Seating depth / longer bullet question.

[Maxxis31]

I'm currently shooting a 108 in a .243, I'm .020 off the lands at almost max mag length. Would there be any advantage going to a 116 bullet with higher BC? I'd imagine I'll have to stuff it further down in the brass/powder since I'm almost at jamb anyway and will likely still be at the same coal with the mag. It's a tikka so I could swap to a M+ magazine but I'll only gain .020 before I'm touching.

Just curious, I'd imagine pressure will go up with a heavier bullet, especially one stuffed deeper into the brass. I could run a slower powder and go compressed but is it even worth the time and effort?

I like the idea of heavy for caliber bullets and sierra is releasing a new TMK that I'd like to try.

 

[Mikecr]

Don't choose a bullet, or load, based on COAL/CBTO, nor vice versa.

 

[jseandsje]

If the 108 shoots to your standards, leave it alone.

There will be practically no improved range for hunting, nor targets shooting

 

[MagnumManiac]

Firstly, what ranges are you shooting to be concerned about raising BC?
TBH, unless you're shooting beyond 700, BC really doesn't do much to this point other than less wind drift, but, as muzzle velocity rises, TOF reduces.
Need more info.

Cheers.

 

[lancetkenyon]

WHAT 108 vs 116?
That makes more of difference than just weight alone.

 

[Maxxis31]

WHAT 108 vs 116?
That makes more of difference than just weight alone.

I'm shooting an ELDM, I just put the gun together and haven't done much load development besides load to max coal for my magazine and tried a max load and .5 under max.

It shoots about 3/4" for 5 shots, actually shot 3/4" for 9 shots and the 10th shot out and turned it into an 1 1/8" group.

I'm planning on using either Sierra TMK107's or 116's. I have 107's on the way but 116's aren't shipping yet. The rifle has a 16" barrel and will be used for killing all varieties of big game. TMK's have lower upset velocity than most and great BC which are both ideal from a 16" barrel with lower muzzle velocity IMO. BC of the 107 is .574 and the 116 is .609, both are good in a .243.

 

[MagnumManiac]

The rifle has a 16" barrel and will be used for killing all varieties of big game

For such a short barrel, you want as much muzzle velocity you can get, which means going heavier is not your answer here.
BC is not constant, it has velocity windows that are correct only at that velocity, you drop below that velocity and BC falls away.
This can be proven by doing a simple drop test shoot to 600.
The other thing is, BC does not come into play until you are beyond about 500, 600 shows up more info than 500, but regardless of this fact, BC means diddly squat inside of 500, so worrying about BC is fruitless at this point.
You have not mentioned what ranges you expect to shoot at. This matters…

Cheers.

 

[Maxxis31]

For such a short barrel, you want as much muzzle velocity you can get, which means going heavier is not your answer here.
BC is not constant, it has velocity windows that are correct only at that velocity, you drop below that velocity and BC falls away.
This can be proven by doing a simple drop test shoot to 600.
The other thing is, BC does not come into play until you are beyond about 500, 600 shows up more info than 500, but regardless of this fact, BC means diddly squat inside of 500, so worrying about BC is fruitless at this point.
You have not mentioned what ranges you expect to shoot at. This matters…

Cheers.

I shoot my 280AI pretty often out to 1K and regularly out to 600. I would like to shoot this rifle as far as it shoots well and depending on that I will decide how far I'll take game with it.

If I can shoot well and it shoots consistent small groups at 700 yards I wouldn't have any reservations harvesting an animal at that range which is why I want to shoot the TMK because they have a lower upset velocity then most other bullets and a high BC.

 

[Mikecr]

I would like to shoot this rifle as far as it shoots well and depending on that I will decide how far I'll take game with it.

Perfect approach right there. We should all be disciplined to think like this.

 

[nube2.0]

Try playing around with your seating depth. Most elms like to jump 60-90 thou vs 20
I would do that before I switched bullets