Which 7mm

[Jedi]

Ideas, thoughts
Non mag, standard bolt face, Short action max OAL 3.00

I like plain jane 284Win

thou 7x57 AI would be sweet also, fire forming not my thing

post your thoughts

 

[762frmafr]

Re: Which 7mm

Those you listed will not be optimized for a short action with the high BC bullets. If it were me, I would do a straight 7-08 or a 7 creedmore.

 

[Chiller]

Re: Which 7mm

7-08 would be tough to top.

 

[turbo54]

Re: Which 7mm

Google: 6mmbr 7mm cartridge guide

Read

 

[Texar2]

Re: Which 7mm

google "7-08 snipers hide" there are some good reads.

 

[bkster]

Re: Which 7mm

7mm08 w/ 162 hbthp@2750=hammer

 

[THT-9]

Re: Which 7mm

.284 WIN would be my choice...

 

[eracer]

Re: Which 7mm

7mm-08

(But I'd get a 7mm SAUM instead...but there's that pesky 'magnum' thing.)

 

[Jedi]

Re: Which 7mm

defiance medium action, so longer than standard short action

so long as OAL is less than 3.00 should be fine

not interested in anything based standard 308 case, maybe 7 SLR as it fixes what wrong with 08 case

 

[turbo54]

Re: Which 7mm

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jedi</div><div class="ubbcode-body">defiance medium action, so longer than standard short action

so long as OAL is less than 3.00 should be fine

not interested in anything based standard 308 case, maybe 7 SLR as it fixes what wrong with 08 case </div></div>

So does a 7-08AI.

Gotta love the'08 brass availability.

 

[Jedi]

Re: Which 7mm

7-08AI reduces neck even further, thou does correct shoulder angle


284, 162amax n RE17
looks pert good

 

[Wannashootit]

Re: Which 7mm

I say ditto on the 7-08 also. I'm planning on re-barreling my 10 twist to an 8 twist to handle the 162 Amax. That's an incredible BC on the bullet...

 

[TEAMSENDIT]

Re: Which 7mm

if not 308 based pretty sure best choice is 7mm creedmoor.

contact mark at Short Action Customs he has worked with this cartridge.

 

[gregsjt]

Re: Which 7mm

If you have a medium action that is capable of 3" oal, I think you'd be crazy not to consider a saum. Just buy a new bolt with a mag bolt face.

 

[Jedi]

Re: Which 7mm

Nope
my thinking is based on this
http://www.6mmbr.com/gunweek095.html

25" barrel, short action, OAL 2.90
re17 3045fps

i have to run some QL sims but looking @ 24" maybe 22" barrel
OAL 2.975 so i have a lil more boiler room, still feed from Alpha mag max is 2.985

Based on article i should be able to run 2900fps from a 22"
thats kinda what i,m looking at.

plain jane 284 hmmm

Melonite barrel, run RE17 162amax
barrel should go 5k maybe more

do able very do able

 

[VJJPunisher]

Re: Which 7mm

i decided on the straight 284, its still being kungfoo'd at gap but cant wait to get it

 

[Jedi]

Re: Which 7mm

waiting on parts myself
RTS chassis
defiance mutant action
currently 6.5x47, 20" 5C barrel
123scenar @ 3023fps via RE17

i,m liking the idea of a 22" 284, 162amax RE17
2900fps should be doable, dont see losing 150fps for 3" of barrel.

But i do have a shit ton of 6.5x47 brass and annealer so ....

 

[Casey Simpson]

Re: Which 7mm


7 Mauser
280 Remington

Load either with 168 Berger VLD, or 162 AMAX.

 

[cd9381]

Re: Which 7mm

+1 7mm08

 

[turbo54]

Re: Which 7mm

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jedi</div><div class="ubbcode-body">Nope
my thinking is based on this
http://www.6mmbr.com/gunweek095.html

25" barrel, short action, OAL 2.90
re17 3045fps

i have to run some QL sims but looking @ 24" maybe 22" barrel
OAL 2.975 so i have a lil more boiler room, still feed from Alpha mag max is 2.985

Based on article i should be able to run 2900fps from a 22"
thats kinda what i,m looking at.

plain jane 284 hmmm

Melonite barrel, run RE17 162amax
barrel should go 5k maybe more

do able very do able </div></div>

I studied the rifle build you linked to prior to building my 284.

My build: http://www.snipershide.com/forum/ubbthre...046#Post3147046

Couple notes:

You're not going to be able to load at 2.985", or even 2.975" with the Alpha mags. The maximum COAL that will feed correctly, and not cock/bind in the mag is 2.950" (+/- a couple thousandths).

I'm getting 2950fps with 162amax with 52.5gr Re17. I don't think it's going to go alot faster with ok pressure. Perhaps my barrel will work in and speed up a little, but I'm not counting on it.

Also, the jury is still out on RE17. Many folks claim they get speed, but poor accuracy. I've read very conflicting information about its temp stability. As far as I'm concerned, if it's not temp stable, it's garbage. It is the only powder out there like it, and the only powder that's going to get a 162amax going ~3000fps from a SA 284. Otherwise, you're looking at H4350 or H4831, and a 100fps+ drop in velocity.

There is no provision for "chasing" the lands when you throat a rifle to seat a bullet on the lands - right at your max magazine length.

284 brass is not real easy to come by. The winchester branded brass is only made once a year, and is of iffy quality, and Lapua sure is proud of their 6.5-284 brass. If you shoot tactically, and lose brass, it sucks leaving $1.25/each brass on the deck when you move to your next position.

The 284 sits in a nice "niche" place between the low and high capacity 7s. It has a definite horsepower advantage over 7-08, but a distinct disadvantage to the 7RSAUM, 7WSM and 7-300WSM. That all said, when forced to load a max COAL of 2.950, the 284 has about an 8gr of powder advantage over 7-08.... With new dies, new brass, new inventory of powder etc etc etc (tooling up for a new cartridge), consider wisely if you REALLY don't want the extra steam the higher capacity 7s offer... I only have 50 rounds downrange with my 284, and I'm already thinking my next 7 will be the 7RSAUM or 7-300WSM.

Lastly, the 162amax and 162hpbt bullets are extremely well designed bullets, and have great BC. Anything over 2700fps is going to be quite flat, and drift little.

I'm not trying to talk you out of 284, just suggesting you think long and hard about it - particularly because we're talking about a COAL-limited 284...

 

[bkster]

Re: Which 7mm

in my 7mm08 at 2750 the 162 vs 284 at 2900 = .1 mil/600&.2mil@1000
2 mph wind difference is more than that
when it was a 7 saum/ 190 matrix at 2750-2850
but then it wont feed in a short action period
i loved the 7saum and im thinking of a 284 as well
but in a long action to shoot the 180-90 size bullets
and for hunting not comps

 

[Wannashootit]

Re: Which 7mm

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Casey Simpson</div><div class="ubbcode-body">
7 Mauser
280 Remington

Load either with 168 Berger VLD, or 162 AMAX. </div></div>

.280 Rem is (30-06) long action, no?

 

[pwc001]

Re: Which 7mm

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Wannashootit</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Casey Simpson</div><div class="ubbcode-body">
7 Mauser
280 Remington

Load either with 168 Berger VLD, or 162 AMAX. </div></div>

.280 Rem is (30-06) long action, no? </div></div>

Correct, the .280 is a LA round based off of the 30-06 case.

 

[Trevor300wsm]

Re: Which 7mm

So what your saying Turbo, is to build a long action .284 and all those problems go away, other than brass availability?

 

[mattsnuked]

Re: Which 7mm

Running some very generic data with the 162 amax I get:

@2750 8.3 mil to 1k, 1.8 mil for 10 mph wind

@2950 7.0 to 1k, 1.6 for 10 mph wind

@3050 6.5 to 1k, 1.5 for 10 mph wind

Even at 2k yds the wind difference is only .4 mil between the lowest and highest velocities listed.

So to me dialing elevation is no big deal, and the wind is very similar. I'd go with a 7-08 if you want a SA.

 

[mwroseberry]

Re: Which 7mm

Running a 7-08 now with a 162 bthp at 2780 and love it for anything from 0-1500 yards. Building a 7stw for targets to 2500 yards using the new 195s.

Barrel life on the 08 is also the top of the pack with the choices you have.

Good Luck,
Merritt

 

[Jedi]

Re: Which 7mm

I have modified AICS mags that feed @ 2.975, not sure of issue with Alpha but they tout 2.985 as max so it should work.

RE17 i have been shooting for 3yrs, no issues it works believe the hype.

Real issue here is it offers no performance gain over my x47

http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=2276506&page=1

this works just dandy from a Short action, based on a 6rem which is mauser X57 derivative
284 is closer to 55mm than 57, Amax is no longer than Dtac
Not seeing any validity to issues other than the performance gains (little to Non) dont warrant expense
Stick with x47 for now

 

[pyplynr]

Re: Which 7mm

The .284 Win is an great round. It becomes an amazing round out of a long action. I love mine. If your planning on building a short action, IMO the 7-08 will be a better choice.

 

[turbo54]

Re: Which 7mm

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: trevor300wsm</div><div class="ubbcode-body">So what your saying Turbo, is to build a long action .284 and all those problems go away, other than brass availability? </div></div>

Yes, no, maybe...

I was well aware of the issues I faced in building a SA 284, but did it anyway for a number of reasons:

When I'm comfortable on a LA rifle and have everything adjusted so I'm happy, the bolt will hit me in the nose, meaning I've got to break my cheekweld each shot.

I really like the FN SPR action, and it doesn't come in a LA.

I like a challenge.

Whoever said that "284 is a great cartridge on a SA, but an amazing cartridge on a LA" nailed it. I'm not unhappy with mine, but as mentioned, there are definite drawbacks. Perhaps the biggest drawback (for our kind of long-range use) is only having one or two good bullets availabe; the 162gr Hornadys. The 180-class bullets really need the LA case capacity advantage to work well.

 

[Jedi]

Re: Which 7mm

Normally i build guns for a specific goal

ie
284 SA
re17 162amax

i would never try running heavy bullets as thats not intent
of build
but 22" barrel n 2900fps .... sure

lastly its a defiance medium action, point many keep over looking
but gain dont warrant $$

i will not use a standard 308 type case, 708 lol never
7 SLR hmmm but if 284 wont do it then SLR for sure wont

 

[turbo54]

Re: Which 7mm

Trouble I see with such specifics like "162amax, Re17" is your backup plan if it doesn't work like you hoped. What then? In this example, you can bank on a reduction of 100+ fps if your rifle decides it doesn't like Re17. If it doesnt lije 162s, youre kinda fucked. Theexpensive berger 168 or the inferior 168smk are your only option.

 

[Jedi]

Re: Which 7mm

Really
Not hard to get a rifle to shoot MOA or better

There is a plethora of data available that greatly reduces likely hood of failure if one is inclined to use it.

Is a 22" 284 RE17 162AMAX @ 2900fps viable
YES
will it meet accuracy requirements of a TACTICAL rifle
YES
Do you have the ability to correctly spec and build such a rig
UNKNOWN

 

[Casey Simpson]

Re: Which 7mm

Anyone who believes a .284" 168smk is an inferior bullet is either kidding, given to hyperbole, or inexperienced. A sleeker profile bullet might perform superior to it at long range, but it might not too.

A good shooter running 7-08, thin walled cases, magnum primers, slow propellant, a long and coated bullet matched to the appropiate twist will shoot well. Remember, this is .5 millimeter larger diameter than 260 but otherwise identical case.

Choose a good bullet, powder and case, fine tune the load and be happy cause you will be.