6BR vs 6CM

[JHardy]

Joesr:

Suppose that someone reading this thread for months makes a decision to chamber a LR prone gun in 6CM. Can he purchase the reamers from, say, Dave Kiff, with a print? Can he have the gun smithed by Al Warner, for example? Can my smith or Jim Carstensen cut the dies?

If the answer to all of these questions is "yes" then I would like to chamber a barrel in 6CM, and will order the reamers ASAP so that I can chamber three barrels: one for my prone gun, one for my F-Class gun, and one for my light class 1000 yd BR gun.

If the answers to my questions are "no", please explain. Tell me something good.

Thanks in advance,

Jim Hardy

 

[243Mendoza]

...
You are the first person I have ever come across that claims 5000 rounds through a 6BR barrel and shooting the longer ranges.

Possibly you just have a great barrel that will not give up. However I would be very interested to know what bullet you are shooting and at what velocity.

I've used about 2000 Sierra 107s and the remainder are Berger 105s moving over 2900 fps.

Furthermore, and I'm not saying you are doing this, but may people over estimate the amount of rounds through a barrel. I know that because I used to do the same thing. I track every round through my barrels in a book that I keep with every gun. If you don't do this the estimation is flawed.

I keep records of every match/practice/load development that I do in a notebook.

...However, I will state that the 6mm's seem to be inherently more accurate than other cartridges.

That may be true but wind performance at 1000yd is also very important and probably more important than performance at shorter distances.

If we limit the discussion to 600 yard shooting. The shooter has to make a choice between shooting a cartridge that has proven accuracy in the short range benchrest shooting and can drive the 107 at velocities at 2700 or 2800 fps. The 6BR has has expected barrel life of around 3000 rounds shooting it this way.

As I said before, and others on this forum have also, 3000 rounds out of a 6BR is low. Maybe you expect more x's!
I would probably agree that the the 6CM is a better XC cartridge as it takes some mods of the magazine to make the 6BR feed reliably.

Or

The shooter can choose to shoot a cartridge that will shoot the 115 at 3000 to 3200 fps with the same accuracy,at these distances) and give you an expected barrel life of 3000 or more. The 6CM, or for that matter the 6XC is far superior to the 6BR simply because of the larger bullet and more velocity. Unless you shoot every match with zero wind the 6BR simply should not be the chosen cartridge for shooting this type of competition.

Agreed, I have not seen anybody shoot the 115 out of 6BR

Once you go to 1000 yard shooting; it is like flipping a coin. The 6CM, 6XC and 6.5x284 are all great choices for this shooting. The one thing that needs to be stressed here is that if you shoot both 600 and 1000 yard matches with the 6CM or 6XC you can shoot both with out giving up anything.

This is were my interest lie. Because of your convincing advocacy that the barrel life of a 243 can be a least 3000 rounds, I am having a gun build based on a modified 243.

 

[joesr]

Joesr:

Suppose that someone reading this thread for months makes a decision to chamber a LR prone gun in 6CM. Can he purchase the reamers from, say, Dave Kiff, with a print? Can he have the gun smithed by Al Warner, for example? Can my smith or Jim Carstensen cut the dies?

If the answer to all of these questions is "yes" then I would like to chamber a barrel in 6CM, and will order the reamers ASAP so that I can chamber three barrels: one for my prone gun, one for my F-Class gun, and one for my light class 1000 yd BR gun.

If the answers to my questions are "no", please explain. Tell me something good.

Thanks in advance,

Jim Hardy

Jim,

I've taken some time to put together an answer for you on the above.

First, let me state that we are having unbelievable success with the 6CM. Every customer is pleased beyond their expectations.

Take a moment and think about that above statement.....

……with all the cartridges out there and so many 6mm's it is unbelievable to me that my cartridge is showing/proving to be as good as it is. I knew, after I shot it the first time in a match, that this was the only cartridge for me, but to have ALL of my customers so pleased with the results is beyond my expectations.

Furthermore, it is beyond comprehension that a new 6mm cartridge could make a truly significant difference to a shooter already shooting a 6mm.

However, that is what the 6CM is proving to be.

I have customers that only shot the 6BR and believed that the 6BR was the cartridge to shoot and once they tried the 6CM we are rechambering their 6BR barrels to 6CM.

What the 6CM is proving to be is a cartridge that is giving as good or better accuracy as the 6BR. Velocities from the 115 of 3050 to 3200 fps, and barrel life of 3000 to 4000 rounds or more.

What we have done with this cartridge is not magic it is based on a commonsense change to the 243 Win cartridge. Improving the shoulder angle, lengthening the neck and adding case capacity is the recipe for the cartridge.

I know that the cartridge is not the only reason for the success. The loading, using very slow burning powders is also very important.

I have worked very hard to put together the package of this cartridge, specific loading techniques, specific cleaning techniques, specific barrels to be used with the 6CM and most importantly I have partnered with a very good...no great...gunsmith to build my 6CM rifles.

We are more than happy to build you a rifle or chamber your existing rifle to 6CM. However, we are not in the business of selling reamers.

I know that every 6CM that comes out of Dave Bruno's shop,Bruno's Gunsmithing Cheswick, PA) is of the best quality.

I would be very happy to build you the best 6mm you ever shot. My pricing is competitive, our turn around time is very fast and our product is second to none.

I apologize for saying no to selling reamers. However, I am partnered on this and we have a special product in the 6CM and we produce a great product in the rifles we build.

If you are still interested in shooting the 6CM you can contact me several ways: email is 6cm@comcast.net and the phone is 724-622-0747 or 724-933-8110.

Joe Hendricks
Hendricks Shooting Improvements

 

[sparker]

Joe,

One problem here is that the lack of availability of reamers does not allow for individual confirmation of results from other sources. It is like the scientist that says cold fusion works but only in his laboratory.

Another problem and by far the more important one, is that it demands that the shooter in casual disregard, cast aside his relationship with his own gun smith, so that he may shoot a different cartridge. My smith has built me one national record setting rifle. Will you guarantee me a rifle that will do the same?

Scott Parker
Bakersfield CA

 

[chrisj]

Joe..don't be offended by this..but..why couldn't anyone take a fired 6cm case and send it to a reamer manufacturer and have a reamer made? That is what I did with the 6.5 Grendel, before reamers were available for that caliber.

Chris

 

[LESLEY]

Im one who has changed to a 6cm i like enough that im having 2 BAT rifles built in it 1 for f class 1 for tactical. I will let eveyone know it works out. The last one i had built was on a 700 action without any blue printing and i shot very very good with it. I won the match shooting with poeple with scopes that cost more that my whole rig. Bruno which is Joes gunsmith built it. And i live right down the road from SGY speedy. That is how good brunos work is

 

[rcw3]

I for one have no problem with Joe Hendricks not putting his 6CM reamer into the "public domain". The guy spent his time and money and developed something different, put it to use, tested it out, and perfected it. Now why should he not be entitled to try to:,1) Recoup what he had to lay out to develop and perfect it; and,2) Make a reasonable profit as well. Seems like "the American way" to me. If I decide to have a rifle re-barreled to a 6CM I would not hesitate to do it through Joe's business.

Joe has a strong conviction in the merits of his cartridge, but one thing is clear, I have not seen any of his customers complaining about the 6CM or the quality of what he offers on the forums. To me that says something.

Robert Whitley

 

[sparker]

I understand completely the idea of recouping on an investment. The obvious way to do that is to be the sole proprietary source for the tooling. That is fair. If the assertion is that only his smith can make the cartridge shoot correctly, well I can not put any stock in that. If one is trying to generate a "cult"-like following then Joe's business methodology is correct.

Scott Parker
Bakersfield CA

 

[joesr]

Scott,

Two very important things you need to understand about me....

First: I did not design the 6CM to make money. I designed the 6CM to give me a competitive edge against other shooters.

You may then, ask yourself why am I then sharing all of the information and basically advertising the cartridge.

It is simple....shooters didn't believe that a 243 sized cartridge could do what the 6CM does. Proving my ideas, personally, drives me. If I kept all of this info to myself and only shared little bits of the success with the shooters I shoot shoulder to should with I would not have been able to prove to the masses that they were wrong.

This is obviously a huge personality flaw. It is probably the personality flaw that has made me the shooter I am and drives me to be even better.

However, I am not and was never interested in turning this into a business. It has become a business that I spend hours working on to make sure that every customer I service is satisfied.

The best part is that I am well on the way to having shooter understand my point and the masses are beginning to catch on to the fact that a 243-sized cartridge can shoot winning scores and most importantly the barrel life from these cartridges is great! Better than the undersized cartridges that come close to the velocity of 3000 fps from the 115,6XC, 240NMC, 6-22-250, etc). These cartridges can yield simular velocities with moly coating and faster burning powders, but the barrel life is limited to 1/2 of a season the way I shoot. The 6CM give better velocity and lasts for a season or more.

The second thing you need to understand is that I have very good friend who is the best gunsmith I know. This doesn't mean he is the best gunsmith in the world, but I think he is.

I have partnered with him on this and this is his business. If I can help him make a few extra dollars then that is a plus to this endeavor.

If I were to give out the specification of the reamer or sell the reamers he would not make any money. He has been very important in the development of this cartridge and he should benefit from every 6CM chambered.

I know that your gunsmith could chamber a rifle for the 6CM and probably it would shoot as well as ours. From the emails I get I could probably sell 15 or 30 reamers immediately.

I understand that most shooters have a gunsmith that they trust and that the shooter wants that gunsmith to do all of their work. This is fine with me. You can always shoot a 243 Win with the same loading techniques and get close to the 6CM or you could take some time and improve the 243 to make it simular to the 6CM. Possibly your first try would not work out, but eventually you will get it correct.

You can spend the time on development and money on reamers and gauges just like I did during this project.

I have no problem with any shooter using his or her gunsmith and recreating the 6CM to the best of their abilities.

If I am generating a cult like following that is great. I never intended to mass-produce the 6CM.

The bottom line is that for myself, and my customers this 6CM is working better than expected and we are reaping the benefits.

There are no hard feelings if you decide not to have us chamber a 6CM for you and I expect there are no hard feelings because I will not sell a reamer.

If you would like to contact me directly so that we can talk this out further you can email me at 724-622-0747 or email me at 6CM@comcast.net

Joe Hendricks

 

[sparker]

Hi Joe,

No hard feelings at all. I was in no way trying to impugn your integrity or motives. I was simply trying to talk through the philosophy of exclusivity of a cartridge. There are ethics involved that go beyond the product. I am trying to sort this out as I will be facing similar dilemmas in the near future. I am happy that your experimenting paid off and more importantly, that you were able to build a better mouse trap. The triumph of creativity should always be celebrated.

Cheers to you,

Scott Parker
Bakersfield CA

 

[JERRYHM]

I would like to thank Joe for my 6CM.
We were looking for a 6mm that would perform with the 6.5-284 and have less recoil with longer barrel life. This was to be for my wife who shoots F class, she had been shooting a 6BR dasher and it just will not hold with the 6.5-284 with the winds we have in Sacramento. The 6CM was chambered into one of my prone rifles for load development and testing. Received the rile last Thursday, I had one day of barrel break in and load testing before the weekend matches. I won our three 600 yard prone matches with a 598-30x using three different loads. Luck would have it I was shooting next to a 6.5-284 and YES the 6CM was shooting inside of it.

I was sharing my chronograph with a well known long range shooter on Friday, we both had new 6mm's and were load testing at 100 yards. His new 6mm was a 6X47 with pretty black 115 bullets, he lost primers just over 3000 fps and his best 5 shot group was in the .8's....He sure wanted to know what I was shooting, I was using copper colored 115's around 3100 fps and all of the groups were in the .3's.

Jerry

 

[mysticplayer]

I have been following this thread with great interest because I love wildcats and better mousetraps. I do a fair amount of wildcatting myself.

The issue some will have with the moderate size cases run at very high velocities is wonderfully illustrated in the post above.

Many barrels/loads will not shoot well,match accurate) when operating pressures exceed 70,000PSI,SAAMI mag pressure is usually 65000PSI). If the shooter is blowing primers, then we are talking 80000PSI and up. Doesn't surprise me his rifle shot poorly. Loaded to where that case volume should perform ie somewhere around 2800fps with the 115gr bullet, I am sure he would be shooting small groups again.

We tend to run small cartridges at elevated pressures in the BR game. Sometimes it works, sometimes is doesn't.

However, there is 'never a replacement for displacement'. It certainly doesn't surprise me to see the results that joe and others are getting with the 6CM given the much larger case capacity compared to the XC and similar cases.

Run an improved 243 at reasonably high pressures with a well matched 'fuel', voila, more velocity with the potential to maintain accuracy. Great stuff and a very nice way to approach the LR game.

Out of curiousity, I dropped some numbers into the JBM program on the internet. Made the assumption that the 115gr 6mm had a BC of 0.575,I have seen this value used in many posts) at 3100fps. Then I compared it to a 139gr 6.5 Lapua,just used the data from the programs library) at 2900fps since this is what I shoot with my 6.5 Mystic. Here is what the program spat out,no changes to any default settings).

Wind drift for the 6mm at 600yds - 20.5"; at 1000yds - 64.9"

6.5mm at 600yds 20.8"; at 1000yds - 65.7"

If the real world BC of the 115gr 6mm bullet is higher, then the difference would of course be greater.

Jerry

 

[rcw3]

Jerry

Thanks for the report.

Your friend is trying to push his 6x47,I assume a necked down 6.5 x 47 Lapua) way too hard, no question about it. In addition, the case capacity of the 6x47 cartridge is not right for 115's - too small to effectively drive that bullet in a 6mm bore at anywhere near 3000 fps without being over "red line". I won't get into the moly debate, but that won't solve his problem either.

Do I gather you are pleased with the 6CM?

Robert Whitley

 

[JERRYHM]

Robert,
Yes I'm pleased with the 6CM.
We shot quite a few 115s in the 6BR dasher,in the 2900 fps range) sometime very well, but it did not have the horse power to push them. It was obvious a large case was needed to get the MV over 3000 fps. I did not think the 6XC, 6-250 or 6x47 would do the job.
Jerry

 

[M700]

Jerry - thanks for the detailed info on this interesting round.

I've been shooting only the .308 Win at long-range, but am always considering different cartridges which will do better.

Regards, Guy

 

[JERRYHM]

I put a BC of .580 in the ballistic program, the come up from 100 yards to 1000 yards was 24.3 minutes. I used 24.25 minutes above the 100 yard zero and the first three shots at 1000 yards were in the X ring. It would seem the BC is in the 570 - 580 area if my scope clicks are accurate.

 

[rcw3]

Well I just could not resist - I just put an order in with Joe for a 6CM - I just have to give the 6CM a try and see for myself. I need another 6mm wildcat cartridge to shoot like I need a hole in the head, but just like a deer staring into the headlights of a car, here I go.

Thanks Joe!

Robert Whitley

 

[Dgd6mm]

could not help myself, had to bring it to the top.

Thanks Joe,
Don Dunlap

 

[teele1]

I too love my 6CM. Wish I had as many as some of my friends.

 

[kombayotch]

What is the water capacity of the 6CM?

What would be a typical powder charge weight with a 115 DTAC and Retumbo that would get 3000-4000 rds. of barrel life?