D_Walt
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280 won’t fit in your action and takes a standard bolt face. I think a 7mmSAUM would be perfect…I’m hoping you build one and you report back that it’s awesome the I’ll build the same
Cartridge for 18" barrel?
- Thread starter VikingsGuy
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7SAUM has more bore length, so will have more bore to burn powder given the same barrel length, so will theoretically be a bit faster.
I pulled up the SAAMI chamber reamer drawing for 280AI and 7SAUM. Recall that barrel length is from bolt face to muzzle. The difference in cartridge base to start of bore measurements is 0.3831" (2.754" vs 2.3709"). So you get 0.3831" more barrel "for free" with the 7SAUM.
But if you've already got dies and brass for 280AI I'd probably just do that. Not worth the maybe 50fps for hundreds of dollars in brass and dies to add another cartridge.
I pulled up the SAAMI chamber reamer drawing for 280AI and 7SAUM. Recall that barrel length is from bolt face to muzzle. The difference in cartridge base to start of bore measurements is 0.3831" (2.754" vs 2.3709"). So you get 0.3831" more barrel "for free" with the 7SAUM.
But if you've already got dies and brass for 280AI I'd probably just do that. Not worth the maybe 50fps for hundreds of dollars in brass and dies to add another cartridge.
BackofBeyond
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Would expected barrel life be sixes as well?
VikingsGuy
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All tikka actions are the same size(essentially long action), they just put a stop in the short action ones to shorten the bolt slide. You can pull the stop and buy a standard long action magazine and you are good to go.
D_Walt
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I must have missed the Tikka part…that’s what I get for paying attention to my meeting when I’m trying to read the forums…
On a tikka IMO the 280 ackley is hamstringed by the 3.34” mag box when running the 150+ grain bullets or long monos. I’ve done the 284 Winchester on a tikka and it feeds like it has eyes. Tikka centerfeed mags are very forgiving for feeding whatever you want
Don Fischer
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Wonder how much muzzle flash he'll get with some of these cartridges?
Not much with a suppressor
R
rwc101
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Well, my 20" barrel Vanguard will be sporting a can while slingin' the mighty .243 (if I ever get that stamp).
Millsworks
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2,000fps at 400yrds, out of a suppressed 18" barrel.....
I would be interested to know if that's possible.
But, I don't think I would enjoy shooting something like that.
I would be interested to know if that's possible.
But, I don't think I would enjoy shooting something like that.
Easily possible. You’d be surprised how many cartridges will accomplish that. A 7mm-08 with a 168 grain Berger at a mild 2500fps accomplishes that. A 120 grain TTSX started at 2850fps gets it done too
ImBillT
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A 308Win should do it with a high BC 168gr and the right powder choice at that barrel length. A 7-08 would almost certainly require a longer barrel or lighter bullet to stay above 2000fps at 450yds, but when you drop to a 150gr, it doesn’t have the energy at 450yds. I know you don’t want to hear it BUT a 6.5 CM with a 156EOL is right on the cusp and beats a 7-08 with a 150gr bullet handily.
Cut your distance to 400yds and a 7-08 with a 168gr is your best option.
A 7-08 would suppress better than a 6.5CM/.260Rem, and a 308Win would suppress better than a 7-08 because powder capacities and chamber pressures are all roughly equal, therefore the larger bore volume means the pressure when the gasses reach the suppressor will be lower. It you want to stick to the three numbers you gave(2000fps, 1500ft*lbs, 450yds) and suppression is important, then a think the .308Win is the winner.
Cut your distance to 400yds and a 7-08 with a 168gr is your best option.
A 7-08 would suppress better than a 6.5CM/.260Rem, and a 308Win would suppress better than a 7-08 because powder capacities and chamber pressures are all roughly equal, therefore the larger bore volume means the pressure when the gasses reach the suppressor will be lower. It you want to stick to the three numbers you gave(2000fps, 1500ft*lbs, 450yds) and suppression is important, then a think the .308Win is the winner.
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ImBillT
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OP said 450yds. A 7mm 168 at 2500fps will not meet the criteria at 450yds, and 2500fps at the muzzle is not mild from a 7-08 with an 18” barrel. Doable from many barrels at near max loads with the right powders yes, but guaranteed from any barrel with most powders and using charges from most manuals no.
Was replying to poster who said 2000fps and 400 yards who was curious if it was even possible. Done 2600-2650 with a 20” barreled 7mm-08 and a 168 Berger. Being on a tikka action makes it even easier as you could run it as a long action and seat your bullet as long as you need so it’s not eating up powder space
midwesthunter
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I'm a sucker for some of the older cartridges, I had a Rem XP100 chambered in 350 Rem mag w/ 18" barrel. You should be able to shoot a 200 grain Accubond at 2800 fps.
brocksw
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In my experience shorter powder column cartridges tend to perform better with short barrels. .308, 243, 7-08, 6.5 creed will be good for standard cartridges. If you want to push velocity more out of that short barrel, going to 20 or 22 might be worth considering and I would look at short mags, saums, prc, or other mag bolt face short fat cartridges.
Or get a 7mm Mauser AI and have the best of both worlds.
VikingsGuy
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I have bounced around 7mm08AI.
brocksw
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Probably depends on expectations. I'm assuming a mauser AI will have a similar increase in vel as other Ackley chamberings. In which case, if you're looking for performance the Saum and PRC will still outperform the mauser ai. I don't know this for a fact, just an educated guess. I'm thinking a 7 mauser AI will throw a 140 gr around 2900-3000 depending on the gun. So pretty close to saum. I've heard of saums going as high as 3300 in a 22" tube but I'd guess that's not the norm and expectations should be 3100-3200 if the right powder is used. My sherman max (7 saum improved) has a 22" tube and can hit 3250-3350 in the 140 class depending on powder.
I think if you putz around with powders, you'd be able to get 3000 with the 140 7mm AI in an 18" tube. I'm easily getting 3050 with a 22" bbl and I've got room to go, pressurewise. The 7mm seems to be in the sweet spot for AI chamberings, along with the 257 Roberts AI.
