Which 7mm ??? picture of new case added

coyote

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With all the new high bc bullets on the market in the past few years I think a new 7mm f-class rifle is in order.

I have been reading up on the 284 win but I would also like to maybe do a wildcat based on a 7mm saum or something.
The thought of a 25 wssm necked up to 7mm or something between the 7mm saum and the 25 wssm .

Winter is coming so it would be a great time to start long nights and lots of wood to burn :D .
 
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If it would be up to me, I would just build a stock 7mm Saum with the throat lengthened to suit a 180 Berger. Dies and reamer are cheap and easy to get compared to a wildcat. However, after shooting against these Mag's and standard 284's I don't see much difference in the scores and the standard 284 will have a lot better barrel life.

Steve
 
The Saum seems to be special, from an accuracy standpoint, the case cap. and long neck seem to work well, mine is deadly though not the kind of gun I would use on big game. Not sure about barrel life, but would be better then the competition(WSM).
 
I plan on building a straight .284 at some point. Seems to be a wonderful round. Good barrel life. Can get the 180's up to 2800+ without issue. Can be used in a short action. Brass can be necked-up Lapua 6.5-284. Reasonable recoil. Sounds like a good combo to me!
 
Straight .284 and 7 RSAUM seem to be the 2 most popular . The .284 has the brass quality advantage, while the rsaum lest you get up to the 3000fps node. If I was playing the open game, I'd go with the golf bag approach- a 6 br or something like it for the shorter ranges, and then a boomer for the longs.
 
I agree that the .284 has much to offer, but if I was going to build a .284, I believe I would choose a long action. The logic is that those long heavy bullets, which are best choices for long range work, can be seated out so they don't extend below the shoulder of the case and eat up powder capacity, thus the full potential of the cartridge can be realized.
 
I have a custom 284 built on a Rem 700 long action. Given the bullet selection that will really make this gun shine I would say you would really sell yourself short going with a short action. Any of the VLD's in the 160 to 180 range a really long. You won't get the powder capacity you need in a short action / SA mag well.

That out of the way, I'm still monkeying around with loads. I have a 24 in barrel on mine and getting up to the low 2800fps range with the 180gr bullets is a stretch. RL17 has the speed but has produced the fewest promising loads and all of the ones that looked good show the very slightest pressure signs when its hot out. H4831SC has produced great results but at a reduction on MV by a good 100-150fps. The powders this caliber does well with are readily available. RL17 was the only one that was hard to get. It has lived up to its reputation for increased speed,,,BUT,,, I have found it to be more temperamental to temperature swings than advertised, AND, has not produced great results for me. All loads that have promise (as stated above) are at the utmost outer limits for powder charges. I'm going to try some N560 next and see what happens.

I find recoil to be mildly more than a 308 (given the same gun weight/style) and is very manageable for anyone with experience shooting high power rifles.

Brass choices are straight 284 Win in winchester brand brass (if you can ever find it) and,,, the 2 bags that I got were garbage. Once I culled for weight and bashed up cases, they still required a mountain of work to clean up and to make them even remotely comparable to lapua brass required neck turning which is way more work than I normally get into. I run Lapua 6.5-284 brass necked up to 7mm. I don't neck turn it for my application and its just fine. Finding Norma or Lapua or Nosler Custom 6.5-284 brass is not hard, thus good brass abounds.

All in all, its been some work finding "The" perfect tac driving load but the 284 has been very promising. As far as a hunting gun goes, its a fantastic caliber which has more than enough jam to take canadian big game.

The bulk of my shooting experience is with a 308 so stepping up into the high BC 7mm bullets has been really fun at long range. It is just such an efficient caliber and way more forgiving making wind and range call estimations.

For anyone considering the 284 winchester,,, stick to the long action and enjoy.
 
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Don't need a long action, or a long action mag for an F-Class gun. If it's a mag fed hunting rifle then yes, a long action would be preferable likely.
 
Short action build is where this is going to go, One shot at a time is good enough for a f-open gun imo.
Norma is supposed to make brass for the 7 saum so this is a bonus if I take this route

This thing will only be for over 600m I already have a 6br and a 6slr for up to 600 ,unless there are some gale force winds lol.

Some of you guys are saying about 2800 fps out of a straight 284 with 180's I thought it was more .

I keep thinking of wildcating the 7 saum pushing the shoulder back maybe 120 to 150 thous and a nice long neck with a 30 degree shoulder.

But if I do this I am creating more work but it would almost be a BR on steroids.
 
im running a 7 wsm on a rem short action and pushing matrix 190grs at 3100 and is deadly at 1000yrds

Very similar setup: 270 WSM 165 Matrix VLD 3000fps.
The performance is fantastic but recoil is significant and barrel life is short.
Total shooting cost is 1$ per round (including barrel cost).

I'll be shooting some 6/6.5 308-based cartridge (or even 223 Rem) next year since I'm simply feed up with recoil and excessive costs.

Alex
 
I have this 7mm STW, i do not shoot it anymore, but it was a hell of a 7mm to shoot, dont even know if the big cie still make it... JP.
 
A 7 stw is to hard on barrels and to long a powder column and I have shot them without a muzle brake it has to much recoil .

Barrel life is something I want and something that could push a 180 vld around 2900-3000 fps would be great.

I just formed up a few pieces of brass one from a cut 300 ultra mag with a 30 degree shoulder and nice long neck holds 58gr of varget to the neck shoulder junction ,this looks good to my eye shorter than a saum and longer than a ssm.
 
7-08 pushing 168 or 162's at around 2700 or so is plenty accurate , excellent barrel life, low on recoil and low expenses.Easy to find brass, many upsides to this one, just not all that popular for some reason.
 
7-08 pushing 168 or 162's at around 2700 or so is plenty accurate , excellent barrel life, low on recoil and low expenses.Easy to find brass, many upsides to this one, just not all that popular for some reason.

I wanted to use a 7mm-08 but the numbers are:
  • 7mm-08 will drive a 162gr 0.625 G1 BC at 2600fps.
  • 260 Rem will drive a 140gr VLD 0.600 G1 BC at 2700fps.
  • 284 Win will drive a 180gr VLD 0.680 G1 BC at 2800fps.
  • 7-300WSM will drive a 180gr VLD 0.680 G1 BC at 3000fps.
Simply put, 7mm-08 delivers the same performance as 260 Rem with 20% more recoil and gets eaten alive by the bigger 7mms.
It's still a superb hunting and metallic sillouette cartridge but simple run outs of steams compared to the "big boys".

Alex
 
Ok, but what about .308's using lower BC bullets than the 7mm's

.223's they also will work to 1000 yards.6BR guys are making it to 1000 yards and winning.

As long as you stay supersonic All should be well should it not, after all it is paper not buffalo.

I think that if you can tailor your load and practice and get consistent, "big boys" or not it shouldn't matter on paper.

The only way to really find out is for us to build many many more rifles and test.;)


I wanted to use a 7mm-08 but the numbers are:
  • 7mm-08 will drive a 162gr 0.625 G1 BC at 2600fps.
  • 260 Rem will drive a 140gr VLD 0.600 G1 BC at 2700fps.
  • 284 Win will drive a 180gr VLD 0.680 G1 BC at 2800fps.
  • 7-300WSM will drive a 180gr VLD 0.680 G1 BC at 3000fps.
Simply put, 7mm-08 delivers the same performance as 260 Rem with 20% more recoil and gets eaten alive by the bigger 7mms.
It's still a superb hunting and metallic sillouette cartridge but simple run outs of steams compared to the "big boys".

Alex
 
How much is 100, 200 or 300fps worth to you?

how much is reducing your wind drift 1, 2 or 3" if you miss a wind call?

How important is an extra 200, 300, 400rds of bore life?

How much does it cost to drop 1, 2, 3 or more points?

If I were to build a 7mm F Open rig, I would want the best ballistics I could shoulder. You don't go to a drag race and ask about fuel mileage. At least not if you are competitive.

There are some superb 284 shot by super competent shooters BUT they have it all dialed in. There are also some 284 rifles that simply do not "work".

The case is just too small to be a no brainer set up. Every 284 can push the 180's to 2700fps, some can go 2800, the very rare bird tickle 2900.

Is this important?

Before choosing the chamber or cal, I would suggest you decide on the ballistics you want and how that will aid you in your matches.

Then build the rig that WILL give you that performance.

There is no replacement for displacement and case volume matters.... You can always load DOWN.

YMMV.
Jerry
 
Left the STW on the side as i had much more pleasure shooting my 308 but now rediscovering the joy of a smaller caliber with a better ballistic coeficient with my Creedmoor... JP.
 
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