Round count

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

Moderator: Mod

Message
Author
locknload
Posts: 6
Joined: Fri Mar 22, 2019 3:42 pm
Location: Mt Isa

Round count

#1 Postby locknload » Thu Mar 12, 2020 2:13 pm

Hi
So many variables to my question.
Assuming I clean my barrel after every shoot using copper brush for carbon remover, then bore tech to remove all traces of copper, topped off with a few patches of hoppes no 9, JB every now and again to keep it humming.
Not running a real hot load with approx 2790 fps 140 gn projectiles.
Has anybody got a reasonable stab in the dark as to what I can expect in regards to round count before the barrel should become uncompetitive ? And is there anything I should be doing that I'm not doing that might give me a longer barrel life.
Thanks in advance
newtshootn
Yesterday is a memory. Today is now. The future is bright.

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

Re: Round count

#2 Postby AlanF » Thu Mar 12, 2020 3:40 pm

We'll need to know the calibre/chambering. That way you may get replies from shooters with direct experience. I'm guessing a medium capacity 6.5mm, but better to be sure.

Tim L
Posts: 876
Joined: Mon May 19, 2014 7:11 pm
Location: Townsville

Re: Round count

#3 Postby Tim L » Thu Mar 12, 2020 3:54 pm

As you say there are a multitude of variables, your cleaning regime being only one.
There us a train if thought that hot vs cold loads has minimal impact and another that suggests hot loads may erode the lead and lands more quickly. A shallow lead angle may also erode more quickly due to less backing material available to transfer heat and or phisically support the lands. The material composition of the barrel, calibre, speed of shooting, bullet profiles, jacket composition all play a part, not to mention what you determine as uncompetitive.
Assuming it's a 6.5 I got a bit over 3000 rounds out of a 6.5x284 shooting 2950 before I rechambered it. It was still shooting extremely well, I just wanted to repurpose it.
What else should you be doing?
Perhaps introduce an abrasive clean every 300-500 rounds. Ioso, JB or KG all produce a paste for this. The need is debatable, the impact on barrel life is also up for discussion but I found it necessary to remove carbon build up in the throat.
Maybe consider not shooting fast when you don't have to, like load testing. Give it a minute between shots, or shoot 3-5 but then let it cool down before shooting the next group.
Ballpark? Maybe start paying close attention to results at the 3000 round mark, but don't just give up on the barrel, you might just be able to extend seating depth and bring it back on line.

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

Re: Round count

#4 Postby pjifl » Thu Mar 12, 2020 6:26 pm

My experience with a 6.5 was mainly an improved 6.5x55 and I found 3000 shots was stretching things too far. Of course, so much depends on other factors which will vary from one case to another. If you are really serious about winning accuracy, I would be working on having a spare barrel ready to go at about 2000 shots - even less with bigger cases. Small cartridges like a 6.5 x 57 will last significantly longer than larger cartridges. My recollections of others use of the 6.5-284 many years ago was that many never got close to 2000 shots - but they were running them very hot. This is partly why people migrated to the 7mms. Common 30 cals usually last a bit longer and a commonly quoted figure was 3500. But people have such different accuracy expectations that this is almost meaningless. I had a 6.5 barrel collapse during a Queens. It was amazing how quickly it 'fell apart'. It was a lesson I never forgot.

While poor practices may shorten barrel life, basic 'wear' primarily is from hot gases or a plasma ''washing away the steel" and, if we want performance, there is no escaping this.

There are a few web sites that try to give comparisons between cartridges or a simple spreadsheet which tries to predict barrel life. While any conclusions are highly subjective they still provide a useful guide when making comparisons between different cartridges.

https://www.accurateshooter.com/technic ... rrel-life/

https://www.accurateshooter.com/technic ... y-formula/

Peter Smith.

Jason72
Posts: 43
Joined: Sat Feb 10, 2018 5:23 pm

Re: Round count

#5 Postby Jason72 » Fri Mar 13, 2020 8:16 pm

So I am only repeating what two reputable gunsmiths have told me and also what an excellent well known fullbore shooter has told me.
Gunsmiths, never use copper brushes, use cleaners and nylon brushes if necessary.
Fullbore shooter, often we over clean the barrel, he cleans his barrel only after 100 rounds,

Interested to see if others agree.
Cheers, Jason

williada
Posts: 969
Joined: Wed Jul 22, 2009 12:37 am

Re: Round count

#6 Postby williada » Fri Mar 13, 2020 11:13 pm

Jason, I think that is poor advice.

Jason72
Posts: 43
Joined: Sat Feb 10, 2018 5:23 pm

Re: Round count

#7 Postby Jason72 » Sat Mar 14, 2020 8:32 am

That was the reponse I was expecting.
I can't bring myself to leave my barrel and not clean it after a shoot but interestly many do.

Pommy Chris
Posts: 441
Joined: Tue Oct 21, 2014 12:05 pm

Re: Round count

#8 Postby Pommy Chris » Sat Mar 21, 2020 10:56 pm

Jason72 wrote:That was the reponse I was expecting.
I can't bring myself to leave my barrel and not clean it after a shoot but interestly many do.

As Peter said it is hot plasma that erodes the barrel not friction. If you own a boreoscope you would use a bronze brush as a nylon brush does not break up the carbon. The solvents you use will only melt the powder fowling they wont touch the carbon. I and any who take this seriously paste every 300-500 rounds. If you look at a barrel after 500 round using also a bronze brush you see the grooves are filling up with carbon. I have seen a berrel from a club member who was just using nylon brushes and solvent the grooves were foll of carbon after 1,000 rounds the barrel was almost a smooth bore.
Re cleaning I leave my gun 150 rounds before cleaning as why clean each week?
Actually a spotless barrel might actually wear quicker as probably suffers heat more and pressures will be higher and heat will be too. A dirty barrel wont suffer that high pressure and heat for the first few shots and the micro-fractures will be full of carbon not empty for the plasma to make them worse.
All is not as you might think..
Chris


Return to “Equipment & Technical”

Who is online

Users browsing this forum: No registered users and 33 guests