6.5 creedmore muzzle velocity from 18" or 20" Barrell

[harry_x1]

Hi Friends - I have a 26 inch (1:8 twist R) barrell in 6.5 C. Am looking to cut It down to 18 or 20 inch to make a lighter hunting setup. Prefer as short a barrell as possible while being within safe range for bullet stability. People who have 6.5C in short length barrels, can they share some data on muzzle velocities they are getting for their hand loads for diff bullet weights ? Appreciate you time and assistance.

 

[6.5SH]

A rule of thumb is 20-25 fps per inch loss with "normal" lengths.

 

[Huskydriver]

I got a 16" 6.5cm...you will be hard pressed to push a 140 class bullet faster than 2650.... Think Im running 2615 iirm with 41.5gr of 4350

 

[celltech]

Bout the same here... 2621 from a 140 ELD-M, Lapua SRP, 42.5 H4350, 16" X-Cal barrel

 

[drwood96]

I got 2667 from 18’ 6.5cm running Berger 140 hybrid. Only 7 mils drop at 850yrd. Used it at a GTI match with zero issue.

 

[spife7980]

18” 8 twist

130 rdf Peterson rl16
39-2490 and 43.5-2800

140 rdf Peterson h4350
39-2567 and 43.5-2863

140 rdf lapua h4350
38.3-2481 and 41-2632 (I had learned to keep pressures down by now so I don’t have any overhead charges for those.

That said I would start at 38 grains and proceed up to say 42 and see where you find accuracy and some heavy bolt lift.
I load between 37.5-38.5 now and take my good accuracy and easy extraction.

 

[mtwarych]

With the same exact loads used in both rifles, My sons RPR with the factory barrel fired the load at 2635fps. The load in my 18" Ruger "tactical" produced 2530fps.

The load is 39.5 grains of H4350 under an 142gn Nosler long range Accu-bond. I know I'm 2 grains under max but the accuracy is pretty darn good.

 

[stello1001]

18” 8 twist

130 rdf Peterson rl16
39-2490 and 43.5-2800

140 rdf Peterson h4350
39-2567 and 43.5-2863

140 rdf lapua h4350
38.3-2481 and 41-2632 (I had learned to keep pressures down by now so I don’t have any overhead charges for those.

That said I would start at 38 grains and proceed up to say 42 and see where you find accuracy and some heavy bolt lift.
I load between 37.5-38.5 now and take my good accuracy and easy extraction.

Am I reading this right? This isn't a typo?

You got MV of 2863 using a 140 grain bullet out of an 18" barrel?

 

[spife7980]

Am I reading this right? This isn't a typo?

You got MV of 2863 using a 140 grain bullet out of an 18" barrel?

Yep. It was mighty hot but no ejector marks. Heavy bolt lift which is the main indicator I use. Shot like shit. Also done in hotter than hell conditions so it was a combination of factors that I never should have went forward with trying.
But when you read on the internet everyone’s loading 42+ grains and getting 2800 easy you try it. Bad idea. My current load in the new 24” barreled action is 37.8 and it’s going 2580 and it’s a dream to shoot and run.

Edit: I also tried up to 43.5 rl16 and in Peterson under the 140 and it hit 2887
What I noticed was that above 41 grains, of either powder, nothing I tried gave me accuracy of any sort. Down below 40 they are all semi accurate.

 

[wade2big]

Yep. It was mighty hot but no ejector marks. Heavy bolt lift which is the main indicator I use. Shot like shit. Also done in hotter than hell conditions so it was a combination of factors that I never should have went forward with trying.
But when you read on the internet everyone’s loading 42+ grains and getting 2800 easy you try it. Bad idea. My current load in the new 24” barreled action is 37.8 and it’s going 2580 and it’s a dream to shoot and run.

Edit: I also tried up to 43.5 rl16 and in Peterson under the 140 and it hit 2887
What I noticed was that above 41 grains, of either powder, nothing I tried gave me accuracy of any sort. Down below 40 they are all semi accurate.

Those loads are way overpressure which I’m figuring you know. I couldn’t comfortably get 2800 fps with a 26” barrel and RL16 (more than one). I could comfortably see 2680 with my 22” barrel which theoretically puts me much slower than what some of the other guys just posted with their 16” barrels at over 2600fps.

I make sure my loads show no pressure in the Texas heat. RL16 seems to really spike in pressure when the temps come up a bit. I allow for that. A load can show safe at 60 degrees and blow primers at 90 with the stuff. My buddy learned that the hard way.

 

[jbuck88]

I'm getting 2670fps out of my 20" 6.5cm with the 143gr ELDX.

 

[dgheriani]

I was getting 2650ish out of a 1:8 19" gas gun with 140 ELDMs over 42.0gr H4350 in Hornady brass at factory OAL. Same load in a 1:8 26" on my bolt gun gives me 2840.

 

[lonestar1845]

I was able to safely get 2800 with 140's from my 20" CTR barrel. No pressure. RL16 and sta-ball will get you speed.