It's pretty amazing to see this cartridge come up again. I built one on a Interarms Mark X and a 24" douglas #3 back in '90. It was my second custom gun and my first wildcat. I even ordered the correct dies from RCBS. I still have it actually. I used PMC brass back then and was getting 3250-3300fps out of 150 B-tips w/4831. I shot a lot of stuff with that gun. I have 3 7STW's and 2 of them I shoot single shot just because they are too long for a Remmie mag box. I might build another so I can actually use the rifle as a repeater with the bullets seated how they should be.
Anyone own a 7mm 300 Win Mag?
- Thread starter Broz
- Start date
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4bycamper
Well-Known Member
Hey guys, thanks for all the fine input. I had no clue. So maybe this Remmy 7 mag I have could get a new life... But all the used barrels I find are 24 inches long. If I can squeeze $300 or so out of the budget this could work.
Kiwi Nate
Well-Known Member
Hi Glenn, sorry for the delay. Case capacity is 89.1gr Water. Brass is Winchester brand. Let me know if you want any more specs / COAL's.
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Stonewall2
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- Dec 5, 2006
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Kiwi Nate
Thank you.
Any further load information such as bullets used and COL would be great.
Also comments on current lots of Winchester brass would be appreciated.
I use Win. .300 Win brass to form my 7mm Rem cases headspacing on the shoulder.
RSI Pressure Trace would work well here.
RSI - PressureTrace
I have the older version but it is still in the box.
Glenn
Thank you.
Any further load information such as bullets used and COL would be great.
Also comments on current lots of Winchester brass would be appreciated.
I use Win. .300 Win brass to form my 7mm Rem cases headspacing on the shoulder.
RSI Pressure Trace would work well here.
RSI - PressureTrace
I have the older version but it is still in the box.
Glenn
Kiwi Nate
Well-Known Member
Thanks for the link, yes that would be a nice piece of kit to own, very useful.
Max COAL's are as follows:
The 7mm Practical. A Practical Magnum.
As to the Win brass, quality is fairly average. I am using unsorted brass and still maintaining both a low ES and desirable accuracy. Bare in mind, the Practical is supposed to be just that, I wanted a wildcat that would perform well in the hands of medium level experienced clients. For example, lets say the client has a basic Lee reloading kit. To this he adds a Hornady neck die and away he goes. My priority list goes something like this:
Good bore
Bore maintenance
Action true
Good bedding
Basic, sound reloading practices
Good shooting technique
If there is a problem with the bore, then we need to start looking at finer variables to relieve harmonic stress, that sort of thing. Thats when I start playing with bullet jump, changes in powder, etc etc. Fortunately, we haven't had any bore problems or sensitivity with the last five rifles. There are another three rifles in progress.
We ran Nosler brass through the Finnbear, good brass but it didn't make any difference regarding ES or accuracy. The Win cases do need annealing though, they split after a few shots if this is not addressed. I find that Win brass is prone to split in the 7mmRM and .300WM also, if left un-annealed. The Nosler brass saved a lot of time in this regard, didn't have to do any special prep, not even a chamfer, just necked it down.
I think the Practical is a great wildcat. As a commercial loading, I don't think its a good idea. A long necked 7mm Ruger would definitely be more popular. As a wildcat, the belt on the .300 case serves a purpose (fireforming). On a commercial loading, the belt would be pointless. FF loads in the Practical can be used out to all ranges. Most guys won't want to do this but at the very least, FF loads can be used with confidence out to 600 yards or so.
Max COAL's are as follows:
- Berger VLD: 92.4mm (3.633")
- Berger 180gr Hybrid: 94.2mm (3.708")
- Amax: 92.3mm (3.633")
- Hornady SST & InterBond: 90.3mm (3.555")
- Hornady Interlock: 89.9mm (3.539")
- Sierra ProHunter & GameKing: 88.3mm (3.476")
- Nosler BT: 90.4mm (3.559")
- Nosler partition: 89.9mm (3.539")
- Nosler Accubond: 90.8mm (3.574")
- Barnes TSX: 89.4mm (3.519")
- Swift Scirocco: 91.2mm (3.590")
The 7mm Practical. A Practical Magnum.
As to the Win brass, quality is fairly average. I am using unsorted brass and still maintaining both a low ES and desirable accuracy. Bare in mind, the Practical is supposed to be just that, I wanted a wildcat that would perform well in the hands of medium level experienced clients. For example, lets say the client has a basic Lee reloading kit. To this he adds a Hornady neck die and away he goes. My priority list goes something like this:
Good bore
Bore maintenance
Action true
Good bedding
Basic, sound reloading practices
Good shooting technique
If there is a problem with the bore, then we need to start looking at finer variables to relieve harmonic stress, that sort of thing. Thats when I start playing with bullet jump, changes in powder, etc etc. Fortunately, we haven't had any bore problems or sensitivity with the last five rifles. There are another three rifles in progress.
We ran Nosler brass through the Finnbear, good brass but it didn't make any difference regarding ES or accuracy. The Win cases do need annealing though, they split after a few shots if this is not addressed. I find that Win brass is prone to split in the 7mmRM and .300WM also, if left un-annealed. The Nosler brass saved a lot of time in this regard, didn't have to do any special prep, not even a chamfer, just necked it down.
I think the Practical is a great wildcat. As a commercial loading, I don't think its a good idea. A long necked 7mm Ruger would definitely be more popular. As a wildcat, the belt on the .300 case serves a purpose (fireforming). On a commercial loading, the belt would be pointless. FF loads in the Practical can be used out to all ranges. Most guys won't want to do this but at the very least, FF loads can be used with confidence out to 600 yards or so.
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Broz
Well-Known Member
I just finished the second one for my friend with the new reamer I designed. It is a tack driver to 1000 yards with Berger 180's. This is the 26" 1 in 9 twist Hart tube and it is sending them at MV of 3144 from RWS brass and H-1000.
I use Redding bushing dies and a 3 step sizing process to get the necks down to .284 dia. This is the best wayI have found and is only needed on the first trip. Then leave the bushing in from then on. The dies I use are simply a set on the 3 die comp series that allow a seperate neck and body die and are 300 Win Mag dies.
Jeff
I use Redding bushing dies and a 3 step sizing process to get the necks down to .284 dia. This is the best wayI have found and is only needed on the first trip. Then leave the bushing in from then on. The dies I use are simply a set on the 3 die comp series that allow a seperate neck and body die and are 300 Win Mag dies.
Jeff
Broz
Well-Known Member
Not sure what you are talking about Boss. But rest assured I have checked pressures and looked for all the warning signs. When I remove primers there is no muffin top , no hard or firm bolt lift, or any other signs.
Jeff
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Broz,
Are you still running the 180's at .040" off the lands? Are the results any different or pressure spikes at .010" off or touching? Does the RWS brass give more velocity than Winchester, or does it just allow for less powder?
Thanks
Are you still running the 180's at .040" off the lands? Are the results any different or pressure spikes at .010" off or touching? Does the RWS brass give more velocity than Winchester, or does it just allow for less powder?
Thanks
Broz
Well-Known Member
The first rifle was .115" off the lands. But this last rifle shot good at .030" , to .050" off the lands with the .050" being a bit tighter groups. The second rifle was with my new reamer. Never had them touching in either rifle as far as my memory serves me.
The RWS brass takes a lesser charge due to it's lower case volume. But we got the same velocity with both WW and RWS.
Jeff
check out www.ballisticstudies.com this guy is makeing rifles like this because thay don,t burn out barrels like the rem ultra mag does he has got some good footage of how well this caliber works I am going to convert my weatherby MK5 8x68s to this cal when the barrel done its dash
Thanks for the info on the brass forming process. I looked at the dies u were talking about and I am going to order a set. I have two more questions for ya!! I saw that the die has what I call a flare on the de-capping pin, and since u neck it further down than a 30 cal does that flare give u problems? The other question that I have for u is what do use for seating ur bullets? Can u just use the 300 win seating die or what?? Thanks
