6mm GT Barrel Life

[Cascade Hemi]

I think low 2900's is a sweet spot for the 109's. I think I can probably get a little more velocity out of my 115s, I just haven't tried yet.

From a wind perspective, the 105gr Hybrid would have to be going 3100fps to match the wind hold of my 115gr DTACs at 2850fps in a 10mph. That speed is pretty easy going for the 6GT and DTAC, whereas 3100fps for the 105 is pushing it pretty hard. You're going to give up some barrel life and load consistency pushing that fast.

Just one reason I lean towards the heavier bullet with this round.

What is your barrel length?

 

[Birddog6424]

What is your barrel length?

26" Hawk Hill

 

[hairy_pineapple588]

Very old thread but give me the real numbers. I’m at 1000 rounds on my 26” CRB running 2850. Anyone with a similar setup shot a crb out? I’m debating between another barrel or starting another rifle build.

 

[John Glidewell]

Very old thread but give me the real numbers. I’m at 1000 rounds on my 26” CRB running 2850. Anyone with a similar setup shot a crb out? I’m debating between another barrel or starting another rifle build.

It depends on how hard you run it. I am at 2500 on one now running 109s at 2930 with RL15.5. Based on what I see in the barrel I think another 500ish and it will start to die. But a lot of folks are seeing 2500ish numbers before they start to any accuracy or performance issues.

 

[Hickswr]

It depends on how hard you run it. I am at 2500 on one now running 109s at 2930 with RL15.5. Based on what I see in the barrel I think another 500ish and it will start to die. But a lot of folks are seeing 2500ish numbers before they start to any accuracy or performance issues.

Impressive barrel life at that velocity!

You think RL15.5 being a slower burning powder than varget is contributing to the longer barrel life?

 

[John Glidewell]

I think that is part of it. We do not run hard IE long fast strings. Our matches are long range varmint and we only do 2 five shot strings at 2 to 2.5 min ea string then guns cool. I think the PRS type shooting is harder on barrels. I will be running 115 DTACs on these next barrels with either N160 or N555 which has barrle life est at 3400 rounds. The barrel life estimator has been pretty spot on for last few barrels too.

 

[Hickswr]

I think that is part of it. We do not run hard IE long fast strings. Our matches are long range varmint and we only do 2 five shot strings at 2 to 2.5 min ea string then guns cool. I think the PRS type shooting is harder on barrels. I will be running 115 DTACs on these next barrels with either N160 or N555 which has barrle life est at 3400 rounds. The barrel life estimator has been pretty spot on for last few barrels too.

Thanks for the detailed info!

What’s this barrel life estimator you speak of?

 

[hairy_pineapple588]

I think that is part of it. We do not run hard IE long fast strings. Our matches are long range varmint and we only do 2 five shot strings at 2 to 2.5 min ea string then guns cool. I think the PRS type shooting is harder on barrels. I will be running 115 DTACs on these next barrels with either N160 or N555 which has barrle life est at 3400 rounds. The barrel life estimator has been pretty spot on for last few barrels too.

Got a link?

 

[John Glidewell]

an XCEL formula. Input powder burn rate (heat of expansion#), diameter, charge, pressure, bullet weight and it gives you barrel life est. You get the data from quick load and a trued profile for a rifle.

 

[hairy_pineapple588]

So at what round count is everyone picking up a new barrel?

 

[Hickswr]

So at what round count is everyone picking up a new barrel?

I’d be real nervous if I didn’t have a replacement barrel ready to screw on by 2K rounds

 

[Dead Eye Dick]

Running 2903 fps with Berger 105 Hybrids, still the rifle I depend on at matches. 2448 rounds down the tube. Just this morning, it was stacking bullets on top of each other in what really amounted to a semi-hurricane.

I have a barrel ready and waiting to replace this barrel with, but guess I’m stubborn. Give me a reason to change and it’s changed. Till then, I’m sticking with what I got.

 

[scissorhands]

1500 rounds on my bartlien 26" and its shooting better than ever. Velocities (2880) have stayed the same, but I do have another replacement on the way. Hoping to get at least 2000-2500 out of it. Last 6 five shot groups out of it.
View attachment tempImageIRsqof.jpg

 

[ma smith]

Alot of PRS guys are shooting 2700 for trace/splash benefit. That means they can also load cooler, slower powder if they want. IMHO, wouldn't take every empirical report of. barrel life as gospel until you cross-reference their loads/speeds. Varget models out at 1800 barrel life max pressure, H4350 is 2,100...so you can see downloading either you will likely extentd life...ie, just use less powder or burn at cooler temps or combo of both.

 

[Dead Eye Dick]

Alot of PRS guys are shooting 2700 for trace/splace benefit. That means they can also load cooler, slower powder if they want. IMHO, wouldn't take every empirical report of. barrel life as gospel until you cross-reference their loads/speeds. Varget models out at 1800 barrel life max pressure, H4350 is 2,100...so you can see downloading either you will likely extentd life...ie, just use less powder or burn at cooler temps or combo of both.

@ma smith that’s what so stupid about all this. Why push these smaller rounds to the max. It would be so simple, If someone wanted more velocity in a 6 go with a 6CM or a custom throated .243. It simple makes not sense. I am running Varget and my load isn’t the lightest in the world, but hardly max. I am still getting more than acceptable accuracy at almost 2500 rounds.

Those little knobs on top and on the side of those $4000.00+ scopes can more than make up for a 100FPS less speed and 10,000 less PSI.

 

[Cascade Hemi]

Alot of PRS guys are shooting 2700 for trace/splash benefit. That means they can also load cooler, slower powder if they want. IMHO, wouldn't take every empirical report of. barrel life as gospel until you cross-reference their loads/speeds. Varget models out at 1800 barrel life max pressure, H4350 is 2,100...so you can see downloading either you will likely extentd life...ie, just use less powder or burn at cooler temps or combo of both.

If you can make downloading work, that's great. I've found it can bring some consistency and fouling issues. I was loading in the lower 50kPSI range and just couldn't get H4350 or Varget to live there without fouling related pressure changes. Throat growth was .060" in 1k rounds.

 

[Dead Eye Dick]

If you can make downloading work, that's great. I've found it can bring some consistency and fouling issues. I was loading in the lower 50kPSI range and just couldn't get H4350 or Varget to live there without fouling related pressure changes. Throat growth was .060" in 1k rounds.

That’s where Superformance comes in. Fired 2850+ rounds though my MPA barreled Curtis. shooting 130 Berger VLD’s at the very bottom of the loading chart. (6.5 CM to be specific). No fouling, single digit SD’s and accuracy that no other rifle I have ever owned shot more accurately. No fouling, nothing. I only pulled the barrel off because I was it had become my backup rifle and was tired of loading two separate groups of rounds for matches.

44 Grains Superformance, 130 grain Berger VLD’s, CCI BR4 primers Lapua SP brass. It shot tighter groups at 300 than just about everything else I owned shot at 100.

I too use Varget in my GT’s. But at my load density, I am getting good enough accuracy, good SD’s and no major pressure signs. But with the cost of Varget, and a good stock of Superformance on hand, I may go back and give it a try in the GT. Down to one 8 pound keg and at $450 for another, it’s getting serious.

 

[Cascade Hemi]

That’s where Superformance comes in. Fired 2850+ rounds though my MPA barreled Curtis. shooting 130 Berger VLD’s at the very bottom of the loading chart. (6.5 CM to be specific). No fouling, single digit SD’s and accuracy that no other rifle I have ever owned shot more accurately. No fouling, nothing. I only pulled the barrel off because I was it had become my backup rifle and was tired of loading two separate groups of rounds for matches.

44 Grains Superformance, 130 grain Berger VLD’s, CCI BR4 primers Lapua SP brass. It shot tighter groups at 300 than just about everything else I owned shot at 100.

I too use Varget in my GT’s. But at my load density, I am getting good enough accuracy, good SD’s and no major pressure signs. But with the cost of Varget, and a good stock of Superformance on hand, I may go back and give it a try in the GT. Down to one 8 pound keg and at $450 for another, it’s getting serious.

Respectfully, I can get all that if I don't light load the cartridge.

 

[Dead Eye Dick]

Respectfully, I can get all that if I don't light load the cartridge.

Of course you can , However, you missed the point. We were discussing making light loading work, not proving that high density loads can work. No one ever questioned that.

 

[Cascade Hemi]

Of course you can , However, you missed the point. We were discussing making light loading work, not proving that high density loads can work. No one ever questioned that.

I didn't miss your point. Reread your second sentence in post #65 then reread post #66.