rra 223/5.56 wylde?

[catargadelendaest]

Actually, the ID of a cylinder can get smaller with heat for what is known as a "thick walled cylinder". This happens because the material expands linearly with temperature. However, the expansion around the circumference is 6.28 times the expansion along the radius. So the geometry of a cylinder imposes an imbalance between radial and circumferential expansion. This creates an internal force imbalance with the OD in tension and the ID in compression. In this case the hoop stress of the OD is sufficient to compress the ID.

It can also happen under transient conditions when heat is moving from the ID to the OD. In this case the cooler OD compresses the expanding inner portion and the ID shrinks. This is the sort of condition a rapidly fired barrel sees as heat moves from the bore to the OD.

I don't have my engineering books with me to run the numbers on a chamber to see if it is in thick walled cylinder territory. This phemonenon only happens when the ratio of OD to ID is high.

I would suspect that thick match barrels in tiny calibers are thick walled cylinders

I do not wish to derail!

JiminAZ, that sounds perfectly reasonable for a "thick walled cylinder" scenario. I'm no engineer so I cannot begin to estimate the degree to which any rifle chamber resembles a "thick walled cylinder." Thanks for the info.

Now back to the discussion of RRA barrels.

[#1gunna89]

Well I ended up able to return the barrel and went ahead and shelled out the money for a noveske 14.5" chf 1/7 twist barrel. After the battle comp 1.5 and having it pinned and welded. My wallet is a little upset with me but ill recover. Thanks for all the info guys.

[fdxpilot]

Im building this riffle for 300 meters max. I may have jumped the gun in purchasing this match barrel. Ill find someone that has a use for it and trade for a standard gove profile one. Thanks for all the input from everyone

Sounds like you got a good barrel. However, if accuracy is your goal, 62g ball ammo (M855) is not a good choice. Mil-spec ammo is not known for great accuracy and M855 has the added disadvantage of an internal steel penetrator. Lack of precision in the placement of the penetrator rod in the bullet leads to inconsistency in ammo ballistics and big groups. I have always had better results using 55g ball (X193) vs 62g M855, even using 1/7 barrels.

Get some good ammo with either a 69g, 75g, or 77g match king bullets if you are going for good accuracy. Hornady, Federal, or Black Hills all make some nice 5.56 match ammo.

[T2C]

Well I ended up able to return the barrel and went ahead and shelled out the money for a noveske 14.5" chf 1/7 twist barrel. After the battle comp 1.5 and having it pinned and welded. My wallet is a little upset with me but ill recover. Thanks for all the info guys.

One of my co-workers owns 2 Noveske rifles and they are nice rigs.

Good luck with your build.

[#1gunna89]

I have read nothing but good about noveske chf barrels. Im sure I wont be dissatisfied

[Backroad]

I've had an RRA Tactical Entry for about 3 years now and love it. Haven't tried any 5.56 in it, but reload and shoot .223 on a bi-weekly basis. I love that gun! I have guys shooting Bushy and Colts on the line next to me. Enjoy watching them misfire and jam while my RRA just keeps on going on. Don't sell them short. You can pay a lot more for a lot less. For some reason, this forum seems to have an anti-RRA cult - probably made up of people who have never owned one, but "have a friend who told me...."

al

[#1gunna89]

Haha I have come to realize this. I have nothing negative to say about rra. I habe never used or owned anything from them. I steered away from this rra barrel because the wylde chambering just didnt sit well with me. Thia is defensive rifle. This barel was just to heavy and not what I needed

[MistWolf]

After three thousand rounds through my carbine, the Wylde chamber has never ever let me down- even when run hard. I've not heard of any problems related to a Wylde chamber

[#1gunna89]

Thays great feed back on that chambering. The riffle this new one is replaceing has roughly 13k down the pipe on it. It had a DD chf on it. Still pushes 2 moa groups at 100.

[waveslayer]

Thays great feed back on that chambering. The riffle this new one is replaceing has roughly 13k down the pipe on it. It had a DD chf on it. Still pushes 2 moa groups at 100.

Out of 3 RRA rifles I can easily get sub MOA out of them. The new R3 is nice as well. I'm getting .890" at 200 yards with mine. I love RRA. I make a lot of guys sad at the range when their 2K AR's can't even do a MOA...