6.5 TCU

[Knotwild]

This question is for my own education. In another forum, a guy claims he is shooting the 6.5 TCU with 100 gr bullets at 2900 fps with a 24" barrel. I don't see that kind of velocity on the web any where, but he claims he has chrono'ed it at 2900. Is that safely possible with the little 223 case? He did mention cratered primers being the norm, but has not as yet mentioned the load.

 

[bheadboy]

in hand gun sil the 6.5 tcu with 100 sierra is outstanding - most shooters get 2500fps and that is out of max length bbls of 14"

another 10 inch bbl should give a major uptick in velocity but i dontknow how much.

Bob

 

[Knotwild]

Most of my reloading has been 6mm Rem, 243 AI, and 222. I guess what I want to be educated on is whether the cartridge is so efficient that it can accomplish this, or is it pushing the limits of safety?

 

[buffybuster]

I have a 6x45 (6mm-223Rem) with a long throat. I shoot 107SMK's loaded long (2.5") at 2600fps from a 20" barrel. A 6.5mm should be good for a bit more velocity in the same bullet weight but I don't know about 300fps more.

 

[Knotwild]

Thanks Buffybuster. I just wanted to know if it was feasible to get that kind of velocity and I don't have any experience with that cartridge. With the 24" barrel length, it seems feasible and it should be easy on barrel throats.

 

[65BR]

Figure 150 fps gain w/a rifle bbl vs. handgun.

A 120 will crack 2550, no more than 2600. I'd fathom anything over 2750-2800 w/100 in a rifle is over pressue IMHO.

 

[KevinThomas]

Simplest (and safest) way to reach these velocities is to move the screens closer together. Beyond that, I wouldn't stand too close, if you get my drift.

 

[Knotwild]

The high pressure issue is what I was thinking, since the guy said the primers were flowing into the firing pin hole. I realize the barrel is long, but I cannot find anything that backs up his claims of 30 gr of H322 pushing the bullet that fast safely.

I have a 600 Remington that I might re-barrel one day to something interesting for deer hunting here in the south, but I think I will stick with my original idea of a 250 Savage AI or something else that will allow a velocity of 3k or so and still give me room to play with seating depth in the limited magazine length the 600 has.

 

[65BR]

I assume it's a 222, possibly a 223. If so, stay w/same bolt face if you want something new, go w/a 6x45, possibly a TCU though the brass forming is not going to gain you much.

Shoot an 85 Partition, or Sierra 85 GKHP, or the 87 SP/HP (not vmax) and you will
kill all the deer you need w/in 250-300 yds or so.

I'd spin it 8twist, my TCU Carbine was a 12, marginal w/GKHPs. An 8 gives you options thru 107s...and a 105 Amax is what I killed a deer using a 6BR at 400 yds.

 

[bheadboy]

knotwild,

i have had a number of 600s and they can be very accurate. i think you may be overlooking one very good caliber for your use.

The 250/3000AI it is easily a 100gr 3000fps round and will take deer while being very accurate. lots of good .257 pills out there to choose from.

Bob

 

[Knotwild]

Thanks 65BR and bheadboy. John Lewis at CPR in Jackson, SC suggested the 250 Savage AI also. I used a 257 AI in a LA rifle for a couple of deer seasons, and liked it fine. I was initially thinking a short, efficient case to fit the short magazine box in the 600/660's. I also have a 6mm 660 that is factory and good for 1/2 inch groups with handloads. It is my "go to" gun for deer and much less finicky than my custom 243 AI.

You also made a good point about twist that I had not considered. My 243 is a 10 twist and is not fond of anything over 85 gr.

 

[BoilerUP]

I have a 6x45 (6mm-223Rem) with a long throat. I shoot 107SMK's loaded long (2.5") at 2600fps from a 20" barrel.

Mind sharing your recipe for that?

2600fps with 107s from a 20" barrel and a 5.56 case seems fantastic...