long neck 300 win mag

[old fart]

old fart here - talking to a fellow today thats shooting a long necked 300 win mag - 8mm rem mag case necked down to 300 . thought I saw this cartridge on one of these threads but did a search and found nothing - I know u guys have messed with this combo - any body tell me more? curiosity ,just trying to learn . he told me the long neck gave better support of the bullet and allowed him to seat the bullet out which also gave more room for powder. seemed quite pleased with the cartridge . seems to me theres alot of things that will do the same thing , without forming brass . any comments on this - thanks

 

[a.JR]

Old F,I shoot a 300 winmag improved in h/gun bench...Good results so far ...The effort for me was to reduce the original case capacity and get a long neck...Specs are case length 2.590,neck length .340,shoulder angle 35deg,standard body taper...i get 3230 fps with a 187 BIB @ 77.3 gns of vv 560 from a 30 in barrel..JR..Jeff Rogers

 

[Austin]

I've tried the 30/8mm case combo and didn't notice that much improvement. It was a wildcat that required a lot of attention and the bbl life was pretty short. The 300WM DOES have the short neck which has been the focus of continued criticism in the past, but the critics have been unnecessarily hard on this point. I have 5 300WM's and they are all EXCELLENT performers! I seat the bullet WAY out there in my Weatherby and I still get sub MOA accuracy at 100yds with no problems. There is always a lot of hype about seating the bullet at least the diameter of the cal. you are loading, but I have NEVER in twelve years of reloading found this to be a problem in ANY caliber I have ever shot. I have a 7mm/.338 which I seat bullets only .190" into the neck and it is still a tack-driver. Just my .02....

TH

 

[JBM]

if you want a 300 Mag with longer neck, just get the .308 Norma Mag. One of my favorite 30 calibers and reasonably accurate (didn't it hold the 1000 yard world record at one time?). Factory ammo is available too.

 

[old fart]

guys - thanks for the input , am going to improve the rifles I have , and spend alot more time shooting and reloading - thanks again

 

[D'Arcy Echols]

Jeff
At this time I'm having Hugh Henriksen re-grind a Std 300 Win reamer with what appears to be the same specs as your 35 degree/300 Win. The re-grind will move the neck/shoulder location rearward enough to change the shoulder angle from 25 to 35 degrees with no other changes except the advantage of having the longer neck as a result of this modification. I gather re-forming the new shoulder with virgin brass is fairly trouble free. Do you use a 35 degree form die cut with the same reamer as a seperate first step?

 

[Brent]

D'Arcy,
I'm forming 338 Lapua brass down to 30 cal, but also pushing the shoulder/neck junction back to for the 40 deg shoulder, and a .405" neck length. This is done in the FL die with a .334" nk bushing alone and it works fine.

The only reason I fire form them with cream of wheat instead of seating a bullet and shooting it, is because it has a .335 nk and has to be turned first. COW forming first makes the neck walls perfect before turning/reaming with the K&M tool.

The original neck/shoulder junction is now up in the neck of the new formed case, so necks will be thicker at, and below this point until you do neck turn, so seating a bullet into this area or below might spell chamber clearance trouble, so it should be monitored closely to be safe.

No special dies to form the cases though, and I wouldn't think you'd need any on the 300 WM, a lot less forming on it than the 30/338 Lapua Imp.

 

[Guest]

I had a 30-338 that was sold due barrel burn out , the 338 win brass is actualy pretty accurate and consistant , just run it through the FL die and their you have it. It has a little less case capacity but I was able to run it up to and past the 300win.
I currently have a 300 Dakota chambered rifle that is an awsome round , good brass and no belt!!

 

[jb1000br]

a 308 bear sound like what you are looking at--it is a long neck 30 cal that can be made from the H&H's or the 300-340 WBY

the 8mag would give a little too much air space and give up a lot of efficieny to the 308 baer.

also Jeff Rogers shoots his special round which is a long neck 300Win.

JB

 

[a.JR]

D'Arcy,My first concideration in designing my "300 Redneck" was to reduce case capacity,but sadly it only lost 2 gns of water(holds 92gns full with Lapua Brass)..The minium amount of case reforming while getting the required case capacity is the best route...Yours will have more capacity than mine as the neck will be closer to 300 thou..I start forming by pushing the shoulder back with 2 diff dies i made with a 20 deg angle,these 2 dies are used because it's easier on the brass and a lot quicker to get a piece of brass to a shape that is right for competition(less firings) ...Then move the shouler just enough to the final shape with a chamber die to get a crush fit against the new shoulder..Make sure you build a chamber die(7/8x14) the same as the rifle chamber so you can bump the shoulders back as required aswell..Then fire form without a projectile,neck turn the 1st time to approx 1thou total clearance,then neck turn 2nd time to 2.2 thou..This is done with an neck I.D.of.307 thou and the 2.2 spec taken from the driving band dia which is between .0004 and .0005 over an even .308 ..If you are throwing your rounds around huntin and stuff i would suggest more neck tension,i run the minium i can get away with as this reduces the vertical dispersion for me..Hope this helps..JR..Jeff Rogers