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Zee
Posts: 28,409 Senior Member
7mm Remington Ultra Mag Range Report
Zee
Posts: 28,409 Senior Member
I got "The Sister" awhile back, as you might remember. I've been waiting for a gifted stock to arrive before any real range work. Well, it finally did.
Choate Tactical
It's a beast of a stock with a full length aluminum bedding block surrounded by 80/20 polypropylene/fiberglass, a forend rail system, and 4 QD sling studs. Don't know the weight of the actual stock, but the shipping was 6 pounds and the rifle set up as so weighs 12 pounds with a sporter barrel. It's a haus!
I was unable to find any load data using Retumbo and 162gr A-Max bullets, so I went off Hodgdon data for the 162gr Hornady PSPBT. Max load listed was 95gr of Retumbo. So, I started at 94gr and went up in .5 grain increments to 95.5 grains.
94gr / 94.5gr / 95gr / 95.5gr
Seating depth is somewhat of an issue with this chambering. As you might recall, Remington gives this chambering 10mm of freebore in an attempt to create a pressure chamber for the bullet. Well, I don't want that. So, seated out about as far as I can, I still can't touch the lands.
As you can see, only half the bearing surface is in contact with the case neck. Seated as such, I obviously can't use the rifles magazine. That is no big deal. Only issue is that I can't extract a loaded round without pulling the bolt out with the bolt release. Oh well.
At the range, the stock is rather comfortable and stable. The wide forend rides the front rest well.........
........and the cut out in the butt stock rides the rear bag. Very nice, actually.
It's a very LONG stock overall, which I like. With the adjustable length of pull, I was able to take a spacer out and make it a little mo betta for me.
Group wise, just as the "Other Sister" or .300 RUM did, this rifle likes max loads and more. At the 95gr book max, I was seeing and feeling no pressure and the group was looking pretty good. So, I went ahead to .5gr over max and fired the 95.5gr loads.
Now, the off round was the third shot. It did it on the previous groups as well. I tend to think that by the 3rd shot, the barrel is getting pretty stupid hot and throwing the last round. I was allowing the rifle to cool between groups, but not between shots. I think I will need to allow the barrel to cool a bit between shots as it seems the last round is suffering. At least.........that's my story.
So, I am happy with the preliminary tests.
Going to load up another batch of the 95.5gr loads as is. I will also load a batch of the same powder charge, but seat the bullets so the bearing surface is at the base of the neck. Just to see if there is a difference in accuracy. Once I get an accurate load, I'll chronograph it to get an idea of the velocity.
Once all the load work is done, I'll paint the stock.
Oh, gonna try some 160gr Speer Hot-Cor bullets as well. They don't seem to shoot in anything else I have. Might as well try them in this one too.
The 162gr A-Max has always done well for me, though.
7mm-08
.280 Remington
7mm Remington Ultra Mag
Choate Tactical
It's a beast of a stock with a full length aluminum bedding block surrounded by 80/20 polypropylene/fiberglass, a forend rail system, and 4 QD sling studs. Don't know the weight of the actual stock, but the shipping was 6 pounds and the rifle set up as so weighs 12 pounds with a sporter barrel. It's a haus!
I was unable to find any load data using Retumbo and 162gr A-Max bullets, so I went off Hodgdon data for the 162gr Hornady PSPBT. Max load listed was 95gr of Retumbo. So, I started at 94gr and went up in .5 grain increments to 95.5 grains.
94gr / 94.5gr / 95gr / 95.5gr
Seating depth is somewhat of an issue with this chambering. As you might recall, Remington gives this chambering 10mm of freebore in an attempt to create a pressure chamber for the bullet. Well, I don't want that. So, seated out about as far as I can, I still can't touch the lands.
As you can see, only half the bearing surface is in contact with the case neck. Seated as such, I obviously can't use the rifles magazine. That is no big deal. Only issue is that I can't extract a loaded round without pulling the bolt out with the bolt release. Oh well.
At the range, the stock is rather comfortable and stable. The wide forend rides the front rest well.........
........and the cut out in the butt stock rides the rear bag. Very nice, actually.
It's a very LONG stock overall, which I like. With the adjustable length of pull, I was able to take a spacer out and make it a little mo betta for me.
Group wise, just as the "Other Sister" or .300 RUM did, this rifle likes max loads and more. At the 95gr book max, I was seeing and feeling no pressure and the group was looking pretty good. So, I went ahead to .5gr over max and fired the 95.5gr loads.
Now, the off round was the third shot. It did it on the previous groups as well. I tend to think that by the 3rd shot, the barrel is getting pretty stupid hot and throwing the last round. I was allowing the rifle to cool between groups, but not between shots. I think I will need to allow the barrel to cool a bit between shots as it seems the last round is suffering. At least.........that's my story.
So, I am happy with the preliminary tests.
Going to load up another batch of the 95.5gr loads as is. I will also load a batch of the same powder charge, but seat the bullets so the bearing surface is at the base of the neck. Just to see if there is a difference in accuracy. Once I get an accurate load, I'll chronograph it to get an idea of the velocity.
Once all the load work is done, I'll paint the stock.
Oh, gonna try some 160gr Speer Hot-Cor bullets as well. They don't seem to shoot in anything else I have. Might as well try them in this one too.
The 162gr A-Max has always done well for me, though.
7mm-08
.280 Remington
7mm Remington Ultra Mag
"To Hell with efficiency, it's performance we want!" - Elmer Keith
Replies
Seating the bullets half in the neck bearing surface seems counter intuitive. First, you have turned that gun into a single shot rifle, and second, how stable are those bullets in the casings when there is just half the neck to stabilize them? If the did fit in your magazine I am betting recoil might change their COAL.
Looks like fun and I bet that thing is loud. Almost 100 gr of powder! About 2x of what I stick in the 30-06. Did you chrony the loads?
D
Alcohol, Tobacco, Firearms and Explosives.... now who's bringing the hot wings? :jester:
Ha! Truth be told, I got the rifle because someone gave me 200 rounds of ammunition. Ever done that before? Hehehehe.
I was planning to build a fast 7mm anyway. Once I burn this barrel out and shoot the life out of the brass, I'll rebarrel to 7mm STW in a heavy barrel. Until then, it'll be a LR deer rifle.
Most of my bolt guns are single shot rifles due to seating the heavy for caliber bullet, long. Hasn't bothered me yet. Only need one shot anyway, right?
ill chrono the loads once I find the most accurate one.
Well, since I'm far from coke can quantity of powder..............I must be good to go.
you have the high speed program, what's my burn ratio out of a 26" barrel?
Am I launching half as much as I burn?
Cash? Ain't like its a high volume rifle.
Breeze was nice.
;-)
No, wait. That's not necessarily true anymore.
:-)
I'd be curious to see the velocity difference between the long and short rounds. If there is any.
How's she now in the recoil dept? I remember you said it was pretty lively before.
Brake and can adaptor?
Mike
N454casull
22.3% sucks....kinda.....there's worse, but not by much.
Mike
N454casull
You might want to read mine.
:-)
Im curious on the velocity difference as well. Maybe the greater bearing surface of seating deeper will result in an increased velocity. I've seen that in the past.
Recoil is painless but still abrupt. Less than before, though.
The powder issue is one of the reasons I dumped my .300 ultra mag a few years ago.
Zee, I do like the looks of the rifle!
AKA: Former Founding Member
Yes.
Not the greatest looking recoil pad, I agree. Might look to change that, down the road.
Surefire? Is that what your asking?
Good shooting as normal and expected.
"The Un-Tactical"
What's the recoil feel like? Wow, 95.5 grains of pulver (That's **** fer gunpowder) Lets see I can load/you could load almost 4 rounds of .223 and over 2 rounds of .308 and about 2X .270s and so on.
One pound = 7000 grains divided by 95.5 = 73.298 per pound of powder. I imagine it would take quite a few range visits to burn up that much ammo in that rifle.
From Hodgdon's website. I would think you will get somewhere around 3100-3200 FPS when you Chrony your loads.
Wow, over 500 FPS more than a .270 shooting 160 grain Noslers. And a few hundred FPS over a .270 Weatherby Magnum. Even shuts out the 7mm STW.
Very interesting, I have no need or desire for such a chambering, but do have to :applause::applause: you on your various caliber quests/endeavors and the results you get :guns::guns:
162 GR. HDY SPBT Hodgdon US 869 .284" 3.650" 100.5 3075 58,700 PSI 103.5 3173 62,800 PSI
162 GR. HDY SPBT Hodgdon H50BMG .284" 3.650" 94.0 2979 56,000 PSI 100.0 3119 62,600 PSI
162 GR. HDY SPBT Hodgdon Retumbo .284" 3.650" 89.0 3009 53,100 PSI 95.0 3223 62,700 PSI
162 GR. HDY SPBT Hodgdon H1000 .284" 3.650" 84.0 2993 55,600 PSI 89.0 3127 62,500 PSI
Words of wisdom from Big Chief: Flush twice, it's a long way to the Mess Hall
I'd rather have my sister work in a whorehouse than own another Taurus!
I have a picture that shows what the recoil feels like! :tooth:
The RUM family isn't for the weak of shoulder, but if you want to put the ultimate hammer on something, there isn't an equal. The 338 & 375 versions are monsters!
MHS remarked that of all the elk he's seen shot, both in person and on TV, he's never seen one go down as fast as the one I shot with my 300 RUM last year. It went maybe 30 yards at a run, and dropped dead.
Is that one of those bullet tip melters??
Once I get an accurate load, I'll test the velocity.
I think I've got the powder charge. Going to verify the charge and see if I can seat deeper and maintain the accuracy. Also, want to see the difference in velocity between seating deep and long with the same powder charge.
Words of wisdom from Big Chief: Flush twice, it's a long way to the Mess Hall
I'd rather have my sister work in a whorehouse than own another Taurus!
Just one of the other ways to find a sweet spot.
"The Un-Tactical"
Recoil isn't bad. Heck, the gun weighs 12 pounds!!!
Understood
"The Un-Tactical"
I was home on leave and borrowed my uncle's 7 mm RUM for a quick day hunt. I want to say I had 150gr rounds...I shot a doe at ~ 275m. I pulled the shot and went through a little high in the lungs. She dropped like a rock, not from the poor shot...but because the round broke her back!!
Yep, I have had the same experience with my 7mm RUM, the few I have shot with it leave GAPING EXIT HOLES.