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Range Report 6GT Project/Range Report
- Thread starter NorCal Vu
- Start date
This is a pic of the chamber with the first 30rds fired after a chamber cleaning. I don't see any major carbon issues and I'm pretty diligent on cleaning the carbon out of my chambers to avoid getting a carbon ring. Especially after a bad experience I had with a Creedmoor.
This is a pic of the rifling after 650 rounds on the barrel.
This is a pic of the rifling after 650 rounds on the barrel.
I don't have the reloading software or first hand knowledge to prove it , but I bet that has something to do with you higher velocities. In FL I may be 20-30 ft above sea level on a good day. I can still get 109s to 2950 on a 26" proof, but that's about max.
Interesting. The correlation in moisture content and powder being what? The humidity is very high here, but the powder is kept indoors where the AC regulates the RH to about 45-50% @ 74* at all times.
see thats what is crazy cause you're in WI, correct? im in MI and there are 5-6 of us that shoot with no issues and faster speeds. i think all of us over here have the first lot of hornady brass. 34.5 varget with A-tips gave me 2960. i'll have to go back and look at what the RL16 load i found was but it was running right at 3000 with no pressure issues. i stuck with varget cause it seemed to be more consistent.
Im in WI. I can get 2920 out A tips and 34.4 of Varget but I start getting heavy bolt lift and ejector swipe, especially if its warm out. It's enough that I dont want do a water test on it.
This is why I decided to go back to dasher. I couldn’t figure out what caused the indiscrimination. When I ran initial tests on alpha brass I had, I went to 36.0 without issue. Then not long after, on three barrels (clean), I had issues all the way down to 31.7 grains of varget.
This combined with many other I trust having similar issues (even with hornady brass at times), I couldn’t figure out what the common denominator was as it was all over the place. And, some guys are having really good luck with alpha and hornady.
So, I went back to a cartridge you don’t hear a lot of wild stuff happening randomly.
Yep. A proof stainless and two bartleins.
Ai, Lone Peak, and Terminus actions.
All had heavy bolt lift with virgin and fired brass. New and post 200 round count on barrels.
I know some are having good luck with gt. And I trust their numbers in the 3050 range. But I didn’t experience the same thing and couldn’t find exactly why not. And I haven’t had any similar negative experiences with any other round I load for except dasher using alpha.
I had my proof barrel fall out of a node around the 1200 round mark and start shooting poorly. Played with seating depth without any luck. Ended up droping the charge by .8 grains and found another node at a lower velocity. I shoot it around 2890-2900 with SDs below 6 generally.
I just shot a match with it and did pretty well with zero dope data on it. Made contact out to 1300 yards and placed in the top ten. I have one more match this month that I'm going to shoot with this barrel then Im going to switch over to a Bartlien 4 groove. If the Bartlien is as hard to tune and doesn't get the intended velocoties, I will be ditching the caliber and likely switching over to a dasher or BR for the ease of use.
I just shot a match with it and did pretty well with zero dope data on it. Made contact out to 1300 yards and placed in the top ten. I have one more match this month that I'm going to shoot with this barrel then Im going to switch over to a Bartlien 4 groove. If the Bartlien is as hard to tune and doesn't get the intended velocoties, I will be ditching the caliber and likely switching over to a dasher or BR for the ease of use.
1300 rounds later 105 Bergers, Hornady brass, CCI450, 34.0 gns Varget, started at 0.020” jump when barrel was new. Never chased lands. Kept recipe same throughout life. FPS stayed 3,000 fps to 3,010 Last 100 yd group still 0.29 moa 
i did shoot 200 of Clays Cartridge’s 6 GT ammo and speed was spot on out of my rifle at 3,020 ish as he advertises
Impact action
Stuteville 26” M24 barrel
Foundation stock
My experience w 6GT has been awesome
i did shoot 200 of Clays Cartridge’s 6 GT ammo and speed was spot on out of my rifle at 3,020 ish as he advertises
Impact action
Stuteville 26” M24 barrel
Foundation stock
My experience w 6GT has been awesome
After reading through this, seems the only common item is Varget and H4350. I could be way off base, but that's what I'm seeing.
I've had great success with RL16. Started with 109s and initial load was 3005 w/o any pressure. After a 2 day match and the expected
speed jump, velocity was 3085 with a slight bit of primer cratering and a smidge of ejector shine (new Hornady brass)
Have since moved to 105s at 2960 still using RL16. Have some N150 on the way to give a try.
I've had great success with RL16. Started with 109s and initial load was 3005 w/o any pressure. After a 2 day match and the expected
speed jump, velocity was 3085 with a slight bit of primer cratering and a smidge of ejector shine (new Hornady brass)
Have since moved to 105s at 2960 still using RL16. Have some N150 on the way to give a try.
Kind of what I thought. But, being as I've been having trouble finding H4350 and Varget in stock anywhere for the last several months, I decided to
find some other powders.
I'm getting 2950 out of mine w/ 110 A-tips & 36.9gr of H4350 in Hornady brass. 30" tube though.
I did get some weird pressure signs initially when shooting with Alpha brass and Shooters World Precision; velocities were well under 'max' levels. Unsure what that was all about, but it subsided.
I did get some weird pressure signs initially when shooting with Alpha brass and Shooters World Precision; velocities were well under 'max' levels. Unsure what that was all about, but it subsided.
This chamber is speced tight on the neck. Have any of you getting high pressure/low velocity neck turned your brass?
Yep. I turn necks to .006 clearance.
Regardless, .003 shouldn’t cause issues. It’s not that tight.
I turned my Alpha brass down to .012" thickness using a 21st century powered lathe; factory alpha was right around .014". I had heavy bolt lift issues within the first ~50 rounds, but it had nothing to do with the neck diameter or carbon ring. The pressure/bolt lift stuff only happened once on low charge weights of Shooters World Precision (low FPS over the LR too), and never came back after it was once fired. Action has a blade/mechanical ejector so it doesn't leave marks on the brass, and the primers looked fine; just a heavy bolt lift (Panda F-Class action).
Oddly enough, my completely untouched Hornady brass seems to shoot better than the Alpha stuff. Go figure.
My barrel was done off the standard .120fb reamer; not some custom tight-neck deal.
Oddly enough, my completely untouched Hornady brass seems to shoot better than the Alpha stuff. Go figure.
My barrel was done off the standard .120fb reamer; not some custom tight-neck deal.
I’ve had nothing but incredible results from my experience. Ordered an Impact/Bartlein barreled action from Impact to start the build. Did zero load development - threw 33 grains of Varget in virgin Hornady brass with Berger 109 Hybrids at .060 off. First target is rounds 21-25 of the barrel break in, the second target is rounds 196-199. Started with a velocity of 2767 and I’ve jumped to 2830 at the 199 mark. Zero pressure signs at all at any point yet. The only issues I’ve had is having the open up the front of the feed lips on Accurate-Mags to get reliable feeding. This was my first jump into the 6mm world and I’m thrilled so far.
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Here’s some interesting words of wisdom from Tate Streater on the 6GT speeds. The top guys are running them on the slow side in competitions. I hear Tate knows a thing or two about shooting LOL
I believe prior to switching to 6GT, Tate was running 6BRA. Probably won the championship in that caliber. Would be interesting to know the reason for his switch to GT even after a huge success with 6 BRA
Switched out my proof barrel for a Bartlien 4 groove and all I can say is WOW!. What a difference. Gun just seems to shoot whatever I put in it. Only have 30 rounds down the barrel now but the gun is grouping incredibly well, even while cleaning between rounds and just using a random mild load for break in. My proof barrel that I took off was quite picky and finicky, to be honest. Glad to get some confidence back.
I’d imagine 1: it’s 110 a-tips. Straight BR might get a little hot pushing them 2775-2800 unless a 28”+ barrel. And 2: he was running 6bra. So it’s just load and shoot a match or practice for Fireforming. Might as well have the option to run faster if you want when it’s that easy.
I’m personally running a dasher at 2800 or so. I have the option to go faster if I want, but I also have extra capacity so I know I’ll never be close to pressure at 2800-2850.
We put people on a pedestal and try to emulate them. Who knows? Maybe he just wanted to try something different like the rest of us. He probably still has the BRA and you may well find out he went back to it in a year.
Human nature. People are always looking for "the next best thing" or the "easy button/fix". People at the top of any game aren't immune to that, and in fact may even feel pressured and more inclined to act on that human trait in order to maintain or advance a competitive edge.
I was running a mild break in load for the first 100 rounds. New hornady brass, CCI 450, 34.5gr H4350, 109 berger .020" off. Velocity started at 2670 cleaning between each round, (which knocks some velocity off), but after 100 I'm right around 2745 with not much more gain after about 75 rounds. If I have time this week, I plan on running a ladder test. I'm thinking I'm going to end up somewhere arpund 2850-2900 aand not chase velocity. I have a match Saturday, and if I dont have time, I'm going to run my break in load. May be a little slow but shoots one hole groups at 100 yards with SDs below 5.
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That’s unfortunate I don’t do social media for professional reasons but I would have loved to see hunting load data for the 6GT. I don’t shoot PRS but I hunt and love working with wildcats and other special purpose cartridges. Anyone have data for good hunting loads in the 6GT?
Depends on what bullets your pushing. 34-34-5 varget has been good for many of the 6mm bullets from 105-110.
Im on that group, I haven't read any hunting load ups. Every gun is different, you still have to do the work.
So the backstory here for me is that I had a 22” 1:7 Bartlein 3B contoured barrel made for my Bighorn Origin action to run as a spot and stalk lightweight bolt gun that runs 6mm hunting bullets efficiently. 6GT really caught my eye based on what I’ve read and looking to push 95gr Berger Classic Hunters, 103gr ELD-X, and maybe some others too a little more efficiently than 243 Winchester.
You’re right I do have to do the work especially since my scenario is entirely different than PRS setups. I have a 22” 1:7 Bartlein 3B contoured barrel for a Bighorn Origin for a reasonably light hunting rifle that hopefully pushes hunting class 6mm billets more efficiently than 243 Winchester. So this will be interesting to say the least. I’d like to see if this cartridge is a viable hunting caliber.
Hey hope the match goes well... if you don’t mind referring where you got your barrel.
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I ordered the bartlien blank from altus and had a guy from my local gun club who is machinest chamber and thread the barrel. Did okay in the match today. Had a rough couple stages because apparently I knocked my zero out of whack by almost half a mil. Once I got it back, I was doing pretty well.
Some progress. Looks like 33.5 grains of Varget works well in yet another 6GT.
26" 7.5 twist Bartlein 5R HV
Tikka factory action and trigger
Area 419 Hellfire brake
All rounds fed easily from AICS mags
Bipod and rear bag on a bench
Little to no wind, ~95 degrees F, 70% relative humidity, near sea level
Loads tested with 105 RDFs
32-33.5 grains Varget
32-33 grains N140
34-35.5 grains N150
Loads tested with Barnes 112 MB
34-35.5 grains N150
36-36.5 grains H4350
No pressure signs on any of the loads.
All targets at 200 yards
1-2. 33.25 and 33.5 grains of Varget CCI 450
105 RDF 2.516/1.948 COAL/CBTO .020 off lands
1x fired Hornady brass, FL sized with .267 bushing*, bumped .0005 back, 1.718 trim
3. 35.0 grains of VV N150 CCI 450
105 RDF 2.513/1.945 COAL/CBTO .023 off lands
virgin Hornady brass, mandrel sized, 1.717 trim
4. 36.0 grains of H4350 CCI 450
112 Barnes MB 2.590/1.950 COAL/CBTO .024 off lands
1x fired Hornady brass, FL sized with .267 bushing*, bumped .0005 back, 1.718 trim
I'm betting this load will do better. The horizontal stringing is me having too much coffee on a too hot day.
*I had to use the .267 bushing because my .268 bushing is actually .269 and bullets did not have enough neck tension to stay in place. Whidden die and bushings. Kind of disappointing since the Whidden dies produced a batch of 50 with a maximum of ±.001 runout. Most were 0.
I'm going to work up more of the best loads for longer range, and chronograph testing . . . maybe. It was just too hot to f#(k around with it last week.
26" 7.5 twist Bartlein 5R HV
Tikka factory action and trigger
Area 419 Hellfire brake
All rounds fed easily from AICS mags
Bipod and rear bag on a bench
Little to no wind, ~95 degrees F, 70% relative humidity, near sea level
Loads tested with 105 RDFs
32-33.5 grains Varget
32-33 grains N140
34-35.5 grains N150
Loads tested with Barnes 112 MB
34-35.5 grains N150
36-36.5 grains H4350
No pressure signs on any of the loads.
All targets at 200 yards
1-2. 33.25 and 33.5 grains of Varget CCI 450
105 RDF 2.516/1.948 COAL/CBTO .020 off lands
1x fired Hornady brass, FL sized with .267 bushing*, bumped .0005 back, 1.718 trim
3. 35.0 grains of VV N150 CCI 450
105 RDF 2.513/1.945 COAL/CBTO .023 off lands
virgin Hornady brass, mandrel sized, 1.717 trim
4. 36.0 grains of H4350 CCI 450
112 Barnes MB 2.590/1.950 COAL/CBTO .024 off lands
1x fired Hornady brass, FL sized with .267 bushing*, bumped .0005 back, 1.718 trim
I'm betting this load will do better. The horizontal stringing is me having too much coffee on a too hot day.
*I had to use the .267 bushing because my .268 bushing is actually .269 and bullets did not have enough neck tension to stay in place. Whidden die and bushings. Kind of disappointing since the Whidden dies produced a batch of 50 with a maximum of ±.001 runout. Most were 0.
I'm going to work up more of the best loads for longer range, and chronograph testing . . . maybe. It was just too hot to f#(k around with it last week.
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I'm curious as to what your brass in the 35gr of N150 looked like, and what your speed was. Mine was 3056 at 34.3 of N150 and was way too hot, blowing a primer on one, and severe ejector marks on the other 4. That was with 105 hybrids at -.035
Brass and primers were fine (sorry, no pics). In my previous tests at those charges I DID get sticky lift and slightly burnished headstamps, but after checking my CBTO with an actual fired case, I found that those loads may have been right on the lands or even jamming a little.
I haven't chronographed anything, yet. Only 150 rounds though it, and I figure the speeds will pick up, so I've put it off. Plus, it has been just hot as balls and I'm old and lazy. I will try to check it next time out (which might be a while since work is picking back up).
For what it's worth, I used 1.5 MOA up for 200 and 3.75 MOA up for 300, which Strelok puts at ~2950 for the 105 RDF.
Thanks @Professor Oblivion . It's been hot a blazes here in the skinny part of VA as well. I'm off to the range shortly to check some
lower charges of N150.
lower charges of N150.
Yep. Eastern NC here. I don't compete, just a hobbyist, so my powder situation is not too dire, but I really want N150--and maybe N140, but it ain't lookin' good--to work, since Varget and H4350 are as scarce as unicorn farts.
Reloader 16 is another good powder if available.Yep. Eastern NC here. I don't compete, just a hobbyist, so my powder situation is not too dire, but I really want N150--and maybe N140, but it ain't lookin' good--to work, since Varget and H4350 are as scarce as unicorn farts.
Right! Forgot about that. Works about as well as H4350 in my .243 and 6.5CM, and seems to be somewhat available still. Will try to test next time out.
Not sure what BulletDrop you’re running but when I did the load work up for 110 A-tips it was somewhere in the 37-37.5 range of I recall correctly. Faster velocities than I got with varget before pressure issues but not quite as consistent as varget but if it’s available will probably be your best bet. When I first got my GT last fall and started tearing powders Varget was the best, followed by RL16 and then H4350. Of corse others may have different results but that’s just what I personally found.
Thanks man. Looking to get a new barrel in the pipeline and looking for options. Sucks on the match but you’ll get it back..
That's what I'm using now. I'll be sticking with that through this barrel. All of the current loads I've tried are all single digit ES.
Running 105 hybrids. After it finally sped up, 37.2 was 3085
, and no pressure signs with new Hornady brass. I'm going to back that off to around 2920 or so.
That’s pretty hot! I ran a similar MV, at 3030-3050, my Hornady brass got very lose primer pockets after 2x. Had to shitcan a bunch of it. Like you I made the decision to back down to that 2900 area.Running 105 hybrids. After it finally sped up, 37.2 was 3085
I ended up switching from Varget to 4350, 36gr is at 2920, alpha brass, CCI 400s, 109 Berger’s. Pulled a 3 SD.
Varget for me just ended up being too much pressure. I wanted to try Alpha brass so far so good, heard of the inconsistency that people had with Dasher at least. I’ll keep testing it but initially it shoots just fine and has tight primer pockets.
I didn't have any pressure signs at the 37.2 load (RL16). I just don't see any need to be running that fast. I should be able to shoot something in the low to mid 2900s in a monsoon without problem.
Nice
I have some r16 I want to mess with next month. Overall I’m happy with 6GT, 105s and 109s have been very easy to load for.
