6x47L minimum barrel length

[Dusty Stevens]

What is the min length for a 6x47L shooting 105-107gr bullets out to 1000yds? Anybody have any experience with the real short barrels in this combo?

 

[280nosler]

I don't have experience with a short barrel, but from a ballistic's standpoint, you only need 2450 FPS to launch a 107 Sierra Matchking (.527 BC), and still have it arrive on target with 1115 FPS at an altitude of 800 feet. In looking at the Berger Manual, 2900 is essentially the top floor of velocities for the 105-108 grain bullet through a 24" barrel, and they specify you would loose roughly 28 FPS for every inch you remove. There is a point where your powder will not have stopped burning if you go too short, and your velocities will drop well in excess of this number. My guess with 4350 and RE17, that would be around 19-20 inches. Given you have 450 FPS to play with, in theory, you couple probably go to 19 inches if you stayed with a faster burning powder.

 

[Dusty Stevens]

Thank you sir. Very informed answer and i appreciate it

 

[johara1]

I cut back from 30" to 28' on the Dasher and it does a lot better but now i just cut an excellent barrel down to 26" to give it a try. I don't worry too much about speed it small i'm looking for………. I had only lost 7 FPS. per inch from 30 to 28"and i'm not shooting at the top so it was easy to make up……. jim

 

[Dusty Stevens]

Yea im kinda on the other end here im trying to see if a 20 or 22" is feasable. You put a suppressor on a 28" barrel its hell. Just trying to keep it short as possible.

 

[rickiesrevenge]

I had an xp-100 with a 18" barrel. I shot it a lot at 600. Shot it some at 1000. It did just fine IMO.

Aaron

 

[LCazador]

I've got a 6X47L with a 22 inch barrel and shoot the 105's at 3100fps with RL17. IMHO I'd say that's about the minimum with the slower burning powders like RE15, RE17, and 4350.

 

[alf]

What is the min length for a 6x47L shooting 105-107gr bullets out to 1000yds?

My 22" runs 105 VLD's at 3030 and I've gone as far as 1408.......



12" at 1408

 

[Jason Boersma]

Al, that's some good shooting with a hunting rifle. I run 105 vld's at 3005fps with h4350 out of a 30" barrel but I'm not pushing them hard

 

[alf]

Thanks Jason....that gun's a shootin' sum bitch.

Got another 700 built with a #3 22" Brux that the upper node with the 105's are at 3100 even. I've only taken that one to 1200 or so.

I think 25 FPS per inch loss/gain is a good estimate. I have yet another with a 26" barrel, that the accuracy load is the same as the Bat gun, but pushes the 105's at 3125, a 95 fps gain over the 22".

 

[Jason Boersma]

Mine is built with a savage target action in a hs precision stock. I haven't tried to find a faster node but this spring I will be moly coating all my 6mm bullets and then I will try and see if it likes it faster also. Just got it done this fall and haven't shot it farther than 200yds yet.

To the OP If your shooting varmints or steel I think a short 21" or 22" barrel with a suppressor on it will work just fine just make sure the barrel has the right twist for your intended bullets and work up a great load and you won't see much difference in barrel length.

 

[4xforfun]

Thanks Jason....that gun's a shootin' sum bitch.

Got another 700 built with a #3 22" Brux that the upper node with the 105's are at 3100 even. I've only taken that one to 1200 or so.

I think 25 FPS per inch loss/gain is a good estimate. I have yet another with a 26" barrel, that the accuracy load is the same as the Bat gun, but pushes the 105's at 3125, a 95 fps gain over the 22".

Al, Can I assume ( ) that you are running moly bullets?

 

[alf]

Al, Can I assume ( ) that you are running moly bullets?

Yupper, always.....and no need for that wet crap either.....

 

[Jason Boersma]

I agree, I use a dry method and I don't have a mess at all, it's easy and clean

 

[4xforfun]

I think 25 FPS per inch loss/gain is a good estimate. I have yet another with a 26" barrel, that the accuracy load is the same as the Bat gun, but pushes the 105's at 3125, a 95 fps gain over the 22".

I just did a little re reading of this thread. My question here is the 25 fps/inch theory. You are getting 3100 out of a 22. Do you think you could get 3300 out of a 30 inch tube running the same PSI? Just wondering if the moly may be giving you an unfair advantage in the physics department!! ;D I used the 30 inch number because there are many out there (me included) who run 30 inch tubes. I am running 3080 out of a 30" with non-moly 108 Bergers / H4350 and I am at the upper node and it wouldn't take much more powder to show PSI issues. I may have a slow tube because lots of guys run 3050 out of a dasher. I just got a new Kreiger blank that will finish at 30, and it wouldn't break my heart to lop it off at 25 - 27 inches.

Tod

PS. Do you get your steel from JC Targets?

 

[alf]

Tod,

Let's back up a bit.......

When doing original load work up, best accuracy in the first 22" gun was at 3030, and I ran that gun and load out to 1400+.

I then had another action chambered in a 26" tube, and that gun's best accuracy load ended up at 3125, with surprisingly, the exact same load, tested to 1300+.

That's why I said it looked as though around a 25 fps gain/loss per inch with this cartridge.

The 3rd gun was chambered with a 22" barrel, and that barrel needed another grain over the other two guns, to find best accuracy, which came in at 3110.

I highly doubt you can get to 3300 in 30" and get many firings out of your brass. I'd hazard a guess at around 3200 would be more likely, based on my 26" results.

I run all my Dashers at 3075 in 28" tubes.

Moly adds nothing to the speed potential, it only makes cleaning a snap.

Yes, targets are from JC.

 

[stroked96s10]

I don't have the gun in hand quite yet, but for what it's worth, when I walked in to get my 1000 yard gun built I asked him for his best advice because I'm quite new to this. The 6x47L was one of the 3 suggestions, other being 6mm dasher and another 6 but I forget now since it was 11 months ago! But anyways, I went with the 6x47L with 28" kreiger barrel that he recommended. So I'd have to think he wouldn't steer me wrong since he's been in this business for quite a while with several awards.

 

[OK243]

I just had my 243 cut down to 20" to run a suppressor on. I haven't had time to shoot it or work on loads yet but I will follow up when I get around to it.

 

[JLR]

I have been running a 24" 6x47 this past year for PRS matches and have been steadily running 3150 with the 105 Hybrids. It's got around 1700 rounds on it now and is probably reaching the end of it's useful life. I am playing around with DTACs now and have them running right around 3070. Prior to this barrel, I had a 28" tube on it and ran the Hybrids at 3275 and DTACs at 3150.