I recently had built a 6x45 (6/223) and would like any loading info you may have-Rem action-Donnaly barrel 26" or any other info ykou may have about this cal-I use 65gr Vmax
THANKS

i use 24 gr of H335 with a 70 gr nosler bt, if you do a search in reloading there's been quite a bit of discussion on the round in the past nice round, kind of like a 223 but bucks the wind better, nice soft recoil low noise. good stuff

Thanks for the reply-Ive been using 27 gr h335
with a 65 gr vmax-do you have any idea what speed you are getting? THANKS

never crono'd it, but i would tend to think its in the 2900 category

Any idea how the 70gr 6x45 load would compare with a 70gr 223 load? Noise, wind bucking, velocity, trajectory, striking power, etc?

noise is about the same, wind bucking is much better, bullet is more explosive, trajectory isn't much different. recoil seems much less, mine is in a redone mini 14 and is just used mostly for PD shooting

quote:

Originally posted by butchloc:
noise is about the same, wind bucking is much better,

My mind is a bit foggy this morning Why would a 6mm 70gr. bullet buck the wind MUCH BETTER than a 70 gr. .224 bullet assuming that the velocities are near equal. roger

Well Roge,

once the fog lifts... do you think maybe that the style of bullet might have a little to do with it??....

we have in one corner a Semi Round Nose ( of the design I prefer)...

in the other we have a sleek Spitzer bullet with a plastic insert, AKA Ballistic tip....

Based on both bullet construction design upon impact.... on small game I'd give the winner's award to the Ballistic tip... for heavier game, I'd pick the 70 grain Speer as being more lethal...

for trajectory,I'd give the nod to the Ballistic Tip as better at bucking the wind...

now when the argument over trajectory was going to be between a 69 grain Sierra Match and a 70 grain ballistic tip.. then at least in that sense, you then have a valid point.....

So.... as much as I like the idea of the 6x45, can I achieve the same using the range of modern 0.224 bullets and a fast twist barrel?

303Gy

quote:

Originally posted by seafire2:
Well Roge,

once the fog lifts... do you think maybe that the style of bullet might have a little to do with it??....

we have in one corner a Semi Round Nose ( of the design I prefer)...

in the other we have a sleek Spitzer bullet with a plastic insert, AKA Ballistic tip.....

What I'm reading does not , or is not comparing semi RNs to pointed bullets. I'm getting bullets of similar construction, same weight with the 6mm flying through the air a whole lot better. This ain't going to happen if they leave the barrel at the same or near same velocity.Is there some sort of divergence being entered here? roger

Well Roge,

Now being an aeronautical engineer, I can't statistically answer that question then.. but in experience I can see a flatter trajectory with a 70 gr 6mm bullet at x speed, versus the 70 grain 22 Cal Speer, at the same MV...

So I guess we have to chalk it up to magic...

Those are the results I am seeing, although my thought corresponded to yours until I tested it side by side and saw the difference at 300 yds...

of course once again, it could have just been the barrels in the various rifles...

but there was a difference when I wasn't expecting to see one..

maybe Clark can clarify it with some of his engineering explanations...

From one of my ballistics softwares here are some calculations of similar bullets in .224 and .243;

Muzzle Velocity = 3400fps.for both

400 yard drop. .243= 15.85",--->224= 13.04"

Remaining Energy at 400 yds..243= 663 ft.lbs. .224= 994 ft.lbs.

After all the .224 bullet is going to make a smaller hole in the air, displacing less molecules and using less energy to do so. A comparison of their BCs would have been faster.

roger

quote:

From one of my ballistics softwares

Show off.....

Yes, but you won't get the same velocity from your 224 and 243 pair. If, for example you shoot a 60 gr bullet from a 223 and a 6*45 (i.e. the same basic cartridge), the 6mm will have a solid speed advantage at launch.

quote:

Originally posted by jb747:
Yes, but you won't get the same velocity from your 224 and 243 pair. If, for example you shoot a 60 gr bullet from a 223 and a 6*45 (i.e. the same basic cartridge), the 6mm will have a solid speed advantage at launch.

You are exactly right.

As part of doing some study of the 6x45 cartridge (I'm thinking of building myself one) I compared a 6x45 shooting the 55g Nosler BT (BC=.276) with a .223 shooting the 55g Nosler BT (BC=.267). The 55g bullet from the 6x45 enjoys a significant MV (and thus energy) advantage when it leaves the muzzle, has a better BC and thus has a longer PBR and less drop. The results look like this.



Why? (retorical question since I'm pretty sure you already know the answer.)

The effective piston area on the 6mm 55g bullet vs the .22 caliber 55g bullet allows the 6mm bullet to be accelerated faster at the same pressure than the .22 caliber bullet. That, coupled with a slightly higher BC for the 55g 6mm bullet is why the ballistics are better for the 6mm bullet of the same weight.

I have to say I'm warming up to the idea of rebarreling a .223 sporter of some make or other to 6x45. I think it would be a heck of a fun walk around varmint rifle. Right now my favorite walk around varmint rifle is my CZ 527 in .223 Rem. I think the magazine is a bit short on the CZ for it to make a good 6x45 rifle other than single shot, but some other rifles might work just fine.

Fitch

quote:

Originally posted by jb747:
Yes, but you won't get the same velocity from your 224 and 243 pair. If, for example you shoot a 60 gr bullet from a 223 and a 6*45 (i.e. the same basic cartridge), the 6mm will have a solid speed advantage at launch.

I waited almost two years to reply to this. If you consider the published difference of 40 fps for the 70 gr. bullet a solid speed advantage than you are right. If you consider total tajectory influenced by BC you are a little bit off base. Check it out I did. roger