6mm tcu vs 6mm bullberry imp

[Oklacoyotekiller]

am saving up to get new barrel for contender carbine. toss up between tcu and bullberry. only load data I've found for tcu is for 14 inch barrel. curious about real world velocity from rifle. anyone had experience with bullberry? will mostly be with 70gr and lighter bullets.

 

[Oklacoyotekiller]

guess no info on tcu carbine?

 

[LoonWulf]

Cant help you with the TCU or bullberry. Ive got a 6x47 (222rem mag) and drive 70grn balistics to 3000 and change from my 24" barrel. The TCU i belive uses around the same volume of powder, so velocity should be pretty similar. Ive found my 6x47 will drive the same weight bullets as its parent cartridge at the same velocity or just a tad faster.

 

[Oklacoyotekiller]

thanks! What kind of groups you getting? what powder and bullets? any idea if offered for contender?

 

[LoonWulf]

Bullberry offers 6x47 for the contender in both standard and improved form (basically a .204 necked up to 6mm). I use w748, imr4895, and BLC2 in my remington 700adl. Best groups with those noslers ran right around 1/2". Velocity should be 2900-3050 with the 70s.
Most of my work has been with heavier bullets, ive driven 88grn berger vlds to 2950 and 95s to 2900 and change, but those loads are on the ragged edge, they will blow standard winchester primers, Federals and CCI magnums dont have an issue. I couldnt get decent accuracy till velocity go up that high tho, 1-10 twist is a bit slow for those long bullets. best i could get out of 100s grn spitzers was about 2600fps, but they shoot very well.

 

[Oklacoyotekiller]

thanks again! may go that option. slow twist shouldnt be problem with lighter bullets i use. love 243 for yotes but looking for little more efficient load.243 eats to much powder.

 

[LoonWulf]

yeah i have a .243 also and i dont use it nearly as much as my 6x47. I think the whole family 6x45,47,TCU etc. are a great compromise, much better bcs then .22s at the same velocitys. Ive just finished loading some 65grn vmax over the same charge of w748 i used with my 95s, goes to show how short the bearing surfaces is on those VLDs. I hope to get out and shoot them this week.

 

[Oklacoyotekiller]

the 65gr v-max is my favorite bullet out of 6mm. absolutely devastating on coyotes. let me know how they work out.

 

[LoonWulf]

will do, i dont like shooting on the weekends so ill probably go monday.

 

[Kernel]

Just spit ballin’…. the 6mm Bullberry imp is based on a .30-30 case. It will hold about 48 grains of powder. The 6mm TCU is based on a .223 case and holds around 33 grains of powder (the TCU I have, in a 14“ Contender barrel.. also the near identical 6x45 in a 24” Ruger Ranch Rifle). As a result of it‘s lager volume, the BB has a 30% advantage in powder capacity. Everything else being equal (bullet wgt, primer, barrel length, powder type, pressure, etc.) and using a long accepted handloading rule-of-thumb, the BB should yield a 15% velocity advantage with any given bullet.

 

[Viper225]

I have a Super 14 Barrel in 6 Bullberry Imp.

My loading data on my ammo box says:
70 grain Ballistic Tip
36.0 grains of 748
2950 FPS

Making brass from 30-30 is interesting. Best I remember I sized it in a:
7 X 30 Waters
6.5 X 30 JDJ
25 - 35 Winchester
6 Bullberry Improved
Trimmed for length
Then used an inside neck reamer, best that I remember.
Then Fire Formed the cases

It is one bad looking case. No one would ever believe it started life as a 30-30 Winchester until you look at the rim.

If I seam a little vague, I probably have not fired my 6 Bullberry Improved in over ten years, and possibly 15. I was planning on doing some Coyote hunting that I have never got around to doing.



If you end up going with a 6 TCU give me a shout, I have a set of dies I would part with.

Bob

 

[Oklacoyotekiller]

thanx viper. when i decide which way to go will let you know.

 

[LoonWulf]

Thought id give you a heads up. The 65vmax shot into a 1/2" or so cluster out of my 6x47. It started raining so i didnt get velocity, will try later.

 

[vmthtr]

http://www.bullberry.com/6mm.html

Link to Bullberry loading data

 

[Oklacoyotekiller]

man. that thing shoots like a laser. still tryin to decide which way to go. Eds contenders in okc has tcu in stock though. have bucket of 223 brass also. decisions decisions

 

[LoonWulf]

I like the tcu lol, i also realy like my 7-30 waters contender. I have thought about a 6.5 bassed off the 7-30 case. I think jdj actualy has a version on the 30-30. Push come to shove if you go with the tcu and dont like it you could get it rechambered to bullberry.

 

[Fatelvis]

Go with the Bullberry. It is a more powerful cartridge. You can always load it down, if you like. You can't load the TCU up any more.

 

[LoonWulf]

Personally the only thing with the bullberry is that i dont see a huge advantage over my 6x47 or the 6mm TCU, or even the normal 6x45. The load data posted shows it using a grain or two more powder and generating about the same velocities. IMO it dosnt justify the case forming. I dont know much more about the cartridge then that, so if there is hotter data available i havent seen it.
NOW that said, I also dont see anything WRONG with the bullberry.