6mm Creedmoore vs. 6mm SLR

[Rtheurer]

Not Knowing a lot about the 6mm Version of the Creemoore round I will have to only comment on the 6mmSuper Long Range. (SLR)

Been playing with this round since its early years. Mostly for shooting NRA Long Range events. Back then it was still called the Super X and that is what my Reamer and Reamer print still read so its been a spell.

You can run the 105 class bullets at that 3200fps with a few powders and its been pointed out here over several years. A few that come to mind are N160, N165, IMR 7828, R25. I have obtained over that speed with all of those powders. The Caviate to that is that I shoot a 30" long barrel. I don't know ANY one who can get those speeds (without blowing up there gun) out of 26" length barrel that is more in line with the PRS type of shooting. So your kinda chasing your tail I think and running up over 61,000 PSI no matter what Case brand you run is going to ruin brass, or at least that has been my experience. Small Primer 308 Brass is not going to get you where you want to be I am thinking. How much more pressure do you think it can take vs a Large primer case? Few Thousands PSI or a few hundred PSI?

Then I have to think of how I used to sit down and study cases too and ballistics trying to GET A LEG up on the others when I first started shooting matches only to find out through lots of years that.... Hey its not the cartridge choice as much as it is the shooter and getting out there actually learning how to shoot. Trying to Buy points... Folks have been doing it for ever it seems. I bet David was looking for a Better BC rock before the Slaying of Goliath.. Ha!. Even with my Hot rods of the time I was getting beat by better shooters with inferior ballistics...Just sayin. Fun to sit and figure this stuff out though and I am still guilty of today. : )

 

[MOShooter]

If ballistics are mean that much, why do I keep getting beat by those damn 6 dashers.

 

[SHootSTraight22]

Not Knowing a lot about the 6mm Version of the Creemoore round I will have to only comment on the 6mmSuper Long Range. (SLR)

Been playing with this round since its early years. Mostly for shooting NRA Long Range events. Back then it was still called the Super X and that is what my Reamer and Reamer print still read so its been a spell.

You can run the 105 class bullets at that 3200fps with a few powders and its been pointed out here over several years. A few that come to mind are N160, N165, IMR 7828, R25. I have obtained over that speed with all of those powders. The Caviate to that is that I shoot a 30" long barrel. I don't know ANY one who can get those speeds (without blowing up there gun) out of 26" length barrel that is more in line with the PRS type of shooting. So your kinda chasing your tail I think and running up over 61,000 PSI no matter what Case brand you run is going to ruin brass, or at least that has been my experience. Small Primer 308 Brass is not going to get you where you want to be I am thinking. How much more pressure do you think it can take vs a Large primer case? Few Thousands PSI or a few hundred PSI?

Then I have to think of how I used to sit down and study cases too and ballistics trying to GET A LEG up on the others when I first started shooting matches only to find out through lots of years that.... Hey its not the cartridge choice as much as it is the shooter and getting out there actually learning how to shoot. Trying to Buy points... Folks have been doing it for ever it seems. I bet David was looking for a Better BC rock before the Slaying of Goliath.. Ha!. Even with my Hot rods of the time I was getting beat by better shooters with inferior ballistics...Just sayin. Fun to sit and figure this stuff out though and I am still guilty of today. : )

I hear what your saying and you are right and wrong.. Every advantage helps!! Just look at the Olympics.. People and companies spend billions on trying to find the leg up in every sport.. I just figured from playing with the Applied Ballistics calculator that going from 54% to over 72% hit probability atb 1,200yds (when I do my job) would be a great step... Also increasing my BC by pointing combined with that 150fps increase in speed.. If not, where do you draw the line at when it comes to getting an advantage.. Everyone's line is at a different place and I haven't reached mine yet.. I'll be there although when I have a 6mm shooting H1000 over 3,200-3,250(for long barrel life) with 105gr Hybrids(I want a 120gr Hybrid prototype) getting .3-.4moa accuracy ( no more only less).... Like I said earlier, I'm just trying to play the statistics here by increasing velocity and BC for added performance... I also need a grid/chrismas tree style reticle to be more comfortable never dialing... All that I named here would keep me shooting in the top 15-20 out of 150 people with my current shooting ability...

 

[Conrad]

Shooting 105 hybrids, 100 fps increase from 3130 to 3230, gets you ~4" of less wind drift at 1000. 1 mph of wind changes drift by 6" at 1000...just sayin. As already mentioned, most tac matches have a 3100 to 3150 speed limit, and I'd rather run my equipment easier anyway. There's something to be said for a smooth running bolt, no over pressured rounds on a hot day, a node that is easy to stay in even as the barrel wears, etc.

 

[MOShooter]

The 6.5 rsaum may be what you you are looking for. But some tac matches have a restriction on mag carriages. Might also look at a 6-284 or 6-06. Even running H1000 I bet your barrel life will be 1000 rounds at best running any 6mm at 3200+.

Scott

 

[Dgd6mm]

Things have changed over the years. About 4 -5 years ago the speed limit and cartridge was faster and bigger. The competitiveness has tightened up quite a bit. Steel last longer and shooters shoot better without those big thumpers. A good 6mm cartridge with a brake or a suppressor will make things better for you in the long run. Today the norm is .300 WM for the largest cartridge allowed and a speed limit of 3150 fps. I consider myself a novice because I only shoot these matches once in awhile, but have seen what has evolved over the years.

 

[SHootSTraight22]

Things have changed over the years. About 4 -5 years ago the speed limit and cartridge was faster and bigger. The competitiveness has tightened up quite a bit. Steel last longer and shooters shoot better without those big thumpers. A good 6mm cartridge with a brake or a suppressor will make things better for you in the long run. Today the norm is .300 WM for the largest cartridge allowed and a speed limit of 3150 fps. I consider myself a novice because I only shoot these matches once in awhile, but have seen what has evolved over the years.

Correct, the 3,150fps speed limit is what I'm pondering out smarting.... Guys shoot slightly over it all the time depending on the altitude the match is at... One thing I noticed is guys that traveled to a certain 454ft above sea level range were all shooting low but liked to blame it on the mirage or humidity.. I say it's because their load development was at a higher altitude and they traveled down south and shot the same load plus the slow 1-8 twist instead of a 1-7.5 or 1-7.7 using a 105gr 6mm hybrid... When they dropped to a lower altitude the effects of not having a 1.5 and greater stability factor was more noticable compared to guys whom had 1.5 and higher...

 

[Rtheurer]

Why do I even get suckered into these hypothetical probability threads ????
Arrhh

Russ T

 

[XTR]

Why do I even get suckered into these hypothetical probability threads ????
Arrhh

Russ T

Suckered in trying to explain to someone that you can't buy enough points to win if you have middle of the pack skill, you will still be middle of the pack, but you will spend more on components; and the only way to improve the skill is to get out and shoot. One of the guys at Oak Ridge commented to me a couple of yrs ago, "this isn't a bullet race; there aren't any prizes for fastest".

 

[Rtheurer]

Why do I even get suckered into these hypothetical probability threads ????
Arrhh

Russ T

Suckered in trying to explain to someone that you can't buy enough points to win if you have middle of the pack skill, you will still be middle of the pack, but you will spend more on components; and the only way to improve the skill is to get out and shoot. One of the guys at Oak Ridge commented to me a couple of yrs ago, "this isn't a bullet race; there aren't any prizes for fastest".

Ding ding ding!!! Winner!

 

[joelpend]

I will take accuracy over speed any day. When you start stretching out accuracy matters way more than speed as long as you have enough velocity and BC to get you to the target. This my friends is why the 6BR and variants do so well at distance.

 

[Conrad]

Altitude and other atmospherics really does not change internal ballistics ie muzzle velocity. It does change external ballistics drastically, ie trajectory. I really hope for the sake of your safety and any one else shooting next to you that you consider the law of diminishing returns here. And if you really want to push a bullet that fast use enough case capacity to get it done at safe pressures. PRS is getting much more popular and there has already been talk of random velocity checks between stages so I wouldn't try to game that.

Things have changed over the years. About 4 -5 years ago the speed limit and cartridge was faster and bigger. The competitiveness has tightened up quite a bit. Steel last longer and shooters shoot better without those big thumpers. A good 6mm cartridge with a brake or a suppressor will make things better for you in the long run. Today the norm is .300 WM for the largest cartridge allowed and a speed limit of 3150 fps. I consider myself a novice because I only shoot these matches once in awhile, but have seen what has evolved over the years.

Correct, the 3,150fps speed limit is what I'm pondering out smarting.... Guys shoot slightly over it all the time depending on the altitude the match is at... One thing I noticed is guys that traveled to a certain 454ft above sea level range were all shooting low but liked to blame it on the mirage or humidity.. I say it's because their load development was at a higher altitude and they traveled down south and shot the same load plus the slow 1-8 twist instead of a 1-7.5 or 1-7.7 using a 105gr 6mm hybrid... When they dropped to a lower altitude the effects of not having a 1.5 and greater stability factor was more noticable compared to guys whom had 1.5 and higher...

 

[Rtheurer]

I am going to for go the thought of trying to buy points for the lack of skill on learning to read wind and trying to get a leg up on fellow shooters.

The meat and potatoes of the question minus all the gamesmanship is 6mm Creed or 6SLR for a case to run a 105 class bullet at 3200fps +

I went back and looked at some of my notes on loading the 6SLR. I have tried a lot of powders or at least gave them a quick try to see what would work. Sometimes just to see what kind of Velocity and Pressure I could get. One of the powders I looked at was Retumbo

Looking at Pressure and Velocity when testing. Here is a few that I got to test before work got in the way.
Winchester cases, Tula Primer, 105Hyb 22 thou off the lands.

Control Group.
Powder Velocity PSI ES
H4831 SC 43.52 3006 @ 56,022 18
H4831 SC 43.50 3019 @ 54,179 33

Retumbo 49.50gr 3208 @ 63,299 26 ( Note on test. Compressed with late ignition on 3 of 5 shots)
Retumbo 50.02gr 3229 @ 64,902 18 ( Note on test. Very Compressed, Late ignition on 5 of 10 shots,
.75 Milisecond later in pressure curve.) Loose pockets and leaking.

H1000 47.12 3086 @ 58,131 36 ( note on test, Good Fill Ratio, good Accuracy, high ES )

Only One shot each on the N160.

N160 44.02 3184 @ 69,477 ( Note on test Flat Primer, almost pierced)
N160 44.24 3190 @ 72,909 ( note on test, Blown Primer)
N160 44.42gr 3203 @ 71,519 PSI ( Blown Primer Brass Ruined)


Russ T

 

[Rtheurer]

I would like to Note that the H4831SC loads that I shoot are nice and mild and the brass didn't need to be full Length Sized until about the 5th Reloading. I expect it to go over 10 reloads. Once I hit the 61,000 Plus in PSI I need to Full Length size every time. I bet the brass only lasts about 5 shots and its toast.


Russ T

 

[Conrad]

Reloader 26 will do it but we've already gone over speed limits and such....

 

[SHootSTraight22]

Why do I even get suckered into these hypothetical probability threads ????
Arrhh

Russ T

Suckered in trying to explain to someone that you can't buy enough points to win if you have middle of the pack skill, you will still be middle of the pack, but you will spend more on components; and the only way to improve the skill is to get out and shoot. One of the guys at Oak Ridge commented to me a couple of yrs ago, "this isn't a bullet race; there aren't any prizes for fastest".

I don'[t think your understanding what I'm asking here... I've already evaluated my shooting and what is the most obvious is "my time and my mag/action feeding..." I lost half my points because of these matters alone... The points lost from these issues equals a greater number compared to points lost because of wind and skill... It's that simple!!! So, what I did was fix my chamber feeding problems by "milling out my feed ramp," plus I discovered my gunsmith didn't chamfer the entrance of the chamber... So, then I had a machinist make up a reamer to chamfer the entrance to my chamber so nI wouldn't have anymore feed problems... Okay,,, now we have that part solved, next is time!!! With time in mind I noticed that if I stopped dailing my scope as much but held for distance I could completely eliminate that issue as well!!! Simple!! Okay,,,,, now by having an extremely flater shooting gun I would make it a lot easier to be accurate during my hold overs.. Plus, with a flater shooting gun I have more lead way to be wrong on my dope or yardage, so when I'm wrong their will be less of a miss then if I were off on my dope with a slower gun.. That should be common scents...

 

[SHootSTraight22]

I am going to for go the thought of trying to buy points for the lack of skill on learning to read wind and trying to get a leg up on fellow shooters.

The meat and potatoes of the question minus all the gamesmanship is 6mm Creed or 6SLR for a case to run a 105 class bullet at 3200fps +

I went back and looked at some of my notes on loading the 6SLR. I have tried a lot of powders or at least gave them a quick try to see what would work. Sometimes just to see what kind of Velocity and Pressure I could get. One of the powders I looked at was Retumbo

Looking at Pressure and Velocity when testing. Here is a few that I got to test before work got in the way.
Winchester cases, Tula Primer, 105Hyb 22 thou off the lands.

Control Group.
Powder Velocity PSI ES
H4831 SC 43.52 3006 @ 56,022 18
H4831 SC 43.50 3019 @ 54,179 33

Retumbo 49.50gr 3208 @ 63,299 26 ( Note on test. Compressed with late ignition on 3 of 5 shots)
Retumbo 50.02gr 3229 @ 64,902 18 ( Note on test. Very Compressed, Late ignition on 5 of 10 shots,
.75 Milisecond later in pressure curve.) Loose pockets and leaking.

H1000 47.12 3086 @ 58,131 36 ( note on test, Good Fill Ratio, good Accuracy, high ES )

Only One shot each on the N160.

N160 44.02 3184 @ 69,477 ( Note on test Flat Primer, almost pierced)
N160 44.24 3190 @ 72,909 ( note on test, Blown Primer)
N160 44.42gr 3203 @ 71,519 PSI ( Blown Primer Brass Ruined)


Russ T

Thanks for the info! Do you have any data for H4350!! I'm interested in where the ejector marks start showing while doing a load work up with H4350.. I'm trying to see how much difference the greater case capacity makes compared to a 6mm Creed or 6mm Lapua... That in it's self will show the superiority of Lapua small primer cases because the little 6mm Lapua hits 3,150fps with no problem.. The 6mm Creed shoots there easily with some tweeking to the system, so it just makes scents that the 6SLR will do better given case capacity... I'm interested in how much better and how much is gained by this increase in capacity?? In other words is the increase in capacity just a waste of space and the 105gr hybrid won't hit a node around 3,200fps???....

 

[Conrad]

I think most everyone understands what you're asking, but I'll bite one more time, then I hope to be done.

H4350 is going to hit pressure in a 26" barrel, even 28" doesn't get you much extra. Again you need to think about effects of a hot day, or a rainy day. It will screw you if you're walkin the ragged edge. You said yourself you lost 1/2 the points due to time and feeding. If you fixed your chamber now all you have to do is practice on time. Get quicker with your thinking, positions, etc. The top shooters are the top shooters because they practice more. I'm not real sure why you've chose to ignore the speed limits, except that you made it evident you don't understand internal vs external ballistics. You're just asking for a DQ.

Christmas tree reticle allows for versatility, but it doesn't mean the problem is completely solved....in fact you introduced another variable...what if you hold the wrong dot in the heat of the moment again because you're not good with the time limit. It happens, trust me. Most of the matches give you the exact range to target. Some you have to range yourself, but usually by laser. I already posted 100 fps doesn't get you much and gravity is easy enough to dope if you keep up with DA through the day. 1 mph miss in wind call gives up all the wind you gained with 100 fps gain.

To come back to your missed points, you can't assume you have the skill to hit all the shots you didn't take due to time because you never got to take them. Speeking of feeding how fast is your rifle going to feed with a sticky bolt? There goes your time advantage. I seriously hope no one is shooting next to you, and I hope you're shooting an AI after seeing the guy on the Hide walk away from a catastrophic failure when using one. If you want more speed, use a bigger case.

Sorry to be brash, but you're walking a fine line of only listening to what you want to hear, and hoping to will physics in your favor....not wise.

Take this as me trying to beat some "sense" into you....not "scents"....

 

[SHootSTraight22]

I think most everyone understands what you're asking, but I'll bite one more time, then I hope to be done.

H4350 is going to hit pressure in a 26" barrel, even 28" doesn't get you much extra. Again you need to think about effects of a hot day, or a rainy day. It will screw you if you're walkin the ragged edge. You said yourself you lost 1/2 the points due to time and feeding. If you fixed your chamber now all you have to do is practice on time. Get quicker with your thinking, positions, etc. The top shooters are the top shooters because they practice more. I'm not real sure why you've chose to ignore the speed limits, except that you made it evident you don't understand internal vs external ballistics. You're just asking for a DQ.

Christmas tree reticle allows for versatility, but it doesn't mean the problem is completely solved....in fact you introduced another variable...what if you hold the wrong dot in the heat of the moment again because you're not good with the time limit. It happens, trust me. Most of the matches give you the exact range to target. Some you have to range yourself, but usually by laser. I already posted 100 fps doesn't get you much and gravity is easy enough to dope if you keep up with DA through the day. 1 mph miss in wind call gives up all the wind you gained with 100 fps gain.

To come back to your missed points, you can't assume you have the skill to hit all the shots you didn't take due to time because you never got to take them. Speeking of feeding how fast is your rifle going to feed with a sticky bolt? There goes your time advantage. I seriously hope no one is shooting next to you, and I hope you're shooting an AI after seeing the guy on the Hide walk away from a catastrophic failure when using one. If you want more speed, use a bigger case.

Sorry to be brash, but you're walking a fine line of only listening to what you want to hear, and hoping to will physics in your favor....not wise.

Take this as me trying to beat some "sense" into you....not "scents"....
[/quote

I guess I'm just looking at this as a challenge, to have a 6mm shoot 105gr Hybrids at 3,250fps accurately.. I have excess to plenty of Bartlien Gain twist 1-7.7 6mm .237bore barrels and I just can't help the ich to try.. I feel with Lapua Palma brass, a .180FB give or take, Russian 223M primers and H4350 I should have this puppy beat... I'll post back when the builds done... With that said what is it you think that makes a certain weight/caliber bullet not like to shoot accurately over a certain speed??? A lot of people agree the 105gr doesn't like to shoot over 3,200fps so what is it??? See, I'm a scientific minded person an instead of saying quit I say "will changing the bullets FOB enhance accuracy" at the higher velocities??? Will adding steel tips work?? That's what I ask..

 

[Conrad]

Fair enough, just do it safely. Gain twist, Reloder 26, and maybe hBN coated, and you will probably attain your speed goal. I mentioned RL26 in a previous post as did others, but I think it was overlooked.

I never said that the bullet couldn't be shot accurately over a certain speed. I said you were reaching diminishing returns while walking a fine line that could cause your the same problems you're trying to avoid in competition. To be fair this thread started out with you trying to push or "out smart" the PRS velocity limit, and most of us tried to say, "what's the point? just practice"....now we've settled on "let's just see if it can be done".....so in that light, sure, it can be done....

Understand I would never do this with any other powder. I got a good feel for pressures I might encounter first with Quickload. I am also shooting RL26 in other cartridges and realized significant velocity safely that I then backtested in QL. I pushed hBN coated 115 DTACs with RL 26 out of a 6xc with 26" Bartlein to 3237. 6xc Norma brass. Strictly a velocity/safety test, 1 shot each, and I really shouldn't have pulled the trigger on the last one because I had a decent extractor swipe on the previous, but bolt lifted ok on previous. I've put 1000's of 6xc rounds (multiple barrels) through this rifle and know it well. I would stop at sticky bolt lift. Last one at 3237 heavy extractor swipe, bolt sticky but not too hard to lift. Ran back through the first 3 charges, but did not fire 2nd lot of the last 2, deemed them unsafe. Last shot was probably pushing 71k psi. Verdict, I can push a 115 decently safe at 3140 to 3150 with RL26. I'd suspect I'd back off a little more from there looking for accuracy. Wasn't an accuracy test, but shots showed promise at 200 yards with magnetospeed on barrel. Read accounts of another guy pushing 105's to 3400 fps in .243, but there again he's working with a little more case capacity. He also had a 28" barrel.

I'm an engineer, and I'm all for testing and learning, but I also try to balance results with safety, equipment fatigue, and ease of use. I wouldn't run the above in a match. I'm happy running 105's at 3070 with a quick cycling bolt.

Good luck.