The classic magnums - will they see a renaissance?

Belted magnums given a make over with faster twists, added freebore, better reamers will sing like never before. Add in longer heavier higher BC bullets and they will hold their own.

300WM in 1:8, at least 3.7" magazine, freebore, 26" barrel, Serengeti Bore Rider reamer will be "special"! This is actually my next build. My Sendero 300WM has over 1600 down barrel and still shoots fine but I want to kick it up.
How will factory ammo shoot with a big jump?
 
And another from Paul
My favorite rifle is the 300 H&H; second is a 338 Jarrett; third is a 375 H&H. Next come the 06 spawn, 280; 25/06; 35 Whelen and the like followed closely by the 275 Rigby, 257 Roberts and the 6.5 x 55.
My opinion the 6.5 creedmore is the most over rated cartridge, I’ve owned three and still have one for some reason, the 280AI the most under rated. Thankfully we can own and use them all if we want.
 

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How will factory ammo shoot with a big jump?
Factory ammo already has a big jump, this would add to it. If you build a 300WM like this, you are using longer heavier higher BC bullets so jump is minimal. I shoot lighter weight bullets in couple rifles that are maxed out for jump to magazine and shoot fine.

If you are going to shoot factory ammo, you can still go this route but reduce freebore to gain best performance from factory offerings. A reamer can do quite a bit for even factory ammo.
 
I doubt they’ll go away for a long time, but in my specific niche of the shooting world they’re nearly dead already. I’d estimate belted magnums represent 1-2% of the center fire rifles I see in use.
 
Factory ammo already has a big jump, this would add to it. If you build a 300WM like this, you are using longer heavier higher BC bullets so jump is minimal. I shoot lighter weight bullets in couple rifles that are maxed out for jump to magazine and shoot fine.

If you are going to shoot factory ammo, you can still go this route but reduce freebore to gain best performance from factory offerings. A reamer can do quite a bit for even factory ammo.
If you reduce freebore for factory options - you're no longer set up for long bullets.
 
The belt is there for headspace on the original belted magnums that had little shoulder. Not really needed on the modern belted magnums that should headspace on the shoulder.
 
I don't think 300WM will ever go away, more likely some of the PRC cartridges will fail, just as the short magnum craze faded.

H&H, another matter. .375 will be around for a long time due to the Africa buffs. .300 is a different matter. I finally have enough brass to last me and the one I'm passing it on to for our lifetimes, but eventually I think that will go away.

Let's face it, it's rare to see a rifle with a nice walnut stock, much less a classic caliber.
I'm trying. Here is my first rifle. I bought it at Kmart when I was 13 and just had it refit with a new stock and a fast twist Kreiger. -7mm Remington Magnum!
 

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I'm trying. Here is my first rifle. I bought it at Kmart when I was 13 and just had it refit with a new stock and a fast twist Kreiger. -7mm Remington Magnum!
I have no clue what the "bought it at Kmart" stock looked like, but you made a great choice on the new look.

I wish .350 Rem Mag and .257 Wby Mag brass were cheaper and easier to find.
 
How will factory ammo shoot with a big jump?
I think its rifle/load/shooter dependant. The 300wm SenderoSFII rifles (sample size of two) I have shoot little 139gr Evo's all the way up to 215 Bergers with the same accuracy. Obviously it's going to be a different POI but both rounds are grouping .75" or better.
139EVO
3.3195 COAL
2.609 CBTO (OGIVE INSIDE NECK)
3370fps

215BERGER
3.596 COAL
2.718 CBTO
2942fps
20250527_204707.jpg
 
If you reduce freebore for factory options - you're no longer set up for long bullets.
I erroneously assumed not reloading and trying to max factory ammo performance.

The age old problem deciding on chamber dimensions is what bullets are you intending to shoot the most? I've never really had any issues with big jumps. Ever shoot a 55gr in .243? The jump can be measured with tape measure! Still accurate. A 150gr in 300WM jumps a mile.

Me? I believe the 300WM is best with 180gr plus to max its potential. I like ~200gr type bullet best. Though a 181grHH @3300 is hard to ignore.
 
I have sold two of my magnums...a Winchester Super Grade stainless in .264 Win. mag, and a Weatherby Mark V Sporter in .300 Wby. mag. I still have my Remington LSS in 7mm Rem. mag, and my Weatherby Lazermark in .257 Wby. mag. Those two aren't going anywhere. I have sold several of my standard calibers as well. Recoil really doesn't bother me, and I have always shot magnums as well as any other.
 
I have a Seekins PH2 in 7mm Rem Mag that is my favorite rifle to shoot. Does everything I need it to and then some. Second favorite is my dad's .264 win mag Winchester Model 70 Sporter with the original wood stock on it. Sure the recoil is noticeable and more than my .308 but usually if I do my part the rifle checks all the boxes for me. I use a brake for the 7mm just because it came threaded and it makes the recoil like that of my son's .243. I can use either one for whitetail and I took my 7mm to Colorado last year for elk.

They will always try to develop new cartridges to increase performance of ballistics/shooting. They do the same with cars, computers, so on and so forth. Is there something wrong with the old cartridges, sure there are probably some. Are there issues with the new ones, sure there is. You just have to pick the ones you want to deal with. Me personally I'm not all about going out and getting all these new cartridges because #1 they are new and the kinks will need to be worked out just like anything else and #2 if the cartridges I use now work for me, why change it? I don't own one but just ask any World War 2 veteran or someone born during that what the best rifle caliber is and most will go with the trusty 30-06 or 30-30. The other thing is some people choose to harvest animals at ranges that some may agree with and some others strongly disagree with which is a whole other discussion, so here we are with new faster, flatter shooting cartridges.
 

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