• Watch Out for Scammers!

    We've now added a color code for all accounts. Orange accounts are new members, Blue are full members, and Green are Supporters. If you get a message about a sale from an orange account, make sure you pay attention before sending any money!

Fastest 6mm

orkan

orkan

Primal Rights, Inc.
Banned !
Minuteman
    • Oct 27, 2008
    4,268
    4,001
    South Dakota, USA
    www.primalrights.com
    Over in this thread: http://www.snipershide.com/shooting...on-rifles/212974-opinions-22-243-caliber.html ... I saw a 6WSM mentioned with a 55gr nosler going 4500fps. I'm liking that!

    So, I'm going to start planning on a laser beam 6mm. Why? Because I want one. If I had a racecar, I'd go into it knowing I was going to burn tires. So yes, you fun haters I know it will burn barrels. Don't care. What I'm looking for is the fastest 6mm I can build, which is easiest to achieve, that will get me to that 4400-4500 or faster with those 55gr noslers. No, I don't need to hear about necking down a 50bmg case. I'm talking reasonable stuff here... that will cycle from my DTA. That being the case, I have 3 bolt face options: 308, 300WM, and 338LM.

    Zero consideration to barrel life please. If you want to start preaching barrel life, and how I should use heavy bullets in a fast twist barrel, know that I (absolutely) will not listen, and you are only bringing it up because you are a troll that can't keep with the spirit of a thread. :) What I'm looking for is good brass options (lapua), accuracy, and blistering laserbeam speed.

    So if you were going to wring as much speed from a 55gr nosler as possible, which direction would you go, and why?
     
    I would go with a 18 twist or slower to help gain velocity and keep the jacket in one piece.

    I shoot a .300 RUM with a 19 twist pushing 130gr Barnes TTSX's at 4200fps
     
    • Like
    Reactions: Bbarker71
    I'd neck down any of the RUM's and it will get you your velocity with a heavier bullet. It's been done before so I know there are reamers out there.
     
    Lazzeroni 6.17 spitfire claims 4200 fps out of a 24" 1:10 barrel using 55g varget. I bet you could push that a little faster with a longer barrel and faster twist. Dies and reamers are readily available as well
     
    Will a .243ai with a longer barrel do it? Components are very plentiful and it would take minimal case prep.

    If I recall correct I read in one om my varmint magazines the 6mm X 284 was a top leader.

    If your goal is just outright velocity the .204 with 20 grain slugs will get the job done.
     
    Sounds fun. I would also run a slower twist barrel in the 1:15-1:14 twist range. Still be able to shot 75grainers etc. Should gain you a little and help keep bullets together. I had a 243AI that would do 4200 in a 26" 1:12 barrel but had to piss pound them out to do it. Hell on brass.
     
    Been happy with my 243 catbird. It is a 270 Winchester blown out and necked down. I get about 4000fps to 4100fps with 70 grain bullets. One thing you need to know about the fast 6mms, is to stock up on barrels if you plan on shooting it much. I am one my fourth barrel, but I love the round.
     
    The time tested and truly awesome 6mm remington will give you 4 grand and a bit of change with 55 grain jhps and ballistic tips and powders such as H380, among others.
     
    Ork. The RUM case won't fit more than one in the Mag so you are limited to a 2 shot capacity. A 300 RUM out of a DTA is doable and a 130 is CRUISING out of it.
     
    I used to shoot a 6mm Remington Ackley Improved. It had a 1:8" barrel, but the 58 gr V-Maxes would run up over 4200 fps. The downside, the jackets separated and accuracy sucked. I found the 75 grs usable and the 87s best.
     
    The 510 Allen Magnum case standing next to a 338 Lapua case looks sort of like the 338 Lapua case standing next to a 5.56x45 case. That is some kind of magnum!

    I think that keeping jackets from coming apart at those velocities will be a problem. I like it when people know what they want, and look for a way to get it. Something like the Allen Magnums may be the way to go if you really want to get to 4500 fps out of your b bullets. Either a slow twist, or maybe a solid bullet will solve the jacket separation issue.
     
    A friend of mine had a 6mm-06 AI for a while, it was good for putting 70gr flat base bullets into ground hogs at 45-4600fps from a 26" barrel.

    Like you can already appreciate, the barrel didn't last long. He necked down 25-06 brass so that he didn't have to turn necks.

    He tried another one in an 8tw and gave up with the caliber because the 105 Amax wouldn't hold together over 3350-3400fps and the caliber was good to push them closer to 3800fps. He went to a 6mm Rem AI'd instead after that.
     
    From a specific energy standpoint, something in the 300 WSM to 300 WM necked down to 6mm should get you in the 4,500 range, potentially up to nearing 5,000 depending on losses of SE with the neckdown. If you really wanna get serious about velocity though you must think outside the powder-fired conventional cartridge box. Rail guns are where it is at - a 5,000 grain projectile at 25,000 fps. Packing the generator around could be problematic though.
     
    orkan , Yes my 6 WSM as you've stated is 4,530 ft/sec with the 55g'er with Winchester brass ( Don't use the Norma ) Fab thread , love the attitude and the bit about the ' Trolls ' :D

    Less than 3 inches of drop at 300 yards and when you get to the fox it's like it swallowed a grenade ! :eek:
     
    CMH said:
    From a specific energy standpoint, something in the 300 WSM to 300 WM necked down to 6mm should get you in the 4,500 range, potentially up to nearing 5,000 depending on losses of SE with the neckdown. If you really wanna get serious about velocity though you must think outside the powder-fired conventional cartridge box. Rail guns are where it is at - a 5,000 grain projectile at 25,000 fps. Packing the generator around could be problematic though.
    Click to expand...
    Yes, that fits the OP's bill nicely, a rail gun barrel he can mount up in his SRS...........
     
    6mm-338 Norma could be absolutely insane. Although you do a Lapua Improved for absolute max speed. You'd need to thin the necks a ton though. I'm sure you could get powder slow enough too
     
    I'm wondering if any case capacity past what's available in the 338LM as compared to a 300 RUM or others, would matter in the slightest? Due to the overbore condition... I can't really see it creating more velocity.
     
    You can push a 110VMAX 4000fps out of a 300WSM. So I assume you could neck it down to 6 and do what you want to do. Still probably run it in your DTA.

    If it was me, I'd keep it a 300 though and not go through the extra trouble and enjoy the extra carnage.
     
    Last edited:
    Quickload shows a 6mm-338 Lapua getting 4100+fps from a 115 grain bullet with a 32" barrel...wouldn't last long.
     
    3400 fps with a 75gr AMAX is pretty fun and brass prep is relatively painless! The 22 Creed is a bunch of fun, and very accurate. Josh @ Copper Creek easily shot an 1" group at 700 yards in some high winds with it.
     
    orkan said:
    I've thought about a .22CM more than once! You ever try any lightweight pills through the chrono?
    Click to expand...

    I have not. Going to be pretty strict with this first barrel to get a better judge on barrel life. Thats why I want everything exactly the same for its life span.
    Maybe once this one burns out I will play around with lighter loads. Josh felt comfortable going down to a 62gr bullet or even a 55gr. I would say around 3600 fps with a 55gr pill. But you would only have a 400 yard and in gun.

    I like the 75gr amax for its balance on speed, accuracy, and distance.

    Our next will be a 6mm-WSM. Going to use a 270WSM case and stick a 105gr Berger Hybrid in it. Looking at nearly 3800 fps. Easy to form the brass and a reamer is already on the files at PTG. Now to figure out barrel twist. :)
     
    4500 doesn't interest me as you will not go over 600 rounds per barrel. I would like to at least get 1500-2k range. Otherwise it's not cost effective. A 105gr bullet doing 3800 is pretty impressive!

    Good Luck on your choice. :D
     
    Gray said:
    This might have been covered already, but why not 6mm SAUM with H1000?
    Click to expand...

    Pressure might come into affect and necking down from 30cal to 6mm.... you will have a lot of case/neck separations I bet.
    I would also think barrel life would take a huge dip. Im hoping this 6mmWSM performs well, we shall see when the barrels arrive. :D
     
    I read an article several years ago that stated the weight of the propellent gasses was becoming the limiting factor in projectile velocities. The author claimed that "light gas" guns were the future of high velocity. I'm thinking highly compressed hydrogen. Lightest gas I can think of. :)
     
    KYS said:
    Pressure might come into affect and necking down from 30cal to 6mm.... you will have a lot of case/neck separations I bet.
    I would also think barrel life would take a huge dip. Im hoping this 6mmWSM performs well, we shall see when the barrels arrive. :D
    Click to expand...

    Maybe if George gets this 6.5 SAUM brass connection, necking down to 6mm won't be that bad. I'll definitely be the guinea pig when that comes to fruition :)
     
    I can save you a lot of thinking and decision making but it isn't what you want to hear. Build a 6mm-284 or one of the 06 versions.
     
    orkan said:
    How many rounds are you getting from each tube? This is precisely the kind of first-hand experience I'm looking for. Thanks for your help.
    Click to expand...


    Sorry so late responding, been on a 5 day hike/camping trip. I get around 1,000 to 1250 rounds before accuracy starts dropping off. 1 barrel usually last one prairie dog (try to get in 3 trips a year) / ground hog season and may make it till the end of gun season for whitetails.
     
    You must log in or register to reply here.

    Similar threads

    BravoSector1
    6mm BR vs 6mm BR Norma...are we talking the exact same cartridge???
    Replies
    6
    Views
    213
    MarkyMark007
    MarkyMark007
    Krob95
    22cm issues
    Replies
    9
    Views
    273
    Slides
    Slides
    C
    22 Nosler review on Coyotes with factory ammo
    Replies
    9
    Views
    268
    Cwyscarver
    C
    sacklunch
    Quickload alternatives?
    Replies
    18
    Views
    302
    secondofangle2
    secondofangle2
    P
    6mm ARC bolt gun for competition?
    Replies
    110
    Views
    10K
    Hunter280
    Hunter280
    Top Bottom
    Back