Anyone own a 7mm 300 Win Mag?

[chuckhammer]

Nice groups Skyking!

Chuckhammer: I have a 7mm/375 Ruger not the LRM. It is a 375 Ruger case necked down short neck and all.

Using RL-33 with 180 Berger target hybrid. Barrel is a SS 29 1/4" 6 groove lilja.
Most accurate load is 83 grains for velocity of 3175 fps. I did work up to over 85 grains with velocities over 3200 fps but groups opened up.


I am certain RL-33 would work with the heavier 7mm bullet offerings in a 7mm/300 win mag.

Good info, thanks. I believe I'll reach 3200 with a 180 in my Valkyrie but it may not be at a node. The full 1"bull contour should help soften the nodes.

 

[Skyking]

Really great groups, Skyking!!! What velocity with that load?

I did not crono it. I went from Nosler brass to Norma and had a new lot of h1000. So I backed it down. I am guessing in the 3030fps range. My normal load is 74g of Retumbo gives me 3140fps

 

[garou22]

SkyKing,
When I Tested REtumbo And H1000 In My 30Inch 3 Groove Lilja, I Didn't Crest 3000 Fps Until 80+ Grains Of Charge. I'm At A Mean Elevation Of 3450 Ft, But That Doesn't Account For The Drastic Difference In Velocities. Any Ideas On What Is Going On? My Chronograph Is An Oheler 35.

 

[Dick Tinsley]

I did not crono it. I went from Nosler brass to Norma and had a new lot of h1000. So I backed it down. I am guessing in the 3030fps range. My normal load is 74g of Retumbo gives me 3140fps

Thanks for the info! I understand that brass varies an some more than others. That being said, I've got a lot of remington an Winchester brass that I'm getting ready now. My 7/300 will have a 28 kreiger, 700 rem action! I'm just trying to get a starting point. Guess I'm putting the cart before the horse. I've got about 4 pounds of Retumbo an 6 pound of H-1000. Anyway, thanks for your info!

DT

 

[Skyking]

SkyKing,
When I Tested REtumbo And H1000 In My 30Inch 3 Groove Lilja, I Didn't Crest 3000 Fps Until 80+ Grains Of Charge. I'm At A Mean Elevation Of 3450 Ft, But That Doesn't Account For The Drastic Difference In Velocities. Any Ideas On What Is Going On? My Chronograph Is An Oheler 35.

If you look back on page 44 i think you can see the delays of me gun. 80g. HOLY COW! I have no idea how you are not seeing pressure with that much powder, and that slow of speed. I know those chrono are a great one, but I would not live and die by those numbers. Have you tested you actual drops at distance? That will give you your true speed. I am shooting at 4500FT, I have always heard that Lilja barrels are slow, but something is definitely not right.

 

[LONGSHOOTER]

So fellas, I read through this entire thread. What is the con census, can the 7mm RM be improved upon?

 

[chuckhammer]

For bullets >140-150 gr, it appears so. Efficiency and bbl life appear to lose more ground for bullets lighter than that.

 

[300stw]

been loading for my 7-300 i had longrifles build,,, anyway. 180 berger 27in barrel, win brass, retumbo 74 gr 2860 fps shiny elector mark, h1000 73 gr 2861 ejector mark, 7828ssc 73.5 3072 10 shot ave, high low spread 14 fps,
shot thru a chrony

retumbo and h100 no velocity, 72 gr retumbo shot .3 in group 150 yards at 2760 fps,, the 7828 load right at .7 in, no other messing around with oal ,,,

any thoughts,,

 

[Broz]

any thoughts,,

Get an Oehler or a Magneto Speed.

73 gr of H-1000 and a 180 should be well over 2861 from a 27" tube.

In all honesty, I will say your are shooting on different days under different light and the Chrony is fooling with you.

Have you tested drops out to 1000 to see what velocity is needed to match?

Jeff

 

[300stw]

all loads were shot in a 1.5 hour time frame this afternoon, chrony and shooting bench stayed in same exact spots, overcast the whole time, no acces to anothe chronograph,,,, havent shot it for drops yet,,, was disappointed with the retumbo velocity, i shoot alot of 7828ssc in my standard 7mag,,,

 

[LONGSHOOTER]

Why is is it that I can look in an older Nosler manual (#4) and not see any improvement with a 7STW as compared to a 7RM? If the STW can't do it, how can the 7-300 do it?

 

[garou22]

Fellas,
Me Thinks Something Strange Be Going On With Powders... Between 300Stw's 27 Inch Pipe And My 30 Incher, There Should Only Be An Approximate Velocity Difference Of 75 To 125 Feet Per Second. Given The Numbers He Reported, That Is Holding True. However, 300, Be Wary Of Your 7828SSC Charge, I Got Shiny Extractors, Stiff Bolt Operation, And Loose Primer Pockets Starting At 76.5 Gr. But I Use 76.0 Grains To Propel The Sierra Gameking 180Gr To 3056Fps In My Model 70 .300 Win Mag For Years. Why It WorkS In The Straight .300, But Shows Over Pressure In The 7/.300, I Don't Know.

As For 7 Rem Vs 7STW, I'm Not Sure, All The Data I've Seen Puts The STW Out Front With Velocity. My Brother-In-Law Has A Tikka 7 Rem Mag, And Can Barely Get 2900Fps WitH A Sierra 160 Gameking. My 7/.300 Pushes A Berger 180 At 3056 And Uses Less Powder Than An STW Or RUM to Do It, Which Should Help Increase Barrel Life - Which Is Why We Are Using This Wildcat.

 

[LONGSHOOTER]

But isn't your 7 300 pushing a sleeker bullet down the bore?

 

[Dick Tinsley]

This is just my 2cent's! There are some calibers out there that suited to the case capacity, some are a hot rod, some are slower(but work)! That being said( an I'll be the first one to say I'm not a genus!) the 7/300 just seems to be one of those wildcat's that just work!! Maybe someone else out there, that has more Knowlege than me can explain it better than me. That being said, like I said, the 7/300 just works. Powder to case ratio, bullet BC, powder technology an many other things that just fall in to place! Guess that's one reason it's called wildcatting! I'm in the middle of a build now(7/300) an looking forward to the end result! Many thanks to everybody on this thread for great input an info!!! Many,Many thanks to Broz for him starting this tread an his help!! That's just my 2cents!!

DT