6gt

[diggler1833]

Well, piss.

27" Krieger, M24, 1:8
108gr ELD-M
Alpha brass
Fed 205MAR
H4350
1.962 CBTO / 2.524ish OAL

Decided to try H4350 and the 108gr ELD-M in this barrel. Made an arbitrary guess at .025 off as the ELDs always seem to shoot well somewhere between .020 - .040 for me. I went what I thought was "safe" on the charge weight range, and immediately exceeded my velocity goal of 2,925 - 2,950 on the very first weight (37.2).

Making matters worse, I managed to let a round slip low on that first group too . The comp trigger on my AT-X is just too low for my numb fingers.

37.4 and I got a bit of a sticky bolt lift, and 37.6 raised an ejector mark on the brass.. I called it good there.

I'll probably drop down to 37.0 and play with seating depth a touch.

Not what I wanted, but it is difficult to get too upset when I have yet to fire a group that exceeded MOA regardless of bullet and powder.

 

[diggler1833]

^Redemption...maybe.

Pulled my last two loads, dropped charges, and shot them. 37.0 looks promising, but one 5-shot group is a fluke. I was getting pretty excited though when the first three shots all went into the same exact hole..
I literally started scanning the target thinking I had wild fliers.

36.8 dropped one right that was unexplained, and the left flier was probably due to that bullet having a jacked up tip that I created when I pulled it (inertial). It had a pretty good lip put in it.

One group does not make a load, so I've loaded a few more at 37.0 H4350, and have played with seating depth on a few of them.

 

[drglock]

^Redemption...maybe.

Pulled my last two loads, dropped charges, and shot them. 37.0 looks promising, but one 5-shot group is a fluke. I was getting pretty excited though when the first three shots all went into the same exact hole..
I literally started scanning the target thinking I had wild fliers.

36.8 dropped one right that was unexplained, and the left flier was probably due to that bullet having a jacked up tip that I created when I pulled it (inertial). It had a pretty good lip put in it.

One group does not make a load, so I've loaded a few more at 37.0 H4350, and have played with seating depth on a few of them.

View attachment 8358281

I’m on my third barrel and in that time I’ve used 109 hybrids, 109 ELDMS , 115 DTACS, Varget. RL15.5 and H4350 and all those combos have shot exceptionally well in the 2775-2850fps range.

 

[John Glidewell]

Wife's GT just went over 2k rounds. Adjusted jump for erosion and added some powder. Still shooting great. 109 LRHT and RL 15.5. And this was her shooting. 12th firing on Alpha OCD brass.

 

[Jefe's Dope]

Wife's GT just went over 2k rounds. Adjusted jump for erosion and added some powder. Still shooting great. 109 LRHT and RL 15.5. And this was her shooting. 12th firing on Alpha OCD brass.

View attachment 8358390

How was it shooting before you made those changes?

 

[drglock]

Wife's GT just went over 2k rounds. Adjusted jump for erosion and added some powder. Still shooting great. 109 LRHT and RL 15.5. And this was her shooting. 12th firing on Alpha OCD brass.

View attachment 8358390

I still think RL15.5 is the perfect powder for the GT too bad you can’t hardly find it and the price being so high.

 

[WyomingShooter]

Wife's GT just went over 2k rounds. Adjusted jump for erosion and added some powder. Still shooting great. 109 LRHT and RL 15.5. And this was her shooting. 12th firing on Alpha OCD brass.

View attachment 8358390

Great stuff. Thanks! What's been your experience with the "TS" feature of RL 15.5? Here in the Big Empty, I can expect to shoot in temps from + 10F to + 85F. Thanks again.

 

[John Glidewell]

How was it shooting before you made those changes?

It was still shooting good, but velocity dropped 30 - 40 fps and it was grouping in the .4s.

 

[John Glidewell]

Great stuff. Thanks! What's been your experience with the "TS" feature of RL 15.5? Here in the Big Empty, I can expect to shoot in temps from + 10F to + 85F. Thanks again.

It has not been an issue. I have been very happy with the 15.5 so far. We have shot in the 30s to 90s without any issues, it is very consistent.

 

[4O6shootist]

I still think RL15.5 is the perfect powder for the GT too bad you can’t hardly find it and the price being so high.

Does it build mad carbon rings like rl16? I have a bunch of 15.5, just haven't tried it.

 

[John Glidewell]

Does it build mad carbon rings like rl16? I have a bunch of 15.5, just haven't tried it.

Not in our experience. I have run lots of both and only had issues when I did not clean regularly. We clean every 150 - 200 rounds now and have not seen any issues with carbon. I had a nasty carbon ring (many years ago) with 16 but it was because I did not clean for 800 rounds - ruined the barrel.

 

[Jefe's Dope]

Wife's GT just went over 2k rounds. Adjusted jump for erosion and added some powder. Still shooting great. 109 LRHT and RL 15.5. And this was her shooting. 12th firing on Alpha OCD brass.

View attachment 8358390

Also, how often are you annealing the Alpha brass and how are the primer pockets holding up? I'm on my 9th loading and while not dropping primers, they sure are easy to seat.

 

[John Glidewell]

Also, how often are you annealing the Alpha brass and how are the primer pockets holding up? I'm on my 9th loading and while not dropping primers, they sure are easy to seat.

Anneal every firing. Still cannot get the go gauge all the way in the pocket, only goes half way.

 

[diggler1833]

Not what I was hoping for. I did a small seating depth test with the 108gr ELD-M and H4350. Unfortunately I just didn't get the accuracy I was looking for. I have it with the 105gr Hybrids, but the 107gr SMK and 108gr ELD-M are a bit lacking.

I'm confident that I've exhausted reasonable attempts. Velocity, ES and SD are good, but I'm hunting for better accuracy.

No called fliers, those two that pushed way out on the first and last group were solid shots.

 

[4O6shootist]

Not what I was hoping for. I did a small seating depth test with the 108gr ELD-M and H4350. Unfortunately I just didn't get the accuracy I was looking for. I have it with the 105gr Hybrids, but the 107gr SMK and 108gr ELD-M are a bit lacking.

I'm confident that I've exhausted reasonable attempts. Velocity, ES and SD are good, but I'm hunting for better accuracy.

No called fliers, those two that pushed way out on the first and last group were solid shots.


View attachment 8359053

Never tried 108eld cuz their bc sucks, but I bet they shoot low to mid 2900s jumping 50k. 107smk do very well at same velocity jumping 40k with N150 in my woman's rifle.

 

[diggler1833]

Question:

I ran the factory Eagle Eye Ammo over my chronograph, and got 2,967 FPS with an ES of 12 and SD of 4 (105gr Hybrids, and it shoots well). Barrel is a 27" Krieger.

^ I pulled two rounds and weighed charges, and they were both only 33.5gr. I'm at 37.2gr of H4350 to get that same velocity. I was thinking before when I looked at the powder granules that it might be Reloader 16...but that seems like the charge weight and velocity don't match for RL-16. Anybody try N540 in their GT? What kind of weights to velocities were you getting?

My apologies for the newbie question. This is my first attempt in the 6GT. I'm a huge fan of the 6.5x47L, but I wanted to try something different.

 

[diggler1833]

Never tried 108eld cuz their bc sucks, but I bet they shoot low to mid 2900s jumping 50k. 107smk do very well at same velocity jumping 40k with N150 in my woman's rifle.

.040 off was actually where the 107s shot best in my rifle too. I just couldn't shake the 20% fliers that would open the group from a .3 to a .6...I'm probably just pushing them too hard. Usually a small seating depth change knocks that crap out, but it just made it worse in this case.

I had 200 of the 108gr ELD-M on hand to tinker with until I found some more Hybrids. I've found the Hybrids, so I'm abandoning this combo.

 

[drglock]

Does it build mad carbon rings like rl16? I have a bunch of 15.5, just haven't tried it.

No worse than any other powder but I also clean mine after ever match. So around every 120 rounds or so. I did feel like it was a tad dirtier than Varget.

 

[Jefe's Dope]

You guys clean your rifles?

 

[mdram]

Question:

I ran the factory Eagle Eye Ammo over my chronograph, and got 2,967 FPS with an ES of 12 and SD of 4 (105gr Hybrids, and it shoots well). Barrel is a 27" Krieger.

^ I pulled two rounds and weighed charges, and they were both only 33.5gr. I'm at 37.2gr of H4350 to get that same velocity. I was thinking before when I looked at the powder granules that it might be Reloader 16...but that seems like the charge weight and velocity don't match for RL-16. Anybody try N540 in their GT? What kind of weights to velocities were you getting?

My apologies for the newbie question. This is my first attempt in the 6GT. I'm a huge fan of the 6.5x47L, but I wanted to try something different.

maybe varget?

 

[LR1845]

Not what I was hoping for. I did a small seating depth test with the 108gr ELD-M and H4350. Unfortunately I just didn't get the accuracy I was looking for. I have it with the 105gr Hybrids, but the 107gr SMK and 108gr ELD-M are a bit lacking.

I'm confident that I've exhausted reasonable attempts. Velocity, ES and SD are good, but I'm hunting for better accuracy.

No called fliers, those two that pushed way out on the first and last group were solid shots.


View attachment 8359053

How much 4350 with the 107s and what was the farthest off the lands you tried?

 

[Jefe's Dope]

Wife's GT just went over 2k rounds. Adjusted jump for erosion and added some powder. Still shooting great. 109 LRHT and RL 15.5. And this was her shooting. 12th firing on Alpha OCD brass.

View attachment 8358390

Sorry to keep asking questions, but how much throat erosion did you measure?

 

[John Glidewell]

Sorry to keep asking questions, but how much throat erosion did you measure?

.012" @ 2k rounds

 

[diggler1833]

maybe varget?

That would be about where I was at velocity -wise with Varget, but the Eagle Eye kernels are black, and not that Varget-gray. I probably should have stated that.

 

[diggler1833]

How much 4350 with the 107s and what was the farthest off the lands you tried?

I used Varget with the 107s, and I'm left thinking that perhaps my barrel likes the slower burning powders. I went from 33.0 - 33.8, and the ES and SD were pretty crap until I got up to 33.6, where they dropped in half to about 15/7, and stayed there. H4350 gave me much tighter ES/SD across the entire range.

I ran the 107s from .010 - .050 off. Best accuracy was at .040. By .050 off I'm under 2.500 OAL, so I didn't continue with it. If they run better at .060+, I'll have to start over. I'm not opposed to that.

Will probably give H4350 and the 107s a try at some point.

I'm a component hoarder and I have a half dozen rifles that use similar components, so I'm literally sitting on a bunch of Varget, N150, RL-16, H4350, and 3-4 other less popular powders in that range. It's just a matter of tinkering around until I land on the right combo.

Any insight is appreciated.

 

[LR1845]

I used Varget with the 107s, and I'm left thinking that perhaps my barrel likes the slower burning powders. I went from 33.0 - 33.8, and the ES and SD were pretty crap until I got up to 33.6, where they dropped in half to about 15/7, and stayed there. H4350 gave me much tighter ES/SD across the entire range.

I ran the 107s from .010 - .050 off. Best accuracy was at .040. By .050 off I'm under 2.500 OAL, so I didn't continue with it. If they run better at .060+, I'll have to start over. I'm not opposed to that.

Will probably give H4350 and the 107s a try at some point.

I'm a component hoarder and I have a half dozen rifles that use similar components, so I'm literally sitting on a bunch of Varget, N150, RL-16, H4350, and 3-4 other less popular powders in that range. It's just a matter of tinkering around until I land on the right combo.

Any insight is appreciated.

Seating test with 107s 5 each at 100yds….steel 550yds 5 rounds
4350, alpha, CCI 450s, 27” barrel .180 freebore

 

[diggler1833]

Seating test with 107s 5 each at 100yds….steel 550yds 5 rounds
4350, alpha, CCI 450s, 27” barrel .180 freeboreView attachment 8359143View attachment 8359144

Crap, .080 off would be a short round for me.

I'm also running a .120 freebore.

 

[LR1845]

Crap, .080 off would be a short round for me.

I'm also running a .120 freebore.

I think a .180 freebore in the GT.

 

[4O6shootist]

I think a .180 freebore in the GT.

All mine are 0.170 cept the womans, and a barrel I bought second hand. I now have 6 on hand and have burned a few lol. I def prefer the long freebore.

 

[LR1845]

All mine are 0.170 cept the womans, and a barrel I bought second hand. I now have 6 on hand and have burned a few lol. I def prefer the long freebore.

Years ago I'd start close...like at or maybe .005 off then work back. When Mark Gordon did the seating testing in 2020 I think I had just replaced a 6BRA barrel and thought I'd try what he recommended. I started with a known load in my BRA and started seating at .050 off back to .080 off .010 at a time...I wish Ida kept the pics.....050 to .070 all shot 1 hole...not ragged but 1 hole... .080 started to open up but was a tight clover so I have been starting seating testing at .040 off every since and will work back to .080 and just about every time it ends up at .070-.080 I have never made .002-.005 jumps always .010 at a time.

 

[DeathBeforeDismount]

RIP Barrel #4. Bartlien M24 from Stuestville.

steady diet of 109 hybrids at 2840-2930 with 36.1 gr H4350.

Gave up the ghost in middle of match at around 2200.

Lesson Learned.

 

[LR1845]

RIP Barrel #4. Bartlien M24 from Stuestville.

steady diet of 109 hybrids at 2840-2930 with 36.1 gr H4350.

Gave up the ghost in middle of match at around 2200.

Lesson Learned.

What barrel length?

 

[DeathBeforeDismount]

26in

 

[DeathBeforeDismount]

So the new barrel has about .060 tho of jump from my current load of 6GT. I think it was around .030 on the last barrel. Shooting 109 hybrids.

Worth bumping the bullets out or just leave as it?

 

[LR1845]

So the new barrel has about .060 tho of jump from my current load of 6GT. I think it was around .030 on the last barrel. Shooting 109 hybrids.

Worth bumping the bullets out or just leave as it?

I would jump as far as you can without the bullet being in the neck/shoulder junction.

 

[4O6shootist]

So the new barrel has about .060 tho of jump from my current load of 6GT. I think it was around .030 on the last barrel. Shooting 109 hybrids.

Worth bumping the bullets out or just leave as it?

If it's shoots good at 60k, leave it. My second barrel was all 109s, started at 40k jump and by 2200-2400, when puller, it was jumping around 110k at the end, and still shot well. I did have to up a half grain of powder in its life span. So I had 70k of throat erosion in it's life. Which I feel is normal for a high rate of fire 6mm running mid-upper pressure.

 

[LR1845]

If it's shoots good at 60k, leave it. My second barrel was all 109s, started at 40k jump and by 2200-2400, when puller, it was jumping around 110k at the end, and still shot well. I did have to up a half grain of powder in its life span. So I had 70k of throat erosion in it's life. Which I feel is normal for a high rate of fire 6mm running mid-upper pressure.

This is exactly why I think big jumps are best.

 

[MilSpecOkie]

I think a .180 freebore in the GT.

AFAIK .120" is SAAMI and anything different is a custom reamer order.

 

[LR1845]

AFAIK .120" is SAAMI and anything different is a custom reamer order.

.120 is SAAMI but there is also a .170 reamer that’s popular my reamer will be a .274 neck and .180 freebore….if I shot 115s it would most likely be .200 I’d have to play around with the 115s to figure that out.

 

[mdram]

some depth resting. all 10rd groups
108bt over 34gr varget, 2950fps

 

[LR1845]

some depth resting. all 10rd groups
108bt over 34gr varget, 2950fps

Love the 108s…not the highest BC but they just shoot.

 

[WyomingShooter]

RL TS 15.5 shoots well in my rifle. This is from a 7.5 twist 22" barrel. Temp was + 24 F. Shot 3 was operator error. MV and SD are for 10 shots.

 

[4O6shootist]

RL TS 15.5 shoots well in my rifle. This is from a 7.5 twist 22" barrel. Temp was + 24 F. Shot 3 was operator error. MV and SD are for 10 shots.


View attachment 8363933

That'll kill medium sized game out to quite a ways! I'm sure the 109 expands like a 108! Good shooting!

 

[Jmccracken1214]

Got my criterion 26" mtu barrel on my 700 action today.

Local store only had 109 hybrids and 112 match burners.... The barnes were $100 less for 500, so I got them to try.

Going to load some from 33.8-34.8 of varget and shoot in the morning. I seated a test load at 2.6" and it chambered fine, so ill run with that for now.

 

[4O6shootist]

Got my criterion 26" mtu barrel on my 700 action today.

Local store only had 109 hybrids and 112 match burners.... The barnes were $100 less for 500, so I got them to try.

Going to load some from 33.8-34.8 of varget and shoot in the morning. I seated a test load at 2.6" and it chambered fine, so ill run with that for now.

Found them to shoot really well 10k jump in my 120k freebore barrel. In my last 170k freebore barrels, they run well back at 60-70k jump. 2900-2920fps is what they liked with H4350 in my testing.

 

[mdram]

i used on target tds to overlay som groups

 

[DubfromGA]

My CDG action is en route and 6GT PBB 26” MTU standard fb barrel has “entered production”.


The only bullet I have on hand is the 109gr ELD-M

Are there other bullets you’d recommend to have ready to try ?


Was thinking about grabbing some 105gr Hybrids.


Will be working within the col allowed by AIAW mags.

 

[mdram]

you wont have col issues, the gt is short.
i would go with what you can get for a bullet

 

[diggler1833]

My CDG action is en route and 6GT PBB 26” MTU standard fb barrel has “entered production”.


The only bullet I have on hand is the 109gr ELD-M

Are there other bullets you’d recommend to have ready to try ?


Was thinking about grabbing some 105gr Hybrids.


Will be working within the col allowed by AIAW mags.

Definitely won't have OAL issues.

105 Hybrid, 107 SMK, 108 ELD-M have all done pretty well so far in my .120 freebore chamber. I bet your 109 does well too, and you might want to give those a try before you start buying other components.

 

[Malum Prohibitum]

Anybody running Hornady 106?

Hornady 106gr A-tip factory seconds

I saw powder valley has 106gr tipped bullets on sale. Was told they are 106gr Atips and they're factory seconds because the firsts are for DOD 6 ARC contracts at the moment. Anyone tried these and have any results they could share?

www.snipershide.com