Advice on 7-300 win mag

[Jakeonthekob]

Hi everyone, new member here. I was wondering what people use for action, stock/chassis and magazine for a 7-300 win mag gun. What COL do you get? I am interested in getting mine built by PMAC precision.

I was thinking of getting a Stiller tac300, or maybe even a Defiance deviant, or Surgeon action. Something with a Rem700 footprint. I plan on shooting out to 1 mile, not past 2000+ yards. I also have two barrels, a 1 in 8.5 twist Bartlein and 1 in 8 twist Brux for running 195gr Bergers.

I do have reloading experience with .308, but have never necked down brass before. Any recommendations for dies and neck sizing bushings? Powder?

Thanks a lot guys!

 

[jda2631]

If you want DBM I'd look at getting CIP length so that you don't run into overall length issues when using the larger 7mm bullets. If not using DBM, look at Wyatt's extended box for an internal magazine. You are probably going to need 3.650"+ COAL for the 195's. I don't have a 7-300, but do have a 300WM. I could be wrong on the COAL, but those 195's are long.

As for powder, again I haven't used a 7-300. But for 300WM H-1000 is great for bullets up to about 200gr, anything over that I use Retumbo.

 

[Barney88PDC]

Get 300 Win Mag Redding FL Type S dies. Put a 7mm bushing in it and that will neck it down. You may need to get a 7mm seater stem to change out in the seater die and you would be GTG. Powder would be H1000, Retumbo or RL33 would be good places to start. Use the 8 twist if you want to shoot the 195 and I would make a dummy round and send that in with the build with the heal of the bullet just above the neck shoulder junction and tell the smith that I want a 0.020" jump. The exact bushing needed would need to be determined with the brass you select but about a 0.311 would be close.

 

[Jakeonthekob]

If you want DBM I'd look at getting CIP length so that you don't run into overall length issues when using the larger 7mm bullets. If not using DBM, look at Wyatt's extended box for an internal magazine. You are probably going to need 3.650"+ COAL for the 195's. I don't have a 7-300, but do have a 300WM. I could be wrong on the COAL, but those 195's are long.

As for powder, again I haven't used a 7-300. But for 300WM H-1000 is great for bullets up to about 200gr, anything over that I use Retumbo.

Hey thanks for the info jda. I plan on getting a MDT ESS chassis with magazines but just wanted to know if I should run a 3.85" mag or 3.715" mag. Someone else told me that H-1000 is a good place to start too, and Paul Mccoy apparently sells redding 7-300 dies so I don't have to go the neck bushing route.

 

[Jakeonthekob]

Get 300 Win Mag Redding FL Type S dies. Put a 7mm bushing in it and that will neck it down. You may need to get a 7mm seater stem to change out in the seater die and you would be GTG. Powder would be H1000, Retumbo or RL33 would be good places to start. Use the 8 twist if you want to shoot the 195 and I would make a dummy round and send that in with the build with the heal of the bullet just above the neck shoulder junction and tell the smith that I want a 0.020" jump. The exact bushing needed would need to be determined with the brass you select but about a 0.311 would be close.

Hey that is really good info, thanks Barney. I will have to pick Paul's brain more, but I trust that he knows exactly what to do and can tell me good starting places in terms of reloading.

I do have a Bartlein 1-8.5 twist barrel, but I also have a Brux 1-8 twist barrel. Paul actually told me that he usually runs 1-8.7 twist barrels for 195gr Bergers but Bryan Litz's data call for a 1-8 twist so I'm kinda torn on which barrel to go with.

 

[Dirty D]

@TresMon had a thread on this very subject before the Scout era, maybe he can weigh in.

 

[Barney88PDC]

Hey that is really good info, thanks Barney. I will have to pick Paul's brain more, but I trust that he knows exactly what to do and can tell me good starting places in terms of reloading.

I do have a Bartlein 1-8.5 twist barrel, but I also have a Brux 1-8 twist barrel. Paul actually told me that he usually runs 1-8.7 twist barrels for 195gr Bergers but Bryan Litz's data call for a 1-8 twist so I'm kinda torn on which barrel to go with.

I would trust the rocket scientist. And there are benefits to bushing dies.

 

[Brentc]

My 7-300 is built on a standard Savage LA I had collecting dust in the safe. I had Pac-Nor spin up a pre fit 8 twist SS 28" bbl. I then screwed the barrel on, torqued everything into an MDT LSS XL and let it rip. I run 195 Bergers at 3030 fps with 80 grains of RL33. They are seated .050" off and they fit and function fine in a standard 300 WM AI magazine.

For dies, I use my Redding 300 Win body die and a Redding 7RM neck die. For seating, I use a Hornady 300WM seater with a 7mm seating stem. It's a little cobbled together, but my ammo comes out straight.

 

[Hawk in WY]

I swore no more odd ball cartridges after my 7mm Dakota.

Load data is scarce.

Brass is expensive.

Sure do love my 7mm Dakota.

Sure would like a 7mm-300.

 

[RNWRKNP]

My 300 RUM loves H1000 and I intend to delve into the RL33 as well. For me, Retumbo is good but have found that H1000 performs better and less concern with compressed loads.

 

[Just Macca]

7-300 Norma using Lapua brass would seem to be the go....

 

[Jakeonthekob]

7-300 win and 7-300 norma is a wash for me, in terms of being able to shoot to a mile. However, it seems that there are more gunsmiths knowledgeable about the 7-300 win, such as Paul, which makes me more at ease. Who knows, maybe it will be commercialized one day =)

 

[Jakeonthekob]

My 7-300 is built on a standard Savage LA I had collecting dust in the safe. I had Pac-Nor spin up a pre fit 8 twist SS 28" bbl. I then screwed the barrel on, torqued everything into an MDT LSS XL and let it rip. I run 195 Bergers at 3030 fps with 80 grains of RL33. They are seated .050" off and they fit and function fine in a standard 300 WM AI magazine.

For dies, I use my Redding 300 Win body die and a Redding 7RM neck die. For seating, I use a Hornady 300WM seater with a 7mm seating stem. It's a little cobbled together, but my ammo comes out straight.

Sweet setup. Some other members suggested me running H1000, which sounds like a safe bet to me. Someone told me that Paul has custom made dies for this caliber, so I think I can't go wrong at this point. Not to mention going at roughly 3000fps with 195 grain bullets is pretty damn good, and not too much overbore like a 28 nosler.

 

[Silverjay]

One thing to consider on the ESS chassis is the need to move the cheek piece to clean. Not sure if they offer a folding version now, mine is fixed and I can not run a rod through it without loosening the set screw and changing the position. I count the rotations down and bring is back the same when done. Not the end of the world, but annoying.

 

[Jakeonthekob]

M that's a good point. Thanks for bringing that up Silverjay! I may have to look at some other chassis or stock if MDT doesn't offer a folding adapter. I hate removing cheek pieces to clean.

 

[MachoKing]

What's cleaning?

 

[Brentc]

One thing to consider on the ESS chassis is the need to move the cheek piece to clean. Not sure if they offer a folding version now, mine is fixed and I can not run a rod through it without loosening the set screw and changing the position. I count the rotations down and bring is back the same when done. Not the end of the world, but annoying.

I have an XLR on mine and I just take loosen the castle nut and completely separate the stock from the chassis. I clean it so infrequently that it doesn't matter too much.

 

[Jakeonthekob]

I have an XLR on mine and I just take loosen the castle nut and completely separate the stock from the chassis. I clean it so infrequently that it doesn't matter too much.

Actually I spoke with Anthony at MDT and he said they are going to make a folding stock adapter for the ESS chassis. Unfortunately they cannot open up the magwell to 3.850in so I may go with another source. Gotta contact XLR and see what they can do.