6gt

[Niles Coyote]

Stability Factor is one of those things that is misunderstood as it's not necessarily the hard rule it sounds like... it's not a black-or-white, stable vs unstable thing. Its usefulness depends on, and is subjective, depending on what distance one is shooting.

I've shot a lot of bullets that fall into the "marginally stable" range using Berger's twist rate stability calculator that positively hammer downrange.

Different bullets will stabilize at different distances, and some bullets stabilize faster than others, so just because a bullet may not fully stabilize by 100 yards doesn't mean it can't still hammer downrange (you just may or may not be able to squeak out the smallest groups inside the range when it does fully stabilize, which could be 120, 130, 200, etc). @John Glidewell describes it happening to him the other way, good groups but wonky vertical downrange, and while I've heard other guys talk about experiencing that, for me, having never really shot anything lighter than a 108 in 6mm, it's almost always been the opposite.

Longer VLDish and/or heavyish-for-caliber bullets like 115 DTACs, 110 A-Tips, and 112MBs are almost always going to come up slightly "marginally stable" with Berger's calculator, yet they are efficient and still shoot great, yielding .300+ G7s without having to push the speed limits.

If it makes one feel better, just don't use Berger's calculator, use this one where anything between 1.3 - 2.0 is considered good to go lol: https://www.jbmballistics.com/cgi-bin/jbmstab-5.1.cgi

After may years of running bullets in the 1.1-1.3 range in my 223 and 7mm factory barrels I can see why Brian Litz advises a 1.5 or higher. I struggled with a ever changing ballistic curve when running ballistic programs vs what I was seeing for actual drop at distance when my stability numbers were below a 1.5, I found they were highly dependent on atmospheric conditions. 1.5 or higher have not been a problem with getting predicted drop and actual drops to match up. So while the bullets may still group well with low numbers the BC will changing with temperatures and air pressures.

 

[4O6shootist]

Are there carbon wrapped barrels that do not do this?

I thought there was a reason why you do not see them at competitions.

My proofs have held pretty good groupings through 10 rounds, get em HOT and they'll drift. I've never had a barrel that walked cold, and settled in once hot.

 

[CK1.0]

After may years of running bullets in the 1.1-1.3 range in my 223 and 7mm factory barrels I can see why Brian Litz advises a 1.5 or higher. I struggled with a ever changing ballistic curve when running ballistic programs vs what I was seeing for actual drop at distance when my stability numbers were below a 1.5, I found they were highly dependent on atmospheric conditions. 1.5 or higher have not been a problem with getting predicted drop and actual drops to match up. So while the bullets may still group well with low numbers the BC will changing with temperatures and air pressures.

I hear you, and know that scenario exists, where some guys have experienced their dope going to shit under varying conditions while their 100 yard groups still look good.

But, in certain cases, IME, a stability factor that dips into the 1.4s isn't necessarily the end of the world. Chad Heckler and Francais Colon talked about it a couple of times in their Miles to Matches podcast a while back...

It seems to be mostly about yaw. Some bullets come out of the barrel as stable as they'll ever be, and then start to yaw later down the road (the classic good groups, but shit vertical downrange), while other bullets can yaw earlier in their flight and take a bit to settle down, and when they do they sail along just fine... this is my experience with a lot of the 110-115gn 6mm bullets that hammer a distance but stubbornly always seem to hover around 1/2" at 100 unless I'm luckier than usual.

Then there are the bullets that yaw right out of the barrel and never settle down... I think that's the real boogeyman that probably shows up once you get into a SF in the 1.3s (luckily I've never tried/experienced this)...

 

[briang7511]

Having an issue with flow around the primer with hornady brass. Row of brass on left. Not sure what causes it or what to do to prevent this. Any insight would be helpful. Current load is 32.6 of N150 and cci450 runs 2890fps.

 

[4O6shootist]

@briang7511 what action?

 

[briang7511]

@briang7511 what action?

Defiance deviant action, bartlein barrel 7.5tw

 

[CK1.0]

Having an issue with flow around the primer with hornady brass. Row of brass on left. Not sure what causes it or what to do to prevent this. Any insight would be helpful. Current load is 32.6 of N150 and cci450 runs 2890fps.


View attachment 8229219

View attachment 8229221

View attachment 8229222

Your load seems pretty safe/typical, but I've never experienced flow around the primer... what is the issue you're experiencing (besides funny-looking brass lol)?

Are you getting gas/smoke in the face, accuracy problems, or does the recoil feel differently or something?

 

[briang7511]

Your load seems pretty safe/typical, but I've never experienced flow around the primer... what is the issue you're experiencing (besides funny-looking brass lol)?

Are you getting gas/smoke in the face, accuracy problems, or does the recoil feel differently or something?

velocity E/S has opened up. seeing a 30 fps variation. not sure if that is related to this but possible.

 

[MilSpecOkie]

What do you mean by primer flow. The primers look normal to me. It does look like your pockets may be loose and you are leaking gas between the primer and primer pocket. How many firings on the brass?

 

[briang7511]

What do you mean by primer flow. The primes look normal to me. It does look like your pockets may be loose and you are leaking gas between the primer and primer pocket. How many firings on the brass?

There is some black residue around the primer pocket after firing. approx 25% of my brass has this. the rest does not. pictured brass is after 2nd firing.

 

[MilSpecOkie]

There is some black residue around the primer pocket after firing. approx 25% of my brass has this. the rest does not. pictured brass is after 2nd firing.

Have you done anything to the primer pockets? Ran a hotter load before this?

 

[briang7511]

Have you done anything to the primer pockets? Ran a hotter load before this?

no prep/uniforming. only tumble in walnut media. same load. all the brass in the last lot of 500 has had this issue for a while. i dont remember seeing this in the last lot.

 

[357Max]

no prep/uniforming. only tumble in walnut media. same load. all the brass in the last lot of 500 has had this issue for a while. i dont remember seeing this in the last lot.

Pop some of the primers out that did this and look carefully around the perimeter under magnification.

I remember Winchester SRP having an issue with pin holes & results were sim to what you have. Never heard of it with cci 450 though.

 

[CK1.0]

velocity E/S has opened up. seeing a 30 fps variation. not sure if that is related to this but possible.

Hmm... I'd look for a simple explanation first, and work back from there, it might be your barrel and not your load (especially if your velocity is getting wonky).

Any chance you're seating them long enough where they're jammed or too close to the lands (maybe causing an intermittent pressure spike), or have you checked for a carbon ring that might need some attention? Does a borescope show anything strange going on in there?

 

[briang7511]

will have to find a bore scope, but i do clean after every outing with bore tech carbon remover. my jump started at .067 from the first round and have not checked it since. i am goint to inspect those 20 pieces and report back. i use the same primers in lapua 6.5cm brass and they seat more firmly.

 

[4O6shootist]

will have to find a bore scope, but i do clean after every outing with bore tech carbon remover. my jump started at .067 from the first round and have not checked it since. i am goint to inspect those 20 pieces and report back. i use the same primers in lapua 6.5cm brass and they seat more firmly.

I've got some my original batch of 500 ocd cases from 21 that are on their 4th barrel. 12-14 firings? Ran around 2850-2920 depends on bullet, with H4350 and 450s. Still good on pockets, don't feel like virgin, but still snug. I'd measure your firing pin diameter, VS the diameter of hole in the bolt. Low psi loads won't show flow, but medium and high will if the clearance is too sloppy in the clearance of this twos fit. I get primer flow/dimpling on zermatt actions on medium to higher psi laods but still have round edges on the primer.

Hornady brass(used this before Alpha ocd) has soft pockets and will only last 4-5 reloads at 2900+ with 109-115gr in 26" barrels. Cleaning pockets with certain tooling like the RCBS stiff steel pocket brushes can enlarge and loosen them even faster.

 

[CK1.0]

will have to find a bore scope, but i do clean after every outing with bore tech carbon remover. my jump started at .067 from the first round and have not checked it since. i am goint to inspect those 20 pieces and report back. i use the same primers in lapua 6.5cm brass and they seat more firmly.

If you started jumping 67 thou, it's not that.

Yes, Hornady brass is shittier than Alpha, and it might be as simple as some of those cases starting to quit after only 2 firings...

...but IDK, I cleaned my barrels for a long time using only Boretech Eliminator... up until I got a borescope and was surprised to learn it wasn't really doing shit besides turning some patches blue while I conducted my very poor (unbeknownst to me) cleaning ritual/routine.

If you haven't looked, I'd assume there's a ring or at least the start of one until you know...

I suppose looking at the firing pin thing is worth a try as well, I'd just rule out the barrel first.

 

[Malum Prohibitum]

I’m using the SAC die with .267 bushing for 6GT & .247 for 22GT.

Modular Sizing Die – GT

GT dies with .20 Caliber Bushings will not come with a decapping pin. If using an existing GT die, please reach out to us so we can send you a plug for your die to function properly [email protected]

shortactioncustoms.com

357Max, how did you decide on the .267 bushing, and what brass are you using?

 

[357Max]

357Max, how did you decide on the .267 bushing, and what brass are you using?

I started with a whidden FL non bushing die that sized the neck down to .263 (expander ball removed). Made great ammo, but I just wanted to work the necks a little less.

Hornady brass so far & loaded necks measure .272

.267 + a little spring back = .2675 - .268. I use a 21st Century expander die + .2415 or .242 mandrel to finish.

Right or wrong my logic is that I want the expander mandrel to open it up .0015 - .002 to set final neck dimension. No less than .001 as I want the inside of the neck truly round. Working well for me.

I have some new Alpha ocd brass, but haven't loaded any yet.

 

[Malum Prohibitum]

@357Max, I have Alpha brass, new. The only rounds I have shot in this rifle are the Hornady Match factory ammo (which I stopped using after pierced primers broke my trigger) and a friend's handloads with better primers than Hornady is using.

So I do not have any Alpha brass loaded rounds to measure the neck.

357Max, do you have any suggestions for how I should go about selecting the correct bushing size from SAC?

Initially, as I was researching, I liked the idea of an expander die and mandrel, but I read so many opinions against it here on this site. I don't really know what to do, and, since I am just starting out, I wanted to keep it simple. So I figured I would not use an expander mandrel for now and maybe experiment with it later to see if it makes my groups better.

I have new brass (Alpha). I was going to just primer, chamfer the case with a VLD type chamfer tool in a drill, dump powder in the case, and seat the bullet to start out. So I guess I do not need to resize new brass, right? But when it comes to the second loading, I wanted to use the same SAC sizing die you are using. I had not ordered yet because when I went to order I saw it comes with only one bushing, and I had no idea what size to select.

Any advice you could provide, dumbed down for me, would be very appreciated.

I will be loading either Berger 109LRHT or Sierra 107 SMK (I have both, so probably the Sierras to start out). Varget. CCI 450. If you need to know anything else to answer my question, just ask. Thanks for taking the time to review my overly long post.

 

[briang7511]

update. got out to shoot today after a very thorough cleaning. appears i had some carbon build up. Es has come back down to normal levels. velocity has dropped off, about 50 fps. should have a few more matches in it.

 

[96C]

Keen to hear from your experience - With 110gr ATIP', what seating depth did you find worked best?

 

[RS14]

So not reloading related. But it is 6gt specific.

Mags question. Who’s had the best luck with what mags?

Ive ran the AW mags in my AI and Rukus. But trying another action that doesn’t work with AW mags. So what’s everyone having the best luck with?

 

[4O6shootist]

So not reloading related. But it is 6gt specific.

Mags question. Who’s had the best luck with what mags?

Ive ran the AW mags in my AI and Rukus. But trying another action that doesn’t work with AW mags. So what’s everyone having the best luck with?

I run the recently discontinued ARC aics mags with mkm followers, never had a hiccup, but I try to keep them clean and out of the shit at dirty matches.

 

[Shiftyk5]

So not reloading related. But it is 6gt specific.

Mags question. Who’s had the best luck with what mags?

Ive ran the AW mags in my AI and Rukus. But trying another action that doesn’t work with AW mags. So what’s everyone having the best luck with?

I’ve been using the magpul aics 10rd mags with no issues so far.
Origin action with KRG bravo and MDT XRS

 

[Malum Prohibitum]

So not reloading related. But it is 6gt specific.

Mags question. Who’s had the best luck with what mags?

Ive ran the AW mags in my AI and Rukus. But trying another action that doesn’t work with AW mags. So what’s everyone having the best luck with?

MDT is bringing out any day now ribbed (5 ribs), metal 12 round magazines that are rumored to function flawlessly in 6GT.

Accurate mags are right now the best answer. https://www.shortactionprecision.co...roducts/accurate-mag-308-10-round-regular-mag

I had decent luck with the ARC mags, until I started trying to modify them to hold more than 10 rounds.

 

[4O6shootist]

MDT is bringing out any day now ribbed (5 ribs), metal 12 round magazines that are rumored to function flawlessly in 6GT.

Accurate mags are right now the best answer.

I had decent luck with the ARC mags, until I started trying to modify them to hold more than 10 rounds.

That's quite odd on the arc. I have 2 at 10 rounds, 2 with Altus +2 extensions, and one with a419 +4 extension. No issues, other than the spring pressure is very low on the 14rd mag on last round, occasionally passes over last round. I do run mkm followers tho. I stretch the springs always when adding a mag extension.

 

[Malum Prohibitum]

Same one I used. I stretched the spring. I also did not get anywhere near +4 out of it.

Maybe I did something wrong.

I have not tried the Mk Machining follower.

I did try LRI's expensive billet follower, which from what I can tell made the situation worse.

I cannot put 14 rounds in. It is more like 11 or 12, and the last one or two nose dive and cannot be loaded.

 

[Malum Prohibitum]

So not reloading related. But it is 6gt specific.

Mags question. Who’s had the best luck with what mags?

Ive ran the AW mags in my AI and Rukus. But trying another action that doesn’t work with AW mags. So what’s everyone having the best luck with?

RS14, check out this thread.

6GT Mag Suggestions

I am currently running 6GT with a Bighorn Origin in an ACC chassis and since day one having issues with mags. i have tried 2 x 10rnd 308 mdt poly mags and 1 x 10rnd 308 metal mag. I always had to advance every round in the poly mag and the metal mag was not 100% reliable but for the most part...

www.snipershide.com

 

[Dead Eye Dick]

My son put me on the MDT Poly.metal 10 round mags. I tried them and they ran flawlessly, loading ten rounds and every round fed perfect from round 1 to round ten. He has same results. He runs them in his Bighorn action and I ran them in my Curtis action.

Currently on back order of course. So, what else is new?

 

[MilSpecOkie]

If you don’t mind a little longer single stack single feed magazine the Magpuls AICS version works great. I’ve used them to feed everything from 6 BR to 6.5 Creedmoor without any problems. Whenever someone is having problems with their magazine at a match I hand them a Magpul to finish the match. They have ran in everything so far.

 

[drglock]

So not reloading related. But it is 6gt specific.

Mags question. Who’s had the best luck with what mags?

Ive ran the AW mags in my AI and Rukus. But trying another action that doesn’t work with AW mags. So what’s everyone having the best luck with?

I’ve shot 11 matches so far since getting my GT using AICS mags. One 10 rounder , one with atlas +2 and one with Area 419 +4 extension. I’ve had zero issues in matches or at the range with them. I did tune the feed lips on all three mags but just for smoother feeding. P-Mags seem to work well as long as you don’t get the mag hard into your bag or cram the bottom of the mag into a prop. I tried AW mags but couldn’t get them to work with my setup. I also tried MDT mags and they were so bad I sold them the next day.
Impact action in a Foundation stock with Hawkins DBM.

 

[Jakeweb09]

Shot my gt at 510 today. 5-7 mph crosswinds. 5 rounds. Woulda been pretty good had the one not came out of the group! But still pretty happy. Load info
Alpha brass
37.2g 4350
Cci450
Berger 108 bt.

 

[Bolt Thrower]

Tried out some RL 15.5:

26" Bartlein M24, 1:7.5" twist @ 1,933 rounds:
Berger 105 gr Hybrid
CCI 450
Alpha non-OCD Brass (6x fired)
+/-0.050" jump

33.0 gr Reloder TS 15.5
Ave MV: 2,758
ES: 6
SD: 2.4

33.5 gr Reloder TS 15.5
Ave MV: 2,798
ES: 9
SD: 6.6

34.0 gr Reloder TS 15.5
Ave MV: 2,835
ES: 11
SD: 4.6

*SD/ES is likely a direct result of barrel heat. Shot quickly with no cool down.

 

[Gray shooter]

Tried out some RL 15.5:

26" Bartlein M24, 1:7.5" twist @ 1,933 rounds:
Berger 105 gr Hybrid
CCI 450
Alpha non-OCD Brass (6x fired)
+/-0.050" jump

33.0 gr Reloder TS 15.5
Ave MV: 2758
ES: 6
SD: 2.4

33.5 gr Reloder TS 15.5
Ave MV:
ES: 9
SD: 6.6

34.0 gr Reloder TS 15.5
Ave MV:
ES: 11
SD: 4.6

*SD/ES is likely a direct result of barrel heat. Shot quickly with no cool down.

Was you able to get a MV for the top powder charge? How were the groups?

 

[Bolt Thrower]

Was you able to get a MV for the top powder charge? How were the groups?

I am an idiot. Yes, post edited. 34.0 gr was 2,835 FPS. No pressure signs.

 

[Josebd]

Cci br-4 primers and hornady brass powder charge was 34.0 grains

what powder?

 

[John Glidewell]

RL 15.5. in his orig post

 

[ECK]

I’m at 1,400 rounds and change on this barrel. My original load work-up averaged 2,845 fps. Accuracy is still pretty good. Was wacking clay pigeons today @ 550 yds. I think the barrel still has some life left on it.

115 gr DTACs and H4350, .040” jump.

 

[drglock]

I’m at 1,400 rounds and change on this barrel. My original load work-up averaged 2,845 fps. Accuracy is still pretty good. Was wacking clay pigeons today @ 550 yds. I think the barrel still has some life left on it.

115 gr DTACs and H4350, .040” jump.

View attachment 8261647

Mines got a tad over 1900rds with DTACS and 4350 but I’m running mine at 2770fps. Since I only shoot one day matches I’m gonna see how far it’ll make it.

 

[CK1.0]

I'm at 1850rds through my first 6GT barrel and it's still shooting great. I've already got another barrel, but I'm going to try and hold off on pulling my first one as long as I can as I'm curious how long it'll make it?

I've never run it real fast (2750-2900fps), but shooting longish 112gn Match Burners hasn't allowed me to jump as much as I usually like to so IDK? I was used to jumping 100 thou with my 6CM, but with the GT anything more than 10 thou off the lands puts the bullet's bearing surface below the shoulder/neck junction (which I'm not totally convinced actually matters).

I ran the first 1500rds through it at 50 thou off with the bearing surface well past the shoulder/neck junction (with the base of the bullet about at the start/bottom of the shoulder), and it shot great, no issues. I've loaded the last few hundred rounds longer, keeping the bullet's bearing surface above the shoulder/neck junction to see if it shot any better... and it seems to shoot the same (I almost think my vertical was a little better downrange with more jump and the ass of the bullet deeper in the case but IDK?).

I've actually been slowing it down to make it easier to see impacts on plates inside 600 yards, and other than my SDs opening up a little (still in the single digits), it's shot great at 3 different charges/speeds with no load development (Shooters World Precision Rifle):
34gr / 2850fps / SD~3 / 50 thou off
33gr / 2804fps / SD~4 / 10 thou off
32.5gr / 2760fps / SD~6 / 10 thou off

 

[4O6shootist]

I'm at 1850rds through my first 6GT barrel and it's still shooting great. I've already got another barrel, but I'm going to try and hold off on pulling my first one as long as I can as I'm curious how long it'll make it?

I've never run it real fast (2750-2900fps), but shooting longish 112gn Match Burners hasn't allowed me to jump as much as I usually like to so IDK? I was used to jumping 100 thou with my 6CM, but with the GT anything more than 10 thou off the lands puts the bullet's bearing surface below the shoulder/neck junction (which I'm not totally convinced actually matters).

I ran the first 1500rds through it at 50 thou off with the bearing surface well past the shoulder/neck junction (with the base of the bullet about at the start/bottom of the shoulder), and it shot great, no issues. I've loaded the last few hundred rounds longer, keeping the bullet's bearing surface above the shoulder/neck junction to see if it shot any better... and it seems to shoot the same (I almost think my vertical was a little better downrange with more jump and the ass of the bullet deeper in the case but IDK?).

I've actually been slowing it down to make it easier to see impacts on plates inside 600 yards, and other than my SDs opening up a little (still in the single digits), it's shot great at 3 different charges/speeds with no load development (Shooters World Precision Rifle):
34gr / 2850fps / SD~3 / 50 thou off
33gr / 2804fps / SD~4 / 10 thou off
32.5gr / 2760fps / SD~6 / 10 thou off

I have a 120fb 24" 6gt, the 112 shoots small at 10k jump, it's a relatively small window as 7k and 13k jump open up to half moa or slightly bigger. I'm running at 2905 with 36.3gr H4350. It's a hunting/varmint barrel so really not concerned with life. 4 my other 6gt barrels are 169fb, this barrel and the womans are the only ones I have with short fb. Idk if being below the neck matters much, but I just don't like it personally. I'll usually take a long freebore as I found the jump windows are larger the further you get away from lands, although the precision isn't quite as tight as close, however a much more forgiving stable load you can shoot for a long time without retuning.

 

[mdram]

curious if anyone is running varget with 105's. what your load and speed are?
im currently running 34gr under a 108bt for 2880 from a 24", but may try some 105's

 

[4O6shootist]

curious if anyone is running varget with 105's. what your load and speed are?
im currently running 34gr under a 108bt for 2880 from a 24", but may try some 105's

I'd think a 105 will tune in with another half grain +-, 105s usually have shot around 2920-2950 in my barrels, but using H4350.

 

[mdram]

I'd think a 105 will tune in with another half grain +-, 105s usually have shot around 2920-2950 in my barrels, but using H4350.

thanks, i looked at the data on hodgdon, and it was confusing
why is the 105 so low?

 

[4O6shootist]

thanks, i looked at the data on hodgdon, and it was confusing
why is the 105 so low?
View attachment 8261813

I don't know why they tested a 105amax, pretty sure that bullets been discontinued for near a decade. The 105hyb has less bearing than an 107smk and is lighter, I'd say you're max would be half way between the 107smk and 103vtac.

 

[mdram]

I don't know why they tested a 105amax, pretty sure that bullets been discontinued for near a decade. The 105hyb has less bearing than an 107smk and is lighter, I'd say you're max would be half way between the 107smk and 103vtac.

that was my that also, thanks

 

[CK1.0]

YMMV, but I'm done with chasing speed, now I'm chasing slow lol... I think for me the goal now is actually finding the slowest load that shoots that I can (while staying supersonic out to just past ~1250 yards and having enough case-fill so that SDs don't go to shit).

I guess I'm really just treating the GT as a "Dasher without the headaches", and at middle-of-the-road Dasher speeds, mine has been shooting great.

If I'm honest I think I lost a little something going from 33gr/2804fps to 32.5gr/2760fps... 33gr/2804fps was hammering and allowing me to see what I needed to with impacts at closer distances, but I figured I'd try to back it down a little more since less powder equals less recoil.

That said, I'm starting to think the magic recipes have more to do with case-fill than speed. But there also seems to be something magical about the Varget/SWPR burn-rate powders as compared to slightly slower powders like H4350/RL15.5... so there's that.

As far Varget and Varget-alikes like SW Precision, N150/N140, etc... does anyone know which one at the same charge weights, has the highest load density to yield the most case-fill..? I think that might be worth a little further experimentation...

And if I ever come across some H4831 I might try some of that as I should be able to fill up the case with no problem and still end up with slower speeds, but IDK if that'll lose some of the magic I've been getting with the faster SWPR (where everything shoots and yields single digit SDs without really trying).

Lastly, does anyone know if anyone has ever done a recoil comparison with different powders..? While recoil is a little softer with my 6GT and 33gr of SWPR versus my 6CM and its 41gr StaBall load, it's also "snappier" and less of a "slow push" type of feel (kind of like the difference between a 9mm and a .45ACP).

I'm wondering what would feel softer: ~33gr of Varget/SWPR versus ~38 of H4831..?

 

[Cascade Hemi]

YMMV, but I'm done with chasing speed, now I'm chasing slow lol... I think for me the goal now is actually finding the slowest load that shoots that I can (while staying supersonic out to just past ~1250 yards and having enough case-fill so that SDs don't go to shit).

I guess I'm really just treating the GT as a "Dasher without the headaches", and at middle-of-the-road Dasher speeds, mine has been shooting great.

If I'm honest I think I lost a little something going from 33gr/2804fps to 32.5gr/2760fps... 33gr/2804fps was hammering and allowing me to see what I needed to with impacts at closer distances, but I figured I'd try to back it down a little more since less powder equals less recoil.

That said, I'm starting to think the magic recipes have more to do with case-fill than speed. But there also seems to be something magical about the Varget/SWPR burn-rate powders as compared to slightly slower powders like H4350/RL15.5... so there's that.

As far Varget and Varget-alikes like SW Precision, N150/N140, etc... does anyone know which one at the same charge weights, has the highest load density to yield the most case-fill..? I think that might be worth a little further experimentation...

And if I ever come across some H4831 I might try some of that as I should be able to fill up the case with no problem and still end up with slower speeds, but IDK if that'll lose some of the magic I've been getting with the faster SWPR (where everything shoots and yields single digit SDs without really trying).

Lastly, does anyone know if anyone has ever done a recoil comparison with different powders..? While recoil is a little softer with my 6GT and 33gr of SWPR versus my 6CM and its 41gr StaBall load, it's also "snappier" and less of a "slow push" type of feel (kind of like the difference between a 9mm and a .45ACP).

I'm wondering what would feel softer: ~33gr of Varget/SWPR versus ~38 of H4831..?

I don't believe H4831 will hit the minimum pressure threshold to seal the case before reaching 105% case capacity. I've been using H4350 and am planning on working up Varget due to the carbon issues I've been having with H4350.

 

[4O6shootist]

@CK1.0 N150 is probably the bulkiest of which you listed. I'm my ladies rifle I tested 107smk with N150 and 32.7gr is running 2940 and shoots well, I need to back off to. Mid 2800 and see if it still shoots there. That's a 26" 7tw 120fb chamber. Her barrel has always built pressure sooner than my other 237 bore HH pipes, but mine are all 7.5tw. In my experience in the 6bra, ts15.5 was bukier and produced slower velocity than varget. N555, Rl23, SW4350 are all 1-2gr slower than H4350 in the gt.