.243 Barrel Questions

[idunham]

Hey all.

Couple questions about a .243 Barrel.

I've had a 110 in my cabinet for awhile now. Getting ready to dig into the build.

I'm looking at creating a 1000 yard gun. (I'm still unsure about using a .243 AI or a .243 Win. So, with that, i'll be pretty general about my questions.)

With the .243, what length of barrel should i be shooting to obtain maximum velocity? I've ready everything from a 20" barrel to a 26" barrel.

And, with that, I'm wondering what twist i should use. I would like to be able to shoot a heavier bullet, and at the same time be able to load a light bullet, and maintain excellent accuracy.

Thanks in advance.
Isaiah

[DrThunder88]

I used my .243 Winchester out to 1000 yards this summer, so it is definitely capable of going the distance. If you're planning on hunting large game with it at that distance, something a little more potent may be called for. Still, it will swing steel and punch paper without trouble.

Mine is a 26" Shilen pre-fit varmint contour with a 1:8 twist. I have been able to stabilize Berger 115gr VLDs at around 2900fps. Berger and many barrel makers will warn you that the 115s will need a 1:7 twist, and they are, of course, experts on their products whose counsel is worth more than mine. I am just telling you I have done it. There are plenty of great options in the 105-107gr range should 115s not be your style. I did get good results during load testing with 105s, but that was about as low as I had tested.

I believe LoneWolf runs a 26" 1:8 using 105s and is a far more accomplished long range shooter than I. Similarly, a young guy I met at the long range class I went to was shooting 115gr DTACs through (I believe he said) a 1:7. He too is experienced in the long range world. Moreover, he is another guy who knows what's up and is not pushing the limits. I'm neither.

[stomp442]

A 1:8 twist will stabilize the 105gr Berger Hybrid just fine as well as any weight bullet on down to the 55gr Nosler no problem. The 105 Hybrid actually has a higher BC than the 115 and can be pushed to higher velocities. If it were me I would run a 26" tube with the 105's as fast as I could accurately push them and 1000 yards should be just a walk in the park. Since you are building have you looked into the 6mmXC or the 6mm Creedmoor? These have a better case design and are a bit more efficient to help with barrel life.

[idunham]

A 1:8 twist will stabilize the 105gr Berger Hybrid just fine as well as any weight bullet on down to the 55gr Nosler no problem. The 105 Hybrid actually has a higher BC than the 115 and can be pushed to higher velocities. If it were me I would run a 26" tube with the 105's as fast as I could accurately push them and 1000 yards should be just a walk in the park. Since you are building have you looked into the 6mmXC or the 6mm Creedmoor? These have a better case design and are a bit more efficient to help with barrel life.

I've definitely considered a 6mm Creedmoor. I've also considered the .243 AI. But, my thought with a .243 win is simple to find ammo for, in quick situations.

Obviously i'd reload all of my ammo, but you never know what might happen.

So, with What you said, and DrThunder88. If i went with a 26" with 1:8, i should be able to shoot anything. Even 115s, if i really want to try?

[DrThunder88]

I'm just going to say that I have. Maybe not every barrel with every load can. What I'm trying to convey is that 115s are not out of the question with a 26" 1:8 barrel, but the people who make the bullets and the barrels will be able to say "told you so" if the combo doesn't work for you.


A 1:8 twist will stabilize the 105gr Berger Hybrid just fine as well as any weight bullet on down to the 55gr Nosler no problem. The 105 Hybrid actually has a higher BC than the 115 and can be pushed to higher velocities. If it were me I would run a 26" tube with the 105's as fast as I could accurately push them and 1000 yards should be just a walk in the park. Since you are building have you looked into the 6mmXC or the 6mm Creedmoor? These have a better case design and are a bit more efficient to help with barrel life.

I was always a bit confused by the BCs on the Berger 105gr hybrids. The G1 is higher than the 115s, but the G7 isn't. I had thought it was better to go by the G7 when using boat tail bullets. At any rate, a reasonably high MV for 105s would be 3100ish? At 1000 yards one of my 115s would be hitting just less than a mil lower, but most of the other measurements would be comparable. Still, it would be an excellent load, as you said.

[stomp442]

They are essentially identical .278 vs .279 but the extra velocity achieved by the lighter bullet would give it the advantage although slight. You might be able to stabilize the 115 out of an 8 twist but you more than likely will be leaving some BC on the table due to marginal stability which brings us right back to the 105 hybrid.

[LoneWolf]

I just switched to the 105 AMAX. In my 26" 8Twist. A couple of reasons.
1. Cost
2. OAL in the .243 is 2.75
3. Nearly identical ballistics with the Hybrid.

I also found with the same charge of H4350 I got 2965fps with the Hybrid and 3025fps with the AMAX.

The AMAXs seem to have very consistent BC's and match up perfectly with the Shooter APP and litz's data.

If you go 6mm I would go with the 6 Creedmoor, 6x47 Lapua, or 6XC.

You get a lot of mag length back and the same performance with less powder. I stayed 243WIN because I was already tooled up for it. It's still a great performing round, but it has its draw backs.

[mikgarus]

I just switched to the 105 AMAX. In my 26" 8Twist. A couple of reasons.
1. Cost
2. OAL in the .243 is 2.75
3. Nearly identical ballistics with the Hybrid.

I also found with the same charge of H4350 I got 2965fps with the Hybrid and 3025fps with the AMAX.

The AMAXs seem to have very consistent BC's and match up perfectly with the Shooter APP and litz's data.

If you go 6mm I would go with the 6 Creedmoor, 6x47 Lapua, or 6XC.

You get a lot of mag length back and the same performance with less powder. I stayed 243WIN because I was already tooled up for it. It's still a great performing round, but it has its draw backs.
What are the drawbacks?

[LoneWolf]

Running out of mag length with the longer pills, hitting pressure signs sooner, shorter barrel life due to using more powder to get the same velocities. I dumped my first barrel at 1400rds due to not being able to reach the lands due to mag length restrictions.

[idunham]

So much information. Thanks guys!

I think i'll stick to the 26" 1:8 twist. And if i decide that i -MUST- shoot 115s, then i'll buy a new barrel.

[idunham]

Last question (for now):

If i got a 1:7 twist - would that have any negative impact on 105s?

[LoneWolf]

Nope I started with 115 DTACS in a 7 twist and switched to the 105 Hybrids without issue.