Anyone own a 7mm 300 Win Mag?

[chuckhammer]

I use RL33 in my wildcat that is an improved 7-300. Works great with 180s.

 

[Jakeleg]

I just am in the beginning stages of trying r33 in mine,hope it shines with 195s. Love this round. Am having a second one built.

 

[FURMAN]

The problem I've always had with reloader powders is they have always been temperature sensitive which does not work for long range hunting.

 

[chuckhammer]

There's a thread a few years old on temp sensitivity of RL33, started not long after this powder debuted. It's been a while but I recall it being better than most of the previous offerings in that regard. Search might turn it up.

 

[One_Duck_Limit]

I use RL33 in my wildcat that is an improved 7-300. Works great with 180s.

Chuckhammer,

I just picked up a few pounds of RL33 to use in a 7 Practical with 180 Berger VLD's. Can you share the load for your 7-300 wildcat? I'm having trouble determining a starting point. PM it to me if your not comfortable posting it.

Thanks

 

[chuckhammer]

When forming from 300 Win Mag brass my necks were coming out pretty short, .210 or so. I switched to 300 H&H Mag brass trimmed down to 2.660 or so before fire forming. After fire forming my necks are now around .250-.260 with a case length of 2.650 or a little more. This version is a bit over 93 gr of water capacity, perhaps 93.5 or so when using WW Super headstamp brass. 7mm Valkyrie I call it.

My standard load for the 180 Hybrids is 86.0 gr RL33 with a CBTO length of 2.920 using the Hornady gauge. That's a .020 jump in my chamber. This load shows belt diameter expansion of .001-.002. Moving up a grain to 87.0 shows another .001-.002 of belt growth so I backed it down to 86.0 again. The primer pockets have stayed tight over 3 loadings at this level thus far. Case head marks show just a hint of flow into the ejector hole. Primer cups are not totally flattened, either, and cratering is very minimal. This is good for 3250 fps in my 28" barrel.

Retumbo was a bit too fast for max velocities using this combination of bullet and case. Maybe about right for 150s. Ran some 120 Ballistic Tips with IMR7828 and was getting 3850+ fps but with stronger pressure signs than I like. 82.0 gr is the downsized version that is waiting on my bench. The barrel heats up QUICKLY using large loads of 7828. I plan to use it for water jug exploding but it would also be a death ray on predators. I have some 162 AMAX loads to try as well with RL33. I'm also now playing with RL50 and the 180s. Haven't tried any 195 EOLs yet.

 

[One_Duck_Limit]

Thanks for the info Chuckhammer. I made it to the range to today to test a few different RL33 loads. Accuracy was outstanding. Three different powder charges were sub 1/2 MOA at 100 yards. The amount of RL33 I'm using is much lower than your load. I may be hitting the lower node. I didn't chronograph anything today. I'll post chronograph results later this week.

 

[chuckhammer]

If yours is a straight 7/300WM then somewhere around 84-85 gr of RL33 behind a 180 Hybrid would be max for WW Super brass without jamming the rifling.

 

[Lrt307]

Broz, I have the numbers somewhere on exactly what you are gaining. I had considered having my .338 Win Mag reamed out to .338-300 Win Mag, but I was only going to get another 100 fps or so.


Running it through Quickload , real quick, I'm getting 3100-3150 with a 168 SMK with a 28" tube using RL22 & RL25. My guess is it will run 100-150 fps faster than a 7mm Rem Mag.

7mm RM with a 168gr SMK set at 3.4" has a usable case capacity of 75.645, using the .300 WM case at the same coal it shows 85.512

Not sure on the 7-300 but My 7rem mag is running a brux 26" with .025 off lands 71.0 grains retumbo and 180 Berger @ 3078-3082 fps. This load also shoots sub .5 moa from 100 yds out to 1000. It still shoots real good out to 1220 but that is where I have quit with it. My buddy has the same chambering same smith and same load and it is identical to mine. Speeds were verified with a Magneto speed and Oehler. Good luck.gun)

 

[backwoods83]

I still haven't jumped on the whole 7x300wm kick **** either, I have a 7mm wby mag with a 27" Kreiger that runs 180s at 3120 with 73.5grns of H1000, some of my brass now has 3 firings and some that I tested Retumbo in have four firings, pockets still tight, brass holding up great, annealed after 2nd firing. I pushed Retumbo to 76grns compressed with no excessive pressures, primers were flat but I couldn't care less about that, since the web expansion is only .0015", and I haven't had to use the Innovative Tech die to size the base yet, at any rate, the 76grn Retumbo load had 180s going 3212 but the ES was horrible and I had vertical from hell at 300yrds, so the 73.5grns of H1000 at 3120 avg with an avg of an 8fps ES and less than a 1/4" of vertical at 300, is the obvious keeper. I can't justify going to a bigger case and using 10grns more powder for 30-80fps, just isn't enough gain for the hassle, and I can shoot factory ammo if I get in a pinch, not likely, but possible.

 

[Santiam338]

Thought I would contribute..This is my 7x300wm.. I am working on breaking it in on a Oregon spring bear..

A Win 70 classic,27 inch Bartlien 9 twist..Loves 180 Berger VLD's with 76 gr Retumbo.. Runs'em right at 3160fps..

I did play with some RE 33..Went up to 83 grs and I didn't see where it was helping me any over the Retumbo..

I was going to wait for a 8 twist,but after comparing the 9 twist and 180's to the 195's I ain't giving up much..

 

[One_Duck_Limit]

RL33 didn't do it for me. I had excellent accuracy at 79g but it gave up too much speed for my liking, 2940 with 180 VLD. I worked up to 85 grains hoping to hit a high node but it didn't happen. I started showing slight pressure signs at 84.5 and clear ejector marks at 85.

 

[just browsing]

Sorry if this has been asked already, but 84 pages is a lot to sift through...

Has anyone tried the 195gr EOLs yet? What kind of results are you getting? Mainly looking at velocity/accuracy as I'm wondering if I'd be able to push them north of 3k.

I'm debating between a .300 Norma and a 7mm-300 when my current .300wm barrel gives up the ghost... Just trying to figure out if the .30 230 OTMs @ 2900 are going to have a significant advantage over the 7mm heavies.

Thanks.

 

[etisll40]

interested