6.5 Creedmoor Rifle
12-04-2016, 07:30 AM
#31
Nontypical Buck
Join Date: Nov 2003
Location: Texas
Posts: 2,695
numbers from hodgdon data
6.5 creed 140 gr 2555 fps @60,400 PSI
260 140 gr 2677 fps @58,400 PSI
6.5x55 140 gr 2517 @45,700 PSI
SAAMI specs for the 6.5x55 are lower due to older military rifles it came chambered in, its been known for a long while that in modern firearms loaded to max pressures in that firearm it will run away from the 260, and badly trounce the creed. there is no magic in efficiency, the faster you run a bullet the more powder it requires, its not possible for less powder in a smaller case to make more velocity with the same weight bullet
RR
Adam, a 22 creed would be almost exactly a 22-250 AI, be a decent rifle in an 8 twist, I would prefer the 22/6mm AI even though ya need a long action
6.5 creed 140 gr 2555 fps @60,400 PSI
260 140 gr 2677 fps @58,400 PSI
6.5x55 140 gr 2517 @45,700 PSI
SAAMI specs for the 6.5x55 are lower due to older military rifles it came chambered in, its been known for a long while that in modern firearms loaded to max pressures in that firearm it will run away from the 260, and badly trounce the creed. there is no magic in efficiency, the faster you run a bullet the more powder it requires, its not possible for less powder in a smaller case to make more velocity with the same weight bullet
RR
Adam, a 22 creed would be almost exactly a 22-250 AI, be a decent rifle in an 8 twist, I would prefer the 22/6mm AI even though ya need a long action
i get it you dont like the creed, it shows, you continue to try and discredit it, first by claiming its a necked up puny little 22-250 case, which is false, and now posting the worst load for it in a 140 gr, a fair comparison is noslers load data, the fastest of all 3 cartridges
12-04-2016, 07:35 AM
#32
Nontypical Buck
Join Date: Feb 2015
Location: Illinois
Posts: 3,695
zrex, as Jeep stated, no cartridge design is more accurate than another. It's a combination of bullet, cartridge, rifle, and shooter. Are there cartridges out there that are better at long distance than others? Of course there are. But that better accuracy is because of that combination of bullet design (high BC) and knowing how fast that bullet design can be pushed as well as knowing all the other factors that effect bullet travel.
12-04-2016, 07:53 AM
#33
Nontypical Buck
Join Date: Nov 2003
Location: Texas
Posts: 2,695
.
wrong, cartridge effiefincy is not just a made up word, short fat cartridges are inherently more accurate, its why the 308 toppled the 30-06 in 1000 yd matches, so bad that the target size was reduced to half the size, its why all bench rest shooter use the br or xc or ppc case design, it why the 6.5x284 dominates as well, case design is everything.
zrex, as Jeep stated, no cartridge design is more accurate than another. It's a combination of bullet, cartridge, rifle, and shooter. Are there cartridges out there that are better at long distance than others? Of course there are. But that better accuracy is because of that combination of bullet design (high BC) and knowing how fast that bullet design can be pushed as well as knowing all the other factors that effect bullet travel.
12-04-2016, 08:45 AM
#34
Nontypical Buck
Join Date: Oct 2009
Location: Kansas
Posts: 3,902
Zrex, Could you elaborate on what, in particular, makes a short fat case with a steep shoulder more accurate than a traditional long body, slope shoulder case? Also, I would be interested to learn your experience for what aspect in particular about shooting your 6br, 6.5-284, and 6.5 creed has proven to be the key element making them more accurate for you than your other benchrest rifles in traditional cases?
Last edited by Nomercy448; 12-04-2016 at 08:52 AM.
12-04-2016, 09:10 AM
#35
Nontypical Buck
Join Date: Nov 2003
Location: Texas
Posts: 2,695
Zrex, Could you elaborate on what, in particular, makes a short fat case with a steep shoulder more accurate than a traditional long body, slope shoulder case? Also, I would be interested to learn your experience for what aspect in particular about shooting your 6br, 6.5-284, and 6.5 creed has proven to be the key element making them more accurate for you than your other benchrest rifles in traditional cases?
some cartridges are inherently more accurate than others, thats a fact, maybe theyre sprinkled with magic fairy dust, the .222 remington was one of those cartridges
Last edited by zrexpilot; 12-04-2016 at 09:14 AM.
12-04-2016, 09:25 AM
#36
Nontypical Buck
Join Date: Nov 2003
Location: Texas
Posts: 2,695
the creed was specifically designed in a joint venture with hornady and creedmoor to deliver a true factory chambered 1000yd paper puncher using factory ammo, its another cartridge that been sprinkled with magic fairy dust.
the 17 hmr is another, take the 22 mag neck it down and shoulder it and bam more fairy dust. the .17 isnt even allowed in rimfire competition it had to get its own class cause it decimated rimfire records
the 17 hmr is another, take the 22 mag neck it down and shoulder it and bam more fairy dust. the .17 isnt even allowed in rimfire competition it had to get its own class cause it decimated rimfire records
12-04-2016, 10:25 AM
#37
Nontypical Buck
Join Date: Feb 2015
Location: Illinois
Posts: 3,695
LOL..NoMercy, I have a feeling we have us a reader with no practical experience to back up what he thinks is reality.
1: zrex, could you give the class your reasoning on how a cartridge case in ANY way effects SD (Sectional Density) or for that matter how SD (Sectional Density) effects bullet flight in any way whatsoever?
2: One of the reasons medium and short action cartridges are more accurate has absolutely NOTHING to do with the cartridge itself but in fact the ACTION itself! Shorter action means STIFFER action. Less "flex" means more accuracy.
3: The pressure curves in medium and short action cartridges are different and reach maximum pressure quicker, throttling up bullet speeds a bit faster. We are talking dang near nano seconds here. Your efficiency argument is pretty much moot since, as RR already stated, burn rate is the director here not cartridge shape. You put a faster powder in a smaller space then yes you will have faster bullet speeds because there is unfilled space in the longer cartridge that has to pressurize before bullet movement. Again, nano seconds but yes there is a difference.
4: The 6mm bullet is by far one of the best long range PAPER PUNCHERS out there no question about it. But there is a reason it's not used for long range big game hunting or for Long Range Military uses. Retained energy just sin't there.
zrex, you are sitting here arguing with 3 or 4 folks that have PRACTICAL knowledge in the long range shooting world. Not just reading about it. Nomercy is a top shelf engineer, RR has been in the long range game for over 25 years or so. Jeep Kid works for a company that DESIGNS long range custom firearms! And I myself have been in the shooting/hunting game longer than all 3 of them combined! Over the years I have been asked to test ammo from dang near EVERY American ammo manufacturer. I've been wildcatting cartridges since the 60's. So yeah we have just a tiny bit of a REAL clue there kiddo.
1: zrex, could you give the class your reasoning on how a cartridge case in ANY way effects SD (Sectional Density) or for that matter how SD (Sectional Density) effects bullet flight in any way whatsoever?
2: One of the reasons medium and short action cartridges are more accurate has absolutely NOTHING to do with the cartridge itself but in fact the ACTION itself! Shorter action means STIFFER action. Less "flex" means more accuracy.
3: The pressure curves in medium and short action cartridges are different and reach maximum pressure quicker, throttling up bullet speeds a bit faster. We are talking dang near nano seconds here. Your efficiency argument is pretty much moot since, as RR already stated, burn rate is the director here not cartridge shape. You put a faster powder in a smaller space then yes you will have faster bullet speeds because there is unfilled space in the longer cartridge that has to pressurize before bullet movement. Again, nano seconds but yes there is a difference.
4: The 6mm bullet is by far one of the best long range PAPER PUNCHERS out there no question about it. But there is a reason it's not used for long range big game hunting or for Long Range Military uses. Retained energy just sin't there.
zrex, you are sitting here arguing with 3 or 4 folks that have PRACTICAL knowledge in the long range shooting world. Not just reading about it. Nomercy is a top shelf engineer, RR has been in the long range game for over 25 years or so. Jeep Kid works for a company that DESIGNS long range custom firearms! And I myself have been in the shooting/hunting game longer than all 3 of them combined! Over the years I have been asked to test ammo from dang near EVERY American ammo manufacturer. I've been wildcatting cartridges since the 60's. So yeah we have just a tiny bit of a REAL clue there kiddo.
12-04-2016, 10:43 AM
#38
Nontypical Buck
Join Date: Oct 2009
Location: Kansas
Posts: 3,902
So if I load a 7-08 with Varget under 140 AB's and I'm seeing a 17 ES, I should see a reduced ES and better precision with my 6.5 Creed because of the straight body and steep shoulder. Right? How much should my group size shrink if I swap my 7-08 barrel for a 6.5 creed barrel? Or if I just ream it out to an AI type chamber?
Or is the 6.5 creed just as accurate at range as the 7-08 even if it's loaded less consistently with a greater ES?
How much reduced ES should we expect from the new Lapua brass for 6.5creed with it's small flash hole and small primer compared to the Hornady stuff we've all been living with so far which has 20 thou flash hole and large primers? How much are my groups going to shrink out of my RPR swapping to these small primer brass?
Or is the 6.5 creed just as accurate at range as the 7-08 even if it's loaded less consistently with a greater ES?
How much reduced ES should we expect from the new Lapua brass for 6.5creed with it's small flash hole and small primer compared to the Hornady stuff we've all been living with so far which has 20 thou flash hole and large primers? How much are my groups going to shrink out of my RPR swapping to these small primer brass?
12-04-2016, 11:36 AM
#39
Nontypical Buck
Join Date: Feb 2015
Location: Illinois
Posts: 3,695
Tried the 7mm-08AI route back in 2007 NoMercy.. With 139-140gr bullets I saw around 50-100fps on average velocity increase. Needless to say, wasn't worth the effort of resizing and fireforming. Pretty sure it was one of my Hart barrels that I had Bill ream an AI chamber for. RR loves AI conversions. I myself just don't see enough improvement in MOST cartridges to find it worth the effort.
