- Thread starter Dthomas3523
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Not completely done with load development but it’s looking damn good. Just need to bump up the charge weight a tad more.
Impact 737
Proof 1-7 comp contour @ 26.75”
.185 freebore
Alpha OCD brass
H4350
CCI 450
115 DTACS
5 shot groups at 500yds with 35.8grs of 4350
BTO 1.9935
2778 fps avg
9 fps ES
SD 3.5
BTO 1.9835
2776 fps avg
26 fps ES
SD 8.9
BTO 1.9735
2774 fps avg
14.9 fps ES
SD 5.1
This combo trued out right at 2794 on my Kestrel. The .190 freebore though is looking really good with the DTACS out of my gun and my sons so far. Looking for a load that puts it in the 2800-2830fps range.
Top to bottom on the IPSC is 1.9935-1.9735 BTO.
Total round count on the barrel is 206
Impact 737
Proof 1-7 comp contour @ 26.75”
.185 freebore
Alpha OCD brass
H4350
CCI 450
115 DTACS
5 shot groups at 500yds with 35.8grs of 4350
BTO 1.9935
2778 fps avg
9 fps ES
SD 3.5
BTO 1.9835
2776 fps avg
26 fps ES
SD 8.9
BTO 1.9735
2774 fps avg
14.9 fps ES
SD 5.1
This combo trued out right at 2794 on my Kestrel. The .190 freebore though is looking really good with the DTACS out of my gun and my sons so far. Looking for a load that puts it in the 2800-2830fps range.
Top to bottom on the IPSC is 1.9935-1.9735 BTO.
Total round count on the barrel is 206
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I am doing a final test this weekend. 2 good charge weights. I will shoot 1k for water line, best verticle wins. OBT on upper load is 37.6. 36.4 is the other OBT, on the money. We will see. TL3 in JAE with ZCO and Xcaliber straight taper at 27" - .120 freebore and 1-7.5 twist. Alpha OCD brass and Fed 205m primers. I could see my heart beating in the scope when I shot the 37.5 group. It was getting warmer out and I am still not 100% post knee surgery. I think that load can shoot tighter. I was just not shooting my best. We shall see how this goes. These were 4 shot groups. Garmin Xero and labradar capture.
This will be the second year for me running the DTACS in a GT and so far I’ve been really impressed with them. To date I’ve shot my smallest 500 and 1000 yard groups with them. Last year I ran out of 109 ELDM’s halfway through the session and switched over to the DTACS. That barrel had a .120 freebore but was probably closer to a .150 from erosion when I made the switch. Even with the erosion I was below the neck shoulder junction and could only push them right at 2780 but it shot them lights out. That’s the reason this year we switched to the longer freebore.
This barrel is still fairly new. I shot 110Atips at 2890 (37.7 N555) and was impressed with how flat they shot. I only had a few hundred but looked at all the high BC bullets available. I like Sierras too so DTACs were easy choice. I like heavier bullets shooting long range varmint silhouette matches, easier to see impacts at distance. I am right at or slightly into neck shoulder junction but not past it at .045 jump. .040 shot well too but .045 was slightly tighter, shot them both 3 times before settling on .045. I will go to the longer throat next barrel.
So I've shot the 115 dtac out a few 169fb 6gt. One 26" the other pair at 28". Have a couple buddies running 26" too. The 26" barrels have all done really well around 2820-2840, my two 28" barrels have liked 2850-2870 range. Both achieved with 35.2-35.4gr H4350. Running 25-30k jump, anything deeper than 40k jump is going below the neck with bearing surface. I think I need to order a 190-200 freebore reamer.
I’m a fan of the heavier DTAC115s/MB112s running a slow-ish ~2800fps in the GT… it’s like a Dasher, just throwing a bigger “rock” (with a higher BC) downrange.
I’ve been running the standard .120” freebore though and it’s been kind of a PITA since I’d prefer to run a longer jump. I can’t wait to try a longer .190” freebore like some of y’all have been running… though, I ran a few hundred rounds with the bullets fairly deep into the cases (bearing surface below the neck/shoulder junction) and it shot great even though that’s supposedly “against the rules “ lol, so who knows…
I’ve been running the standard .120” freebore though and it’s been kind of a PITA since I’d prefer to run a longer jump. I can’t wait to try a longer .190” freebore like some of y’all have been running… though, I ran a few hundred rounds with the bullets fairly deep into the cases (bearing surface below the neck/shoulder junction) and it shot great even though that’s supposedly “against the rules “ lol, so who knows…
From what we’ve seen and tested so far I think a freebore of .185-.190 is going to be the perfect spot for the 115 DTACS. I tried a freebore of .215 but couldn’t get the velocities I wanted and the ES and SD’s were not that good. I think it was just too much freebore to get a good pressure curve.
Don't you think after 1k rounds you'll have eroded away to around 210+ freebore anyways? With your theory, at that point it's going to start shooting poorly due to the pressure curve changing? If you need more more psi curve without adding more velocity, go up an extra few thou neck tension, and add 0.1-0.2gr more powder and it should keep velocity same.
My second gt barrel had 80k of erosion from 200-2300 rounds when pulled, Bart ModBB steel, and I did nothing throughout it's life but add a lil more powder to always try keeping it at 2910-2930fps it shot well till the end.
We’ll find out later on this year. But starting out at .215 would have been to much especially after erosion. I know on my first barrel running 109 ELDM’s, once I had my seating depth I never changed it over the life of the barrel. Charge weight yes but not depth.
An observation on freebore and these heavies - in load development for my 6 GT I tried the 112 MB and 115 RDF, and noticed the 115 RDF requires a LOT more freebore than the 112 MB because of ogive geometry. The 112 MB has a much longer nose and shorter bearing surface, so I ended up with a lot longer OAL when loading out towards the lands with it.
I haven't tried the 115 DTAC yet, but going by pictures and some math with posted CBTO numbers vs throat length, it looks like it's more similar to the 115 RDF in that regard. Has anyone here compared the DTAC and RDF side by side, maybe taken some OAL and BTO measurements?
I haven't tried the 115 DTAC yet, but going by pictures and some math with posted CBTO numbers vs throat length, it looks like it's more similar to the 115 RDF in that regard. Has anyone here compared the DTAC and RDF side by side, maybe taken some OAL and BTO measurements?
Where are yall getting your Proof pre-fits for Impacts?
Altus
Recently got one from Walls Rifles. Loaded up some ammo to start load development, shot some old ammo to get a “zero” with the new setup. Fired this 6 round group.
Attachments
Just started load development with my 6GT. I wanted to narrow things down while I'm toying with virgin brass, and then finalize after my first firing.
27" Krieger, 1:8.
107gr SMK
Fed GM205MAR
Virgin Alpha
Varget
.030 off (1.945 CBTO)
Surprisingly, I was getting a wide ES (about 25-30) from 33.0 - 33.6gr. Once I filled the case up a bit more it came down. 33.6 - 33.8 knocked that in half with single digit SDs.
33.0 - 2,860 FPS
33.2 - 2,876 FPS
33.4 - 2,888 FPS
33.6 - 2,906 FPS (best accuracy, but need to tweak seating depth)
33.8 - 2,924 FPS
> 33.7 - Just shot to see what would happen if I cut 33.6 and 33.8 - is a winner, but need to tweak the depth a touch. This and 33.6 put (4) shots into the .2s, but kicked one out a half inch.
*******
I will probably see how H4350 does next.
27" Krieger, 1:8.
107gr SMK
Fed GM205MAR
Virgin Alpha
Varget
.030 off (1.945 CBTO)
Surprisingly, I was getting a wide ES (about 25-30) from 33.0 - 33.6gr. Once I filled the case up a bit more it came down. 33.6 - 33.8 knocked that in half with single digit SDs.
33.0 - 2,860 FPS
33.2 - 2,876 FPS
33.4 - 2,888 FPS
33.6 - 2,906 FPS (best accuracy, but need to tweak seating depth)
33.8 - 2,924 FPS
> 33.7 - Just shot to see what would happen if I cut 33.6 and 33.8 - is a winner, but need to tweak the depth a touch. This and 33.6 put (4) shots into the .2s, but kicked one out a half inch.
*******
I will probably see how H4350 does next.
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I called Proof this morning to ask what their FB is on their pre-fits. The guy told me .119" FB. Has this been a problem for anyone shooting 109/110 gr bullets? That seems really short. If its not an issue, I may give the Gay Tiger a try. Id like to go back to regular AI mags with no spacer kits.
I haven’t seen any issues with the .120” freebore in my Proof with any of the bullets I’ve tried (108, 109, and 115). I found a nice accuracy node jumping bullets at .040” with the 115 DTACs.
It is kind of short, I have to seat 112MBs .010" off or closer to keep that bullet's bearing surface above the neck/shoulder junction of Alpha Gay Tiger headstamp brass... but @ECK is right, it's not an issue. IME it hammers from 10 thou off to jumping 50 thou off (with the bullet set deeper in the case).
That said, I've been thinking of buying a hand-throating reamer to take the freebore out to ~.170" like the Alpha reamers', or even further... ideally I'd like to be able to shoot 109s/112MBs/115DTACs jumping 100 off, while still obeying the reloading "rules" that say no bearing surface below the junction... I'm not sure it'll matter, but I'd like to see what I get?
But... TBH, I've shot a shitload of rounds in both 6CM and 6GT with the bullet's bearing surface below the junction before I "knew any better"...15+ firings on the same brass in 6CM with no sign of any dreaded donuts... so who knows... some reloading lore is just BS that just keeps getting handed down by guys who've probably never burned out a single barrel, like "nodes" and shit, so it probably doesn't even matter lol...
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i have tested varget to 34.3 with 108s, settled at 34.
Yeah, there's more velocity on the table for sure, and I might go for it if I cant fine tune the seating depth to give me the results I want. There were zero pressure signs at 33.8.
2,900 was my "content with " velocity as long as I could get single digit SDs.
Mine shoots great from 33.8-34 of varget with 108’s and cci 450’s
It is stupid how far I have to pack up and drive to get to a range where I can bang on steel targets.
Stupid, I tell ya.
One of these days I'd love having a spot of my own.......drive a 4wheeler to the mailbox, shooting bench, deer stand, targets, etc. One of these days..........
In case you had any doubts, it’s absolutely wonderful. I drive my CanAm everywhere. From my living room, it’s less than 7 minutes to my (private) range where I can shoot 500yds one direction and 1100 yards the other direction. This is also the same spot I have my deer blind setup, so I can hunt both ways during season. I have a small flatbed trailer I shoot off of if it’s wet/muddy. I just built a PRS barricade from 3” rectangular tubing. Gonna concrete it in the ground Monday. I sometimes take for granted how lucky I am.
Forgive my ignorance.....green as hell, here.
By "good-good"....I assume you mean the Alpha OCD ?????
Or are you talking about the lower initial cost Hornady brass ???
I grabbed some Hornady cases while waiting on my action & barrel. Figured I'd have the brass prepped and ready to go, at least. Not sure how many firings to reasonably expect from it vs the Alpha OCD (which may prove more economical in the long run).
They also had the "gay tiger" head stamped brass. Hard passing on that stuff.
I grabbed some of the Hornady brass from the start as well, it is half the price! I also started with a 100 of the Alpha brass and I now have about 400 rounds through the GT and the alpha is superior to the hornady. I have used the hornady brass for barrel break in and sighting in with different scopes as well to keep the firings down on the Alpha. The hornady brass is not bad brass, the alpha is just better. Don’t worry about it to much, save your lunch money for the alpha. The GT has been a super accurate caliber for me, have fun with it and enjoy the journey to 2000 rounds.Forgive my ignorance.....green as hell, here.
By "good-good"....I assume you mean the Alpha OCD ?????
Or are you talking about the lower initial cost Hornady brass ???
I grabbed some Hornady cases while waiting on my action & barrel. Figured I'd have the brass prepped and ready to go, at least. Not sure how many firings to reasonably expect from it vs the Alpha OCD (which may prove more economical in the long run).
They also had the "gay tiger" head stamped brass. Hard passing on that stuff.
I have a box of 112 Match Burners to experiment with. Any suggestions using Varget or H4350? Thanks.
Try 32gn of Varget and see what MV it nets for you... safe, and you'll be right in the neighborhood of where you'll probably want to be. I'd guess 2800-2850fps in the summer...
The 112MBs are long, but the ogive isn't that far back, so .010" off in a SAAMI .120" freebore should have the bearing surface above the shoulder/neck junction (but IME they'll shoot with lots more jump if you're willing to seat them deeper into the case).
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I've found the 112mb to be a destructive killing bullet. I have a lighter build 24" barrel gt that I'm running them at 10k jump due to the 120fb chamber, 36.2 H4350 at 2910fps, shoots half moa or better for 5 shot groups at distance. Believe they seemed to like 70k jump in my first barrel 3 years back, but found the Barnes then to be extremely inconsistent bullet to bullet when the 112 first came out, they measure a lot better now.
@Trevor300wsm do you shoot Fouled Bore matches
I shot the match that Justin had there in January. I’ll probably shoot it again in March. I took a pretty long break (5yrs) from the PRS scene, but I’m gonna make a run at it again this year.
I loaded up 10 rounds of the 112 Matchburner over 36.3 grains H4350. The results were mediocre. I've had much better numbers with Varget.
Just ran 45 rounds thru my new gt.
24" ace barrel, 7tw
H4350
35.5/35.7/36/36.3
Shot this 10 shot (shots 16-25 on new barrel) group with 35.7 avg was 2780 I think. 115 dtacs 30 thou off. .170fb.
24" ace barrel, 7tw
H4350
35.5/35.7/36/36.3
Shot this 10 shot (shots 16-25 on new barrel) group with 35.7 avg was 2780 I think. 115 dtacs 30 thou off. .170fb.
That's pretty slow, you'll probably see better accuracy results up around 2810-2830 avg. What's ur barrel length? I have several 8# jugs of H4350 from different lots, and velocity varies quite a bit.
That's WAY slower than most of us seem to get with that load - I'm using that exact load in Hdy brass and see 2920 fps from my 26" barrel.
I don't know much about the Sig Cross though, other than handling one a bit - is that a factory barrel/chamber? If so that might be part of it. And what barrel length? If it's a short barrel like a lot of people seem to be using on the Cross, that'd be important context to give us here. If it's a short barrel you're not going to match the numbers most of us are getting, but ultimately H4350 will be able to push faster than Varget. If it's a looser factory chamber & throat, then you'll most likely need to bump the charge weights up a bit to end up at similar pressures to most of us with tight custom chambers.
I do hope you understand that if you're seeing higher velocity with Varget, then you're running it at higher pressure than H4350 with this bullet and cartridge combo. That's just how it works.
IDK guys, @CJC73 I don’t think that’s too slow for this time of year… some of the top PRS guys are running speeds in that neighborhood, 2700ish fps is the new “2800” for most of the Dasher guys lol.
I was going just over 2700fps the other day and printed a fist-sized 5-shot group at 1000 yards.
Speed has little to do with accuracy IMHO.
I was going just over 2700fps the other day and printed a fist-sized 5-shot group at 1000 yards.
Speed has little to do with accuracy IMHO.
Totally agree with this.
Guys that rifle @WyomingShooter has is built on a sig cross, they come with 18" barrels oem, and the new barrel is probably on the short end as well. So I'd expect low velocity.
As to @CJC73 rig, that's a new 24" barrel, I think the upper 2700fps with 115s is about where that barrel should be with his charge of H4350. I run 35.3gr H4350 in a 28" at 2850-2850fps, round count of around 1k.
As to @CJC73 rig, that's a new 24" barrel, I think the upper 2700fps with 115s is about where that barrel should be with his charge of H4350. I run 35.3gr H4350 in a 28" at 2850-2850fps, round count of around 1k.
I actually slowed my rounds down on purpose a little while back...
I dropped a whole grain and went from ~2900fps at 88F to ~2800fps at 81F... and the only thing that changed is: now I can tell you which way a plate rocked and whether I was high or low on it inside 600 (at ~2900fps I couldn't pick it up as well until out to ~750 yards).
This is me maintenance checking on my current load (33gn SWPR) at 2 different temps (81F and 48F), then trying 32.5gn before deciding on 33gn (mostly based on 33gn being easier to remember than a number with a decibel point lol), and then when I was running 34gn and getting ~2900fps.
26" Proof SS Origin prefit (SKU 133484).
You can probably tell that I don't believe in any of that "nodes"/"ladder test" stuff, I do it like NASA does it: more/less fuel = more/less speed.
I dropped a whole grain and went from ~2900fps at 88F to ~2800fps at 81F... and the only thing that changed is: now I can tell you which way a plate rocked and whether I was high or low on it inside 600 (at ~2900fps I couldn't pick it up as well until out to ~750 yards).
This is me maintenance checking on my current load (33gn SWPR) at 2 different temps (81F and 48F), then trying 32.5gn before deciding on 33gn (mostly based on 33gn being easier to remember than a number with a decibel point lol), and then when I was running 34gn and getting ~2900fps.
26" Proof SS Origin prefit (SKU 133484).
You can probably tell that I don't believe in any of that "nodes"/"ladder test" stuff, I do it like NASA does it: more/less fuel = more/less speed.
@CK1.0 Impressed with the low SD with swpr powder, rhat low of case fill at 2800fps. I plan to try dropping my 115dtac load down to low 2800s as well, but the 28" barrel isn't helping matters!
Yeah... that's something I can't quite explain... for now my theory is something along the lines of Varget (or Lovex SO62 aka SWPR in my case) being the magic-sauce some guys make it out to be lol. I hadn't used it before, I was only really familiar with H4350 or Sta-Ball 6.5 in 6CM, but It's the whole reason I went to the 6GT, to be able to use Varget/SWPR and see what all the fuss was about? I've seen consistently great SDs that are amazing sometimes and I don't know exactly why?
I've always noticed that all the smaller 6mms that most rifle-nerds associate with accuracy and good manners (6BR, BRA, BRX, Dasher) all use Varget in their bread-and-butter recipes... and after shooting SWPR for a while now (Varget was unattainable and SWPR is as similar as it gets) I do think there is something to it... IDK, I don't have the PhD in Combustion I'd probably need to explain it, but I also don't t believe in coincidence lol...
I'm not saying that using other powders or going for more of a traditional case-fill isn't a valid way to go, it is... I'd like to try H4350/RL16 at some point in the GT maybe, but man this SWPR shit is easy, and Varget is supposed to be even more temp stable and f'ing easier. I've heard/read guys say the same things about VV N140/150 (which I'd also like to try)... so maybe it's a burn-rate thing? IDK...
That said, and it's pretty important, every single round this barrel has ever been fed has been loaded after I got my Ingenuity Precision trickler... so every single round has been loaded to the kernel (+/- 0.02gn), none under or over, no cheating, ever, not a one, if I was loading 33gn I accepted 32.98gn or 33.00gn only (the IP trickler virtually never overthrows, maybe once in 100, by .02gn, makes it easy to be OCD lol)... that's a key data point lol!
Maybe it has nothing to do with kind/burn-rate of the powder?
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I load on a IP trickler and auto throw as well. Awaiting their new thrower setup to compete that system. I don't load to dead nuts, I typically go one kernal over or under so a +- 0.04gr range, I typically see es of mid teens maybe low 20s on a 10 shot string. I may have to source a jug of this and try it, along with varget in the gt. I run N150(closer to varget) in my woman's 6gt with 107smk and it shoots very well, but I've found that powder to not deliver great SD numbers in 3 or 4 different cases, however accuracy is good! Es in low to mid 20s is typical of a 10-20 shot sting.Yeah... that's something I can't quite explain... for now my theory is something along the lines of Varget (or Lovex "Varget" aka SWPR in my case) being the magic-sauce some guys make it out to be lol. It's the whole reason I went to the 6GT, to be able to use Varget/SWPR and see what all the fuss was about? I've seen consistently great SDs that are amazing sometimes and I don't know exactly why?
I've always noticed that all the smaller 6mms that most rifle-nerds associate with accuracy and good manners (6BR, BRA, BRX, Dasher) all use Varget in their bread-and-butter recipes... and after shooting SWPR for a while now (Varget was unattainable and SWPR is as similar as it gets) I do think there is something to it... IDK, I don't have the degree in combustion I'd probably need to explain it lol..?
I'm not saying that using other powders or going for more of a traditional case-fill isn't a valid way to go, it is... but man this SWPR shit is easy, and Varget is supposed to be even more temp stable and f'ing easier.
Also, and it's pretty important, every single round this gun has ever been fed has been loaded after I got my Ingenuity Precision trickler... so every single round has been loaded to the kernel (+/- 0.02gn), none under or over, no cheating, ever, not a one... that's a key data point lol! Maybe it has nothing to do with kind/burn-rate of the powder?
IDK, the jury is still out for me on a lot of this stuff.
I feel like there's a lot of legacy "reloading lore" to get past with this stuff that is actually/probably BS, and we all can only wade through so much of it with our limited funds and time...
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Thanks for the feedback. The barrel is 21.5" from Straight Jacket Armory. My sense is that Varget is the optimal powder for the 6GT. I'm not sure it's worth my while to use anything else.
I ran rl16 in my first barrel, and H4350 in the last 3. Very good results with 26-28" barrels and 109-115gr bullets. The lighter stuff with shorter bearing surfaces, maybe varget is the way to go. I've ran a lot of varget in two 6bra barrels and I found that 31gr load with 105s at 2850 built carbon rings faster than my 36.3-36.7gr H4350 gt loads. Varget has 15% high flame temp and burns a larger % of its charge in a shorter length distance than H4350. Sorry just nerding out over here........
Yeah... that's something I can't quite explain... for now my theory is something along the lines of Varget (or Lovex SO62 aka SWPR in my case) being the magic-sauce some guys make it out to be lol. I hadn't used it before, I was only really familiar with H4350 or Sta-Ball 6.5 in 6CM, but It's the whole reason I went to the 6GT, to be able to use Varget/SWPR and see what all the fuss was about? I've seen consistently great SDs that are amazing sometimes and I don't know exactly why?
I've always noticed that all the smaller 6mms that most rifle-nerds associate with accuracy and good manners (6BR, BRA, BRX, Dasher) all use Varget in their bread-and-butter recipes... and after shooting SWPR for a while now (Varget was unattainable and SWPR is as similar as it gets) I do think there is something to it... IDK, I don't have the PhD in Combustion I'd probably need to explain it, but I also don't t believe in coincidence lol...
I'm not saying that using other powders or going for more of a traditional case-fill isn't a valid way to go, it is... I'd like to try H4350/RL16 at some point in the GT maybe, but man this SWPR shit is easy, and Varget is supposed to be even more temp stable and f'ing easier. I've heard/read guys say the same things about VV N140/150 (which I'd also like to try)... so maybe it's a burn-rate thing? IDK...
That said, and it's pretty important, every single round this barrel has ever been fed has been loaded after I got my Ingenuity Precision trickler... so every single round has been loaded to the kernel (+/- 0.02gn), none under or over, no cheating, ever, not a one, if I was loading 33gn I accepted 32.98gn or 33.00gn only (the IP trickler virtually never overthrows, maybe once in 100, by .02gn, makes it easy to be OCD lol)... that's a key data point lol!
Maybe it has nothing to do with kind/burn-rate of the powder?
I was initially all in on H4350 due to speed and accuracy. I switched to Varget due to insane hard carbon fouling with H4350. It seems with Varget I can't get over 6 SD no matter how sloppy my reloads. There is something to the Varget claim.
