Best Cartridge for 7mm VLD's?

[PeterPHWS]

Hello Everyone,

This is my first post here and after checking this web-site and www.benchrest.com forum this seems to be the most applicable forum for my query.

I shoot F Class here in the UK using a 7mm Boo Boo with 176g Carterucio's and as a back up 180g Berger's and I am presently doing quite well with this combination.

I am aware of the barrel life issues associated with the cartridge - I presently use a single base powder - 74.4grs H1000 with 210M primers - to try to maximise this - and the load puts these bullets out at 3050 to 3200 depending on the powder Lot.

What I would like as an option is a mini- Boo Boo case which needed less powder but still give similar performance with these bullets.

Over here in the UK the only serious competition for a similar cartridge capable of launching these bullets at 3000+ fps is either a 7mm WSM or the 7mm/300 WSM necked down. The barrels chambered for these rounds in our competitions seem to have a hit-miss success rate often with problems with primer pockets and blowing primers or carboning up and accuracy tailing off.

However notable bench rest records have recently been done at 1000 yds with the 7mm/300wsm but this is a much shorter form of string fire compared to F Class.

The problems may be the brass - Norma is hard to acquire and in some cases it may be the barrels themselves on carboning issues.

I would like to know if anyone has any other suggestions for a cartridge which could still give a 3000 fps load with these bullets?

From researching a bit the 7mm Dakota or the older 7mm x 66 Super Express Vom Hoffe cases based on the .404 Jeffreys case seem capable and they do not suffer the headspacing difficulties of a belted case.Has anyone tried these out as LR benchrest or F Class calibres? Who makes the brass for Dakota? Is it Bell? I don't know of anyone making brass for the Vom Hoffe case and would welcome any information.

Belted cases are not my prefered option so replies on wildcats using belted cases are not what I am after albeit I apprreciate these are accurate cartridges. The SAUM has brass quality issues and necking down the RUM would be more over-board than the Boo Boo. Shortening the Boo Boo is possible and a project is being undertaken over here for this for 1000yd benchrest but for an F Class cartridge it would take too much time to prepare the cases needed.

Ideally what would be interesting is if anyone has experience of using good European brass cases and wildcating them such as the 7 x 64. Is there any data on Akleying this type of round? Or is this type of option about the same as a .284 Lapua which is at present the probable favourite for me if I wanted to change and I would have to accept coming in at under 3000 fps.

My thanks in advance to those who reply.

Peter Wilson.

 

[sewwhat89]

Lapua is supposed to start making the Dakota brass if they are not already making it for them. That's all I can help with.

 

[jb1000br]

a straight 284 and 30" barrel will do 2800 easy, and 2900 on the high side with 180 bergers...

JB

 

[Cheechako]

Peter

JB is correct about the straight 284 being able to get close to the velocities you are looking for with the heavier bullets. Another choice would be the 280 Ackley which I shoot and which, of course, would be the same thing as the 7 x 64 that you mentioned. But, the bottom line is - if you want 3000 fps or more with the 175-180 grain bullets you have to burn more powder than either the 284 or 280 can hold. And burning more powder means shorter barrel life. But for many shooters, including me, barrel life is secondary to accuracy and if I can get 1000 rounds from a long range rifle I am happy.

There are alternatives. Two that come to mind are longer barrels and larger diameter bullets such as 30 caliber. I'm not an F Class shooter so I can't say if either of these are an acceptable answer. Of course, there is always the well beaten path - 6mm or 6.5 and don't worry about barrel life.

Ray

 

[Wild_Bill]

Hi All here in Australia there are a lot of people going to the 284 Win i have one with a 9 twist barrel and it shoots anything up to 180gr Bergers. You can push the 175-180gr's at 2850-2900 depending on the barrel this gives you a much better barrel life with a slightlu better ballistic efficency than a 6.5-284 but the biggest advantage is in fish tail winds the 7mm just flys better and is less effected than the 6.5's. You could go up to a short mag but when you go to 30 cals the recoil is a lot heavier and you have to compare a 210gr 30 cal to a 175gr 7mm at the same velocity to get an advantage and no brakes being allowed in F Class it can get unplesant. There are 2 shooters using 300WSM's here though with 190gr Sierra'a and we have just chambered 2 30-284's and they will push the 190gr sierra at 2980fps just as fast as they are using in the 300WSM's so it seems a better design. We are waiting to try some 210gr Sierra's when they get here.



Cheers Bill
Australia

 

[M9Powell]

I would like to know if anyone has any other suggestions for a cartridge which could still give a 3000 fps load with these bullets?

From researching a bit the 7mm Dakota or the older 7mm x 66 Super Express Vom Hoffe cases based on the .404 Jeffreys case seem capable and they do not suffer the headspacing difficulties of a belted case.Has anyone tried these out as LR benchrest or F Class calibres? Who makes the brass for Dakota? Is it Bell? I don't know of anyone making brass for the Vom Hoffe case and would welcome any information.

I think you are on the right track with your thinking. I'm an ex military 1000 yd high power shooter who hasn't competed in several years & currently have an interest in a long range tactical type rifle. I ended up with a heavy Kreigher barrel
in 7mm Dakota through a long convulted trade. So I have had some very simular thoughts myself. I've been told that some of the Dakota brass is made by Norma, supposedly if the headstamp has a Dakota logo its made by Norma. Norma does make 404 Jeffery cases.
Neiska & Dakota just filed for Bankruptcy protection by the way.
I think the 7mm Dakota has just a little more capacity than needed & the 7mm WSM has way to short a neck. I think a shortened 7mm Dakota or a stetched 7 mm WSM is the way too go. I'm contemplating either stretching & necking 325 WSM cases to 7mm or shortening 7mm Dakota or 404 Jeffery cases, maybe even 338 reminton Ultra mag cases. In any event what I want is a case length of about 1.850" inchs from the base to the shoulder, a 30 or 35 degree neck & about a .400" long neck to launch the berger 180. My application requires a repeater, but for a single shot a 40 degree shoulder might be preferable. I like the Norma 404 Jeffery brass the best for a starting point but it is very cost prohibitive compared to Win or Rem cases for a tactical application. For a benchrest gun though that might be the way to go if their price doesn't give you sticker shock. The Dakota brass is even more overpriced & resupply would be iffy given their current chapter 13 status. You can have custom dies made for less than factory Dakota dies. No wonder they are bankrupt.
M9

 

[sewwhat89]

376 Steyr necked to 7mm would be close. I don't know how the case capacity would compare though.

 

[rhino]

How about a .280 AI, yep the 7 WSM has a short neck...you figure they would make a longer neck...but they must have it in with the barrel makers. The 7 SAUM you would have a longer neck, but your stuck with Remington brass.

Norma is going to be making 300 SAUM brass I hear...but they have soft batches of brass too.

I think you'd best be served with a 7 WSM and live with the short neck.

RHINOUT!

 

[chrisj]

I wouldn't worry about a short neck on the 7mm WSM. The 300 WSM has always been a top 1000 yd performer and the neck is exceptionally short.

Chris

 

[M9Powell]

I wouldn't worry about a short neck on the 7mm WSM. The 300 WSM has always been a top 1000 yd performer and the neck is exceptionally short.

Chris

The 7mm WSM neck is considerably shorter than a 300 WSM. In addition to the neck you lose in necking down to a smaller caliber, Winchester also moved the shoulder forward on the 7 so as to preclude anyone chambering it in a 270 WSM. This results in more powder capacity in the 7 compared to the 300 or the 270, but the price is less neck. Considerably less. Here are the figures.
300 WSM neck length = .298"
7mm WSM neck length = .244"
7mm Rem SAUM neck length = .311"
7mm Dakota neck length = .333"
IMO it should as a minimum be caliber length or .284" & I like .350" to .400" a lot more. Its going to be a barrel eater. Though probably not a problem for a single shot with the bullets seated into the lands, this short neck will cause problems in repeaters due to the lack of neck tension. The 7mm Rem SAUM has a decent neck length but has a lot less powder capacity than the Winchester. If I were stuck with a short action repeater, it would be the better of the 2. For a long action the Dakota would be better purely from a dimensional POV.
IMO the optimum would be something between the 7 mm WSM & the Dakota with a neck length of around .350" to .400". This would require a long action & brass formed from 7mm Dakota, 404 Jeffery or 338 Remington Ultra mag cases shortened. All of these ctgs are basically 404 Jeffery cases of varying length. What makes the 338 the interesting case out of the Ultra mag family is its already considerably shorter than its siblings & is available at a reasonable cost. What makes the 404 case interesting is its made by Norma. What makes the Dakota cases interesting is they have a conventional rim & are already almost short enough & some at least are also made by Norma. M9

 

[chrisj]

Please forgive me. I meant to say "300 Winchester Magnum"....not 300 WSM.

Chris

 

[M9Powell]

Please forgive me. I meant to say "300 Winchester Magnum"....not 300 WSM.

Chris

Yea it does have a very short neck. .264". Which is why MTU came up with the 30-338 which was better than the 300, particularly in barrel life. Note the 300 & 30-338 are identical except the shoulder is pushed back on the 30-338, giving it a .300" neck. But you are right the 300 did pretty well even with the short neck. The 7mm WSM though is even shorter than it. I think they cut the neck on this 1 just a little too far. I don't think it will hurt the accuracy with a single shot & the bullet into the lands, but it will hurt the barrel life. M9

 

[manitou210]

I have never shot 1000 yards yet but, I have a hunting weight 7mmwsm with a Hart 1/9 twist 24" on a Rem Action that shoots 140gr Lost Rivers 644BC very good and 140 gr noslers, with Hodgens 4831sc both under 1/2 at 200 yards, I see gun of week 64 Ric Horst's 7mmwsm he used same powder with 162gr Hornady A-max,BC .625, 5 shots under 5" at 1000 yards
I see Lost River makes a target bullet 162gr,7mm with a BC of .778 but there sure are not cheap.

 

[NeilNE]

I have everything for the 7SHV, make from 404 Jeffery case's.. This is a Dave Tooly cartridge. I've been shooting this at 1K for 3 or 4 years and doing OK until this year. Barrel is going, I think. Couldn't be me. Anyway if you interested let me know. I have the forming dies, made by Neil Jones and die set make by Tooly.

 

[M9Powell]

What do you get for rim dia on the 404 cases? I have a Remington bolt set up for the 7 mm Dakota's .545". Looking at a case drawing of 404 Jeffery gives .537" which looks to me like might work better in a std magnum bolt face set up for .535". I have a bare action & bought this bolt for it, but after I bought it, I found out that its an older bolt without a anti-bind groove that my receiver needs. I think I can have it machined though & it'll work. Do you have a case drawing for this ctg.? Thanks M9

 

[NeilNE]

I think I still have a drawing, I'll look for it.

 

[NeilNE]

I see you like muscle cars. I have a Selby AC Cobra with a 460. I need a new clutch and rear tires for it already. What an adrenalin rush.

 

[PeterPHWS]

My thanks to everyone for their help. The Tooley 7SHV I remember now from reading Dave's web site when it was up. The steps involved in shortening the 404 Jeffries will probably be the same as those required to shorten the 8 x 68S parent case for the 7mm Boo Boo.

Allowing for each possibly having a different bolt face I think for M9 the 7SHV would be the best route and for me if I wanted to go that route the shortening of the 7mm Boo Boo case would be the best.

The quality of the brass on the RWS parent Boo Boo case and that of the Norma 404 Jeffries would perhaps lend me to the Boo Boo version but there would not be much in it.

The real issue is the amount of time needed to prep the amount of cases required for F Class. Given that I need 350 rounds for Canada in the next week or so and nearly have them done - I will stick with the 7mm Boo Boo in standard format for now.

There is for me at least one big advantage with the 7mm Boo Boo rifle I presently shoot and that is that it shoots non fireformed cases as accurately as it does the fire formed cases provided the load is the same. This makes the most out of barrel life and probably gives a greater advantage than if you went for a slightly smaller case but found you needed to fire form the cases before you could compete with them. The standard Boo Boo cases also seem to last well.

Is'nt it suprising how shortening and turning 150 cases makes you see the benefit of "if it aint broke don't fix it" when thankfully you already have 200 done?