This is what I do. just keep the bearing surface and neck shoulder junction close ish and run it.
6gt
- Thread starter Dthomas3523
- Start date
For PRS, no it doesnt matter as much....
It seems to be super dependent on a number of factors, including the throat profile, the rifling style, the bullet itself, etc (mostly the bullet design). When everyone was trying to run VLD style shapes, it mattered more - those bullet profiles seem to be really picky about it. For tangent and hybrid style designs, it matters much less, seemingly. Anecdotally, we've seen some combos locally where that doesn't seem to hold true - but even then, you have to change jump by large amounts (.030 intervals) to see the difference.
Big difference too between PRS and benchrest. Your discipline of choice will have a lot more to do with shooting skill than reloading intricacy.
I think the problem is guys make too many decisions based on what they get at 100 yards. I think sometimes guys are chasing ghosts and that's where the unnecessary hair-splitting begins.
I don't give a shit about groups at 100 yards, and personally think it's a poor metric to use when measuring what our rifles are capable of. I can shoot bugholes one day, and 3/4" of inch another depending on the million and a half variables in play, but in general, if I average ~.3"-.4" and can print 1/2" on demand I move on.
(Most of my shooting at 100 is in the interest of having a really solid zero on my gun.)
I agree with this all. That’s my thoughts also. Get a solid zero and take out to distance. Under half moa, I am happy.
A lot of people shoot 100yd for load development because it typically requires less components, not factoring in environmental variables as much. But anyone not doing load confirmation at distance after choosing their final load is just asking for unknowns when it counts, whatever your game of choice is...
I do all my load development and seating depth testing at 100 or 200yd then do load confirmation at 800 or 1000yd. If all goes well, I true my Kestrel at the longest distance then dial up some dope at 400, 600, 800 and makes sure everything is spot on.
For example, the above seating depth test I posted above... I tested that load at 800yd after settling on my seating depth test and it hammered. I then trued my kestrel at that 800yd and here is the very next shot dialing what the kestrel spit out for 400yd after truing.. Doesnt get much more dead on then that..
As long as you have a good system and its repeatable and know what your doing and why, then youll get the results you want.
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A lot of people shoot 100yd for load development because it typically requires less components, not factoring in environmental variables as much. But anyone not doing load confirmation at distance after choosing their final load is just asking for unknowns when it counts, whatever your game of choice is...
I do all my load development and seating depth testing at 100 or 200yd then do load confirmation at 800 or 1000yd. If all goes well, I true my Kestrel at the longest distance then dial up some dope at 400, 600, 800 and makes sure everything is spot on.
For example, the above seating depth test I posted above... I tested that load at 800yd after settling on my seating depth test and it hammered. I then trued my kestrel at that 800yd and here is the very next shot after truing.. Doesnt get much more dead on then that..
As long as you have a good system and its repeatable and know what your doing and why, then youll get the results you want.
I get it.
I guess my point is that sometimes guys go overly bananas with "load development" at 100 yards to the point where they're chasing their tales.
At my club at least, there are routinely a few guys who are on never-ending "load development quests", and I hear shit like "My load was shooting great the other day and today I can't beat a 1/2", so it's back to the drawing board" and then they'll say something about going up or down a couple of tenths of a grain in powder, or playing with their seating depth some more, etc, blah, blah, blah.
With me, if my gun was shooting good and printing my usual (~.3-.4", 1/2" on demand), and then the next range trip it's not... I'm just more the type that will look in the mirror instead of dicking around with my load. I'll maybe just throw on a ball cap (because maybe it's just the different lighting conditions?) or rebuild my position, or IDK, just try harder, and it usually fixes itself.
Like a lot of reloading stuff, I feel like there's a point where it can become a Rorschach test and guys will see what they want to see or keep unnecessarily dicking around with stuff until they think they are seeing what they want to see, when the truth is probably that most of the time the gun is working fine and it's the shooter that needs the adjusting lol.
IMHO, a plate at 500-600 yards on a calm day is way more useful for finding out if my load/gun is working good than 100 yards, as that close-in, it can be hard to determine anything concrete as to why a group is a .3" or a .5".
(I'm with you though lol) 1250 yards:
Doesn't that say 400?
It does, Im not sure what your getting at? Very next shot at 400yd after truing at 800yd... ??? I never said that was at 800yd... I said I confirmed my load at 800yd and trued my kestrel at 800yd then this was the very next shot after truing.. Confirming my load and my trued kestrel was dead on....
WHAT HE SAID ^^^^^^
Call me crazy, I get a 100 yard zero on a new barrel and do my best to never worry with 100 yards again for centerfire. I check hits on steel out to furthest distance the range offers, and then true the Kestrel and let it go.
Why would anyone, even when DT has just been elected president would anyone, ANYONE want to waste precious bullets, powder and primers on silly holes in paper.
When I do check grouping, I do at 300 yards. Rather have a one inch group at 300 yards (with the rounds hitting where I was aiming) than a thousand tiny groups spread all over the paper at 100 yards.
Because the way you wrote it - "I then trued my kestrel at that 800yd and here is the very next shot after truing.." implies that next shot was at 800... And I was just giving you some (intended to be good natured) crap about it....
Seating depth matters, these are 10 shot groups from a 22cm with 88eldm, rifle def prefers that 40-50k jump range. Round count was around 60 when I started on the new barrel. Now it's over 350 rounds, still shows major preference to 40-50k jump over anything closer to lands.
Reason for cut and placed targets, as I shot the last 3 groups next day, and I had the target put upside down. So I interpolated them over same poa is previous seating depths.
Reason for cut and placed targets, as I shot the last 3 groups next day, and I had the target put upside down. So I interpolated them over same poa is previous seating depths.
Shooting VLDs is really the only time I’ve ever really messed with seating depth and felt like I saw a real change.
For example, lots of guys seem to hate 108ELDMs because they’re long as hell and are VLDs, but I’ve shot thousands of them and think they’re just fine, just IME they kind of suck at the usual 0.020” off everyone always defaults to. From jam to ~0.010” off they seem to work ok, and IME they work even better at 0.060”-0.100” off jumping a bunch.
But interestingly, depending on one’s freebore, even with those, if I were to try them again I’d still probably do what I’ve been doing lately and load them as short as I can while keeping the bullet’s bearing surface above the neck/shoulder junction… as that'd put them close to jam in my SAAMI 6GT (IIRC .123” freebore) and would have them jumping a healthy amount in my SAAMI 6CM (IIRC .183” freebore).
26" Bartlein barrel, 1:7.5 twist
Berger 109 LRHT
Alpha Brass
Federal 205M
Varget 33.8gr, 2922.9 fps, SD 2.4, ES 6.1 @ 90*F, 2906.6 FPS @ 35*F (super temp stable)
0.20 off lands
0.2-0.4 MOA
This may be a little spicier than a lot of people are running for PRS these days, but this is by far the most consistent speed and precision in my specific rifle.
Berger 109 LRHT
Alpha Brass
Federal 205M
Varget 33.8gr, 2922.9 fps, SD 2.4, ES 6.1 @ 90*F, 2906.6 FPS @ 35*F (super temp stable)
0.20 off lands
0.2-0.4 MOA
This may be a little spicier than a lot of people are running for PRS these days, but this is by far the most consistent speed and precision in my specific rifle.
Look what showed up on Midway’s page! Yay…more options. Now, where’s that Lapua brass we’ve been waiting for?
No Lapua 6GT brass here (UK) yet. I'm expecting it sometime in Q1...
The .300WSM announced at the same has been shipping for a couple months too…what are those Finns up to?
Waiting on Lapua brass and then paying a premium for it when Aplha is just as good, cheaper and currently AVAILABLE!
Yep, I had pre-ordered a bunch of Lapua and then missed the boat on the Alpha stuff when it was available again… never again lol.
Can't be harder to get than Lapua as it is still not available, you could do 6.5x47 Lapua and then resize to GT as that is the parent case
Lapua as a brand is much easier to obtain. There hasn't been any 6.5x47 available for quite some time and it is a lot of work to make 6GT from it. Far easier to wait for the launch
With it being only 5 shot strings you can see if one round was way off from the others.
Either way I wouldn’t worry about it. If your velocity is that close you would have a great numbers.
With it being new brass there is no telling where that one piece was in the scope of things. I wouldn’t worry just continue to shoot your “break in” then do another load development after 200 rounds or so on the barrel.
Edit I can’t read lol. See you already have 400 rounds then I would just keep on loading and increase by little bits to gain a bit more velocity and see if the numbers get better.
Another edit. You typed there was a spread of 60FPS but your photos show they are almost identical.
Either way I wouldn’t worry about it. If your velocity is that close you would have a great numbers.
With it being new brass there is no telling where that one piece was in the scope of things. I wouldn’t worry just continue to shoot your “break in” then do another load development after 200 rounds or so on the barrel.
Edit I can’t read lol. See you already have 400 rounds then I would just keep on loading and increase by little bits to gain a bit more velocity and see if the numbers get better.
Another edit. You typed there was a spread of 60FPS but your photos show they are almost identical.
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I'm shooting a 26" proof prefit in my AI AT. Running Hornady 105s to bang steel. Touching lands, 34.2 gn of Varget with an average of 2,983. I think I'm seeing a little pressure sign (very slight ejector swipe) so I'm going to back off to 34gn even and see what that produces. Still under 100 rounds down the new tube and produced a .37" 5 shot group last outing. Looking forward to a full summer of shooting and see what this thing will do.
I doubt you'd lose any accuracy backing it down even more if you wanted to.
IMO/IME anywhere in the ~2800-2900fps range is kind of magical with the 6GT, without ever having to step on the brass, smoke the barrel too fast, or think about pressure issues.
I've been shooting only 33gn of Shooter's World Precision Rifle for 2000+ rounds now with 106s getting 2800fps, and it's a pussycat recoil-wise and still hammers out far and prints small groups in close with SDs in the 4-6 range over 20 shots. The only reason I'd dial up to 2850-2900fps is for more smack on plates with the 106 (and I might at some point), but it's been shooting so well "slow" that I just haven't fucked with it, and running it slower has probably made me better at picking up impact locations on closer steel inside 400-500 yards.
I switched up to the 109 this year rather than increasing speed for that same reason - carry just a little more ass to longer range targets….
Barrels matter. Shot 32.8 of varget with Alpha and Berger 109s most of last year. Had single SDs and right at 2835fps.
Switched to an ATX with a CRB. Same barrel length, 26". But after just 100 rounds I'm seeing 2890-2900.
I have found past 850 the GT with 109s struggles with consistency. Last weekend I watched it bounce all around a target at 1000. I'm going back to 6.5 creed for matches that go out past 900.
Switched to an ATX with a CRB. Same barrel length, 26". But after just 100 rounds I'm seeing 2890-2900.
I have found past 850 the GT with 109s struggles with consistency. Last weekend I watched it bounce all around a target at 1000. I'm going back to 6.5 creed for matches that go out past 900.
Yeah I’m in that range with 36.3g h4350 with my crb. Seems to be faster than some.
I haven’t found consistency to be an issue at all with 109’s. 1200 is where it started to get dicey but a full size plate isn’t hard to hit it’s the smaller 1moa ish targets.
You’re likely starting to go transonic about 1200, for whatever that’s worth. While truing the 109 out, I had a chance to run it out to a mile (cause why not). Interesting thing was, the next closest target was 1150y. Using the AB CDM, I was spot on to 1150. At a mile, the data was .8 low. I ran the same environmentals and rifle/load setup through a couple other solvers (4DOF, Eagle, Geo), and all of them were .7-.8 mils off (and basically the same at 1150 and in. But it hit consistently at a mile, while accounting for the shifty winds.
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Single digit SDs over 40 shots ain’t hard to live with lol.
I dig the DTACs having used them in 6CM, and I think it’s kind of strange that for heavier 6mm projectiles they’re really the only game in town besides the straight-up VLD-type Sierra and Nosler RDFs…
I’ve run a bunch of the heavyish 112 Match Burners in the 6GT and they were great (which are still more VLD than Tangent/hybrid like the DTAC), and I have kind of missed them compared to the 106 A-tips I’ve been running. I think I prefer what the heavier 6mm bullets do compared to what the 105/106 class bullets do.
115 DTACs should be even better.
I've been running dtacs in the 6gt for last few years when it's been shot in matches. 170fb, 35.2-35.6gr H4350 depending in the barrel, they've shot really well at 2820-2860fps. I think I'll be shooting my 25x47 this season once the weather warms up here in the north.
I personally think varget is on the fast side for 115s. It builds carbon quickly in my experience, as does N150, ts15.5,and RL16. H4350 has been the best performer for me to be able to run 400+ rounds without having to tune, clean or get funky velocity creep. If you want to us varget with the dtac, I'd start at 31.5 gr and work up to 33 max. The long bearing surface of the dtac creates a lot more resistance than the other heavy 6mms.
I honestly wish the 6x47 had caught on more. 0.300 long neck, holds a bit more powder than the GT, but this allows you to use a broad spectrum of powders. Pretty much varget through H1000. XC and 6creed have that ability as well, but the extra capacity isn't needed. If all you want is a ceiling of 2900 w/ dtacs on top end, 6gt is ur baby.
I had 6x47 years ago... technically I guess it was a 6-6.5x47L... shot great, never had a problem with that cartridge. I was watching one of the Hornady podcasts where they had George & Tom on talking about the 6GT; I think George mentioned that the 6x47L was sorta fussy to get to shoot. Not in my experience, but I'm guessing between him and his customers he saw a few more of those than I ever would.
I recently got back into a 6CM, loving it so far... but I'm keeping an eye on the 6GT thing as more brass becomes available.
For the money and ubiquity, 6CM does everything 6x47 and 6XC does but for less money. my 24" 6CM can push 115DTAC to 3200fps with RL26 or turned down to 2850fps with 4831SC. In the US, CM just makes more sense until you get to lower capacity cartridges like GT and smaller.
I have 3x 6cm tubes, all 18-22" hunting rigs, they shoot great, I use the case capacity advantage to keep mv above 2900 from the shorter barrel. They've been very lethal for me on deer/Antelope out to near 700y. I lovw the 6cm, just not for high volume match style shooting.
The 6-6.5x47 lapua was the correct way to run that cartridge, there were a lot of different reamers that used different body dimensions VS the 6.5 parent case, this is what made some them fussy from my research. 6xc had some this going on too, as the original 6xc was based upon 22-250 parent case and Norma 6xc, then the 6xc II came along with a larger base diameter I believe more along the lines of a creed. This was using Peterson and Alpha brass I believe. I could be mixed up, but I know there were new reamers for new brass.
Any of these 6mm cases from BR to creed are very easy to get shooting small groups with low recoil.
The 6-6.5x47 lapua was the correct way to run that cartridge, there were a lot of different reamers that used different body dimensions VS the 6.5 parent case, this is what made some them fussy from my research. 6xc had some this going on too, as the original 6xc was based upon 22-250 parent case and Norma 6xc, then the 6xc II came along with a larger base diameter I believe more along the lines of a creed. This was using Peterson and Alpha brass I believe. I could be mixed up, but I know there were new reamers for new brass.
Any of these 6mm cases from BR to creed are very easy to get shooting small groups with low recoil.
I’m chasing my tail with a shoulder bump issue trying to get consistency and can’t figure it out.
Using CoAx with RCBS match dies. I think my equipment is quality enough. It’s clean, concentric, no slop, etc. Witness marks on the FL die.
So instead of getting a .003 bump, I’ll get anywhere from that to .006 or 7. I’m annealing.
Could this be a function of hydraulic pressure from lube, Hornady brass, both or other? Different load pressures from testing which may fire form differently from case to case from some of the virgin firings? Hornady brass was all I could find.
The only variable I can think of is I didn't measure every piece of 1F brass with the comparator before sizing. If it's possible the first firing doesn't fully fireform due to some random lower charges from ladders, maybe it's giving me a false sense reading because the case never fully maxed out in the chamber? Meaning, it never grew to maximum length to be bumped .003. So in theory, I'm resizing the case, but it was never long enough to bump. Is this possible? I assumed a piece of brass regardless of a lower starting pressure in the gt would be soft enough to form maximum length in the chamber.
On another note. I spoke with Lapua and 6gt brass should drop next month.
Using CoAx with RCBS match dies. I think my equipment is quality enough. It’s clean, concentric, no slop, etc. Witness marks on the FL die.
So instead of getting a .003 bump, I’ll get anywhere from that to .006 or 7. I’m annealing.
Could this be a function of hydraulic pressure from lube, Hornady brass, both or other? Different load pressures from testing which may fire form differently from case to case from some of the virgin firings? Hornady brass was all I could find.
The only variable I can think of is I didn't measure every piece of 1F brass with the comparator before sizing. If it's possible the first firing doesn't fully fireform due to some random lower charges from ladders, maybe it's giving me a false sense reading because the case never fully maxed out in the chamber? Meaning, it never grew to maximum length to be bumped .003. So in theory, I'm resizing the case, but it was never long enough to bump. Is this possible? I assumed a piece of brass regardless of a lower starting pressure in the gt would be soft enough to form maximum length in the chamber.
On another note. I spoke with Lapua and 6gt brass should drop next month.
The lube you use, the amount and consistency of application play a large role in this in my experience.
**After re-reading your post**
If you are shooting new brass and at different charge weights you will see differences in the shoulder as pressure increases. In that case I would take measurements off the higher charge weights and because they were once fired, I'd bump those one to two thou and check them in the chamber. After you get a second firing on them check them again. Just be aware that if you are running a lower pressure load you may have to go through this cycle a few times. Another trick you can try is to intentionally not size one completely for shoulder bump and do a chamber check with that piece, if it doesn't fit, keep bumping it back tell it does while taking measurements. Once it chambers write that down and subtract your 3 or so thou from it.
**After re-reading your post**
If you are shooting new brass and at different charge weights you will see differences in the shoulder as pressure increases. In that case I would take measurements off the higher charge weights and because they were once fired, I'd bump those one to two thou and check them in the chamber. After you get a second firing on them check them again. Just be aware that if you are running a lower pressure load you may have to go through this cycle a few times. Another trick you can try is to intentionally not size one completely for shoulder bump and do a chamber check with that piece, if it doesn't fit, keep bumping it back tell it does while taking measurements. Once it chambers write that down and subtract your 3 or so thou from it.
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I experienced something similar with SAC dies loading in my MEC Marksman - but the fix there was to buy a set of Redding Competition Shell holders, and use one that left more headspace, and adjust it like that. I was getting a .012 bump with the die touching the shell holder but no cam over. After switching shell holders, I've got it dialed to a very consistent .003 bump.
That said - your thought of "the brass did stretch enough" - how long are your cases vs. your chamber? Is your starting base to shoulder measurement (before firing) really .006-.007 shorter than the chamber? If not, that theory doesn't make sense.
That said - your thought of "the brass did stretch enough" - how long are your cases vs. your chamber? Is your starting base to shoulder measurement (before firing) really .006-.007 shorter than the chamber? If not, that theory doesn't make sense.
