6gt
- Thread starter Dthomas3523
- Start date
Cloverleafs at .060". Both 105's and 109's from a .120 FB reamer.
0.080 I’ve found that anywhere from 0.060-0.100 all work well.
The beauty of the hybrids are they are incredibly jump tolerant.
From the 2 people I know that did they basically kept the same load as their 109 Hybrids and just played with seating depth. We’re within 10fps.
Have you tried SW4350 in any these cases? It seems a lil slower than H4350/RL16.
Just for future reference for others.
36.0g H4350
Berger 109 LRHT, .050" off the lands.
CCI 450
Alpha OCD twice fired, annealed.
26" Bartlein 1:7.5 rht, .120" freebore chamber
Yielded good results yesterday at Pawnee from 400 - 1000 yards.
Much thanks to those who advised where to start.
36.0g H4350
Berger 109 LRHT, .050" off the lands.
CCI 450
Alpha OCD twice fired, annealed.
26" Bartlein 1:7.5 rht, .120" freebore chamber
Yielded good results yesterday at Pawnee from 400 - 1000 yards.
Much thanks to those who advised where to start.
Finally got back out to test RL15.5 in this rifle. I used the profile built for another rifle, but it was off a bit. Then my labradar quit working. 4 years of abuse lol. I borrowed one from a friend and was able to get out today. Top row is 10th firing on OCD brass. Bottom row is 4th firing on OCD brass. (Annealed every firing) QL has max at 36.5 and barrel time was 34.6 and 34.7 for the 2 lots of OCD at 2952 and 2954 fps. This barrel is 1st of 6 we have for our match rigs. X-caliber 3R 7.7 twist straight taper with target crown, no muzzle threads. Shouldered on TL3 bedded in Manners TCS mini chassis with ZCO 5-27. Interesting results.
I've got a bunch of rl15.5 sourced.....does it burn on the dirty side like 16 does?
It is a little dirty, not as dirty as some of the N500 powders. Great powder for GT. Best out of all the powders I have tested so far.
Some velocity testing today with another one of my 6GT's.
@reubenski I think I've lost count of the total now
GAP PPR 6GT
107 SMK, 34.5 grains of H4350
New GAP/Hornady brass, old cci 400
Series,16, Shots:,10
Min,2689, Max,2718
Avg,2702 ,S-D, 9.4
ES , 29
Series,Shot,Speed
16, 1, 2713, ft/s
16, 2, 2697, ft/s
16, 3, 2705, ft/s
16, 4, 2706, ft/s
16, 5, 2718, ft/s
16, 6, 2691, ft/s
16, 7, 2689, ft/s
16, 8, 2696, ft/s
16, 9, 2701, ft/s
16,10, 2710, ft/s
----,----,----,----
@reubenski I think I've lost count of the total now
GAP PPR 6GT
107 SMK, 34.5 grains of H4350
New GAP/Hornady brass, old cci 400
Series,16, Shots:,10
Min,2689, Max,2718
Avg,2702 ,S-D, 9.4
ES , 29
Series,Shot,Speed
16, 1, 2713, ft/s
16, 2, 2697, ft/s
16, 3, 2705, ft/s
16, 4, 2706, ft/s
16, 5, 2718, ft/s
16, 6, 2691, ft/s
16, 7, 2689, ft/s
16, 8, 2696, ft/s
16, 9, 2701, ft/s
16,10, 2710, ft/s
----,----,----,----
Stick it back in the safe, pull another out to shoot
Nothing really, dunno if I'd even work up a load specific to this rifle.
Velocity's are fairly close between the GAP cut chambers, all Bartlein's of course.
Nothing really, dunno if I'd even work up a load specific to this rifle.
Velocity's are fairly close between the GAP cut chambers, all Bartlein's of course.
I havent tried that powder in the Dasher or GT.
I did some work up in the Dasher today with H4350. I thought it would work out with the heavy 95gr SMK. I found a pretty good load with it at 33.4grs @ 3060fps. It is full case fill at 35grs.
SW Precision pressured out way too quickly. That powder always seems to underperform compared to Varget in every caliber I've tried it.
But it's good to know I can run the 4350 in both. I would probably try the SW version if I ever found it on the shelf. But they haven't had any shipments come stateside in a pretty long time..
I've heard of people hitting pressure in Dasher before, but not GT. Know a few guys who run it as a substitute for Varget because that's all they could find and it seems to work well for them in the GT. I've got a bunch of it but haven't tried it in my GT. Still one of the few burning through circa 2004 Varget lot numbers.
Did you have good luck with the dtacs? I switched to 109 lrht but have been thinking about trying out some dtacs.
Ive read the only SW powder with similar temp stability as the Hodgdon equivalent was Precision being near same as Varget, the rest being noticeably more prone to temp related velocity swings. Have you found SW long rifle to be relatively temp stable?
I use SW Precision in a couple other cartridges and it's very temp stable.
I've heard of people hitting pressure in Dasher before, but not GT. Know a few guys who run it as a substitute for Varget because that's all they could find and it seems to work well for them in the GT. I've got a bunch of it but haven't tried it in my GT. Still one of the few burning through circa 2004 Varget lot numbers.
You can use it. I think it produces good loads. You just have to be willing to accept that it will be about 100fps slower than the same charge weight of Varget. And it seems to run into pressure when you try to increase the charge weight to compensate for the loss of velocity.
So its a slow Varget for these BR variants.
I do like the DTAC. Its the bullet I continue to use. I run it about 2850fps with an AB Lab confirmed BC of .306
They've performed very well for me over multiple lots. I've loaded up on them and CCI 450s for my GT. I'm just going to stick with them.
Well I definitely put Long Rifle to the test last year as I ran the same charge weight from spring, through the brutal heatwave we had here in the northwest from June through August, all the way to the Finale in New Mexico in November. Last year was very hard on that barrel. I shot three Pro Series matches in 100+ degree weather. The throat was gone on that barrel before I even made it to 2000 rounds. But I think the powder performed very well. I would buy it again. Its a great burn rate for the GT.
Another 6GT GAP in a Foundation Stock. First time out with it
Bore sighted, 5 Rounds into some shooter's leftover target still down range. Splatter target even, not good for acquiring a precise bull.
9 shots left to test Velocity....
GAP 737R Foundation 6MM GT
107 SMK, 34.5 grains of H4350
New GAP/Hornady brass, old cci 400
Series,18, Shots:,9
Min,2688, Max,2707
Avg,2695 ,S-D, 6.6
ES , 19
Series,Shot,Speed
18, 1, 2689, ft/s
18, 2, 2692, ft/s
18, 3, 2696, ft/s
18, 4, 2692, ft/s
18, 5, 2688, ft/s
18, 6, 2705, ft/s
18, 7, 2695, ft/s
18, 8, 2707, ft/s
18, 9, 2693, ft/s
----,----,----,----
Bore sighted, 5 Rounds into some shooter's leftover target still down range. Splatter target even, not good for acquiring a precise bull.
9 shots left to test Velocity....
GAP 737R Foundation 6MM GT
107 SMK, 34.5 grains of H4350
New GAP/Hornady brass, old cci 400
Series,18, Shots:,9
Min,2688, Max,2707
Avg,2695 ,S-D, 6.6
ES , 19
Series,Shot,Speed
18, 1, 2689, ft/s
18, 2, 2692, ft/s
18, 3, 2696, ft/s
18, 4, 2692, ft/s
18, 5, 2688, ft/s
18, 6, 2705, ft/s
18, 7, 2695, ft/s
18, 8, 2707, ft/s
18, 9, 2693, ft/s
----,----,----,----
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Thanks...
I love the old school wood look of the foundations.... this one with it's color really has that classic look to it.
N150 starting points with a 105 hybrid. Loaded up a small amount (5rds of ea powder charge) just to get some data as i have none to go off of. 1x fired Hornady brass and a CCI450. 26in bartlein barrel approx 450 rds on it.
32.0 grains = 2840 av fps 27 ES 10.7 SD
32.5 grains = 2870 av fps 19 ES 7.8 SD
33.0 grains = 2900 av fps 10ES 4.5 SD
The 32.0 test had 1 rd that was low (2818) velocity throwing the numbers off a bit but it had the highest es/sd. 33.0 had the best ES of 10 and SD of 4.5. Will update when i get to do some more testing.
32.0 grains = 2840 av fps 27 ES 10.7 SD
32.5 grains = 2870 av fps 19 ES 7.8 SD
33.0 grains = 2900 av fps 10ES 4.5 SD
The 32.0 test had 1 rd that was low (2818) velocity throwing the numbers off a bit but it had the highest es/sd. 33.0 had the best ES of 10 and SD of 4.5. Will update when i get to do some more testing.
Impact 737
Bartlein 1-7.5 MTU @ 26” Ace brake
Foundation Centurion
Triggertech Diamond
Berger 109 LRHT
Varget 32.6
Virgin Alpha brass
CCI 450
.070 jump
AVG: 2780 fps
ES: 12
SD: 4
5 at 150yds while doing setting depth test.
.394 ctc
Bartlein 1-7.5 MTU @ 26” Ace brake
Foundation Centurion
Triggertech Diamond
Berger 109 LRHT
Varget 32.6
Virgin Alpha brass
CCI 450
.070 jump
AVG: 2780 fps
ES: 12
SD: 4
5 at 150yds while doing setting depth test.
.394 ctc
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34.0 gr Varget, Berger 109 @3000 fps. No heavy bolt lift. Back off on charge or keep sending?
Thanks
Thanks
Cratered primers, ejector marks, and 3000fps....
Bro. Where the hell are you going so fast?
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What primers are you using? Just got a barrel and I have pretty much the same components you’ve listed and or pictured just curious as to the brand of primer.
Those primers are trying to tell you something. Actually, they’re screaming it. I’d imagine those primer pockets won’t last long.
But honestly, on paper, that load doesn’t seem overly hot. Especially considering the speed. What else is going on to make those primers crater like that? Can you try different brass? Maybe try another powder.
I'd come down in .1 or .2 grain increments depending on how much brass/powder/time you have and find out A) where that primer issue stops happening and B) where the upper node is and how big it is. For example, let's say the primers start looking good at 33.6 and the velocity is 2990 then you go 33.4 33.2 and they both shoot 2975 with idy bidy groups and the sd is 4-5 you then would know there is a nice velocity node there that's not on the edge of over pressure. I just had my 5th 6.5 SAUM barrel give me a reminder recently that every barrel is different and there are no shortcuts in this game. I was getting all excited at how good it was shooting and tried to rush the process only to have it speed up 100 fps on me at the 150 ish round mark and ended up having to pull about 200 loaded rounds. Bummer, dropped the charge back down in the manner I just suggested and it's hammering again tiny groups and low sd's. It was frustrating and time consuming but the finished product is worth it.
So every time you ad .3 grains of powder you get a 30fps increase? That’s handy I’ll remember that trick.
Except of course when you're in a velocity node when several tenths will make no difference at all which is what I was trying to get at in my last post.
34gr is a pretty standard load for 6GT. No use in doing a bunch of ladder work on a brand new barrel. Plus I had no pressure signs previously. This was the first time seeing something like this, about 300 rounds down the pipe. Obviously- im going to make a change.
would agree that in the neighborhood of 34 g is a standard load, with hornady brass. With Alpha you back off anywhere from .8 to 1.2 less powder. When a cci 450 craters into your firing pin hole thats not good. If it pierces your primer you will have damage to your bolt face and firing pin.
You got rekt. You're getting free advice from someone that could probably sell it to you. It would probably be best to thank him and tell him you're sorry for being an asshole.
You can continue to believe that velocity nodes don’t exist if you want. A guy came in the forum to pose a question and I offered help because I’ve been there. I know, what an asshole. Your buddy comes in and shits all over it, I pushed back a bit and he switched gears to wannabe cowboy psyche major. On one hand saying .1 grains = 10fps on the other saying .1 grains is to small of a change to matter. Totally rekt bruh. Sounds like the guy asking the question is gonna get it sorted out and all is well so that’s that.
My go-to load on this has been 34.1 grains of Varget and 105 hybrids at 0.065" off... CCI450s
Details:
Details:
Impact SA RH
Foundation stock
Bartlein M24 at 25" and 1-7.5 twist
230 rounds down the tube now - Alpha brass
Odd chargers from the data file below.... total of 10 shots...
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