Cartridge for 18" barrel?

[VikingsGuy]

You'll be dancing on 280 AI velocities with that 57 mm case blown out to the 40 degree shoulder. And use can use the seating die for the 280. Just get a neck sizer and use that for all 7mm's. You'll only be spending for brass (get the Norma, it case forms really well) and a sizing die.

It's going to be less than $200 for this. Like, literally 1/10 the cost of your suppressor & ATF stamp. Don't be a punk.

Don't forget the carbon barrel - ouch

 

[brocksw]

Don't forget the carbon barrel - ouch

Check and compare your barrel weights if you havent already. With my 22" #3 bartlein, a carbon barrel cost nearly twice as much and saved me less than a half lb in weight. Plus you deal with all the fudge factors in CF barrels. Some shoot great, but if you get one that doesn't (seems like a much higher likelihood than steel), it will be a royal pain in the ass to have a rifle you can't shoot, waiting for a new barrel, and paying to have your smith take off/on. All that to save less than 8 oz. Taking your morning dump before you leave the tent/truck is a lot better/cheaper/hastle free way to cut 8 oz.

 

[ImBillT]

I like AI, and I like 7mm, so I am now down to 7mm08AI, 7x57AI or 280AI. For the brass I have 280AI and have extra 7mm08 to fire form up to 7mm08AI, 7x57AI would require new brass purchase. For dies I have 280AI but would need 7mm08AI or 7x75AI. So, seems like 7mm08AI might struggle to hit my specs (but hammer bullets may solve that) and the 280AI would be the cheapest option up front but would guess I am just blowing the extra 10-16 grains of powder into the suppressor and that the 7x57AI might be the best balance (of course, leave it to me the choose the most expensive option on the list - i'm looking at you @Ben Lamb).

Any reasons (other than my up front cost) I shouldn't go 7x57AI?

I am going to shoot 140-160 grain monometal hunting bullets (almost certainly barnes ttsx, barnes lrx, hammer hunter or absolute hammer) I am assuming 1:8 twist is optimal?

If you’re willing to do a L/A and don’t mind the extra gasses making your suppressor less effective, there’s no logical reason not to go straight to the .280AI. If you’re limiting yourself to a S/A then you can’t comfortably fit a 7x57AI.

In NORMAL barrel lengths, Ben is being a little zealous with his 7x57AI projections. At 18”, the difference is certainly smaller. In a 6.5mm, you’re very near max performance at 60-66gr H2O and any more powder is mostly a waste of powder and barrel life. In a 7mm that number is closer to 70-75gr H20. By dropping to 18” you can bring those case capacities downward a little in terms of wasted powder for little to know velocity gain, but I would still expect room for improvement over a 7x57AI at just 63gr H2O.


I think the decision should be 7-08AI or 280AI and the deciding factory should be how much velocity are will will to give up in order to increase noise suppression. I don’t know how significant the difference would be. You’ll need to talk to someone with more suppressor experience. The comparison would be similar to the difference between a 30-06 compared to a 300WinMag with the same can.

The Mauser cartridges are ideal for .243”-.264” projectiles in medium or long actions.

If you had a medium action, and thus ruled out the .280AI, and suppression was not a part of the equation, an interested wildcat would be a 7-8x57AI. The 8x57 has a substantially longer body and shorter neck. I’ve never seen a capacity on an AI’s version, but an 8x57AI should be knocking at the door of 30-06 case capacity….it might even equal it.

 

[ImBillT]

Neck sizing only is fine for accuracy, but after 3-5 reloads with a case that size you’ll be having difficulty closing your bolt.

@Ben Lamb How many reloads do you have on your brass AFTER the shoulders were fully formed?

 

[G. McAlister]

RL 17 has been a winner for me in 8mm, 7mm, 35 whelen & 9.3x74R.

Ben, just to make sure I’m reading right, you’re getting over 3k FPS out of 22” barrel 7mm-08? What’s the 35 speed look like?

 

[ImBillT]

I love Norma brass, but I advise against it anytime you are chasing velocity. It will not handle the pressure that Lapua or RWS do. I have used Norma in my 6.5x257AI(and lots of cartridges I prefer mild loads with) and the pressure it will handle is meaningfully behind RWS. RWS will not handle as much as Lapua. If you want a short action, go with the 7-08 or 7-08AI, and use Lapua 308 Palma brass with the small primer pocket. That will allow you to run it as hot as you like. If you go with a long action, I see no need to bother with the 7x57AI other than just to be different.

I would to have a 7x57 or 7x57AI one day, but that’s because I like M98 actions.

 

[mtmuley]

I'm still trying to imagine hunting with an 18 inch barrel. mtmuley

 

[VikingsGuy]

I'm still trying to imagine hunting with an 18 inch barrel. mtmuley

Because with the suppressor screwed on it will be 24" which is about as long as I like to carry in the field.

 

[ImBillT]

Because with the suppressor screwed on it will be 24" which is about as long as I like to carry in the field.

While I wholeheartedly believe that longer barrels are not really as big an impediment as most make it out to be, being forward heavy can be quite the impediment, and I would imagine(but don’t know from experience) that a can would be heavy enough to make things forward heavy rather quickly.

 

[mtmuley]

Because with the suppressor screwed on it will be 24" which is about as long as I like to carry in the field.

I knew that. I like big bullets fast, remember? But, slowly moving toward small monos really, really fast. mtmuley

 

[brocksw]

I'm still trying to imagine hunting with an 18 inch barrel. mtmuley

I felt similar. Once I bought a can, everything became about how short I could go. I don't ever plan on hunting without a can on my rifle again.

 

[noharleyyet]

I felt similar. Once I bought a can, everything became about how short I could go. I don't ever plan on hunting without a can on my rifle again.

Break that down for me please. Im seriously interested why.

 

[mtmuley]

Break that down for me please. Im seriously interested why.

Me too. mtmuley

 

[p_ham]

While I wholeheartedly believe that longer barrels are not really as big an impediment as most make it out to be, being forward heavy can be quite the impediment, and I would imagine(but don’t know from experience) that a can would be heavy enough to make things forward heavy rather quickly.

If it's all Ti, a can set up for supersonics will only weigh a few ounces. I built one for my blackout (subsonic) that has 12 baffles and is 8.5" long that is still under a pound.

 

[brocksw]

Break that down for me please. Im seriously interested why.

For me, putting a 5 to 7 inch can on a 26 to 30 inch barrel isn't handy to pack around. Its unwieldy. Chop that barrel down to 18 to 22 then throw the can on and you're working with the same length rifle with a suppressor on it. No big kaboom, no ears ringing, less recoil.

However, it doesn't make a lot of sense to neuter some of the Long action magnums by lopping off a good chunk of the barrel. So the next step for me was getting rifles that used cartridges that I felt were better suited to shorter barrels.

For instance I used to have a Sako in a 7mm rem mag with a 25" tube. Shot 145 lrxs in that 3200-3300 fps range give or take. I didn't want to stick a suppressor on that length barrel, nor did I want to chop 5" off and Lose 100-200 fps off the top. So I built a short barreled 7 saum improved (7 Sherman max) and stuck my suppressor on that. Now I have a suppressed rifle that shoots 145 class at 3250-3300 and it doesn't have 32" inches of steel waving around with a big boom to go with it.

Now, I almost refuse to shoot without a suppressor. I've gotten so shy to muzzle blast that I can barely shoot my shotgun without earplugs. Suppressors spoil you.

 

[brockel]

While I wholeheartedly believe that longer barrels are not really as big an impediment as most make it out to be, being forward heavy can be quite the impediment, and I would imagine(but don’t know from experience) that a can would be heavy enough to make things forward heavy rather quickly.

Wonder what 6-8” of sporter weight barrel weighs? Guess I’ve got a few laying around that are junk I could put in a chop saw and see. Wonder how close it is to some of the titanium cans that come in at 10oz

 

[brocksw]

Wonder what 6-8” of sporter weight barrel weighs? Guess I’ve got a few laying around that are junk I could put in a chop saw and see. Wonder how close it is to some of the titanium cans that come in at 10oz

Bout a horse a piece. Too close to fret over anyway. With the right cartridge I'd trade 4 to 6 inches of barrel for a titanium suppressor any day of the week.

 

[VOLhunter]

Don't forget the 7mmWSM. Dies are available and while brass may not be, you can resize 270/300WSM brass which will be much easier and cheaper to find than SAUM brass. Not sure why the 7WSM didn't catch-on like the others, but I think it definitely fits all your criteria points.

 

[ImBillT]

Wonder what 6-8” of sporter weight barrel weighs? Guess I’ve got a few laying around that are junk I could put in a chop saw and see. Wonder how close it is to some of the titanium cans that come in at 10oz

6oz for the last 6” of a standard sporter 7mm.

10oz for the last 6” of a light Palma 7mm.

32.5oz for 6” of 1.25” straight 7mm.



Looks like a 10oz titanium can is like adding 6” of a fairly heavy barrel.

 

[Ben Lamb]

Neck sizing only is fine for accuracy, but after 3-5 reloads with a case that size you’ll be having difficulty closing your bolt.

@Ben Lamb How many reloads do you have on your brass AFTER the shoulders were fully formed?

On the 3rd reloading with no issues with brass.

Ben, just to make sure I’m reading right, you’re getting over 3k FPS out of 22” barrel 7mm-08? What’s the 35 speed look like?

No. 3050 fps with a 140 grain TTSX out of a 22" barrel with 7x57 AI. I could probably go up to 3100 without any pressure signs, but accuracy is excellent at 3050. Getting 2650 with 250 grain round nose Hornady's with the 35. 2400 FPS with 250 & 286's in the 9.3. Both the 35 & 9.3 are stout in recoil.