6GT — New Cartridge, Alpha Brass

[Grimstod]

I do love reading about these new cartridges. Short and fat is where its at

 

[Bc'z]

I do love reading about these new cartridges. Short and fat is where its at

Im'ma gonna keep my mouth shut!

 

[Delfuego]

@flatlander I would reach out to Aaron at Zermatt. Some Colorado boys have 10k-30k+ each with the TL3/Dasher combo (Scotty,Kevin,Fred,Etc,Etc). I bet Bighorn/Zermatt will get you fixed up!

 

[Dgd6mm]

Any updates on the 6GT?

 

[GSRswapandslow]

I think this cartridge is going to take off with the crowd wanting to get in the 6BR type family of cartridges but without wanting to fireform or buy mag kits. Mostly PRS/NRL/field type shooters with mag fed rifles.

I'm not going to be throwing away my 6BRA for one, and I'm curious to see how it performs in the benchrest world.

this is exactly why im looking at it. I've always wanted to build a BR...but all of my rifles are repeaters and i don't want to fiddle with a mag kit.

I wanted to go ARC...but the bolt head doesn't work for me...

 

[Alex Wheeler]

@Tom E came in 3rd place in light gun for group with his 6.5mm GT at the IBS 1k Nationals last weekend. Personally I am more interested in the 6.5gt for BR than the 6gt. The other cool thing is this case will fall out of a Bat B drop port without mods.

 

[rockhound78]

So, could you just run a 6.5 creedmoor reamer in short and just use shortened 6.5 creedmoor dies to load it, using 6mm GT brass?

 

[Alex Wheeler]

No, I did a couple holding a 6.5x47 reamer short to put in the neck and throat, then following up with a 6gt reamer to put in the body. Came out well, but the right reamer is coming.

 

[dnellans]

What is the motivation for 6.5 vs 6 Alex? Hoping to use faster powder than those run in 6.5x47’s typically?

 

[Alex Wheeler]

We went to the BRA from the Dasher to reduce case capacity. The idea was to look for something to agg better, and many of us believe it does. Going larger to the gt case would be going bigger yet than a Dasher. I dont think its the right move for BR, unless you matched it with a heavier bullet like a 110-115. That may settle it down. The case size may be just right for a 135-140 6.5mm bullet though. Its just small enough to fall out of a Bat B drop port while the 47 needs a bolt stop or port mod to do it. Some guys are playing with the 6.5 dasher but powder choice is limited do to case size. We'll see how it plays out but I do believe case volume to bore ratio is important to a case you want to agg with. You would likely never see a difference in any other shooting sport. Its going to be hard to beat a 47 but it worth a try.

 

[Evan]

We went to the BRA from the Dasher to reduce case capacity. The idea was to look for something to agg better, and many of us believe it does. Going larger to the gt case would be going bigger yet than a Dasher. I don't think its the right move for BR, unless you matched it with a heavier bullet like a 110-115. That may settle it down. The case size may be just right for a 135-140 6.5mm bullet though. Its just small enough to fall out of a Bat B drop port while the 47 needs a bolt stop or port mod to do it. Some guys are playing with the 6.5 dasher but powder choice is limited do to case size. We'll see how it plays out but I do believe case volume to bore ratio is important to a case you want to agg with. You would likely never see a difference in any other shooting sport. Its going to be hard to beat a 47 but it worth a try.

I agree. I had the thought of taking 6.5x47 brass and pushing the shoulder down 0.030" or so to a 40degree shoulder, kind of "vartarg-ing" it (20 Vartarg pushes down a 221 Fireball shoulder down some and makes it 30 degrees). I think I would have ended up with something about 2gns less capacity and a 40 degree shoulder to make the brass more stable. Ultimately I decided it was silly to spend all that money when the 6.5x47 is readily available and has the reputation it does for accuracy (for me, a BR shooter that is not at the top of the heap looking for every edge available to get ahead).

 

[2moreclicks]

We went to the BRA from the Dasher to reduce case capacity. The idea was to look for something to agg better, and many of us believe it does. Going larger to the gt case would be going bigger yet than a Dasher. I dont think its the right move for BR, unless you matched it with a heavier bullet like a 110-115. That may settle it down. The case size may be just right for a 135-140 6.5mm bullet though. Its just small enough to fall out of a Bat B drop port while the 47 needs a bolt stop or port mod to do it. Some guys are playing with the 6.5 dasher but powder choice is limited do to case size. We'll see how it plays out but I do believe case volume to bore ratio is important to a case you want to agg with. You would likely never see a difference in any other shooting sport. Its going to be hard to beat a 47 but it worth a try.

What kind of velocity or y’all seeing or expecting with the 130-140 pills

 

[Tom E]

With a week and a half to get a new gun and a new cartidge tuned up for the 1000yd Nats, the 6.5 gt performed! 3rd place in light gun group agg. 4.5" over 3 targets , for the conditions I was pretty stoked. Fairly extreme mirage on day 1 and big winds on day 2, 1st in the agg was 3.6" and 2nd was 4.4". I couldn't find center of the target on day one at all. 12 th place in light gun overall due to poor score shooting.

A little info on the 6.5 gt, to my knowledge this is one of two of the first barrels ever chambered for it, all work was done by Alex Wheeler at wheeler accuracy , he had to use a 6.5x47 and my original 6gt reamer to pull it off, we ran out of time waiting on the reamer.
As of now I have one of Alpha Muntions new Legacy reamers in the shop ready to go, looking forward to using it.
The brass i used in this barrel was some of Alphas new pre production , "optimized case head technology " i hope i got that right, Andrew Rixon. This stuff is legit! I only had 50 pieces to start the project, turned the necks, expanded them and i went straight to 1000yds. I did some ladders at a grand to see what it liked, honestly I had a hard time wrapping my head around how forgiving it seemed to be, I saw it shoot good from 2800 to 2950fps, seeing pressure at 3000.
This testing was all done with h4895, and our 133gr and 139 gr bullets. I ended up settling on our 133gr at 2950, 36.7 gr of h4895, with a 205m primer.
Now that I have some time to actually test and not worry about running the match itself, im going to try some more tests, primers, bushings, and slow it down to 2840 ish as well.

These are the things that keep me motivated and this one has sparked my interest for sure!

I think this 6.5 has a bright future ahead

Thanks, Alex Wheeler, Andrew Rixson, Tom Danielson and Robert Danielson you guys are top notch!

TomE

 

[DT]

With a week and a half to get a new gun and a new cartidge tuned up for the 1000yd Nats, the 6.5 gt performed! 3rd place in light gun group agg. 4.5" over 3 targets , for the conditions I was pretty stoked. Fairly extreme mirage on day 1 and big winds on day 2, 1st in the agg was 3.6" and 2nd was 4.4". I couldn't find center of the target on day one at all. 12 th place in light gun overall due to poor score shooting.

A little info on the 6.5 gt, to my knowledge this is one of two of the first barrels ever chambered for it, all work was done by Alex Wheeler at wheeler accuracy , he had to use a 6.5x47 and my original 6gt reamer to pull it off, we ran out of time waiting on the reamer.
As of now I have one of Alpha Muntions new Legacy reamers in the shop ready to go, looking forward to using it.
The brass i used in this barrel was some of Alphas new pre production , "optimized case head technology " i hope i got that right, Andrew Rixon. This stuff is legit! I only had 50 pieces to start the project, turned the necks, expanded them and i went straight to 1000yds. I did some ladders at a grand to see what it liked, honestly I had a hard time wrapping my head around how forgiving it seemed to be, I saw it shoot good from 2800 to 2950fps, seeing pressure at 3000.
This testing was all done with h4895, and our 133gr and 139 gr bullets. I ended up settling on our 133gr at 2950, 36.7 gr of h4895, with a 205m primer.
Now that I have some time to actually test and not worry about running the match itself, im going to try some more tests, primers, bushings, and slow it down to 2840 ish as well.

These are the things that keep me motivated and this one has sparked my interest for sure!

I think this 6.5 has a bright future ahead

Thanks, Alex Wheeler, Andrew Rixson, Tom Danielson and Robert Danielson you guys are top notch!

TomE

The vaportrailbullets link doesn't go to anything connected to VT bullets. What is proper link to get the bullet info please???

 

[Tom E]

The vaportrailbullets link doesn't go to anything connected to VT bullets. What is proper link to get the bullet info please???

Pm me, ill get ya my phone number, my site is currently down.

TomE