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30cal TJ liner As per rsterne and SMP specs.
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Author:  Whitewolf [ Thu Jun 20, 2013 10:20 pm ]
Post subject:  30cal TJ liner As per rsterne and SMP specs.

Well on Monday received two barrels, only one of my barrels arrived. 29" in length, the other was a 25" model for a friend. And as per the manufacture excellent quality of steel and finishing. Just as how he is noted for.

Machined both ends square and beveled. Fed about 12 or so patches thru, alternating 1 wet 2 dry till the barrel looked clean. I then pushed thru 10 JSB pellets. Checking as to how the lead smearing was and the feel of resistance. Then I crowned the muzzle with a 1mm recessed target crown. Breaching was no real effort of polishing in with a brass ream that I had made. Checking routinely until I found a fit for the pellet to be clean with that last mm of a push to engage the rifling. Now pushed thru about another 10 more pellets checking the lead smear. Once I was all happy with the fit and the follow thru the crown. A good polishing of the internals was in order to remove the last of the lead smear that was slightly present upon the pellets. Loaded up the cotton mop and started stroking the polish thru the bbl. The breech 1/3 of the bbl receiving 3 times the amount of strokes as the last 1/3 of the barrel. After a number of strokes. Patches were loaded with cleaner and they were pulled thru till clean and then dry patches pulled thru. Another 3 or 4 pellets were pushed thru and examined. Once I was happy that the rifling cuts upon the pellet head were clean to my satisfaction. I pushed thru a cotton ball. Examining the barrels rifling for any strands being left behind upon the rifling. Its a great way of finding areas that need a little more attention. One outta 2 needed a bit more polishing, but just in one small area.
Now for the last push thrus of pellets. Well it only took a few to push thru to find that they were feeling like a ball bearing leaving the barrel. Shweeeeet. I then pushed thru a few cotton wads loaded with Extreme polish. Its designed for stainless and Aluminum rims. It has an de oxidizing chemical in it. This left the barrel interior with a very high mirrored finish.

Now if our Alberta weather will take a hike with this rain and wind I could put some lead down the barrel and see how these barrels shoot. Barrel is installed into the Condor, tank is filled to 2850 psi, Great White topped up and 2 tins of pellets are sitting waiting their turn....lol

Author:  ralphtonka [ Thu Jun 20, 2013 11:06 pm ]
Post subject:  Re: 30cal TJ liner As per rsterne and SMP specs.

Tease!


It is Sunny here, forecast has Camping and beer clouds!

Author:  Voltar1 [ Fri Jun 21, 2013 12:09 am ]
Post subject:  Re: 30cal TJ liner As per rsterne and SMP specs.

Got that 25" ready to test in the Vulture!

Author:  target man [ Fri Jun 21, 2013 7:25 am ]
Post subject:  Re: 30cal TJ liner As per rsterne and SMP specs.

you take care of that barrel ,like a baby
i dont saw ,what more could be done :lol:

target man

Author:  Daryl [ Fri Jun 21, 2013 8:55 am ]
Post subject:  Re: 30cal TJ liner As per rsterne and SMP specs.

Quite a process, Kim. I'm not sure I'd have the patience. I've still got lots to learn about this hobby, that's for sure.

I watched some 'news' on the flooding - nasty - take care everyone!

Author:  Voltar1 [ Fri Jun 21, 2013 10:20 am ]
Post subject:  Re: 30cal TJ liner As per rsterne and SMP specs.

Initial results
60 yards over the hood of my truck getting 8 shots into 3" ish size group.
Three of them make 1 inch.
Need to shoot off a bench and bags.

Author:  Whitewolf [ Fri Jun 21, 2013 11:04 am ]
Post subject:  Re: 30cal TJ liner As per rsterne and SMP specs.

Well thats good to hear Walter. And yes a bag and shooting bench would be beneficial for a flat out test.

Some things Daryl just plainly take time. Considering I polish in a leade vs cutting one. All a matter of time. And cant get the barrel too hot while polishing in the leade, hard to control the cut then.

Targetman yes will be looking after these bbls. To a degree. One is for testing so chopping it down with different experiments will end up happening. They are the most expensive bbl blanks I have ever purchased for an airgun that is for sure.

No testing for me today 40-50k/hr winds and yep still raining. Weekend is suppose :roll: to have some sunny breaks, time will tell

Author:  Voltar1 [ Fri Jun 21, 2013 7:02 pm ]
Post subject:  Re: 30cal TJ liner As per rsterne and SMP specs.

Bob, Sean, any theories?
What power level should I aim for?

Author:  rsterne [ Fri Jun 21, 2013 8:02 pm ]
Post subject:  Re: 30cal TJ liner As per rsterne and SMP specs.

I would go for about 950 fps, certainly not over 1000, but that's what I do with any waisted pellet.... It's possible it may be more accurate around 900, of course.... I don't know when I will be able to get to work on mine, the Motel is nuts in the summer.... I can spend lots of time on the computer while at the front desk, but not in the shop....

Bob

Author:  SMP [ Sat Jun 22, 2013 6:32 am ]
Post subject:  30cal TJ liner As per rsterne and SMP specs.

Walter from a design standpoint when Bob and I were tossing numbers around I was looking at the 1000fps benchmark... Mostly because I knew Bob would get there. Beyond that I think harmonics in the individual platform is going to be a factor with such a large bore and small OD. In my minds eye I had always envisioned these barrels to be in a tension setup or carbon fibre wrapped.
But I would be aiming for the higher end velocity.

Author:  Voltar1 [ Sat Jun 22, 2013 3:13 pm ]
Post subject:  Re: 30cal TJ liner As per rsterne and SMP specs.

Just laid down a three shot 1/2" group at 40yds
Bipod on tailgate of truck
Was nailing egg sized rocks at 50
Think the trouble was the shooter
Need to bag this baby and see whats up

Author:  rsterne [ Sat Jun 22, 2013 3:23 pm ]
Post subject:  Re: 30cal TJ liner As per rsterne and SMP specs.

That's a bit better!.... :mrgreen:

Bob

Author:  Whitewolf [ Sun Jun 23, 2013 2:19 am ]
Post subject:  Re: 30cal TJ liner As per rsterne and SMP specs.

Image

Well finally got a chance to test the bbl. Now to explain the pic. Sorry that its small. Click on the pic to expand it for grid sizing.

Test platform was an AF Condor frame, modified internals, and custom valve stem, factory valve body. Sun Optics 4x16 x50 Scope. 29" bbl

Each bullseye is 1" circle. 5rnd groups per bull. 50 to 90m in 5m increments. Scope zeroed for 50m. This was my best target page. 5 pages shot in total
I first worked with finding the most accurate fps @ 25m. This I found to be a 921fps average over 5 shots. Each 5 shot group was shot with a tank fill of 2650fps. And just prior to shooting a group I shot 2 to 3 rnds into an adjacent target to make sure I was I was reading my range correctly to the scope. Magnification set at 12.

So draw your own conclusions. And for those that have purchased 30cal bbls from Sean/ SMP. Would like to see your test results. I'm sure Bob would like to know too.

Author:  rrdstarr [ Sun Jun 23, 2013 2:36 am ]
Post subject:  Re: 30cal TJ liner As per rsterne and SMP specs.

Think I will be putting my .30cal 18" barrel on my QB79!

Author:  target man [ Sun Jun 23, 2013 7:31 am ]
Post subject:  Re: 30cal TJ liner As per rsterne and SMP specs.

very interesting result ,
it might be close the limit distance to get accurate
for that speed set-up,,,,
i couldn't bet on the limit ??
i was betting on 28 inches barrel long for esay good long shot ,
29 seem good,



target man

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