6mm ackley and 6/284 barrel life

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Bigbirddog, Oct 15, 2013.

  1. Bigbirddog

    Bigbirddog Member

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    Hey guys new to this great site but I have been reading it for years. I have looked for my question on site but have not seen a answer.

    I am building my first custom rifle and have a Krieger barrel 6mm 1:8 twist 5R heavy palma headed my way. It will be fluted and finished at 26 in. fitted to a savage 110 long action. I want something like a 6mm AI or 6x284. My gunsmith has a 6x284 reamer already so that would save me some money on buying a reamer. Either way I will have to buy dies and brass. My question is barrel life. I want to shoot 105 and 107 gr bullets. I have to fire form the 6mm Ackley but not the 6x284. I am thinking that fire forming the Ackley and then firing the formed cases is working on the throat as bad as the 6x284. I know the 6x284 eats throats but fire forming the Ackley to get the performance also does the same. It looks to me it is a wash. Shooting Ackley twice and shooting 6x284 once. This rifle will be used for paper and Alabama ground hogs which can go from 40lbs to 300lbs. also white tail dear. Please help and sorry if this has been covered before but I could not find the answer. Question is do both have about the same barrel life?
     
  2. AZShooter

    AZShooter Well-Known Member

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    I have had several 284 win chambered rifles and often marveled at what the 6mm-284 would be like. A bit over 3 years ago I had Pacific tool and gauge make me a reamer and since then have made three 6mm-284s.

    The one that would most interest you is a 28" #11 profile 5R Bartlein with 1 in 7.5 twist put together to shoot the 115 DTACs. It didn't shoot them accurately enough for me. I experimented quite a bit wearing out the barrel in the process. Ended up with the 107 Sierra then the 105 Berger target hybrid showed up and I switched. Really like that bullet. Now approaching the 1000 round mark. My borescope shows a horror show of heat cracking way up the bore. Clean up is getting slower but that rifle still shoots very very accurately. I have another Bartlein 5R 1 in 8 twist sitting on the shelf when this one finally wears out and begins to loose its accuracy.

    The other two are sporters with Rem 243 takeoffs rechambered to 6mm-284. The heat cracking shows up early but they still shoot well. They are Remington barrels so they are not as easy to clean as the bartlein was with same round count. The beauty of these barrels is they don't cost much and offer amazing performance.

    The first barrel I ever chambered myself was one of those 243s. It is a 20" barrel I got for $40. To my amazement it shoots the 87 gr hornady V-max at 3375 fps. The other sporter is a 24" barrel and it shoots the 55 gr nos bt at 4175 fps. I'd shoot the 105 bergers but Remington barrels don't have enough twist.

    Enjoy the build and the very best LR performance from a 6mm. FYI I use 6.5-284 Lapua brass and think it is the best brass for the 6mm-284. I used the reamer to make a simple forming die with a section of an old 264 win barrel. Helps get the necks closer to 6mm with no stress or damage. This forming die really helps if you want to neck down 284 win brass.

    Here is a pic of the 20 lb bartlein rig:
    [​IMG]
     

  3. ZSteinle

    ZSteinle Well-Known Member

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    I love my 6mm-284. Fast and flat! I'm sending 105 berger vld's just shy of 3300. They are not the easiest on barrels but barrels are made to be replaced. Plus its as simple as running 6.5x284 brass through a die and load it
     
  4. Trickymissfit

    Trickymissfit Well-Known Member

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    Ackley said the 6mm Remington was about max capacity for the 24 caliber bore. The 6/284 and the 6mm Ackley are both overbore, and will decrease the barrel life. The .284 case will be much worse than the Ackley, and have close to the same velocity. The Ackley ought to show close to 33% greater shot life.

    But on the otherhand, I know some guys that shoot that case, but not like we think of. The started out with a standard 6/284 case and ate barrels so fast that they were a barrel maker's dream come true! One guy got the grand idea of running the reamer in .100" short. He lost about 70 fps, and nearly doubled his barrel life with tighter groups (same reamer everytime). His buddy was so impressed that he did the same chamber .150" short, and lost about 100fps. Later a couple more guys did the .100" short chambers with similar results. The first guy bought his own reamer (identical), but with a .05" longer neck, and did even better. He sent me a couple photos of chucks he shot in the 750 to 850 yard range using Berger bullets. Two of these guys eventually went back to the 6mm Ackley due to cases being next to impossible to find.

    Now I've shot the 6mm, 6mmAI, as well as the .257AI. All shoot very well, and wouldn't hesitate to own any of them. They use about 10% less powder for similar velocities (Ackley verses the .284 case). I like the 35 degree shoulder better than the 40 degree shoulder, and for me the neck length is adequate but would rather saw it at .32". I can't see much difference in recoil between the 6/284 and the 6mmAI. Even the short versions are similar.
    gary
     
  5. Bigbirddog

    Bigbirddog Member

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    Thanks this is what I was looking for. 6/284 burns barrel faster than a 6mm AI even though you are having to shoot to fire form the brass. I like the Ackley but thought of saving some money because my guy already has the reamer for 6x284. Same one used on his gun. But reamers are cheaper than barrels. Just wish the 6mm had as good of brass. Thanks Again
     
  6. Trickymissfit

    Trickymissfit Well-Known Member

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    shop around for brass. Norma does the 57mm Mauser family, and Lapua has started to get a lot of complaints lately (not taking sides here). You do a .264 necked 6mm, and things seriously begin go even out. But if you gotta have a "no turn" chamber, Lapua might be your best bet. I prefer the tighter necks for their built in accuracy, but also others don't.
    gary
     
  7. MontanaRifleman

    MontanaRifleman Well-Known Member

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    I just built a 6-284 with a no turn neck chamber (.281). A loaded case is .271. There is about .002 clearance all around (.004 total clearance) The Lapua brass seems just fine.
     
  8. Trickymissfit

    Trickymissfit Well-Known Member

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    lately there have been a few complaints about Lapua brass on here alone. I've never had a problem with it myself, but only use .223 family stuff. Other folks complain about Norma, and have yet to ever see a problem with it as well. The only brass I've learned to really dislike is Blackhills, and even then I may have gotten a couple bad batches. Never had a problem with Winchester or Remington, while others do

    gary
     
  9. MontanaRifleman

    MontanaRifleman Well-Known Member

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    What are the compliant about the Lapua brass?
     
  10. Trickymissfit

    Trickymissfit Well-Known Member

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    do a search on here. Think it was being soft, but also could be wrong. Like I said I never saw a problem with it
    gary
     
  11. MontanaRifleman

    MontanaRifleman Well-Known Member

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    Did a search and couldn't find much. Maybe an isolated incident(s) Checked Midway reviews for all Lapau offerings and all were rated from 4 to 5 stars with most being 4.7 and above. The 6.5-284 had 7 reviews and all rated 5.

    Have only shot a few break-in rounds with mine, but so far the out-of-the-box quality is excellent.