Originally posted by Xargos
Thank you Capt. I'm trying to remember if I've ever leaned mine hot, that seems very probable and I won't do that again.
I really liked the 300 Winchester Magnum, but was turned off by the increasing changes in accuracy. Now I'm thinking about getting another one since you seemed to have explained so many thing that may have happened. I'm older now and tend to take better care of my things.
P.S. Capt. Could the type of powder you use in your reloads have an effect on barrel life? What type of powder do you use in your 300 Winchester Mag rounds and how much? Do you know how many C.U.P.s it produces?
It is possible that the wrong type of powder could cause erosion issues and other problems.
I've been using IMR 4350 powder for years. IMR was recently purchased by Hogdon. I've begun to do some experimenting with slightly different powders. I used to use 4350 because it worked well in all of my rifles, and those of my friends and family. For the same reason I used WW 296 for my handgun loads, because it worked in all of our large caliber handguns. These days there may be around a 1/2 dozen different powders in my cabinet.
The amount of powder needed varies greatly. Barrel length, chamber depth, overall cartridge length, and the condition of the barrel can all change the pressure and as such the amount of powder. As my load is a near max load from an OLD manual (I've been shooting the same load for decades) I don't tell people exactly what it is, for liability reasons among others. I'm sure my pressure is at or near the top, and in a different rifle could be a proof load levels.
Get yourself a couple of good reloading manuals and work up your loads according to their instructions. Hogdon has a good manual, as does Sierra. What you find is that for example a Sierra manual will only have data for their bullets, and until this year a Hogdon manual only had data for their powders. This year, Hogdon started listing powders that they test and distribute, however the new manual has fewer cartridges in it. I don't have a copy of the new one, mine is a few years old. But you need to get at least a couple of manuals, and read them thoroughly and carefully. Learn all of the signs of excessive pressure, and of other problems. Then carefully work up your loads, remembering that you may reach excessive pressure before you get to their max load, or maybe not until after. Barrels are like people, no two are exactly alike, so no two exhibit the same attributes.
A few tips on the 300 Winchester. The 300 Winchester can be extremely accurate as witnessed by its current use as a mid range sniper rifle and competition rifle by the army. Given the case dimensions, especially the short neck, it should not be as accurate as it is, but it is.
First, get a rifle with a GOOD 26" barrel. If you don't have 26" to work with, forget a 300 Winchester, you're wasting powder making muzzle blast and flash. You want at least a medium taper barrel, not a slim sporter. And 1-10 twist. It IS worth it to by a used rifle and send it to E.R. Shaw and have them put a nice match barrel on it, as well as their other tricks and tweaks. They can take any 30-06 bolt action of good quality and rebarrel it with a nice match barrel as well as do their action magic for under $300. There is a back log of about 4 months. But it is the best budget approach to having a super nice shooting 300 Winchester. If you bought a used Model 70 for $300 or so, and had E.R. Shaw do their thing, you'd be at or under $600, for a better rifle than you can buy for $750. On my Model 70 rifles I adjust my own triggers for release and travel. But I learned how to do it over time.
Fireform your cases to YOUR Rifle, and from then on, DO NOT full length resize, neck size ONLY, and use thme in your rifle only. The 300 Winchester has a short neck, it is less than one full caliber in length. So getting the neck sized correctly is critical, and full length sizing is wasting time and effort, and hardening your brass.
Use a powder that fills the case for your selected power level, so that powder is uniformly distributed. The 300 Winchester is a hot high pressure round, and it likes to be pushed, it does not do well loaded down, so work your way up to something fairly hot that shoots well.
Clean the flash holes and primer pockets, religiously. Measure the case thickness at the neck and beware any changes.
Experiment with seating depth of the bullet. Different chambers are different lengths, you need to find the right length for YOUR gun. Watch carefully for pressure when varying over all length, as length, and how close the bullet is to engaging the rifling WILL change pressure.
Competition dies DO make a difference. RCBS dies are nice, Saeco Redding is even better. When seating bullets and taper crimping the case neck, rotate the case 90 degrees 2-3 times to make sure you have a concentric taper crimp.
That should give you a good start.
