**6 Creedmoor**
- Thread starter Sportin Wood
- Start date
Guess I got it as good as it will go for the 107 SMK / H4350 in this barrel (26", 1:7.25 Bartlein). I had two distinct plateaus in velocity for groups (not a single shot). I usually don't believe in that stuff, but this barrel has shown it enough that I'm starting to drink the "flat spot" kool-aid * in this barrel.
I beat myself about the head and neck trying to get good accuracy out of that slightly higher charge weight. 1/2 - 3/4 MOA...no better or worse.
Loaded back down to the more promising charge weight that gave good results earlier. I did not do as well as last time, but I had more wind today too (excuses, excuses). Loaded one last group and shot it at 300...it held up rather well in the wind. Guess I'm done.
Today's tests:
I tried to move the dime far enough away that somebody wouldn't think I was trying to cover anything.
Whole target:
What I was trying to duplicate and failed:
^ This is 40.0. I ran 39.9 and 40.1 over a chronograph and had an ES and SD average of 25.5 and 8.5 between the two. Velocity is going to be right at 2,950.
I beat myself about the head and neck trying to get good accuracy out of that slightly higher charge weight. 1/2 - 3/4 MOA...no better or worse.
Loaded back down to the more promising charge weight that gave good results earlier. I did not do as well as last time, but I had more wind today too (excuses, excuses). Loaded one last group and shot it at 300...it held up rather well in the wind. Guess I'm done.
Today's tests:
I tried to move the dime far enough away that somebody wouldn't think I was trying to cover anything.
Whole target:
What I was trying to duplicate and failed:
^ This is 40.0. I ran 39.9 and 40.1 over a chronograph and had an ES and SD average of 25.5 and 8.5 between the two. Velocity is going to be right at 2,950.
Just dropping a little more N160 data, as I don’t see a lot and VV powders are becoming the cheaper option…
22” suppressed, Lapua cases/CCI 41/N160/105/2.7” OAL
This was shot left column down, then back up the right. The rifle was allowed to “cool” between strings (about as much as you can in with a little shade, no wind, and high temps). The differences in velocity (in red) for 5 shot strings are… something.
I’ve suspected N160 in this cartridge of being a little temp sensitive when it’s hot for a while now. My previous outings with virgin brass at 70*F averaged 2760 on two different 69*F days, same charge with once fired nets about 2823 at 89*F… unless it’s the last group of the day, then the same charge on a hot barrel averages 2865. I haven’t quite wrapped my head around it yet, but I’ll probably be vacuum sealing some rounds to do some temp testing next time out.
It could have been that the barrel was late to speed up (200 rounds then vs 275 now), 40 rounds of fouling, or maybe the difference in sizing/mandrel/the humidity while I was loading – hard to say. I honestly expected a small drop in velocity once everything was fireformed/resized, which is why I added more powder from the baseline of 41/2760.
Considering the total of 40 rounds aggregates under 1” with a .21” mean radius (and the fact I know that I possess neither diggler's oustanding marksmanship nor penmanship), I think I’ve reached the ‘stop messing with it’ phase- I’d just like to have a good temp sensitivity input to load into the kestrel and to add a little more confidence.
Thanks for coming to my ted talk.
22” suppressed, Lapua cases/CCI 41/N160/105/2.7” OAL
This was shot left column down, then back up the right. The rifle was allowed to “cool” between strings (about as much as you can in with a little shade, no wind, and high temps). The differences in velocity (in red) for 5 shot strings are… something.
I’ve suspected N160 in this cartridge of being a little temp sensitive when it’s hot for a while now. My previous outings with virgin brass at 70*F averaged 2760 on two different 69*F days, same charge with once fired nets about 2823 at 89*F… unless it’s the last group of the day, then the same charge on a hot barrel averages 2865. I haven’t quite wrapped my head around it yet, but I’ll probably be vacuum sealing some rounds to do some temp testing next time out.
It could have been that the barrel was late to speed up (200 rounds then vs 275 now), 40 rounds of fouling, or maybe the difference in sizing/mandrel/the humidity while I was loading – hard to say. I honestly expected a small drop in velocity once everything was fireformed/resized, which is why I added more powder from the baseline of 41/2760.
Considering the total of 40 rounds aggregates under 1” with a .21” mean radius (and the fact I know that I possess neither diggler's oustanding marksmanship nor penmanship), I think I’ve reached the ‘stop messing with it’ phase- I’d just like to have a good temp sensitivity input to load into the kestrel and to add a little more confidence.
Thanks for coming to my ted talk.
A quick follow up: Sometimes I’m wrong.
TL;DR – in my testing, N160 in the 6 creedmoor produced a gain of approx .77 fps per degree F temp increase, in line with the .75fps/1*F I’ve seen listed elsewhere.
I vacuum sealed four 5-round packets and placed half in a thermos with 60*F water, and half in a thermos with 110*F water. They were allowed to normalized for three hours before shooting. I used a food thermometer and recorded the water temp in the thermos. Speeds recorded over a lab radar. While I am certain there is error both in how I estimated round/powder temps, experimental setup, and low round counts, it is in line with what I should have expected. I’m dropping the issue and going back to focusing on basic positional shooting. This was likely the last bit of load development and testing I’ll do in 6CM - this is my last barrel and I don't see myself coming back to the cartridge.
load data for my last 3 6 creed barrels was split between two loads, the higher of which I advise you not to try because I had a custom chamber and gain twist barrel
all loads with 115 dtacs and Federal 205m and lapua 6 creed srp brass
40.5 H4350 with dtac at 2.8" gives 2977 currently and usually around 2950 for me
41.4 H4350 for 3125fps (and excellent accuracy) at 2.8"
fwiw that is about 20 thou off lands for us.
barrel contours have been M24 or heavy Palma, 28 inch finish with a 8.5 transitioning to 7.5 left hand gain twist.
only downside to 6 creed is the 1000-1500 ish round barrel life
all loads with 115 dtacs and Federal 205m and lapua 6 creed srp brass
40.5 H4350 with dtac at 2.8" gives 2977 currently and usually around 2950 for me
41.4 H4350 for 3125fps (and excellent accuracy) at 2.8"
fwiw that is about 20 thou off lands for us.
barrel contours have been M24 or heavy Palma, 28 inch finish with a 8.5 transitioning to 7.5 left hand gain twist.
only downside to 6 creed is the 1000-1500 ish round barrel life
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You aren't kidding about barrel life 
. I went away from the 6CM because of that, but came back again. It is hard to argue against that midrange trajectory/deflection, along with achieving it with so little recoil.
Was cleaning my latest 6CM barrel and a 6.5x47L this weekend. Stuck a borescope down both tubes to verify that I was back to bare metal. The 6CM barrel with exactly 240 rounds on it had more fire cracking and erosion than my 6.5x47 with 625 rounds on it. Granted, I'm not standing on my x47 barrel (123gr @ 2,815 FPS).
Since I don't shoot comps, and 10 shot strings over 2 minutes is as fast as I'll ever take her, I'm planning on 1,400 rounds before I pull it for good (preemptively). That's about how long my last went.
. I went away from the 6CM because of that, but came back again. It is hard to argue against that midrange trajectory/deflection, along with achieving it with so little recoil.Was cleaning my latest 6CM barrel and a 6.5x47L this weekend. Stuck a borescope down both tubes to verify that I was back to bare metal. The 6CM barrel with exactly 240 rounds on it had more fire cracking and erosion than my 6.5x47 with 625 rounds on it. Granted, I'm not standing on my x47 barrel (123gr @ 2,815 FPS).
Since I don't shoot comps, and 10 shot strings over 2 minutes is as fast as I'll ever take her, I'm planning on 1,400 rounds before I pull it for good (preemptively). That's about how long my last went.
I should have mentioned we basically only use our 6 creed barrels for comps so pretty much only 10 shot strings in about 20 seconds give or take, then the barrel could down completely before the next stage. and if we go with a normal, "sane" load I expect 1500 before she gets squirrelly or gives up the ghost.
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I no longer borescope my barrels, it's too scary.
Definitely the #1 source for made up barrel problems
.I still do to check my cleaning and for carbon ring development.
Lapua brass, CCI 41, 40.2gn @ +-2.745" COAL.
I'd say a conservative start with N160 and any 105 class bullet is 39gn. I've run all the way up to 43gn but that was tops, tossing them at 3044 out of a suppressed 22" tube (single digit SD over 50 shots tho
)Thanks. I am running them in a 26" barrel with Hornady brass so I will start around 40grns and work up. Just looking to be around 2850fps or so with the 110 ATips.
Same here, have a box of 109s and 8lbs of N160 for the next 6CM barrel.
Much thanks on the load input.
Much thanks on the load input.
IME the 110 ATips (although I only tried a single box of 'seconds') run just a smidge slower than 109s at the same powder - like 10 fps. Right now, 109s are running 2850ish @ 40.2 but it's the heat of summer...
Every barrel/bullet I've tried ended up running comfortably between 40-42 gn of N160. Should be a quick workup if you're only looking for 2850. My lapua brass averaged 51.34 gn H2o. Peterson was a half gn less. I've never seen hornady 6 creed to compare.
Every barrel/bullet I've tried ended up running comfortably between 40-42 gn of N160. Should be a quick workup if you're only looking for 2850. My lapua brass averaged 51.34 gn H2o. Peterson was a half gn less. I've never seen hornady 6 creed to compare.
No need for velocity for matches. Actually a hinderance as it’s more recoil and burns out barrels faster. The 6 Creed got its “barrel burner” rep back in the beginning of PRS when people ran them at 3180fps and were toasting barrel. Run it slower and barrels last a lot longer.
because it's a test your limits game where there are no sighters and no wind flags and a huge mountain range so the wind wreaks havoc here in south east kentucky. unpredictable directions with no real cues. a high BC (.32 g7)of the 115 gr dtac at 3125 does great against wind and helps get first round impacts on a roughly 1moa target.
oh plus we have to shoot 300 yards and be able to see out impacts so the 6mm is king of the hill where I'm at.
if you want to win you'll need to at least stay on the 1.5ishmoa (#3 out of 5) target at all ranges and never miss to have a chance and you'll likely have to score at least a few on the 1moa #4 target. Last time I went 4 in a row at the #4 target at 1k.
So are you talking about an actual "benchrest" match or just something you guys shoot at your range? BR matches usually have sighters and flags etc. Just wondering as never shot an actual 1000 yard BR but have shot 6mms for 20 years now out past it without issue in heavy winds at less velocity in PRS style matches. Even back when shooting the .243 I only range them at 2990fps when others were running 3150 and did just fine.
oh no, I shoot prone, all the old guys shoot off bench. it's not like nra sponsored or anything, we all use brakes or suppressors.
also winner gets 500$, second place gets 250, third gets 50
everybody else just loses their 35$ entry fee.
super fun honestly. if you're in south east kentucky I'll take you to it.
Attachments
you aren't taking into account you're a talented, practiced shooter. I am not.
I'll take any slight edge I can get baby lol.
I'll take any slight edge I can get baby lol.
Thanks for the info. That does look like fun. Always fun to bang steel. Shot a similar match before and had fun.
I'll stick with the lower velocity to keep some longer barrel life. Just looked at my ballistic program and going from the 2930fps where I am now to 3150fps with the 110 Atips is only a .2 mil difference with a full value 10mph wind at 1000.
My DTACs never trued that high. The BC calc using the labradar tracks was a .296, which shrinks that wind comparison to a .1 mil difference.
My two lots of DTACs also had different lengths and BCs. YMMV.
My two lots of DTACs also had different lengths and BCs. YMMV.
So I picked up a 6 creed BA, mostly bought for the action but should be a fun barrel to shoot. What’s the brass situation? Is lapua no longer making 6 creed brass? I don’t necessarily want to neck down 6.5 lapua brass but could, I don’t want to use alpha because I already have a bunch of 25 creed brass and don’t want to mix anything up, what’s next best readily available, Peterson? Thanks
Nothing wrong with Hornady brass. Been using it for years. I use my once fired from factory ammo and keep loading them.
Peterson brass was just as good as lapua for me, although a bit less capacity.
Grabbing a few boxes of Berger ammo to have the lapua brass for after is always an option.
Grabbing a few boxes of Berger ammo to have the lapua brass for after is always an option.
Question for 6 creed shooters.
This is my second 6 creed barrel, basically only shot at matches in 8-12 shot strings.
First barrel was I would expect, and at 1400 rounds I pulled it to become prairie dog tube for the end of its life.
My current barrel.
22” pva osprey
Shot suppressed its whole life
105 hybrids
39.5 h4350
Alpha srp brass
205m
Has shot well, continues to shoot well but has consistently sped up 20 fps almost every match. I dumped down .5 grains, and still I’m seeing signs of pressure, along with the velocity to go with it. Last match I ended near primer failure.
Fwiw I started at 2920, and last match tried to 3050. At this point it’s at 1000 rounds, cleaned to bare metal (I clean every match) and it’s still doing the same thing.
I pulled the barrel, because I don’t want to have issues at a match, but this is a head scratcher as it was still producing .5moa groups at 400 yards. Also unfortunate in that this barrel has been extremely consistent otherwise. I havnt touched my zero in 900 rounds.
Iv got some shot up lapua and 4831sc but really dont want to be burning components on a 1k round 6 creed barrel thats been shot hot its whole life.
This is my second 6 creed barrel, basically only shot at matches in 8-12 shot strings.
First barrel was I would expect, and at 1400 rounds I pulled it to become prairie dog tube for the end of its life.
My current barrel.
22” pva osprey
Shot suppressed its whole life
105 hybrids
39.5 h4350
Alpha srp brass
205m
Has shot well, continues to shoot well but has consistently sped up 20 fps almost every match. I dumped down .5 grains, and still I’m seeing signs of pressure, along with the velocity to go with it. Last match I ended near primer failure.
Fwiw I started at 2920, and last match tried to 3050. At this point it’s at 1000 rounds, cleaned to bare metal (I clean every match) and it’s still doing the same thing.
I pulled the barrel, because I don’t want to have issues at a match, but this is a head scratcher as it was still producing .5moa groups at 400 yards. Also unfortunate in that this barrel has been extremely consistent otherwise. I havnt touched my zero in 900 rounds.
Iv got some shot up lapua and 4831sc but really dont want to be burning components on a 1k round 6 creed barrel thats been shot hot its whole life.
I'm shooting Peterson in my current 6 CM barrel now. I have no complaints whatsoever about it.
Are you using the same lot of powder and how is it stored? I have ran into the same issue and it was due to fluctuating humidity in the 8lb tub of powder. Also brass neck tension can lead to increase pressure/ velocity. I assume you are annealing?
^ Yes, and if you are cleaning to bare metal, are you verifying with a borescope that the carbon ring is gone?
If you want to use LRPs, Lapua 22-250 brass works great for 6CM.
It'll close on the shoulder and all you have to do to fire-form it on the first firing is use a sensible middle-of-the-road charge (say ~39-40gr H4350), and it is accurate on the first firing too. The only downside is that you end up with a shorter-than-usual neck (kind of like a big Dasher case) so when cleaning the barrel you have to be mindful of that so you don't end up with a crazy carbon ring (it's really not a big deal).
I've got a few hundred with ~20 firings on them over 3 different barrels and they're still performing great (and I've never had to trim them lol).
BTW/FWIW...
Don't believe the naysayers who say it's too fast, Shooters World Precision Rifle and/or Varget work f'ing great for 6CM!
I've been testing different loads for ~500rds and all of them have shot fantastic. (It probably matters that every charge has been to the nearest kernel using an Ingenuity Precision trickler.)
35 grains of SWPR behind a 112MB yields ~2800fps for me in a 26" Proof SS prefit and is as accurate as anything I've ever got with ~40ish grains of H4350, except it's noticeably softer-shooting. SDs have been in the 7-9 range over 20 shots.
Don't believe the naysayers who say it's too fast, Shooters World Precision Rifle and/or Varget work f'ing great for 6CM!
I've been testing different loads for ~500rds and all of them have shot fantastic. (It probably matters that every charge has been to the nearest kernel using an Ingenuity Precision trickler.)
35 grains of SWPR behind a 112MB yields ~2800fps for me in a 26" Proof SS prefit and is as accurate as anything I've ever got with ~40ish grains of H4350, except it's noticeably softer-shooting. SDs have been in the 7-9 range over 20 shots.
Powder stored in a controlled 50% humidity. If anything the powder is seeing slightly more moisture.
I am annealing, with an amp, and seat with an arbor press. Seating force and die have remained the same throughout the barrel producing the same results as far as I can measure and tell.
My only guess is possibly that the alpha brass is producing more bolt thrust and not grabbing the chamber as hard as it should. Or the barrel is just fire cracked enough that h4350 is too hot for it now. The base of my alpha after firing in this chamber is a few thou smaller than lapua fired in my other chamber (same smith)
It’s a brain scratcher just seeing if others have seen similar.
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39.X gr H4350 is a pretty mild charge especially with 105hyb. It's also a relatively clean powder. I run 39.0gr H4350 in my 65cm low and slow with 153.5s and I haven't cleaned that barrel in probably 600-700 rounds and it still shoots great. You most def shouldn't be developing a carbon ring with 100-150 rounds of H4350 if you're cleaning every match.
Alpha brass at the base will usually be 001 smaller after firing VS lapua in the same chamber, the web is just that much harder. Lapua does seem to grip the chamber better. I have a few 6cm with slightly undersized chambers and alpha works very well in them, but the rest I run lapua. Alpha also holds less than lapua, so the same loads will give different speeds.
If you proofed the H4350 load in 50-60 degree and now it's been 90-100 here locally, you will see some speed increase, prob 20fps or so.
Cleaning to bare metal, will usually result in a speed up for me around 80-100 rounds, usually 40-60fps, but it then usually stabilizes there. I don't clean to bare metal anymore because of this. I use clr to get the majority the carbon out, the use a few patches of thoroclean to get the copper/cooked in carbon out. There's usually no copper left after this and a lil bit of carbon staining on the lands for the first 3-4", rest is pretty shiny. It usually shoots back into the previous velocity in 3-5 rounds and stays there.
39.X gr H4350 is a pretty mild charge especially with 105hyb. It's also a relatively clean powder. I run 39.0gr H4350 in my 65cm low and slow with 153.5s and I haven't cleaned that barrel in probably 600-700 rounds and it still shoots great. You most def shouldn't be developing a carbon ring with 100-150 rounds of H4350 if you're cleaning every match.
Alpha brass at the base will usually be 001 smaller after firing VS lapua in the same chamber, the web is just that much harder. Lapua does seem to grip the chamber better. I have a few 6cm with slightly undersized chambers and alpha works very well in them, but the rest I run lapua. Alpha also holds less than lapua, so the same loads will give different speeds.
If you proofed the H4350 load in 50-60 degree and now it's been 90-100 here locally, you will see some speed increase, prob 20fps or so.
The above speeds are after initial speed up. This barrel was a rock star from rounds 200-800.
My normal cleaning regimine isn’t to bare metal.
This is also the first match barrel Iv shot 100% suppressed.
But yea that’s where I’m wondering because 39 grains of h4350 is nothing.
Most temps have been 70-90 for the life of the barrel, but with only early on shots being cooler.
I may try some lapua brass because that’s exactly what I’m seeing as far as growth, and I’m wondering if that extra bolt thrust of the case not grabbing is causing the signs I’m seeing, but then again I am up there for speed as well in a 22” barrel.
I’m going to give 223 a try for our finale with 85.5s only because I don’t feel like wrecking a bolt playing with this at a match.
Yeah those ejector marks are def very apparent. Will likely lead to some brass shavings getting into your plunger cut and causing ejectile dysfunction, don't want that getting you down in a match!
I had a few Hawkhill barrels that sped up around 50-70fps at the 800rd mark. They were 6bra 28" long and running the same bullet powder velocity you are with 33.6gr H4350. I just adjusted powder down to 33.0 and kept on trucking with no issues. Those are the only 2 barrels that have had a mid life crisis for me, they shot extremely well tho. I had to switch from Alpha to lapua brass on those, as alpha gave me bolt thrust/lift issues at much lower velocity.
I’ll have to give lapua a try before I completely give up on it. I hate to shoot 105 hybrids at prairie dogs but I do plan to experiment with this barrel to try and figure it out, just not in a match setting.
I’m moving away from creedmoor though in match guns. After my first few shots with a heavy 223 barrel I’m really wondering why I havnt gone to br earlier. I’m assuming similar recoil…. But I can seeeverythibg now.
Yeah a 6br with 105s in the low 2800s is an extremely easy to shoot rifle, and you can see it all.
An update from my above question.
I swapped to some old lapua brass I have, 5x fired in another chamber.
Gone are the pressure signs. But I’m getting clickers, chambers are just different enough. I don’t think the alpha grabs the chamber walls enough and is giving me holy thrust. H4350 may be too fast as well on this barrel this far along.
The barrel is still shooting extremely well.
I’m going to attempt a slower powder with the alpha, if that dosnt go I’m SOL and will hopefully get my 223 shooting well enough to be competitive.
I swapped to some old lapua brass I have, 5x fired in another chamber.
Gone are the pressure signs. But I’m getting clickers, chambers are just different enough. I don’t think the alpha grabs the chamber walls enough and is giving me holy thrust. H4350 may be too fast as well on this barrel this far along.
The barrel is still shooting extremely well.
I’m going to attempt a slower powder with the alpha, if that dosnt go I’m SOL and will hopefully get my 223 shooting well enough to be competitive.
Try a RCBS matchmaster die, it should size your lapua down enough to mitigate any chamber differences. They size a ton at the bottom side the case compared to most the other die manufacturers.
Idk, I haven't tried sac dies. Get a good micrometer and measure the web area of fired VS sized cases. Calipers are half ass for this a mic is much better tool if you have one. My RCBS sizes lapua brass from 4707-471 to 4692-4695. I haven't had a clicker on anything creedmoor since switching from redding to the RCBS matchmaster.
