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Looking for barrel


Jesseleeg

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I began my build Friday as parts came in. I was going back and forth between going with a 308 build, or a 6.5 Creedmoor. After researching and researching, then test firing with a friend his two ar-10s, I'm pretty decided on doing a 6.5 and a 308 both. I have every part for the 308 picked out, I am struggling to find a 24 inch 1:7 twist 6.5 Creedmoor barrel anywhere due to Google new but horrible algorithm. The old keyword and putting specifics in quotations no longer works as effective as it used to. I'm not sure if I can get any help on this website, but I figured I would try an ar10 specific forum board for help. I'm looking to push this rifle to the absolute max. I want 1000+ yds for my range.

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4 hours ago, jtallen83 said:

If he wants 1,000+ yards he will use every inch. Palma guys often run 30+ inch barrels.

 

1 hour ago, 98Z5V said:

The article I was thinking about when he was talking about 1,000+ yards. You can do those ranges with shorter barrels. So unless he plans to shoot matches, then I would say yeah go for it, but I would also say go for something like a kreiger or a shilen. 

1 hour ago, Jesseleeg said:

That would be a great article if I was running lesser grain. With a 1:7 twist, I'll be using the newer 150 grain rounds. (Oddly the new 150 grain rounds are cheaper). I'll check x caliber. Kreiger can do one, but they are so pricey. Thanks for the feedback. 

What 150gr rounds would you be talking about? Maybe I have fallen behind on 6.5mm lately because the largest rounds I have seen lately for 6.5 creedmoor and .260 rem has been 143gr. 

Also, will 150gr fit in a mag for an ar-10?

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https://www.cheaperthandirt.com/category/ammunition/rifle/65-creedmoor.do 

The federal ammo 150 grain 6.5 Creedmoor ammo top right is cheaper than any of the 140 grains on the page. Any competition I've ever bared witness to, guys are using long barrels. I specifically said I didn't want Kreiger because of the price. With good accuracy, paying the price for one is unnecessary. Long story short, I can't afford a Kreiger. 

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4 minutes ago, Jesseleeg said:

https://www.cheaperthandirt.com/category/ammunition/rifle/65-creedmoor.do 

The federal ammo 150 grain 6.5 Creedmoor ammo top right is cheaper than any of the 140 grains on the page. Any competition I've ever bared witness to, guys are using long barrels. I specifically said I didn't want Kreiger because of the price. With good accuracy, paying the price for one is unnecessary. Long story short, I can't afford a Kreiger. 

Are you planning on shooting competitions? I said in my last comment, if you plan on shooting "matches" then I could see the use of going long. But for most shooting applications that long of barrel is unnecessary. much shorter barrels with the 6.5cm can still get out to 1,000+ yards.

I don't blame you for not being able to afford a kreiger, I can't afford a take down pin at this time. was just my recommendation or something similar, again if you were trying to make the most accurate rifle you could, if you planned on shooting competitions. 

6 minutes ago, Jesseleeg said:

Also for the magazine question. If a larger 308 fits, why would a smaller round not? I'm not sure if I'm understanding the question correctly. It's still a 6.5 mm compared to a 7.62 mm. 

I was referring to length, not diameter. some of the heavy grain rounds have better ballistic coefficiencies because of the long slim shape, but that doesn't mean they always fit into a mag. some people have gotten around this by seating the bullets deeper in the case, but that can affect accuracy, among other things. If it was a bolt gun where you could load one at a time straight into the chamber, that would be less of an issue. 

Federal has never been my favorite ammo manufacture so maybe someone else could give input on their 150gr 6.5cm rounds.

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Yes I plan to shoot competitively. I was using the Federal as an example in comparison to the federal 140 grain, but the federal will be what I use to zero my rifle as its the cheaper end for 150 grain. I don't plan on using a heavy long long barrel for hunting, as that would be impractical. 

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48 minutes ago, Jesseleeg said:

https://www.cheaperthandirt.com/category/ammunition/rifle/65-creedmoor.do 

The federal ammo 150 grain 6.5 Creedmoor ammo top right is cheaper than any of the 140 grains on the page. Any competition I've ever bared witness to, guys are using long barrels. I specifically said I didn't want Kreiger because of the price. With good accuracy, paying the price for one is unnecessary. Long story short, I can't afford a Kreiger. 

I looked on that page, and didn't see any 150gr 6.5C ammo, man.  Federal only had 9 factory loads for Creedmoor, and they're all on this page:

https://www.federalpremium.com/products/rifle?page=0&facets=computed_skucaliber_s=6.5 Creedmoor

For distance ammo, and competition, "cheap ammo" isn't gonna have alot to do with those competitions.  Right now, one of the meanest long distance 6.5mm projectiles you can buy is the 147gr Hornady ELD-M, with a G1 BC of 0.697 and a sectional density of 0.301.  It runs just fine through a 1:8" twist barrel. You need to look at ballistic coefficient and sectional density, more than the projectile weight.  You can get a 160gr Hornady round nose in 6.5mm, but the BC sucks for long distance, though the sectional density is through the roof.

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2 minutes ago, Robocop1051 said:

I remember when the “experts” told me I needed a 26”- 30” barrel for my .338 Lapua Mag... My 22” barrel is spec’d To +2k yards launching Berger VLD pills. 

28-30 may help some, but I've found 22-24 to be sufficient enough from my experience. I'm not going to claim to be an expert though, I just really enjoy shooting. I had concidered doing a 22 inch myself. 24 just has been stuck in my head for whatever reason. I have had countless amounts of people tell me I need a Kreiger level Barrel as well, yet I'm on a budget with this gun, and I'm still going to be purchasing a scope for it, which buying a Kreiger would limit me drastically. I feel the money would be better spent on a great scope. 

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My mind always goes back to the Houston wharehouse testing results on barrel length, they showed 21 3/4 to be the sweet spot.

http://precisionrifleblog.com/2013/10/18/secrets-of-the-houston-warehouse-lessons-in-extreme-rifle-accuracy/

Bartlein is another cut rifling option with a pretty good rep.

If you want the cheaper button rifling then Criterion would be hard to beat if they had your twist. I would do a bunch of research on what the PRS guys are using for a twist before picking an oddball. Oddball stuff means oddball price.

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I always believed that long range shooting that a longer barrel is better even though they are those who don't think so. Anyway, 1-7 would help keep those big BC bullets sping fast enough when you can't shoot them as hard as a bolt gun can. Curious on the competition do you plan making the rifle shoot from mag length or single load so you move that bullet out fwd of the mag closer to the lands?

I was going to suggest if mag length was a requirement to think about buying a 6mm creedmoor, then everything you shoot would be mag length. The BC on those bullets are very high and you its easier to get those up to speed as well.

I had great luck with my x caliber 7mm-08 barrel on my LR. My last string at 600 yds was 200-13X out of 20 shots for record I had only 3 shots not within the 6 inch high xring and I shot 9 x's in a row using iron sights.  I used 160g TMK bullets .050 off the lands. 

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I missed the part about this being for competition. At that point .01% can be the difference of a W and a L. If I thought a few more inches would make a .01% difference, I’d do it too. 

I think the Army Marksman record holder was shooting a .260 Rem with a 30” barrel for a long time. 

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I would also be considering your gas system if you are going with a 24" barrel, that extra 4", (over a 20" barrel and rifle length gas tube) is going to dramatically increase the dwell time in the gas system, ie not so much the pressure but the volume of gas that the BCG is going to have to deal with, the projectile is going to be in the bore for another 4", (still feeding gas through the gas tube), while the BCG is starting to unlock.

Someone here linked a supplier, White Oak Armament???,  that make gas tubes to order/length, I'd seriously be considering this if it was me building this rifle, my goal would be to keep the ratio of the chamber to the gas port to the muzzle the same in your 24" as it is in a 20".

 

 

 

Edited by 308kiwi
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13 minutes ago, 308kiwi said:

Someone here linked a supplier, White Oak Armament???,  that make gas tubes to order/length, I'd seriously be considering this if it was me building this rifle, my goal would be to keep the ratio of the chamber to the gas port to the muzzle the same in your 24" as it is in a 20".

 

Yep, they'll do it. 

20" gas guns with a rifle gas system are running 6.875" gas port distance from the muzzle. 16" with the Armalite AR-10 Carbine gas tube (a tick over midlength gas in the AR15) are 8.375" from the muzzle.   Gotta keep it right in there somewhere, and nail the gas port diameter.  Or start small and drill up.

Or...   just really tweak that gas port diameter, with that much dwell.

Edited by 98Z5V
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9 hours ago, Jesseleeg said:

Yes I plan to shoot competitively.

ok, now we are getting somewhere. lol. 

would have been so much easier if we would have started out with that information. lol.

since you plan on shooting competitions, I say the biggest thing is trigger time and load development. most of the time it seems like rifles these days are far more accurate than the shooters if they have the correct load tuned in. 

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I had a wild cat 6mm LR rifle with the gas port moved fwd 2 inches as the barrel was 26 inch. It worked fine that way. CLE out of Florida has the opinion that moving the gas system fwd is not worth the trouble it could cause. Although I never saw any problems but when you build rifles one might see them more often. But the 6.5 creedmoor using H4350 will have plenty of gas volume to run the BCG as long as the port is big enough.

I have 24 inch barrel on my 7mm-08 and rifle length gas system and I have plenty of accuracy. Going to mid range match this weekend 20 shots at 300yds, then 2 each 20 shot strings at 600yds, scope one day and irons the next day,  Gotta load ammo this week.

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