In Class is 30in barrels better that 26in barrels? I called Hodgdon and they said that all the powder had burned in the 1st 26in of barrel, sierra also so said that the powder had burned in 26in of barrel. my question is if there in not that much gain in velocity having a 30in barrel other than weight, what is the plus of having the 30 in barrel, in f-class sight radius is not a issue.
26in v 30
- Thread starter oldguy65
- Start date
When you asked the question were you being powder specific or did they say that all powders do that?
stool
just because all the powder has burned, does not mean that PRESSURE went away.....bullet still accelerating....
XTR
F-TR obssessed shooting junkie
Can you get a 308 shooting 185 Berger to 2800 FPS w/o blowing something up with a 26" barrel?
You can get too much barrel depending on the powder and bullet. I tested a 34" barrel with my Varget load behind 185 Bergers and found that the 34 was 40FPS slower than a 30" barrel with the same load with the chamber cut by the same reamer, but running slower powders behind the same bullet yields me a 50FPS increase with lower pressure in a 32" barrel.
You can get too much barrel depending on the powder and bullet. I tested a 34" barrel with my Varget load behind 185 Bergers and found that the 34 was 40FPS slower than a 30" barrel with the same load with the chamber cut by the same reamer, but running slower powders behind the same bullet yields me a 50FPS increase with lower pressure in a 32" barrel.
Taking Varget as the powder of choice. 168 gr Hybrid 44 gr of varget 102% case filloldguy65 said:
54823 PSI 2.800 cartrage length 30'' 2785 - 26'' 2713 the 4'' gives you 78 more FPS.
34'' is 2846 FPS. Larry
Keith Glasscock
Gold $$ Contributor
My data contains significant noise because they are two different 308 chambers and two different barrels. Running the same lot of Varget and 200 hybrids, I got 2600 with a 26" 3 grove Benchmark, and 30" 5R Krieger made 2640. With 155's, 2950 and 2995.
To answer your question: It depends on range. I pick up more points with the 30" at 1000 than with the 26" - maybe one point per 50-100 shots more. At mid-range, the difference is simply not there - especially inside 600. Another thing to consider is that shorter barrels are stiffer and tend to shoot smaller.
With the experience I've gained in F/TR, I'd completely change how I build rifles in the future. I do guarantee one thing, I'd not opt for a 30" barrel...
To answer your question: It depends on range. I pick up more points with the 30" at 1000 than with the 26" - maybe one point per 50-100 shots more. At mid-range, the difference is simply not there - especially inside 600. Another thing to consider is that shorter barrels are stiffer and tend to shoot smaller.
With the experience I've gained in F/TR, I'd completely change how I build rifles in the future. I do guarantee one thing, I'd not opt for a 30" barrel...
stool
what CLASS ??
I think he meant 'F', but was too shy to use that naughty term. 
To the OP, here are some other things to consider:
It will be easier to find a 26" bbl vs. the longer one, esp. in a factory rifle, or in a replacement bbl.
The shorter bbl will be lighter
If your ultimate goal is to wring out every last bit of velocity that you can, then you'll need to find the sweet spot, as another poster suggests. Will the higher velocity be accompanied by greater, or even as good, accuracy? No way to know. But maybe not.
A faster miss is still a miss.
Don't overthink this. Get a rifle, and get in the Class, whatever it is. That's the real performance lab. You won't know what you don't know until you get range time.
To the OP, here are some other things to consider:
It will be easier to find a 26" bbl vs. the longer one, esp. in a factory rifle, or in a replacement bbl.
The shorter bbl will be lighter
If your ultimate goal is to wring out every last bit of velocity that you can, then you'll need to find the sweet spot, as another poster suggests. Will the higher velocity be accompanied by greater, or even as good, accuracy? No way to know. But maybe not.
A faster miss is still a miss.Don't overthink this. Get a rifle, and get in the Class, whatever it is. That's the real performance lab. You won't know what you don't know until you get range time.
I have just got into F-class last year. one of the things that I have found that the guys using 308's have talked about was getting 2800 to 2900fps out of the 30in barrels with 185 Berger's or 200's most are using H4895 some Varget, are using Lapua or Win. case's I have tried to load their data, my chamber is 95 Palma reamer but because I am using military case's I can't get the velocity that they say they are getting, I have found out that my load in a military case, it takes about 2.5 grains more Varget to get the same velocity in Win. cases granted I don't seem to have the same pressure problems with the commercial cases. I am just getting into the long range part of it, and I am wanting to build a open class gun, I am thinking about a 260 rem. any thoughts about a 260?
XTR
F-TR obssessed shooting junkie
oldguy65 said:
In F-TR there is a mixed bag of variables to get max velocity. WW cases for more capacity and long throats, much longer than your 95 Palma throat. I've got one barrel that I can't reach the lands with a 185 Berger still in the case (It's not to shoot 185s).
For what they are worth here are my thoughts on the 260 in F-Open, and keep in mind that I shoot F-TR not F Open, but the ballistics are pretty easy to understand.
I have seen a 260 win at least one TN state championship, and depending on the competition locally you may do well with one that is set up for open; however, if you are up against equal shooters running 284s or 7RSAUMs or even 6.5-284 you are going to be losing points to windage that they are not. They are driving equal bullets faster, or driving heavier bullets at about the same speed. All that adds up to fewer points dropped to wind calls.
Winning at the end of the day is about aggregate, and on occasion for one match even the F-TR shooters can out shoot the F-Open guys, but at the end of the day or the end of the weekend the agg tell the story and the point here and the point there adds up.
Just an example, I shot an 800/900/1000 match squadded with an open shooter last yr. He dropped one point at 800, and one at 900, I shot both clean, then he dropped one point at 1000 and I dropped 6.
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