BARREL LIFE

Get or give advice on equipment, reloading and other technical issues.

Moderator: Mod

Message
Author
RAVEN
Posts: 1978
Joined: Sun Jun 19, 2005 9:37 pm
Location: Adelaide South Australia (CTV)

BARREL LIFE

#1 Postby RAVEN » Tue Jul 05, 2005 2:49 pm

any 1 seen this before
Punch your load in very interesting :)

http://rbraund.customer.netspace.net.au/BL

pjifl
Posts: 883
Joined: Fri Jun 17, 2005 12:15 pm
Location: Innisfail, Far North QLD.

BARREL LIFE

#2 Postby pjifl » Tue Jul 05, 2005 9:41 pm

That XL file would have derived from and may be an extension of this

http://yarchive.net/gun/barrel/barrel_life.html

You can unprotect the formular (no password required) and see the actual calculation in the XL file. It would be interesting to know more about how he arrived at the powder and pressure factors - especially the powder heat exponent. Maybe reading more on his the web site would give info on this.

which is part of a very comprehensive web site with a lot of information.

http://yarchive.net/gun/index.html

I read this simpler theory quite a while ago and ever since have compared it with barrels I know about. Unless someone comes out with a better theory, it sounds more or less correct to me. If it is even a reasonable guide, it is a very useful tool helping one decide on a cartridge. The only problem is placing all of our powders on the powder hotness scale.

FWIW, one 6.5 Rogue I knew about was shot to 3000 rounds before rebarreling. Tobler 30 inch - 2209 of about 44 grains. I suspect it may have needed a change at about 2500. I will let you know in time as mine is at about 1500 now and still OK. Have a spare on hand all ready to go, however.

I will take a slight drop in performasnce for an extra 1000 shots.

I do think there may be a future for the smaller cases loaded to their utmost efficiency. Maybe the new longer 6mm projectile (if you could get them) would make the 6mm really competitive, but, at the moment, my opinion is that, unless you accept quite shortened barrel life, the 6 mm is at a distinct disadvantage to the 6.5. But a 6BR - especially lengthened slightly - is a nice cartridge.

Peter Smith.

pjifl
Posts: 883
Joined: Fri Jun 17, 2005 12:15 pm
Location: Innisfail, Far North QLD.

BARREL LIFE

#3 Postby pjifl » Tue Jul 05, 2005 9:58 pm

One thing I will watch with great interest. A friend is building a 6.5 but in the original 6.5x55. Its not the shaped case I would prefer but I think it is about the right volume.

Anyway, the person in question is a perfectionist - he is the person who had his 223 doing 100 on the champ target at 300 and regularly gets 98 - 99. I have never seen anyone do a 6.5X55 to really top standards before. Trouble is that the barrel will not wear out for a few years but I will be very interested in his barrel life.

Peter Smith.

RAVEN
Posts: 1978
Joined: Sun Jun 19, 2005 9:37 pm
Location: Adelaide South Australia (CTV)

#4 Postby RAVEN » Wed Jul 06, 2005 12:01 am

The thing I found interesting is (and that is it is correct) the effect of burn temp with different powder types on barrel life.
Cheers
RB :)

Mark Hamersley
Posts: 102
Joined: Mon Jun 20, 2005 12:25 pm
Location: Perth

#5 Postby Mark Hamersley » Wed Jul 06, 2005 1:23 am

Peter

I referred to the same formula in my deliberations (among other factors such as ballistics, accuracy reports, recoil) when choosing a cartridge. The predictions seemed about right from what I had heard around the clubhouse and other forums. Unfortunately it predicts my accurate barrel life will drop off toward the end of the WA Queens!!

I went with a 6.5x55AI and have 1600 rounds through it, so far so good. When fireforming (43gn 2209 chosen, no load development) it shot very good groups. The 100m SSAA centrefire 10 ring disappeared quickly. I also fireformed at 300 and 500 yds on the fullbore target at club shoots with very good results. Your friend with the standard Swede will end up with a very accurate rifle and good barrel life too.

My battles against the 6BR's here in WA are usually close - sometimes the 6.5 wins, sometimes it doesn't. All being equal I feel the 6.5 has a slight advantage in the wind at the longs but there isn't much in it. Every point helps when competition is tight though.


Mark Hamersley

AlanF
Posts: 7495
Joined: Wed Jun 15, 2005 8:22 pm
Location: Maffra, Vic

#6 Postby AlanF » Wed Jul 06, 2005 8:05 am

I think the 6.5x55 and AI is a good choice. You have a long neck (less throat erosion), long powder column (pressure rises predictably), and with the right powder, a full case.

Alan

pjifl
Posts: 883
Joined: Fri Jun 17, 2005 12:15 pm
Location: Innisfail, Far North QLD.

BARREL LIFE

#7 Postby pjifl » Wed Jul 06, 2005 9:04 am

Everyone seems to agree that the 6BR gives a reasonable barrel life.

I was so impressed with what I saw of this little cartridge that I built one which now has about 500 through it.

I am interested in what others consider a reasonable barrel life in the stock standard 6BR.

Peter Smith.

bjld
Posts: 164
Joined: Sun Jun 19, 2005 10:40 am
Location: South Australia

#8 Postby bjld » Wed Jul 06, 2005 11:48 am

My first open rifle was chambered in 6.5x55. I tested up to 44gr of 2209 but settled on 42gr. Unfortunately, it was chambered with the standard reamer and had a very long throat, although performance did not seem to suffer. I shot close to 2000 rounds with no appreciable loss of accuracy before I rebarreled in 6.5x284. I am only achieving 100fps more velocity now, although I am using AR2217 to attempt to prolong barrel longevity.

Ben

Guest

#9 Postby Guest » Wed Jul 06, 2005 6:31 pm

ed
Last edited by Guest on Sun Oct 30, 2005 9:06 pm, edited 1 time in total.

Mark Hamersley
Posts: 102
Joined: Mon Jun 20, 2005 12:25 pm
Location: Perth

#10 Postby Mark Hamersley » Fri Jul 08, 2005 9:15 pm

Matt

Thanks for sharing info re 6.5 barrel life, I'm still trying to get a handle on how far mine will go (using 52.5gn AR2213SC btw so maybe not too much further). Bill Hallam had a peek at mine with a borescope around 1200 rounds and all looked OK. I've got an order in for a new barrel anyway.

I haven't found the 6.5 too difficult, maybe just luck? One quirk I found was that throat length was important for controlling ES. My original chambering was giving wide MV spreads, consequently I had issues with vertical. Extending the throat (then revisiting OAL and powder charge) resolved this.

The 6mm sounds very attractive,particularly the BRX variant. So many calibres, so little time to play with them all.


regards

Mark Hamersley (dreaming of more toys......)

Cochran
Posts: 26
Joined: Sat Jun 25, 2005 5:42 am
Location: Texas

#11 Postby Cochran » Fri Jul 08, 2005 10:58 pm

I have to agree with Matt. The 6.5x284's can be very fussy compaired to the 6mm's. Maybe a 6.5 with less case capacity would be easier to tune. A friend has had great luck with the 260AI.

As for competative barrel life. I think 700 to 1000 rounds is about all that can be expected from a 6.5x284. In a 6BR, 3000+ should be easy to get.


Jeff

jlorimer
Posts: 77
Joined: Fri Jun 17, 2005 10:40 am
Location: TOWNSVILLE NORTH QLD

#12 Postby jlorimer » Mon Jul 11, 2005 11:54 am

I have been playing with the 6BR for over 4 years. I would say the BR is one of the most accurate cartridges in it's standard form, that one could wish for - for shooting up to 500m in reasonable conditions, however, I do believe the 6.5 139 gn scener bullet from a good rifle, from 500m outwards, is superior.
From my analysis of open F class Queens and prize shoot results, in North Queensland, over the last 4 years, the 6.5 shooting the 139 grain bullet,in trying conditions, is worth a 1-2 shot advantage per range, from 600m out, over the 6mm 107gn bullet. The 6mm bullet will match the 6.5 bullet, only by running over the 3100fps mark.
I think the way to go is - Shoot the BR for the short ranges, and the 6.5 for the long ranges, and you have all options covered.

On the barrel life scene. I have a 6BR that has done just over 3000 rounds, with nude bullets, and 30.4gns of 2208, whilst it still is an accurate rifle, I have detected throat erosion out to 75mm. I think this barrel is at it's useby date. I am at present shooting a 6BR at just under 3000fps, and I expect to get around the 2000 - 2500 rounds out of it. With a 6mmX barrel, using 35gns of 2208, I got around 2000 acurracy rounds. One of my .308 barrels at 2950fps, dropped it's bundle approaching the 2800 mark. I had a 6.5X6mmBr front end, that gave me around 1500 rounds. at present I am trying out a .243 ackley improved, and I think it will probably only make betreen 1100 & 1500 rounds.

I think we all tend to overstate our accurate barrel life. I feel if you want to shoot Open F Class, then you should budget for a new barrel every year, and, have a spare in the cupboard. I made the error of not doing this, and am now paying the penalty, of trying to get a rifle up and running in a couple of weeks.
Keep em in the ten, John Lorimer

Guest

Re: BARREL LIFE

#13 Postby Guest » Sun Jul 24, 2005 10:50 pm

RAVEN wrote:any 1 seen this before
Punch your load in very interesting :)

http://rbraund.customer.netspace.net.au/BL


Return to “Equipment & Technical”

Who is online

Users browsing this forum: No registered users and 40 guests