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 ,,,
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,,,
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.
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!!