Home Forums Hunting & Shooting Custom Rifles & Wildcats More 7mm Mashburn Velocity Test

Randy I think 33 might be on the slow side but maybe with 175-180 gr bullets? Ya never know.

Thanks Bob, I thought that It might be a bit slow. I really like H1000 and will try the old semi pointed 175 Nosler with 74 gr H1000. Randy

I have some RL-33 to try with 175 Sierras. My second Mashburn likes 74 gr. H1000 for 3060 fps. with 175 Sierras/Noslers.

The Mashburn is a very nice round, & I'm not attempting to belittle it in the least, but I've gotten those same velocities out of a couple of long throated (to seat 160 Partitions to the base of the neck) 7mm Rem Mags w/o all the hassle of the fire formed case.

MM

I agree with you just one thing nice about the mashburn is you don't have to lean on it to get it there. I built mine to have something different. I knew it wasn't going to accomplish something that hasn't already been done.

That's it in a nutshell. Yes I have had a few long throated 7 rem mags, set up in a 3.6" box and throated to take the 160 Partition seated with base of bullet even with base of neck. velocities approach but don't equal, the Mashburn.I did it because Hagel and Wooters said it was a good way to go.

And I always had the feeling that I had absolutely maxed out the 7Rem Mag.OTOH the additional capacity of the Mashburn gets 3150-3200 with a 160 rather easily. Max out a Mashburn, you are at 3250. I have yet to see primer pockets opened operating the Mashburn at those velocities.

The other problem with the long throated 7 RM, is that if you throat to the heavier bullets to optimize it in a long magazine, shorter, lighter bullets will have "jump" to the lands. The neck is too short. And you still will not have the capacity of the MashburnThe longer neck of the Mashburn helps alleviate some of this.

Does this matter? To some it does,if they like everything "just so". Holding cartridge OAL to 30/06 levels the 7 RM may be ether because that's how it was developed and designed. But in a 3.6" box, the Mashburn is the better tool.

Thing is, comparing the cartridges is a hollow exercise. The Mashburn came first;it was designed to be (what Doc Bill said this afternoon on the phone) a "cheater" 300 magnum....give a 175 gr bullet over 3000 fps. Without the bounce of a 30 caliber magnum.There really was nothing else that did this.

At the time,the 7mm Weatherby was proprietary, had a 12 twist, and shot 139 gr bullets.It would not stabilize 160 gr bullets...at least then. The Remington came later,and was designed to fit a 30/06 length action and approximate Mashburn velocities, not the other way around.

Case forming is something I used to worry about; for years it kept me from building a Mashburn. I got over it. I can start after breakfast,and by mid afternoon will have turned 50-100 300 Win Mag cases into spanky new Mashburn cases, sealed in plastic bags,and ready to load to hunt about any soft skinned game, anywhere.That includes a break for lunch and driving time to the range. For me and friends who like the cartridge due to its easy going nature and delivered high velocities,this is no big deal.

And after I fire them the first time, it's like loading any other cartridge.

It may turn out I don't even have to do that if i don't want to.....but that's another story.

Bob, to each his own & I see you're drinking the kool aid & are enamored.

But 3170 with the long throated 7 mag is a relatively easy number to achieve w/o leaning too heavily using RL-22; if another 100 FPS is of enough value to you to do all the brass work that the wildcat requires, then by all means, proceed.

At 3170, the extra 80 FPS velocity of the Mashburn doesn't mean much & in fact, in reality, I'm done with the all mags (except the 338) as I am firmly of the belief that a 270/280/30-06 is plenty good for all NA non-dangerous game out to 500 yards; if you really, really intend to regularly shoot longer, then the extra velocity of the mags has merit.

I like the KISS principle, but that's not everyone's cup of tea: as such, YMMV.

MM

MM: I'm not into kool aid and I don't get enamored easily I shoot and load to learn and look at what the numbers tell me.

I have not seen 3170 from a long throat 7 RM without very short brass life.The cartridge was never designed to hit those velocities routinely with a 160 from a 24" barrel....even its designers didn't (Les Bowman) didn't run it that hard.3170 is all it can give with a 150.


I can easily get close to 3300 with a 150 from the Mashburn,over 3200+ with a 160 and close to 3100 with a 175. No 7 RM can do that and last more than 2-3 firings..and with single based powders;not double based which will fool a lot of people with over the top velocities.

Besides, long throating a 7 RM is nothing more that 'wild catting".

The Mashburn is simply a larger cartridge and moves heavy bullets faster....which is what the case is all about. If it were not "good" you would not see so many new designs looking to do nothing more than duplicate its' ballistics with the heavy 7mm bullets.

I love these conversations about it with people who never even have loaded and shot one.

Why shoot a 7 RM when you can shoot a 280AI; why shoot a 280AI when you can shoot a 280? Why shoot a 280 when you can shoot a 7/08? Point is velocity gains usually come incrementally,and the bigger cases always win...and it's up to every one to decide where that balance is for them. But I can't take seriously cartridge comparisons based on inflated figures for smaller cases loaded to redline and then compared to bigger cartridges.....common on here and that's the real kool aid.

Maybe I should have just described the kool-aid drinking & being enamored as looneyism........... Probably a less offensive description.

What I have trouble understanding is that some people simply don't understand that other people just don't need nor want what some other people do.

I've gone to standard calibers because I've tended to move to lighter weight rifles, around 6 3/4- 7 1/2 lb, scoped.

As such, I simply don't want them chambered in the Big 7's or 30 caliber magnum rounds for a variety of reasons including that they don't fit well.

Accepting the limitations of standard calibers in terms of absolute range practicality is a part of the equation.

So you see, I haven't tried the truly wonderful Mashburn or STW not because I think they don't perform as advertised, but simply because they don't fit my needs or profile.

If I felt the need for a Mashburn, I'd do one tomorrow as it's likely the best ever of the Big 7's.

MM

MM I understand....I understand...!!!!


In my posts on the cartridge I am passing along information and NOT advocating for ANYONE to build one,and never have.

Those who want to can and those who don't see the value are free to use whatever else they want.

I only report on what it does...people misinterpret this to mean I think everyone should build one. Not true at all.

I get PM's and Emails about the cartridge all the time...my first question to them generally is...."Are you sure you want to do this....and why?'

If they don't know "why" they should stay away, from any wildcat, not just this one because the reasons for getting one has nothing to do with it being the "best" or anything like that.

And I certainly don't care at all how it compares to other 7mm magnums,although comparisons are inevitable. I had an objective...move 175's at close to 3100,and 160's in the 3200 fps range. It does that. That is all I care about and don't care at all that some others may do the same thing.

So look at what I post as being a "report",not advocacy.

Always knew you were a really smart guy............

MM