Anyone able to get any 7mm Cartridge to 3300/160 or 3200/175gr?

[victor3ranger]

The problem I see nowadays is that most reloading manuals for the big 7s (STW & RUM) list moderate and conservative loads. If I am going to shoot my 7mm RUM, I am going to maximize my velocity while staying around that 62-63k psi range. Just a thought.

I have seen the same thing in the manuals.
Their max book loads are way lower than actual and their stated velocity of the max load is far slower than what they publish

 

[MagnumManiac]

7STW or 7RUM will do it fairly easily. My own 7STW has a 26" barrel and I got 3250fps without pushing 175g ABLR, the 168g ABLR was above 3300fps with one powder (Retumbo).

Cheers.

 

[RevJim]

Thanks Magnum, unfortunately, the ones I had were finicky and slow. They both came in heavier and longer than I really wanted however. My 25" barrel on my 7x57 doesn't seem unwieldy, maybe because its only 8# all up and running. Same with my little Mark V ULTLW and this new to me Kimber 8400, both 24" plus a brake. Just doesn't feel slow or ungainly.

 

[RevJim]

Hey Marty, I looked up that 7 Allen and it is a hoss! ha That would be an excellent LR round I imagine.

 

[Lefty7mmstw]

The problem I see nowadays is that most reloading manuals for the big 7s (STW & RUM) list moderate and conservative loads. If I am going to shoot my 7mm RUM, I am going to maximize my velocity while staying around that 62-63k psi range. Just a thought.

Sorry, but you aren't going to maximize your velocity and stay at 62 Kpsi... That's actually a rather mild pressure for what some of the guys on this thread are talking about. I had a strain gauge on my Sendero 7mmstw. It was a bit of an eye opening experience. Loads that were running 70 Kpsi still functioned well and you had to go above that to even get an extractor mark. The Winchester 150 grain load was hitting 70 Kpsi+ in my rifle and only hit 3300 fps with a 150.
I'm running my current 7mmstw at 3350 fps with a 140ab and my current 7rum at 2900 fps with a 175 eld-x. Could I go faster; sure. I am getting good accuracy where I am though and it doesn't beat things up. If I need more thump, I'll go up in bore diameter.

 

[comfisherman]

Pressure makes the world go round. It's the secret sauce in most if not all wildcats.

 

[Phil Rizzo]

And some cartridge designs do a great job of hiding normal pressure signs.

 

[highfinblue]

N570 pushes 195's out of my 26" barrel in 28 Nosler, but accuracy goes south at anything over 3050 fps, it is amazing at 2950-3050, and had no pressure signs north of there, but I kind of like tight groups more than top end, just me.

 

[Lefty7mmstw]

Pressure makes the world go round. It's the secret sauce in most if not all wildcats.

Yup, take her up till the brass breaks from blown pockets, then back her off a grain. Thank god for modern rifle steel, or a lot more guys would be getting coloring books for Christmas forever.

 

[nksmfamjp]

28 Sherman will get you there!

 

[chav0_12]

I've got a buddy with a 28 Nosler and with 195's hes only getting a bit over 2800 before it gets pressure. I thought it would be faster. Maybe just a slow barrel

Yeah that's slow. What powder is he using and how long is his barrel?

 

[chav0_12]

I got to 3150 with 195s in my 28 Nosler, absent pressure signs. I backed off to around 3050 because I didn't need to be that high. I don't see how I couldn't get 160s to 3300 in this case.

 

[redneckbmxer24]

I stopped chasing super high velocity years ago when I started realizing that it was causing the bullet failures I had many times even with strong bullets. The first time I had it happen was about 20 years ago when I shot a whitetail doe at about 30 yards with a 300RUM with 150gr Sciroccos. I ended up shooting her 4 or 5 times and it was just blowing chunks out. Those are bonded bullets and they failed at close range. I didn't know that at the time though, I didn't know what to make of this doe taking a bunch of hits from a RUM and just making craters on the entrance side. All the other deer I had shot with it were 300+ yards and that didn't happen. Then I had it happen more with some other bullets and cartridges and that's when I figured it out.

Unless you know that you're shots are all going to be way out there, I'd look at max BC over max velocity unless you're just shooting varmints where it doesn't matter.

 

[RevJim]

Well, my good friend sent me a 1986 article by Bob himself on the Mashburn. ( I was super busy back then, preparing to leave Texas and go to Bible College in Tulsa) I missed this publication back then! Anyhow, in his book(with pictures and diagrams) I have owned over 40yrs ( now falling apart) I believe now that either he, or his editor, substituted the 3300/140 with the 3300/160. Seems he got around 3200+ from his Mauser, and probably got that 3300/160 with his 28" barreled #1 Ruger. So, "I apologize to all, to Bob above, and stand Corrected", lol. I for sure was able to get 3300+ in both of the 7 STWs ( 140 NBT) I had and the RUM crowded 3400 with Barnes 140 TTSX (7828). I could not get satisfying results ( accuracy) with the 160 in any of them. That's just the Gamble of Life and/or due to my limited Handloading Knowledge/skill. I have really enjoyed everyone's input!