Any Interest in 6mm ? - Build Thread

[rsterne]

I suppose it's a good idea, but I never bother.... A dust mask would be a good idea.... I think that would look after the amount you release with a couple of cuts and sanding the ends....

Bob

[rintafile]

Inventory run on NOE's forum one missing from 5 signed...Any interested on this bullet here?

http://noebulletmolds.com/smf/index.php/topic,2146.0.html

[YEMX]

Well, I received my barrel from TJ yesterday, my mold is on order- a 4 cavity "Bowman" 60 grain from Arsenal.  I'm still waiting on my CF from fleabay, and I'll send off my breech as soon as I get my CF.  This rifle is becoming more and more of a reality!!!

[rsterne]

I got my barrels today from TJs.... Mike did a fantastic job of hammer-forging them to fit the sample piece of 14 mm ID Carbon Fibre Tubing I sent him.... Both the 6mm and .257 barrels I ordered are a perfect slide fit inside the CF sleeve.... They are both a 10" twist, and the blanks are 29" long....



I am slowly collecting the parts I need for this winter's projects, this was a big step along that path....

Bob

[YEMX]

I got my barrels today from TJs.... Mike did a fantastic job of hammer-forging them to fit the sample piece of 14 mm ID Carbon Fibre Tubing I sent him.... Both the 6mm and .257 barrels I ordered are a perfect slide fit inside the CF sleeve.... They are both a 10" twist, and the blanks are 29" long....



I am slowly collecting the parts I need for this winter's projects, this was a big step along that path....

Bob

Thank you again for letting me know you were having some barrels done up Bob- My barrel also came out about darn perfect!  It slid easily into the CF tube I ordered (via link you provided), with no play.  This is going to be a fun build!!

Only "bad" part is, I can't use a CF tank- I went ahead and ordered the Ninja 4.5k psi in/3k psi out reg.  I could only find an Aluminium tank that would fit the reg's threads (I'm assuming 5/8-18 UNF) on Aliexpress- it's also only 450cc instead of 500 cc...  But, it is a 4500 psi tank.  60mm in diameter.  So about the same size as a "standard" airgun buddy bottle.  Which means I can get a bipod mount for it.

[rsterne]

It's great news that Mike at TJ's can make .22 to .30 cal (maybe even .357) barrels in 14mm OD to fit the readily available CF tubing of that ID.... The only catch is that it's not a standard size for him, and he may not have it in stock.... All he does is hammer-forge the barrel smaller while it's on the Mandrel instead of stopping at 9/16", he goes a bit smaller.... CF tubing is available in 14mm ID with 1mm, 2mm, or 3mm wall thickness, depending on how stiff you need, and what will fit your receiver, and clear your air tube.... The 3mm wall (20 mm OD) tubing I bought is like a rock.... sooooooooooo stiff.... 

My 29" long 6mm CrMoly barrel weighs 1 lb. 10 oz., and with the 6 oz. CF sleeve weighs 2 lbs. even.... If the barrel was the same OD and all steel, it would weigh 3 lbs. 10 oz.... By using the 20mm sleeve on the 14mm CrMoly liner I have saved 45% of the barrel weight, with the same stiffness.... The sleeved barrel is over 4 times as stiff as the 14mm OD liner by itself, for only a 23% increase in weight.... Just 6 oz. of Carbon Fibre does the same thing as adding 2 lbs. more steel.... 

Bob

[YEMX]

It's great news that Mike at TJ's can make .22 to .30 cal (maybe even .357) barrels in 14mm OD to fit the readily available CF tubing of that ID.... The only catch is that it's not a standard size for him, and he may not have it in stock.... All he does is hammer-forge the barrel smaller while it's on the Mandrel instead of stopping at 9/16", he goes a bit smaller.... CF tubing is available in 14mm ID with 1mm, 2mm, or 3mm wall thickness, depending on how stiff you need, and what will fit your receiver, and clear your air tube.... The 3mm wall (20 mm OD) tubing I bought is like a rock.... sooooooooooo stiff.... 

My 29" long 6mm CrMoly barrel weighs 1 lb. 10 oz., and with the 6 oz. CF sleeve weighs 2 lbs. even.... If the barrel was the same OD and all steel, it would weigh 3 lbs. 10 oz.... By using the 20mm sleeve on the 14mm CrMoly liner I have saved 45% of the barrel weight, with the same stiffness.... The sleeved barrel is over 4 times as stiff as the 14mm OD liner by itself, for only a 23% increase in weight.... Just 6 oz. of Carbon Fibre does the same thing as adding 2 lbs. more steel.... 

Bob

That's crazy to think about!!

It is awesome that Mike can offer the 14mm OD- Going with the 18mm OD opens a lot of opportunity for the Brod crowd, as the 18mm is perfect for a factory breech... Not too big, not too small- juuuuuust right!

I too am slowly gathering parts for this build.

[rsterne]

The 18mm OD CF sleeve would only add about 4 oz. of weight (15%), and it would nearly triple the stiffness of the 14mm barrel by itself....

Bob

[Smaug2]

Just curious, why bother with 6mm/.243 when .25 is already so popular? Why not just make the bullets in .25 cal.?

Don't get me wrong, my only centerfire rifle is a 6mm Remington. I think it's a great caliber. But for airguns, where we're shooting much shorter distances? I dunno, it just doesn't seem like we need that many calibers.

[rintafile]

Depends which is shorter distances? Here in Finland we shoot @ 300m soda cans 12oz for fun...Thats basicly longest shooting range where we could go shooting here.
There is topic where Carl shoots 1100 Yards at .257...And soda cans at 800 yards IIRC.
 And my opinion is fun to try find "new" calibers which could perform well 100m 200m 300m or longer or any distance.
And good bench rest airgun is also nice to get.... And at this forum  is guy who shoot .25 Taipan  at 250 yards on golfball... that is long distance for diabolo...can't remember who it was but that topic is here with video.

And there is .25 bullets available on NOE's forum. Few desings by Bob and few basicly desingned for .25 acp...
http://noebulletmolds.com/smf/index.php/topic,1897.0.html and http://noebulletmolds.com/NV/index.php?cPath=374_376
 I've been looking long .25 blank barrel haven't find any suitable yet...

Testing new is part of this hobby and it is interested.

Edit: that user is Bizill and topic is here
https://www.gatewaytoairguns.org/GTA/index.php?topic=130647.0

[YEMX]

Just curious, why bother with 6mm/.243 when .25 is already so popular? Why not just make the bullets in .25 cal.?

Don't get me wrong, my only centerfire rifle is a 6mm Remington. I think it's a great caliber. But for airguns, where we're shooting much shorter distances? I dunno, it just doesn't seem like we need that many calibers.

Page 1, reply 4...  Not being snarky, just wanted to reference that post, in case you didn't want to read through the entire thread. 

No real reason for me- just want to be different.  I'm also still waiting on a .257, and figured this would be a good, relatively simple project that doesn't require too much work on my part.  At it's core, my bottle conversion Marauder is just a jumble of modified factory parts and aftermarket parts fabercobbled together to form a cohesive airgun.  I've been wanting to do up a Brod build for a while, but didn't want to do .30, .25 or .257 because I already have one or more in each of those calibers.  I didn't want to do a .357 because that's not a simple build for me, for what I want it to do, and I also am not ready to flat out purchase an airgun for a sum that's greater than what I spent building my Reminton Model 7 in .300 BLK... Which wasn't too much, considering: well under $1k assembled from parts, aluminium chassis with scope and rings. 

[K.O.]

For me it is two things first is in the long run I would like to see PCPs  available in as many calibers as there are in the other disciplines...

But for me well .243/.244 is a great fit for a near stock Mrod... 1 in 12 to 1 in 14 twist  using 25g to 40g  (Lighter if they started making pellets or Nick started swaging them)...

would not take a really long barrel to get to 60-70 fpe... at that power level 30g-45g cast would work well with good to decent trajectory and given the same design the 243 would have a bit higher sd and slightly better B.C. ...

Not there yet with barrels, pellets, and cast... can only hope and demonstrate for now...

In the end having more calibers is about how each can fit into more niches more closely...

[rsterne]

We can never have enough calibers.... but we always seem to have more than we really need.... A lot of it boils down to availability of bullets and barrels.... and what fits the job you have to do.... I'm not the first to suggest 6mm, Jack Bowman at Scandalous Airguns makes them, and through Arsenal has a 60 gr. bullet available, I have a mold currently at Erik's being hollowpointed.... While I was at it, I had Jared tool up for a 47 gr. in .224 cal which should work in the 14" twist TJ's liner.... so that makes another choice for a similar job....

Realistically, there is not much difference between any of the three calibers.... At 950 fps, with the three versions now available of the venerable Lyman 257420 through Arsenal.... you can choose....

47 gr. in .224 cal.... 94 FPE
60 gr. in 6mm/.243 cal.... 120 FPE
70 gr. in .257 cal.... 140 FPE

The larger the caliber, the more air you will use, and the more report you will get.... but you will put more energy downrange.... I don't think a Ground Squirrel on the receiving end will know what hit him with any of those.... but by the time you get up to something the size of a Coyote, there would likely be a difference in terminal performance....

Bob

[rsterne]

Here is the stock I ordered from DHGate, along with the buffer tube (Mil-Spec).... The fit is perfect, with about 3" adjustment in the LoP, and almost an inch of vertical adjustment for the comb height....



The stock / buffer tube assembly weighs just 1 lb. 5 oz.... and should look great with the PRod trigger group I plan on using on this build....

Bob

[skorec]

We can never have enough calibers....
Bob

I agree absolutely.
Personally I aspire for caliber .13 at 12FPE

Triple the stiffness of the 14mm barrel by verry light CF tube is  intersetng  too.
The qustion only is why they aro not pruducing hole barrel from CF.

[rsterne]

I would think that wear would be the problem.... The CF tubing is carbon fibres in an Epoxy matrix, which is basically plastic.... It wouldn't take long to wear the rifling away....

Bob

[YEMX]

Bob, that stock looks excellent!  I'm glad you're happy with your purchase!

My Ninja 4500 psi in 3k psi out reg should be here any time, and my aluminum tank should be here... soonish?  I've also just received my trigger and bolt from Crosman.  Mrod Gen2 main tubes are backordered.  Not sure when I'll get that.  I ordred mine on the 15th of August.  I've also received my scope for the 6mm build- a BSA 4-14x44 with a 30mm tube.  Midway has them for a whisker under $140 US:

https://www.midwayusa.com/product/456482/bsa-tactical-mil-mil-rifle-scope-30mm-tube-4-14x-44mm-side-focus-1-10-mil-adjustments-first-focal-mrad-reticle-matte

[rsterne]

Yeah, great scope, but shipping scopes out of the USA is almost impossible, Midway won't even consider it.... I got a 1 metre (39") long piece of 7075-T6 tubing from a buddy today, and the plan is to build the .257 around that, unregulated, instead of a bottle.... The tubing is 1.25" OD x 0.130" wall, which means it is good for over 5000 psi MSWP.... which means I can tether the gun at anything up to that.... Here is what I'm thinking it will look like....



The plan is to get another stock, but without the buffer tube.... and simply machine the OD of the main tube for the stock to slide over it.... The ID is 0.010" smaller than the normal 1.00" ID buffer tubes, so there is plenty of wall thickness left.... and NO weight for an adapter.... I am blown away by how light the tube is, even at that length, and with the thick wall.... The reservoir will be 300cc.... 

Yeah, I know this isn't a 6mm, but since I kept mentioning I was also going to build another .257, I though I would put this information in here anyways.... 

Bob

[rintafile]

Well...That 75 grain  NOE's mold is now on Last Call.. I started this project getting molds first     Seriously need to figure that blank barrel... Wan't to buy good barrel...Bartlein, Krieger, Shilen etc. but my wallet dosen't like that idea so I  probably wait some time..

[rsterne]

Teemu, I have asked Al if he can, in addition to making the 75 gr., also shorten the design by 0.080" (at the back), by plunging the tool to a shallower depth in the mold block.... This would give a bullet of about 64 gr.... So far, no answer.... If you are interested in both weights, perhaps post in the Group Buy thread, and send Al a PM, as I have?.... I would like both (2 separate molds)....

Bob