Hey guys im looking to build a 7mm something. Im wanting to shoot the 180gr class bullets at or near 3000fps. I want my barrel to be no longer than 26" and dont want to have to push it super hard to reach my desired velocity. This will be for informal target use so just for fun.
what 7mm?
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A 180gr at 3000 is not a fun gun, it needs to be heavy and have a break. What you are asking for will recoil like a 300 Weatherby or Winchester with a 180 gr bullet. My long range hunting rifle (8 lbs) is a 7mm Rem Mag shooting 168 Bergers at 3050 ft/sec, it is not bad for a few shots but not what I call a fun gun. 223's and 6mm BR's are fun. My 223 that I shoot 600 yds is a lot heavier than the hunting rifle, now that is fun after 52 rounds in a match.
If you go 7WSM / 7x300WSM / 7x270WSM you need to look at something that is long throated to maximize case capacity. Even so you are going to be hard-pressed to find 3,000 fps in a 26" tube with a 180 Berger. My 7WSM is long-throated (to over 3.1" COAL) and I could only get the 2,900 fps node in my 26" tube. If you bump up to 28" you might get there, but maybe not depending upon where you are located. My long-throated single feed only F-Class 7WSM hits 3,000+ but its got a 30" tube on it.
I don't think the SAUM can do it but with some newer powders maybe (I am skeptical w/ the 26" tube).
If you go 7LRM or 7 Rogue (or whatever else they are calling a 300Win Mag necked down to 7mm) you can get there w/ a 26" tube.
My 7 Dakota hits 3,200 fps at its high pressure node and runs @ 3,100 all day long (but its a 29" tube). Cut to 26" it probably gives you 3,000 fps.
I'm not a recoil weenie by any stretch, but all of these will thump you a bit even with a fairly heavy rifle. None of my rigs wear a muzzle break (but none is lighter than 17 pounds). I've run my 18 lb 7 Dakota in F-Class using a bipod. By the time I get to the 50-55th round I'm focused as much on recoil management as I am on shooting for a score. Same for my 17 lb 7WSM - by shot 65 or so in 3-4 hours you want it to be over. If we are talking 10-15 shots its not going to pose a problem at all (at least for me).
convert one of these rigs to an 8 lb pure hunting rig and she will thump you for sure. Doable absolutely, but not for extended range / desert / plinking shooting adventures (at least by me).
Jeffvn
I don't think the SAUM can do it but with some newer powders maybe (I am skeptical w/ the 26" tube).
If you go 7LRM or 7 Rogue (or whatever else they are calling a 300Win Mag necked down to 7mm) you can get there w/ a 26" tube.
My 7 Dakota hits 3,200 fps at its high pressure node and runs @ 3,100 all day long (but its a 29" tube). Cut to 26" it probably gives you 3,000 fps.
I'm not a recoil weenie by any stretch, but all of these will thump you a bit even with a fairly heavy rifle. None of my rigs wear a muzzle break (but none is lighter than 17 pounds). I've run my 18 lb 7 Dakota in F-Class using a bipod. By the time I get to the 50-55th round I'm focused as much on recoil management as I am on shooting for a score. Same for my 17 lb 7WSM - by shot 65 or so in 3-4 hours you want it to be over. If we are talking 10-15 shots its not going to pose a problem at all (at least for me).
convert one of these rigs to an 8 lb pure hunting rig and she will thump you for sure. Doable absolutely, but not for extended range / desert / plinking shooting adventures (at least by me).
Jeffvn
GSPV
A failure to plan is a plan for failure.
If it is for informal target shooting, why are you set on <= 26" for the barrel?
I'd suggest 30 or even 32". It's a lot of barrel, but it also lets you sync with what the long range shooters are doing and be able to use their data as is.
As others say above, I'd build heavy and put on a muzzle break.
I'd suggest 30 or even 32". It's a lot of barrel, but it also lets you sync with what the long range shooters are doing and be able to use their data as is.
As others say above, I'd build heavy and put on a muzzle break.
rickiesrevenge
Silver $$ Contributor
Jeffvn said:
What load do you use in your dakota to get that speed?
I'd build an STW thats throated long. Put a brake on it too.
Aaron
you want 3000 in a 26 inch barrel get a 7mm ultra mag wont be fun tho
Sorry shoulda stated this will be for use in elr out to 2000yds. My 338 lapua with 300s isnt too bad and I expect any of the 7's wont match it. Its a different kind of fun.
284 shehane and a brake. you wont get 3000 fps, but you'll get close if you run a 30" barrel. fireforming is easy in the cartridge and there is a lot of good components out there (180gr hybrids, lapua brass)
you can go 7SAUM with a massive brake and that will probably be fun, but be prepared for a barrel change inside of 1500 rounds so take that into consideration...thats $600+ barrel job. plus, brass is a PITA.
you could also go 6.5 SAUM and some people are claiming longer barrel life...like 2000 rounds. again, run a brake and it should be nice and tame. Again, brass prep is tedious.
you can go 7SAUM with a massive brake and that will probably be fun, but be prepared for a barrel change inside of 1500 rounds so take that into consideration...thats $600+ barrel job. plus, brass is a PITA.
you could also go 6.5 SAUM and some people are claiming longer barrel life...like 2000 rounds. again, run a brake and it should be nice and tame. Again, brass prep is tedious.
My Dakota (w/ the 3,200 fps load) has gone 2,100 yards in the Desert near Las Vegas ( target is an 18x24" silhouette)- still supersonic... granted that site sits at roughly 2,900-3,000 ft elevation - so it would not reach as far at sea level; further at 8,000 ft.
Granted my 338 LM Improved (300 gr. Scenar @ 3,000 fps w/ RL-33 or V.V. 570) goes even further in the desert, since my 300 gr. Lapua Scenar's transition pretty well (Furthest I've had them is 2,300 at our desert site.
I shoot with someone who runs a .284 Winchester - running 180 Berger's @ 2,900+ (from a 32" tube). He runs out of gas at 1,900 on our desert site (same as my 28" 7WSM - running 180s @ 2,900 fps). The 180s don't transition well, so its stay fast or stay at home.
JeffVN
Granted my 338 LM Improved (300 gr. Scenar @ 3,000 fps w/ RL-33 or V.V. 570) goes even further in the desert, since my 300 gr. Lapua Scenar's transition pretty well (Furthest I've had them is 2,300 at our desert site.
I shoot with someone who runs a .284 Winchester - running 180 Berger's @ 2,900+ (from a 32" tube). He runs out of gas at 1,900 on our desert site (same as my 28" 7WSM - running 180s @ 2,900 fps). The 180s don't transition well, so its stay fast or stay at home.
JeffVN
Should have mentioned my reason for the 26" barrel. Often times we have to hike a ways to shoot. A 30" plus heavy contour barrel becomes too much sometimes. Plus I like how the 26" handles off a bipod over the longer tubes.
Alex Wheeler
Site $$ Sponsor
I am building a LR elk rifle. I wanted something capable of pushing the 180s easily 3000 fps. I have friends with 7wsms and 7rsaums. Some will make it to 3000 some wont, and its a top end load. I also wanted a little extra room in the case and a long neck for when the 195 hybrid comes out. I also dont like belts, and did not want to have to buy custom dies or form brass. There is only one case I could find to satisfy that. 7LRM. I did send in a dummy round to have a reamer made as the standard throat is too short and I went with a tight neck as the Hornady made brass neck thickness consistency was horrible.
7mmRSAUM with Berger 180gr Hybrids. 2900fps is pretty easy to attain. I know that isn't 3000 but this set up works very for me.
Alex Wheeler
Site $$ Sponsor
Yes, with the shoulder pushed back as well.
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