6GT?

[Krumfola]

I am very pleased with my two 6GT rifles. In my judgment, it's a great cartridge for anything from prairie dogs to mule deer. It's exceptionally easy to load. I've had good success with 105, 107, 108, 109, and 112 grain bullets. Varget and RL 15.5 have proven to be good powders in the 6GT. I'm now beginning to experiment with 115 DTACs and H4350.

The first rifle is a Sig Cross that I had rebarreled in 6GT by Straight Jacket Armory. It's a 22" 1/7.5 twist.

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The second rifle is the first rifle I've assembled myself. It's an Impact action, Stocky's VFG carbon stock, and 20" 1/7.5 Carbon Six barrel. I wanted a lightish hunting rifle for small to midsize game - e.g. antelope. It turned out pretty well.

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How does the Stocky’s VFG compare to and EH1?

I’ve got a 20” barrel and I’m pushing a 108 ELDM to 2800fps with a mild charge of Varget on my 8th firing in Hornady brass. It’s been pretty easy to get an accurate load, just about everything I’ve tried shoots great.

 

[gwh97]

The eld ms are shooting great. Planning for my wife to use this rifle on a cow elk hunt in January. I may be taking it on an Aoudad hunt as well.

 

[khuber84]

I've pulled 3 6gt match barrels at 2500 rds, all still shooting well under moa. The current one has 2100 on it, took out to zero a new scope today, 4 of 5 in one hole, the other 1/3" away. I run dtacs low 2800s in my match barrels, 34.8-35.3gr, maybe that's why they are lasting.

 

[Jordan Smith]

I've pulled 3 6gt match barrels at 2500 rds, all still shooting well under moa. The current one has 2100 on it, took out to zero a new scope today, 4 of 5 in one hole, the other 1/3" away. I run dtacs low 2800s in my match barrels, 34.8-35.3gr, maybe that's why they are lasting.

Which powder?

 

[khuber84]

Which powder?

H4350

 

[Kimber7man]

George talked me into a build. He mentioned that Berger is going to have factory ammo for it next year now that Lapua is making brass for it, so there will be more factory options in the nearish future.

 

[khuber84]

George talked me into a build. He mentioned that Berger is going to have factory ammo for it next year now that Lapua is making brass for it, so there will be more factory options in the nearish future.

George........as in the G in GT? 6GeorgeTom

 

[khuber84]

The gt has truly been a hugely accepted case. Guys are going 20 cal wildcats, you can buy 22 6 and 25 headstamp brass. There's a 37 cal subsonic based on the gt parent. This all has happened in like 4.5 years. I think it's had prob one the fastest diversities of a case in the modern age.

 

[nm.otter]

15% less capacity than a Creedmoor, and with slightly improved geometry. Seems like a winner.

 

[pathnz]

2 of my 3 centrefire rifles are 6mmGT...

It's the logical next step up from a .223 to increase hit probability with better velocity consistency & wind uncertainty, without excessive recoil. I can't imagine I'll bother with anything else in the near future

 

[Krumfola]

It’s a great little round. Gonna go 16” when I rebarrel.

I saw an old FB post by Tom Jacobs saying he was getting 2950fps with a 108 with H4895 from a 20” barrel.

Anyone else try 4895?

 

[khuber84]

It’s a great little round. Gonna go 16” when I rebarrel.

I saw an old FB post by Tom Jacobs saying he was getting 2950fps with a 108 with H4895 from a 20” barrel.

Anyone else try 4895?

That's a pretty warm load I'm thinking. My 21in 6gt with rl15.5 was at pressure around 2980mv w/ 109 hybrids. 15.5 is a double based high energy powder, which generally provide highest mv before psi. Everybody's limit of acceptable pressure is a lil different tho.

 

[Krumfola]

Yeah I agree @khuber84. I’ve found 2800fps to be accurate, pretty easy on recoil, and it really helps with brass life. I’m on 8 firings with Hornady brass. Makes me wonder if the premium brass is really worth the extra cost.

 

[mwoolsey5]

Indirectly ended up on this thread while researching 6CM vs 25 CM. While I do believe the 6 CM beats the 25 CM for hunting applications, the 6 GT may beat out both of those cartridges…

The differences are small, but the hit probability calculator I was using gave the 6GT a 1-3% advantage over the 6CM at 500 yards when the equipment was standardized (same barrel length, rifle weight, and bullet). I guess I’m struggling to see the downside? Seems Like it has better barrel life, guessing a bit less recoil with less powder capacity, increased hit probability. Is there anything I haven’t accounted for that would make the 6 CM a better option?

 

[nm.otter]

Other than the availability of factory rifles and factory ammo, no real advantage that I can see.

 

[wind gypsy]

Indirectly ended up on this thread while researching 6CM vs 25 CM. While I do believe the 6 CM beats the 25 CM for hunting applications, the 6 GT may beat out both of those cartridges…

The differences are small, but the hit probability calculator I was using gave the 6GT a 1-3% advantage over the 6CM at 500 yards when the equipment was standardized (same barrel length, rifle weight, and bullet). I guess I’m struggling to see the downside? Seems Like it has better barrel life, guessing a bit less recoil with less powder capacity, increased hit probability. Is there anything I haven’t accounted for that would make the 6 CM a better option?

I’m curious how a hit calculator showed better results for a 6GT than a creedmoor that pushes the same bullets faster?

 

[mwoolsey5]

I’m curious how a hit calculator showed better results for a 6GT than a creedmoor that pushes the same bullets faster?

So I’ve been playing around with the hit calculator and chat GPT a bit this morning to see how/what’s affecting the hit rate. Trying to poke holes in why it would be higher if the 6 CM pushes the bullet faster.

Best guess right now is that even though the 6 CM has a bigger case capacity (12%), because I’m limiting it to a 20” barrel (for use with a suppressor), it can’t burn all the powder and can’t take advantage of the extra case capacity, so you are getting almost the exact same MV. I’ll have to play around with it more later or see what others come up with. Pretty fun to theory craft a bit.

Assumptions:
Powder and MV:
6 GT (Varget): 2,820 fps
6 CM (H4350): 2,830 fps
Rifle weight: 8.5 lbs
Barrel length: 20”
Bullet: 108 ELD-M

 

[Kimber7man]

I’m curious how a hit calculator showed better results for a 6GT than a creedmoor that pushes the same bullets faster?

Recoil? I don’t know, I’m not familiar with hit calculators…

 

[nm.otter]

A little less recoil + a little more efficient use of powder.

 

[Lawnboi]

So I’ve been playing around with the hit calculator and chat GPT a bit this morning to see how/what’s affecting the hit rate. Trying to poke holes in why it would be higher if the 6 CM pushes the bullet faster.

Best guess right now is that even though the 6 CM has a bigger case capacity (12%), because I’m limiting it to a 20” barrel (for use with a suppressor), it can’t burn all the powder and can’t take advantage of the extra case capacity, so you are getting almost the exact same MV. I’ll have to play around with it more later or see what others come up with. Pretty fun to theory craft a bit.

Assumptions:
Powder and MV:
6 GT (Varget): 2,820 fps
6 CM (H4350): 2,830 fps
Rifle weight: 8.5 lbs
Barrel length: 20”
Bullet: 108 ELD-M

Regardless what the internet tells you; the 6 creed has more case capacity and will probably the same weight bullet faster regardless what your barrel length is (writhing reason 16+”). Anyone running similar pressure will see a ballistic advantage to the 6 creed, be it very small. But it’s there, there’s just no way the 6gt is going to produce the same results at the same pressure in the smaller case.

Now inherent accuracy, and small velocity deviation in the GT and br sized cases is a real thing and something I would consider, but likely isn’t going to be considered by most software. Recoil will also be so similar I’m not sure if there’s any real advantage to most shooters.

Barrel life is probably a bigger concern, the GT should give you a little more barrel life.

Theres no magic involved with those 2 cases you’re comparing.