5 moa at 100. 1.72 at 600. for every 5 shot group since day one. No load development done. I sit at 340 rounds shot. Sometimes a guy gets lucky.

 

[cuirc]

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 magazine inserts or modifications required.

Optimal case efficiency @ 34-35.5 grains of varget.

3020-3080 fps with 103-105 grain bullets and approx 3000 fps with 115's.

Alpha will be coming out with commercial brass by August of 2019.

Dies are currently available from Hornady. RCBS and Redding are due by late fall of 2019

Reamers and Head space gauges are available through GA Precision.

I was just about to pull the trigger on a Dasher build but the 6GT popped up. After doing some reading and talking to George I decided to get one spun up to gather real world data vs. the Dasher, 6BRA, 6BR, 6BRX, and 6CMs we have in our club.

My wants:

1. Push a 115gn DTAC @ 2920 to 2930fps safely in the Sacramento heat.

2. Commercial brass (soon) I don't mind forming to get the ball rolling, but don't want to make 1000s of pieces from scratch.

3. No freaking mag kits. I want to run the same mag I do with every other caliber I own. 260rem, 6.5x47L, 308win, ect.

4. Barrel needs to go 2200 to 2500 rounds with match grade reliability and accuracy. Subjective and will vary by individual needs. Luckily I don't shoot very tight.

George said the 6GT will do everything I am looking for so here we are.

Rifle specs:

GAP Templar Action

Bartlein 1:7.7 twist 6mm M40 Contour finished @ 26"

Huber Trigger Single Stage

KMW Sentinel Stock

Vortex Optics 4-27 Razor

APA Lil Bastard Brake

He was also kind enough to send me 20 loaded rounds made from 6.5x47 brass, some Alpha brass to test, dies, Giraud shell holder, and answer a bunch of text concerning forming brass.

I have not done a lot of wildcat type rounds so I enlisted Dan Bertocchini's aka "Dasher Dan" help. He likes to geek out on this stuff and has a lot more experience than I do with this type of thing. Dan also shoots a lot tighter than I do.

The 6GT was formed initially from 6.5x47L. The size of the cartridge is between a Dasher and 6x47L.

Left to Right
Dasher - 6GT - 6x47L
Water Capacity of the 6GT made from 6.5x47 is 43.3gn

I am thinking od having a G mm GT built. Looking just at the pictures you provided and sort of playing delves advocate it seems the two most common reasons to pick the 6 MM GT over say the 6x47 Lapua are improved feeding, improved feeding and efficiency with Varget powder. Anyone please comment.

 

[boltfluter]

I am thinking od having a G mm GT built. Looking just at the pictures you provided and sort of playing delves advocate it seems the two most common reasons to pick the 6 MM GT over say the 6x47 Lapua are improved feeding, improved feeding and efficiency with Varget powder. Anyone please comment.

I believe the improved feeding is compared to the 6 Dasher and not the 6x47 Lapua, which feeds great. The smaller powder charge helps with barrel life, as you know. Efficiency with Varget is probably correct as I do not know for sure . Cool little cartridge no doubt.
Paul

 

[cuirc]

I believe the improved feeding is compared to the 6 Dasher and not the 6x47 Lapua, which feeds great. The smaller powder charge helps with barrel life, as you know. Efficiency with Varget is probably correct as I do not know for sure . Cool little cartridge no doubt.
Paul

Thanks for the correction on feeding I am still torn between hte Lapua and the GT

 

[SecondsCount]

Thanks for the correction on feeding I am still torn between hte Lapua and the GT

It depends on the velocity that you need. I've been running 6x47L for about 10 years and am going to step down to 6GT now that Lapua is making brass for it.

 

[Tangent]

This looks a great option to rebarrel my .308 Tikka to. I was considering 6BR but issues feeding from the magazines put me off. Now Lapua are making brass I'm definitely interested. 25CM was also an option but the availability of bullets is an issue here.

 

[kochie]

big news that Lapua will start making brass

i have redding 6.5 x47 dies they should work . so i already have the dies .

 

[boltfluter]

i have redding 6.5 x47 dies they should work . so i already have the dies .

So you are looking to use 6.5 x 47 dies for the GT? I must have missed something.

 

[kochie]

So you are looking to use 6.5 x 47 dies for the GT? I must have missed something.

yes that will work right all but the neck ?

 

[Rob01]

yes that will work right all but the neck ?

You aren’t serious are you?