Author Topic: Any Interest in 6mm ? - Build Thread (Read 44230 times))

skorec · « **Reply #60 on:** July 14, 2017, 04:03:42 PM »

Bob OK. I whish you big success.
You know that that my ambition is similar ( long pellets/bullets whit PCP gun ) but at smaller caliber .177 or better any new caliber .130 with energy 12 ľFPE.

rsterne · « **Reply #61 on:** July 14, 2017, 05:32:53 PM »

Peter.... Check out this 27 gr. bullet in .172 cal.... http://noebulletmolds.com/NV/index.php?cPath=102_440 .... You will need about an 8" twist to stabilize it.... 2600 psi in a 24" barrel should push it into the 900s.... LW have a barrel with a 9" twist, that might work if you don't push it too fast....

Bob

skorec · « **Reply #62 on:** July 15, 2017, 02:43:56 AM »

Thanks Bob,
I am awaiting for FX smooth X barrel.
http://www.airgunnation.com/topic/fx-reveals-the-new-smooth-twist-x-barrel-system/page/8/
I hope that it will able to buy only FX liner itself suitable for .177 JSB Beast pellets.

tronickero · « **Reply #63 on:** July 17, 2017, 01:16:05 AM »

Bob

What benefit does it have carbon fiber jacket in the barrel?

Tron

subscriber · « **Reply #64 on:** July 17, 2017, 01:46:13 AM »

Quote from: tronickero on July 17, 2017, 01:16:05 AM

What benefit does it have carbon fiber jacket in the barrel?

Can stabilize the inner barrel by using the carbon fiber sleeve to "stretch" the steel barrel slightly. Would stiffen it up like a "fat" steel barrel, without adding so much weight.

YEMX · « **Reply #65 on:** July 17, 2017, 06:52:35 AM »

Pretty much what above said- we use the carbon fiber (CF) on the outside of the barrel, to stiffen it up.

As instructed by Bob, the trick is to have the CF extend into the breech, as to not create a fulcrum- potentially making the barrel even more whippy.

For my 6mm build, as suggested by Bob, my CF sleeve will extend into the breech by 1.25".

rsterne · « **Reply #66 on:** July 17, 2017, 01:02:17 PM »

Carbon Fibre is stiffer than steel and many times lighter.... Even when laminated with Epoxy into a CF tube, the stiffness of the least expensive CF approaches steel, and is much stiffer than aluminum.... There are high-modulas carbon fibres (more expensive) available that are significant stiffer than steel, meaning that a CF tube of a given diameter can be stiffer than a steel barrel the same size.... The commonly available CF tubes are nearly as stiff as the same OD steel barrel, but a fraction of the weight....

If weight is not an issue (or even a benefit, as in a benchrest rifle), then using a solid steel barrel of large diameter is preferred.... I keeping the weight down is an issue, then sleeving a steel liner that is realistically too thin for the length to have adequate stiffness by gluing a CF tube over it is a great solution.... Generally, stiffer barrels have greater accuracy potential.... IMO, to provide adequate stiffness, a small caliber barrel should not be longer than about 40 times it's OD, and a large caliber should be even larger in OD.... Certainly once the length of a barrel reaches 50 times it's OD, it starts getting pretty flexible, and can definitely benefit from sleeving.... For best accuracy, even 40 times the OD is probably too great a length/diameter ratio....

Bob

rsterne · « **Reply #67 on:** July 22, 2017, 04:21:05 PM »

OK, so now I'm on a quest.... If you look back at Reply #17 on the first page, you will see that the plan is to use an AR style stock.... I know from nothing about them, other than that there are two styles of buffer tubes (Military and Commercial) and the buttstock needs to be the right one for the buffer tube used.... I will be purchasing a 1-3/16" x 16 UN tap to thread my adapter, so I can use either buffer tube.... I would like a stock that has an adjustable height cheekpiece, if I can find one that won't break the bank.... I will need a buffer tube and buttstock to fit it.... and I'm on a very tight budget.... as in I've sold several guns to finance this project already, and I'm quickly ending up where I will have to subsidize the build with new money, which is hard to come by....

I am open to any and all advice on a suitable buffer tube and adjustable LoP stock, preferably with an adjustable cheekpiece.... Let's start with what are the least expensive ones that will do the job, and where I can get them?.... HELP !?!?!

Bob

YEMX · « **Reply #68 on:** July 23, 2017, 11:32:33 AM »

Now, that's a hard one Bob- An affordable, adjustable AR stock... The only two adjustable stocks that immediately pop into my head are the Magpul PRS and the Luth-AR stocks. Both are expensive, Luth-AR being the least expensive of the two. On average, the Luth-AR stock (for an A2 length tube) is around $140. Which is about $100+ cheaper than the PRS. Luth-AR does make a version for the carbine tube, but its $20 more than the A2 version.

On my 300 blackout build, I one use of Magpul's carbine stocks (for adjustable LOP) with a cheek riser. But that isn't what you're looking for, as the cheek risers are not adjustable- you adjust cheek height via different height cheek pieces.

Just puttering about on the web, there's a new to me stock that's right at $100, from AB Arms. Not sure if they ship to Canada though:
https://www.abarms.com/A-B-Arms-Urban-Sniper-Stock-USS-p/abauss.htm

So far, that's the cheapest "real" adjustable stock I've seen. The cool part is, you use a carbine tube, and you can do the big adjustment for LOP using the carbine tube's indents, and then "fine tune" the LOP using the stock's adjustments... I kind of like the idea- an adjustable "solid" stock...

Now, looking at airsoft options, here's a clone of a Mako stock:
http://www.dhgate.com/product/2016-new-arrival-special-offer-stocks-black/391942204.html#s1-18-1b;srp|1023849275

I'm just not sure of the quality of the plastic- though, since your application is for an airgun, and not a tactical rifle you're going to be beating on, I think this would be a good choice, and cost effective...

Here's another one, a clone of what looks like a CAA stock- much more expensive than the clone Mako stock, but it comes with a monopod and (to me) looks better:
http://www.dhgate.com/product/2016new-ipsc-glock-gun-command-caa-ars-multi/387880774.html#s1-22-1b;srp|1023849275

Just some food for thought.

---EDIT---

ADDITIONAL INFO:

Here's another stock I found, but I don't know if they ship to Canada:
https://www.cheaperthandirt.com/product/imi-enhanced-m4-stock-with-polymer-cheek-rest-imi-zs200-813782025402.do?sortby=ourPicksAscend&page=2&refType=&from=fn

EDIT: Okay, the Cheaper than Dirt stock won't ship to Canada- but what I can do is buy it, and ship it to you... I don't think ITAR's covers stocks, does it? PM me if interested in going this route Bob- $50 for an adjustable LOP and adjustable cheek AR stock isn't too shabby!!

rsterne · « **Reply #69 on:** July 23, 2017, 03:56:49 PM »

Actually, I think the DHGate stock would be fine for my purposes.... I will also need a buffer tube to mount it on (and lock nut?).... Any idea which one, maybe I can get them both from DHGate?.... They do ship to Canada.... Is this the correct buffer tube?....

http://www.dhgate.com/product/223-5-56-model-4-15-mount-carbine-buffer/391941326.html#minicart-1-null

Bob

YEMX · « **Reply #70 on:** July 23, 2017, 04:35:15 PM »

Quote from: rsterne on July 23, 2017, 03:56:49 PM

Actually, I think the DHGate stock would be fine for my purposes.... I will also need a buffer tube to mount it on (and lock nut?).... Any idea which one, maybe I can get them both from DHGate?.... They do ship to Canada....

Bob

Excellent! I'm glad the DHGate company ships to Canada- one problem solved!

As far as which tube to use, I'm emailing the sellers now, as I'm also interested in one of these stocks- so I'll let you know!

That kit should work just fine- as all these parts are being sold as airsoft parts. You won't need the buffer and spring but it's an all-inclusive kit, so you don't really have any say in that. I haven't found individual parts yet, not even sure if they offer them...

So, if using a Mako clone, and getting that buffer tube kit, that's $52 USD rounding up... not sure how much that would be in CAD... Either way, not too shabby for an adjustable AR stock!

rsterne · « **Reply #71 on:** July 23, 2017, 06:20:35 PM »

Thanks, Tom, I ordered that stock and buffer tube, and a short BiPod to replace the one I just gave my son on his Hatsan.... The total (with free shipping) was $91.91 Canadian....

Bob

YEMX · « **Reply #72 on:** July 23, 2017, 06:27:20 PM »

Quote from: rsterne on July 23, 2017, 06:20:35 PM

Thanks, Tom, I ordered that stock and buffer tube, and a short BiPod to replace the one I just gave my son on his Hatsan.... The total (with free shipping) was $91.91 Canadian....

Bob

Most excellent! Please let me know fit and function once they come in...

rsterne · « **Reply #73 on:** July 25, 2017, 06:57:34 PM »

I ordered my barrels today from TJ's.... I'm getting a 6mm and a .257, both in 10" twist, that are 29" long and hammer forged to fit inside my 14mm ID CF tubing sleeves....

Bob

YEMX · « **Reply #74 on:** July 25, 2017, 09:55:10 PM »

Gathering the parts has so far been quite easy... I can't wait to get this build underway!!

rsterne · « **Reply #75 on:** July 25, 2017, 11:37:09 PM »

Tom, did you go with the 20 mm OD CF tube, or the 18mm OD ?.... Mike emailed me today, he has the sample tube I sent, has measured it, and plans to do the barrels this week....

Bob

YEMX · « **Reply #76 on:** July 26, 2017, 03:38:06 PM »

I'm going to go with the 18mm- I was just about to order it now, but wanted to check out what-all was going on here first... I just think 20mm will either be too large, or too close for comfort for me, as far as wall thickness of the breech... 18mm looks like it'll have more meat around the barrel, which I'm much more comfortable with. Of course, I'm just spitballing with a set of digital calipers and my eyeballs...

subscriber · « **Reply #77 on:** July 26, 2017, 06:02:18 PM »

Apologies if this was already mentioned. 20 mm OD by 18 mm ID carbon fiber tube on amazon:

By the way, how does one cut this material?

rsterne · « **Reply #78 on:** July 26, 2017, 10:24:45 PM »

Cut it with a hacksaw or bandsaw, then you can sand the end to get rid of any slivers....

Bob

subscriber · « **Reply #79 on:** July 26, 2017, 10:37:45 PM »

Thanks Bob,

How important is wet sanding and cutting to avoid releasing airborne fibers?

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Any Interest in 6mm ? - Build Thread

Author Topic: Any Interest in 6mm ? - Build Thread (Read 44230 times))