6.5cm barrel length, suppressed, factory ammo

[Jelliott4444]

My suppressed 20" CTR seems about perfect to me. 147 ELDM's at 2700 is a real performer on deer sized game an hogs.

I debated just getting a ctr but i figured it would just be easier to just use what i have. My gunsmith is on the way to work and will cut and thread my barrel for $150 so its not to much of an issue for me.

 

[Jelliott4444]

so, if it was a horse, you'd have to shoot it?

i do like where your head's at, you make some good points..... an 18" creed would do anything i need a rifle to do... i'm kinda pre planning an even shorter one (still not sure on 7-08 vs 6.5cm) for certain hunts... xlr mag atom, 14" barrel and probably a 5" can

my vote for the OP with his criteria is the 18".... easy to get caught up crunching numbers that don't really apply practically to us, i have been guilty of it a lot, and likely will be again

I stay up till 2am crunching numbers that dont matter all the time. Thats why i figured coming here would save me all that by hearing what results people are actually getting in the real world.

I was also looking at the xlr atom mag but unfortunately they only offer it for a remington 700. I think im going to try and find a used mdt lss.

 

[hereinaz]

I stay up till 2am crunching numbers that dont matter all the time. Thats why i figured coming here would save me all that by hearing what results people are actually getting in the real world.

I was also looking at the xlr atom mag but unfortunately they only offer it for a remington 700. I think im going to try and find a used mdt lss.

Whenever I start to get too deep, I just remember that guys and gals are out there killing moose, bear, and elk with a 77 tmk out of a .223…

Pick a bullet, verify the terminal velocity is high enough and make sure you can put the bullet where you want to. That’s all that matters. Bigger isn’t always better.

Look at lots of threads, guys often hesitate to cut their first barrel and compromise at 19 or 20 inches, but the next barrel they do it’s 16.5 inches.

All the math and drama on paper is a whole lot less important than what happens when a guy takes a rifle to the field.

 

[Formidilosus]

Time of Flight will control for both drop and wind drift. It’s what matters at any distance. The bullet that makes it to the target fastest wins. If a lower BC bullet has a sufficiently high MV, it will buck the wind better than a higher BC bullet with a lower MV within a given range. Depending on the circumstances, the higher BC bullet may or may not overtake the lower BC bullet at distance.

For instance, a 123 ELDM with a MV of 3,000 fps will outperform (both in elevation and wind drift) a 143 ELDX with a MV of 2500 fps out to at least 1,000 yards at my elevation.

Except that you are using a top speed for the 123gr and a low speed for the 143gr. The fact is that when both a low bc/high velocity bullet and a lower velocity/high BC bullet fired from the same rifle with top end loads for both, the higher BC bullet will always have less wind drift.

Using your example, when both are loaded to book max, the 143gr has .1 mil less drift at 500 yards than the 123gr at book max in a 10mph wind.

 

[hereinaz]

Except that you are using a top speed for the 123gr and a low speed for the 143gr. The fact is that when both a low bc/high velocity bullet and a lower velocity/high BC bullet fired from the same rifle with top end loads for both, the higher BC bullet will always have less wind drift.

Using your example, when both are loaded to book max, the 143gr has .1 mil less drift at 500 yards than the 123gr at book max in a 10mph wind.

Correct. I poorly tried to point out I t’s a balance of cost benefit. The faster bullet with shorter TOF has less drop. When difference in drift is within that .1 to .3 mil, given the cost benefit analysis I don’t have a problem going to the lighter bullets. But, if I were in a high wind location it would make sense to reduce that potential for error and go heavier.

 

[DJL2]

FYI, time of flight controls at any distance. It’s why some higher MV/lower BC bullets can outperform lower MV/higher BC bullets at certain ranges.

But I generally agree with what you’re saying. There’s definitely a limit to heavy (long) for cartridge. If I had a cartridge in the 2500 fps range, I’d be looking to step down in weight (length).

The difference between vacuum time and actual time of flight is what dictates drift (as a function of drag)… within the same cartridge, it is virtually impossible for a less aerodynamic bullet to best a more aerodynamic bullet’s wind drift barring a massive difference in MV.

To the OP, my 20” 6.5 CM runs 140s around 2600-2650 fps and 130s around 2800-2825 fps. That’s not dissimilar to my 22” 6.5 CM (different brand). I would have absolutely no qualms taking a shot to the limits of my capability, the rifle keeps either weight above 1800 fps past 600 yds.

 

[Formidilosus]

Correct. I poorly tried to point out I t’s a balance of cost benefit. The faster bullet with shorter TOF has less drop. When difference in drift is within that .1 to .3 mil, given the cost benefit analysis I don’t have a problem going to the lighter bullets. But, if I were in a high wind location it would make sense to reduce that potential for error and go heavier.

I generally prefer the 130’s in the 6.5cm/260 class for the lessor recoil and improved impact speeds in the ranges most of my kills happen as well.

 

[Kimber7man]

I generally prefer the 130’s in the 6.5cm/260 class for the lessor recoil and improved impact speeds in the ranges most of my kills happen as well.

Yep, I agree- just throw a 130 hybrid down a shorty 6.5 and get your knife out!

 

[Formidilosus]

Yep, I agree- just throw a 130 hybrid down a shorty 6.5 and get your knife out!

I have used the 130 hybrids a bunch. Only issue is that they really need 2,050fps impact or so to upset reliably. I end up shooting quite a few animals in the below 2,000fps range.

 

[Huntr]

I have used the 130 hybrids a bunch. Only issue is that they really need 2,050fps impact or so to upset reliably. I end up shooting quite a few animals in the below 2,000fps range.

Form- what 130gr bullet do you prefer?

 

[DJL2]

Form- what 130gr bullet do you prefer?

I’m just waiting to see if he gives the nod to the TMK or the ELD-M ;-).

 

[Formidilosus]

Form- what 130gr bullet do you prefer?

130gr TMK for terminal effects. The 130gr ELD-M works fine too. If your use keeps impact velocity over 2,050’ish FPS, the 130gr Hybrid OTM is very good.

 

[Jelliott4444]

Got it cut down. Haven't been able to shoot it but im very happy with it.

 

[ElPollo]

What length? Looks about 20”.

 

[Jelliott4444]

What length? Looks about 20”.

It ended up around 19. I wanted 18 but i forgot to take a piece of tape off and he cut on the opposite side i used to mark length. Not a big deal and it was my mistake anyway.

 

[HGL]

I've got an 18" 6.5 CM, don't use factory, but I get the following speeds from handloads:

H4350 with 139 Scenar at 2700
RL26 with 140 BT at 2775
RL17 with 120 BT at 2915
RL17 with 130 AB at 2800

 

[tak]

I've got an 18" 6.5 CM, don't use factory, but I get the following speeds from handloads:

H4350 with 139 Scenar at 2700
RL26 with 140 BT at 2775
RL17 with 120 BT at 2915
RL17 with 130 AB at 2800

You're getting those from 18" barrel??
Dang, that's impressive!