Martin52

Try this: SC:Plotter

https://shootingcompanion.com

Here's a good outline:

https://www.accurateshooter.com/technical-articles/reloading/complete-precision-case-prep/

Good to hear Geoffrey, will await to hear.

Geoffrey,

Do you have any plans to include Hodgdon Varget, H4895 and 8208 ? Very useful for US palma shooters.

Martin

20 hours ago, Elwood said:

There was a big discussion on one of the Aussie shooting forums titled The death of a barrel. The thread seems to have been taken down which is a pity. Anyway the gist of it was that the gentleman was using JB or losso with a nylon brush and add to that a cleaning rod that wasn't turning or turning properly he totally destroyed his barrel. 

https://www.ozfclass.com/phpbb/viewtopic.php?t=5898&start=105

That was a very good post, I've read it a few times. The primary cause seemed to be the faulty non-turning rod that caused the bronze brush (with paste) to skip over the lands and grooves resulting in the 'vine' looking damage down the bore . 

20 hours ago, KABOOM said:

....What I do  for stubborn carbon is nylon brush 

The Iosso stiff nylon brush is good, I use one occasionally but with a bore solvent, not with the paste. 

There is still carbon remaining and this takes me back to my original query. Having cleaned generally after each shoot,  I was getting an unusual heavy build up of carbon including long black streaks. I asked whether anyone found VFG felts to be more effective because in this particular barrel a normal cleaning regime was not working. I was looking for something that would potentially work. Having now tried the main brands, KG, BT, Sweets and the 'old school' Ed's Red and using bronze brushes, soaks etc. I can only think the heavy carbon is due to hotter loads of 8208, my other barrels only see Varget or H4895 and do not have anywhere near this level of carbon (or firecracking).

 Thanks for your replies.

The throat looks good. 

Mixed up a batch of Ed's Red, plugged the chamber, filled the bore and taped the muzzle. Let it sit for 2 weeks with an empty and refill at the end of week 1.

A bit more scrubbing and some improvement. The 8208 just seems harder on the barrel than Varget and H4895.

pics to be updated

Here are a few 'after' pics. That is after overnight soaks followed up with brushing with BTE and CU2.  The carbon seems embedded,  not much change. Over the next few days I am going to check a retired barrel that only saw H4895 and Varget for comparison with this one that seems to have incurred more wear and tear as a result of a faster, hotter powder, 45.4 gr Benchmark 8208 with 155's.

Martin

l'll post the 'after' photos in a few days and work on the borescope focus.

Just read this interesting test by Shooting Shed:

https://shootingshed.co.uk/wp/2013/01/borebullet-cleaning-comparative-the-last-chapter/

Similar disappointment at Boretech's performance (also KG 12) with C2R and WipeOut Patch Cleaner well ahead.

I have a Sinclair Chamber plug somewhere in my shed, it was new several years ago and never used.

There's the quandary...the rifle shoots fine. 

I was not expecting to see quite so much fire-cracking and carbon build up given a reasonably good cleaning regime and a moderate round count (600). 

The first of my images seems to show a streak of carbon and some fire-cracking in the groove, the second shows black carbon in the groove with copper above, the third image both copper and carbon.

I'll try the plug and soak option as I can do this over the next few days, I'll have to order the C2R.

Thanks

Martin

Thanks, 2 options there,) 1plugging the barrel and letting it soak and 2) CR2.

I have not previously contemplated either, thinking my cleaning regime was doing the job, the recent purchase of a borescope tells me otherwise...

I usually clean after each shoot using Boretech Carbon solvent on a bronze brush then CU2 on a nylon brush, patched out with Ballistol to finish. I clean until the patches come out white but this no longer appears (to me at least) to be a reliable indicator of a clean barrel.

Martin

Would anyone who has used the blue VFG paste on VFG felts care to comment on the results ? 

I am having trouble getting carbon out of my .308 F Class barrel after 600 rounds. Have been using Bore-Tech carbon and copper remover, also their Eliminator.  JB has had minor impact.

The load was probably on the warm side, I changed over from using 45.2 gr H4895 to 45.4 gr Benchmark 8208 (155 Berger FB's) so that may have contributed.

I'd be interested to hear.

Meanwhile, some recent borescope pics:

Any suggestions where I might get a good bag, F Class set up, 30 inch barrel ? The 50 inch bags are just a bit short.

52-55inches preferred.

Martin

 

 

0.298"? Otherwise, it's well on the way to being a 7mm!

Ha....I must have not been wearing my glasses ! Yes, 0.298.

Just checking bearing surface using my new Shooting Shed BS comparator and find the Berger 155.5 is approx 0.015 shorter than the 2156, I expected the reverse. Barrel is 0.288 x 0.3075 with nil freebore so testing 155/156 gr projectiles with shorter bearing surfaces.

Martin

 

Just to be picky, the ICFRA rule state that .308 bullets must not exceed 156 grains or the factory tolerance for 155 grain bullets where factory ammunition is used. This is an important point otherwise it would rule out using Berger 155.5 FB target bullets in reloaded ammunition.

No disagreement re ICFRA, my point was more in response to the comment that 155.5 gr projectiles belong in "yesterday's FTR" and references to 200 + 215 projectiles. That may well be the case in FTR however my previous post was about FB projectiles, in particular the relationship, if any, between bearing surface and chamber/bore dimensions for the 3 listed projectiles (Berger FB 155.5gr, Sierra 2156 155gr and HBC also 155gr).

However, for full bore, ICFRA rules mean TR shooters are limited to 155 grainers for 0.308.

Hi,

This is an older thread, very interesting, and I'm a new subscriber, I am trying to figure out the impact of bore size and chambering on projectile selection, specifically for full bore shooting.

My latest barrel is a 12T 0.3075 x 0.298 with nil freebore and I am load testing at present, using Berger FB's, 2156's and HBC's. I am getting around 2970 fps with 46 gr Varget/AR2208/2156. When chambered, I requested this be done to suit the 2156, the groups are still a bit loose (vertically and horizontally) and I am trying to work out whether a longer or shorter bearing surface is a significant factor hence testing other projectiles. the seating depth for testing is 0.020 jump. Neck tension 0.001. The measurements below, courtesy Laurie H's post, confirm the 2156 is the shortest and would therefore give less pressure for a given load.

Bearing Surface/OAL

Berger FB 155.5 0.265/1.250

Sierra 2156 0.230/1.210

HBC 0.336/1.225

Surprisingly I have not found many posts on sites including the LR US teams site and full-bore UK.

Any comments would be appreicated.

Martin