6CM testing Results

[Gundog64]

10436 +1 views when I read it. I've shot 50 grs. in my 30 inch, settled on 49 grs. Don't know what brass is in the picture, but 49 grs. in my brass is not that high up.

50grs. H1000 in Winchester brass fired 5 times comes up to the shoulder/body junction in my cases. Not sure why it is so high in Robert's photos, interesting.

 

[rcw3]

10436 +1 views when I read it. I've shot 50 grs. in my 30 inch, settled on 49 grs. Don't know what brass is in the picture, but 49 grs. in my brass is not that high up.

50grs. H1000 in Winchester brass fired 5 times comes up to the shoulder/body junction in my cases. Not sure why it is so high in Robert's photos, interesting.

All I know is I have an 8lb jug of it and it seems to take a ton of it to get any velocity. I had no information on how high others H1000 stacks, but mine is as shown in the photos (and that's why I made the posting on it because I don't mind a little powder compression but I'm doing some serious crunching to load with that and it bothers me to compress that hard).

FYI - On a whim, I have ordered another 8 lb jug of H1000 - I hope this changes things or something just does not add up.

The case capacity for the brass used in the photos has 55.3 gr. of water capacity (it's 4x fired Winchester brass re-sized with the 243 Egolf Imp. re-size die I got from Joe).

Do your case capacities fall in line with my reported case water capacity for the 6CM?

Robert

 

[Gundog64]

All I know is I have an 8lb jug of it and it seems to take a ton of it to get any velocity. I had no information on how high others H1000 stacks, but mine is as shown in the photos (and that's why I made the posting on it because I don't mind a little powder compression but I'm doing some serious crunching to load with that and it bothers me to compress that hard).

FYI - On a whim, I have ordered another 8 lb jug of H1000 - I hope this changes things or something just does not add up.

The case capacity for the brass used in the photos has 55.3 gr. of water capacity (it's 4x fired Winchester brass re-sized with the 243 Egolf Imp. re-size die I got from Joe).

Do your case capacities fall in line with my reported case water capacity for the 6CM?

Robert

Robert,
I measured 10 Winchester cases all fired 4 times in my gun Avg.= 55.51 I used the same reamer as the print Joe posted, even checked what was posted to the print Dave sent me. Matches spot on. It may just be your particular lot of powder. Can you post the lot number?

 

[Hoser]

Don't get me wrong, the 6CM is an excellent cartridge, and I am not saying it's not, but it's certainly not somehow magically superior to others (including the plain old .243 Winchester).

You are not directly saying that it is not a good cartridge I will give you that, but it is hard for me to overlook the fact you are going out of your way to bag on a cartridge that is in direct competition to your 6 Super LR...

The 6CM is not the end all of calibers, but in *this* thread most of us are using it and are very happy with it. Shall we go somewhere else to post info about it and brag on it?

 

[Nomad47]

I don't own or shoot a 6CM or a 6SLR so I think I am at least somewhat impartial. That said, some of the posts on this thread imply that the 6CM is some sort of miracle cartridge and far superior to all other 6mm cartridges.

 

[rcw3]

All I know is I have an 8lb jug of it and it seems to take a ton of it to get any velocity. I had no information on how high others H1000 stacks, but mine is as shown in the photos (and that's why I made the posting on it because I don't mind a little powder compression but I'm doing some serious crunching to load with that and it bothers me to compress that hard).

FYI - On a whim, I have ordered another 8 lb jug of H1000 - I hope this changes things or something just does not add up.

The case capacity for the brass used in the photos has 55.3 gr. of water capacity (it's 4x fired Winchester brass re-sized with the 243 Egolf Imp. re-size die I got from Joe).

Do your case capacities fall in line with my reported case water capacity for the 6CM?

Robert

Robert,
I measured 10 Winchester cases all fired 4 times in my gun Avg.= 55.51 I used the same reamer as the print Joe posted, even checked what was posted to the print Dave sent me. Matches spot on. It may just be your particular lot of powder. Can you post the lot number?

8 0426013725 - I have had it a while but it was always stored properly & I never had storage issues with any powders over the years.

Robert

 

[rcw3]

Don't get me wrong, the 6CM is an excellent cartridge, and I am not saying it's not, but it's certainly not somehow magically superior to others (including the plain old .243 Winchester).

You are not directly saying that it is not a good cartridge I will give you that, but it is hard for me to overlook the fact you are going out of your way to bag on a cartridge that is in direct competition to your 6 Super LR...

The 6CM is not the end all of calibers, but in *this* thread most of us are using it and are very happy with it. Shall we go somewhere else to post info about it and brag on it?

Hey if people want to brag, go ahead. I see this forum as more than just a place for shooters to brag.

As far as the issue of the 6CM and the 6mm Super LR being "in direct competition" - I don't know that is so. I don't sell the 6mm Super LR cartridge - - I offer it to people with all the data posted for free - - the reamer prints are posted for all to take and use as they wish. I sell dies for it (as I do for a whole bunch of other cartridges) and that's it. I could just as easy do the same for the 6CM.

If people want to shoot the 6CM - go for it - it matters not to me one way or the other.

One thing I notice on this forum is how "thin skinned" some people are. If you offer any challenge or critique (even if it's true) to what some people post, they get all worked up and personal. I think people lose perspective here - - for gosh sakes, they're just rifle cartridges we're talking about here.

People say they value "freedom of speech" but I don't really know if that's so as it seems for some it means they can say what they want but your not allowed to question or challenge what they say.

Regardless of all this - I appreciate your comment and commentary, enjoy your shooting, keep it fun, and if you love your 6CM that's great!

Robert

 

[davidd]

Way to much internet-in on here.
More shooting needed.
All one can do is post what is known and learned from shooting a cartridge.
That was why the internet was made,exchange information.
Without talking to a person face to face one is on his own to interpret how a post is to be taken....No?
If people take a post as bragging,boasting or claiming the 6CM is the holy grail well then,that's on them not on the person posting.

If anyone makes it to Vegas please look me up so we can exchange ideas and information face to face in a civil manner.
I know of a spot on BLM land 17 miles from my home.
It is ranged out to 1,100 yards in 100 yard increments.
Its is car assailable.
You can drive to and from the target.
If you have the time when in town we can send some rounds down range.
DavidD

 

[rcw3]

Ways to aid/help in "powder crush" is the manner of which one pours the charges into the case, and the length of the funnel used.
. . .

By pouring our charges "slow" and to "the side" of a funnel increases powder room. Using a 6", 10", or longer drop funnel with a "slow to the side" manner, greatly increases the room even more. The amount of "powder crush" can be minimized by simply pouring the powder charges slow with a drop-tube type funnel.

Happy Shooting
Donovan Moran

Donovan

Agreed and understood. If I do a fast pour with 51 gr of H1000 in my 6CM, it's actually slightly mounded up at the mouth of the case, but I don't do that with H1000 because the grain size is big enough it becomes prone to bridging in the funnel. I used a regular powder funnel and poured it at a rate where it does not bridge, then tapped the case a few times. Could I use additional measures to settle the powder more? Yes. Do I want to get into special powder handling techniques when loading? No. With loads like that in that case no matter what you do there's going to be compression.

Thanks for you input and info.

Robert

 

[rcw3]

Hi Donovan

Actually, I don't normally tap cases but I did so for the pics in the photos to settle the powder some (more than it was after just being slowly poured down the side of my powder funnel). So what you see in the photos is more settled than what you might see if I just poured it.

I remember a shooter that hooked up a contraption to his vibratory tumbler to vibrate his cases after loading powder to try settle powder more and avoid compression of the cartridge he was loading - now that's definitely "special".

Robert

 

[mod70]

Back when I used to load 4064 in the 220 swift I used to touch the case to the side of my vibrator tumbler it settled the powder.
John Roberts

 

[HPMike800]

Robert brings up an important point. The 6CM does allow for the use of H1000, but from the pics, 50grs of H1000 is about it. What kind of velocity is the average user getting with 50grs of H-1000? Roberts Ohler is saying 2990FPS with a 105 Hybrid. This may be important to some.

There are a couple of guys here that run "wonder 6's" off a 243 case, We have found that they tend to run best at 3030FPS+ with 115gr and 3080FPS+ with 105 bullets. So if you can't get there with H-1000 and you have to drop to H4831, is there still the barrel life advantage in the 6CM?

 

[doc gordon]

it must be nice to not need a scope,nice shooting !!!!!!!

 

[davidd]

Robert brings up an important point. The 6CM does allow for the use of H1000, but from the pics, 50grs of H1000 is about it. What kind of velocity is the average user getting with 50grs of H-1000? Roberts Ohler is saying 2990FPS with a 105 Hybrid. This may be important to some.

There are a couple of guys here that run "wonder 6's" off a 243 case, We have found that they tend to run best at 3030FPS+ with 115gr and 3080FPS+ with 105 bullets. So if you can't get there with H-1000 and you have to drop to H4831, is there still the barrel life advantage in the 6CM?

I can only respond with my first hand experience with this round.
Using my personally calibrated weight checked RCBS 505 scale 50 grains of H-1000 comes up to the neck and shoulder junction of a Winchester brand 6CM case.
Shooting a 105 Berger Hybrid bullet with 50g of H-1000 in a winchester 6CM case I get 3,287 FPS.
I also have a 3067 FPS load that is 47.5g of H-1000.
Barrel is a Brux Remington Heavy Varmint contoured 1 in 8 twist set at 28 inches as measured from the recoil lug.
All loads I have shot using the HB105s have been 1/2MOA or under.
I load to 2.810 OCL

For me the use of a chronograph is for only obtaining a ES for a round and just a ball park figure for FPS.
In order to get a true muzzle velocity I think it takes much more than just a chronograph.
This is what I do it may or may not work for you.
Now please keep an open mind,mathmatics and physics do not lie
Measure out a 1,000 yard range.
Use a 300 foot steel tape and get the range measured down to the inch (the range needs to be at lest 800 yards).
You need to do this as the difference of +or- 5 yards can be as much as one MOA depending on Velocity and BC of the bullet at this distance
Now take a properly calibrated Kestrel that will give you Denisty Altitude.
Now enter the proper information into a hand held ballistic program such as Shooter and get the firing solution.

Now shoot the rifle at a big paper target.
If you were high or low you then go to this screen and make the correction as to what it actually took to get to the target.
Now hit the calculate butten and if you have entered the proper and true data into the program you now have a true muzzle velocity.
Any range in the world,under any wether conditions be within .01mil/1/3MOA

 

[HPMike800]

I reach pressure at around 3200fps with 105's in my set up so If the 6CM can get that with H-1000 and a little wiggle room it's good to go.

 

[davidd]

What set up is that?

 

[rcw3]

Well, a box from Powder Valley showed up today with a new jug of H1000 (Lot #8 0320125023) and this is definitely different than the other jug of H1000 I have. 49 gr and 50 gr of powder is definitely more compact than the other jug. Below is a pic of the new stuff. More "juice" in it too. Chrono results today with the Berger 105 Hybrids and the new lot of H1000:

47 gr. H1000, BR-2 Primer, Berger 105 Hybrid - 2929 fps, ES 22, SD 8
48 gr. H1000, BR-2 Primer, Berger 105 Hybrid - 3027 fps, ES 25, SD 10
49 gr. H1000, BR-2 Primer, Berger 105 Hybrid - 3065 fps, ES 33, SD 13
50 gr. H1000, BR-2 Primer, Berger 105 Hybrid - 3125 fps, ES 39, SD 15

The thing that concerns me is that as the powder charges went up and compression became more pronounced, so did the ES and SD numbers. This is why I always stayed away from compressed loads and why I typically stayed in the 47 - 48 gr range with H1000. At 47 and 48 gr. there is very little powder compression.

I looked back at the original posting that started this thread wondering what the ES and SD numbers were and I note the ES or SD numbers supposedly would not properly register on his chrono, but that makes no sense to me. How do you register velocities properly but not be in a position to calculate ES and SD numbers? Maybe I just don't get it.

Robert

 

[davidd]

Your FPS with this round are still way,way slow.
Once again you are not achieving the published data for a straight 243win/H-1000 round
I get with 47.5g 3067fps

With a DA of 6234 feet as measured yesterday at the range and the 47.5g/3067fps load it should take 6.4mil to 1,000 yards.
6.4 mil of elevation in the scope was right on @1,000 so I know 3067 is what I am getting for FPS from the 47.5 load

A 50g load will put me @3287fps/5.4mil to 1,000
This is all with a 100y zero on the rifle.

 

[davidd]

How I understand the perpose of this cartridge was to get more than the average barrel life of a 243win.
It was designed to reliably get 3,000fps from a slightly modified 243win case using a slow burning powder.

 

[rcw3]

Your FPS with this round are still way,way slow.
. . .

The numbers are what they are. The chronograph is an excellent Oehler and I can post the printout tapes if people are wondering. I chronoed a number of different rifles yesterday and there's no chrono issue, and I am not buying a third jug of powder because there's no indication there's any issue there either (especially with the second jug). With H1000 - the 47 - 48 gr range loads are workable with that barrel.

The reality is - velocity doesn't matter without accuracy and consistency - it's a three legged stool and without all three you only have a "blaster gun" which is no fun.

I like using 20 shot group sequences (that's how I test). It's so easy on a forum to throw out blistering velocity numbers, but show me things will stay accurate and tight at that velocity for 20 shots and that would impress me a whole lot more because now we have accuracy and consistency coupled with that velocity. What I typically find is that a lot of those blistering velocity loads shoot 20 shot groups that are lousy (usually fall apart somewhere after about 8 - 10 shots). If you don't need to run longer strings of sustained shooting without a break (like in highpower) then maybe it does not matter that the group flies apart after 8 - 10 shots - shoot a 3 or 5 shot group, then take a break and let things cool down and everything looks good.

For me an E.S. that's not in the mid 20's or less with an S.D. in the single digits is also a "no go" for any serious long range work because the vertical component of the group suffers. H1000 has not been particularly good that way in my view.

Robert