Expected velocities from 22” barrel 6.5 CM 129 grain?

[rmiked]

Looking at some JBM ballistics for 6.5 CM. What kind of velocity should I expect from my new Seekins SP10, 22” barrel, 129 grain? The Hornady SuperPerformance looks to be 2950 with 24” barrel. I’m guessing 100 for slower (2850) with 22” barrel. The Hornady American Whitetail 129 looks to be 2820. Guessing 2720 with 22” barrel? Anyone shot these thru chronograph?

 

[bfoosh006]

Careful with the Superformance ammo.. it can be weird in SA rifles. The gas pressure curve is "longer".

And this might help you guesstimate >>
https://rifleshooter.com/2016/02/6-...el-length-on-velocity-cutting-up-a-creedmoor/

 

[rmiked]

Nice article. 2872 fps with Hornady 120 grain factory ammo in 22” barrel. Not bad at all.

 

[Gtscotty]

In general, I'd look for 25-30 fps per inch loss in the 24" - 20" range. Maybe a little more in the shorter barrels, but not much.

 

[LRRPF52]

I’ve shot a bit of 129gr in .260 Rem from a 22” gasser. Expect 2750-2820fps using H4350, and occasional bent firing pin retaining pins.

If you have Extended Length Gas System, it should be easier on your firing pin retaining pin, primers, and brass.

Don’t expect to chase book load data for bolt guns though without consequences.

 

[BCP]

Don't worry about it. I would guess 2850 for 123gr match handloads and 2700 for 140gr handloads. Both of which are enough for "ONE THOUSAND YARDS" lol. Load for accuracy and shoot it a lot imho.

 

[towerofpower93]

Here's data from a 25rd group I put through my 22" 6.5C AR-10 a few weeks ago. 130gr Berger AR Hybrid, but that's pretty close to 129gr. This upper has a rifle +2" gas system and adjustable gas block to deal with the re-cored SDN-6/Ranger 7 can on the end.

18OCT2023 VKX
22” 6.5C AR-10 suppressed w/ SDN-6/R7
130gr Berger AR Hybrid
Rem 7.5 SR primer
Virgin Starline brass FLR’d
StaBall 6.5 45.6gr
OAL 2.750”

Labradar series: 245

25rd group

Lo: 2856
Hi: 2918
Avg: 2882
ES: 63
SD: 15.4

 

[rmiked]

Wow! Very impressive IMO. I am used to shooting 300 WM and accustomed to flat trajectories. I don’t need a 178-200 grain bullet for deer hunting but they are very effective. I have successfully hunted deer with my 25-06 using 120 grain bullets for years also. Looking forward to the 6.5 CM with its nice deer sized bullets and based on your data, flat trajectories should not be sacrificed. My deer hunting shots are typically 250 yds or less with an occasional 400 yard shot over a clear-cut. I like to zero at 200 yards giving a 100 yd elevation in the 1.8” area. I can quickly acquire a target and slightly hold over intended shot placement (using MOA elevation marks in reticle) without dialing a turret or changing scope power levels. I have read about some velocities in the 2550 fps range for 6.5 CM with heavier bullets. 2850 fps is definitely workable! The low recoil of a gas gun in a short action 6.5 CM should be a pleasure to shoot.

 

[BCP]

It's the same idea as a 25/06 or 270. IMHO it's the perfect deer cartridge. Or antelope.

 

[rmiked]

Agreed. I use to shoot woodchucks with 75 grain screamers in 25-06. Then hunt deer with 120 grain. Very versatile cartridge. Seems like 6.5 CM will do same in short action vs long action 25-06

 

[Pappasniper]

6.5CM 140 pills is the new 270 win 130's. Both they are very versatile. The lighter bullets are super soft shooters in 6.5. And I tend to believe inherently accurate with most loads. Not hard to find good shooters with either factory or handholds.

PB

 

[mettee]

130 gr bullets will be from 2800 up to 2900. This is factory hornady 130 eldm from a 260. Unless your barrel is not up to the task.

 

[LRRPF52]

From my 22” .260 Rem gasser with RLGS, I feel like I’m on the edge pushing 2800-2820fps with H4350 under 129gr and 130gr.