Home Forums Hunting & Shooting Custom Rifles & Wildcats New 7mm MSM

Hope yours goes faster than mine. It drug out for 18 months.

Me too. I have a couple others I can use if it takes longer though.

Retumbo is a great powder with 175's. In my old MSM it would easily touch 3100. Might be my go to when I get the new one.

Scotty
The PTG unit for M70's is very nice. It is a simple design. Their stuff for M700's is pretty junky, poor fit and finish.
My M70 unit is alloy and therefore much lighter than a Blackburn steel unit. Incidentally that unit requires another hole drilled into the flat in front of the front screw hole. It will add about 8oz over the alloy.

Got ya. Thank you for the info on it.

Which way would you go with the rifle, if you were building it and trying to keep the finished rifle at 8lbs with a 6x36 or 6x42 on it?

When I built my 7Mag with Mark P. I asked about the Blackburn and he told me the same thing. It weighs a ton and would be exactly the wrong thing to do with my kevlar stock. He said its a pretty unit, but just not the right combination. he strongly recommended the factory original fw bottom metal if you can find one as the best solution.

Scotty,
Remember a hunting rifle is carried more than it is shot.

The bbl...Page used a 22" on his. I don't think you gain anything going longer than 24" ON A HUNTING RIFLE. You get another 25 fps but pay every second with a less handy rifle package. I would cut it to 22". If that is too radical for you then go 23". It should measure about .575" at 22" and .750" about 5" in front of the receiver. The shank should be 1.3-1.5.

I would use a M700 for less weight. Avoid the clones that use either the M16 or SAKO extractor if you use a clone. The Rem factory is better. If you want a clone then use a Bighorn or a BAT. Both use sliding plate extractors.

Trigger...BixNAndy...frightfully expensive but best ever.

The Echols stock is not trim. It was designed for 375-416-458's. I like the compact edge but would have the forend modified to make it a little rounder and wider.

For mounts, Weaver or Talley alloy. Those old cheap common Weavers are low and if set up properly return to zero about as well as anything. They are both light and strong. You can fiddle with Weavers to adjust for windage, something that can't be done with the Talley LW. With Weavers you can carry a spare scope.

PTG alloy or blind magazine.

I don't understand the logic of a sub 24" barrel on a big 7.

If that is what you want for the terrain you're hunting, you'd be further ahead with a .280, or 7-08. Just my Opinion of course.

I remember the disapointment of rechambering a 28" 1885 to 7 STW, only to discover that the accuracy really wasn't there. At the extended ranges I wanted and expected to use it for, it wasn't confidence building.

Today modern optics, LRF and turrets can compensate for slightly less velocity. If the shorter barrel also contributes to accuracy, that is a bonus. Balance, and carry-ability are certainly a bonus.

To me 24" or less is carbine length on a big 7

Back in the early 1950's when the idea of an all round BG rifle was evolving,guys like Art Mashburn, Al Biesen,and Warren Page were building shorter, lighter rifles for general BG hunting worldwide.

You're right; cases of the STW capacity (which really boiled down to full length, blown out 300 H&H brass necked to 7mm,and were in existence a long time before the STW) did not work too well from 22 inch barrels but cases of somewhat less capacity like the 7mm Weatherby and Mashburn did.

Warren Page killed 400+species of BG animals globally with Old Betsy, his 22" barreled 7mm Mashburn with a 175 gr Nosler Partition and 175 Hornady. So the rifles shot well.

Keep in mind back then there was no 7 Rem Mag.

A bit later, Bob Hagel built a Mashburn but used a 24" barrel

You can look this stuff up. Anyway that's where the idea came from.




Here's one of those rifles at work; it was built by Griffin ad Howe, chambered 7 Rem mag with 23" barrel.

So true: very nice but mine weighed over 1/4 lb more than its aluminum counterpart for a Rem 700.

Ballistically, inside 300 yds its pretty much a horse a piece. After that, the launch velocity starts to make a bigger difference. Some of the slower powders we have access to these days probably benefit from an extra couple inches of barrel. Or maybe not. I'm going with 26" on the Mashburn I'm building. The extra couple ounces and slightly longer rifle won't be a hindrance for what I have planned and if they are I'll carry my 280 Mountain Rifle.

A hunting rifle is carried more than it is shot.

For sure Rick. I do carry them a whole bunch. I will stick with the 25" barrel though. Being 6-5 I haven't had much trouble with my P64 338 or 300 so I don't think the lighter contour 25 will be too much. Your input is taken though, I know you've screwed a couple together.

Just got my dies the other day. Sounds like the barrel is on its way to the smiths. Hoping to see it in April. Should be enough time to ring it out I think. Pretty sure I won't have too much load work. The first one that was rechambered with the same reamer was done in about 20 rounds. Hope the new one does as well.

Rick, point taken on the Weavers. I like them as much as anything else.

6-5. Well now I get the 25" barrel.
I am 5-7 so 22 is plenty long.

I don't think there is much difference in real world hunting performance.

Rick,

Please convince Scotty to build as heavy a rifle as possible, it's hard enough keeping up with him as it is. He handles 10-12 lb (scoped, loaded) rifles like they are toothpicks and carries them all day long up steep mountains above 8,000 ft. He's a humble lad and will probably string me up for posting this.

The Mashburns that Bob and I built--I just went prostrate and did as I was told by the Master--use steel bottom metal, Williams on Bob's I believe, and Blackburn on mine. Scoped in Echols Legend Edge stocks with 24" Krieger #2 barrels, they come in around 7.5 lbs, which has been perfect for carrying and shooting. I should weigh the thing again to verify, but this is my best recollection.

For what it's worth, when I built the .270 Pounder according to Bob's blueprint on a pre64 action using a 23" Krieger #0, I used some factory FW bottom-metal I had kicking around. Glad I did. I'm not sure what it weighs, but the rifle is as perfect a .270 as I could ask for.

Great to be here. You'll get sick of me soon.

--Matt

It's good to see you posting here Matt. I figure with a little lighter rifle we may be able to get a little further up the trail.

All Jokes aside, the only place I deviated from Bob's and your MSM is the 25" barrel. If I hate it we can always cut it down. As Bob said Page did it all with Ol Betsy at 22".

Dang I wished I had that rifle today....

Scotty:

It's a perfect platform for all Western big game hunting, period. Just about every rifle thus far has followed the same formula, easy to develop loads for and the cartridge has a habit of dropping stuff in it's tracks using a variety of bullets.

Can't wait to see yours when it gets put together, you won't be thinking about Ol Betsy once it's in your paws.

--Matt

Well, with any luck it'll get used for a Wyoming bull this Fall Matt.. I am really looking forward to that and just hunting hard in the mountains with it.

Should be a few of us in camp this Fall with MSM's.... If you get yours dialed back in..

Hey Matt! Great to see your posts!

v/r
Joel