Reloading 300 win mag

[tontotom]

I've never loaded any really long cartridges like the 300 win mag. In fact it's been a long time since I've had to reload anything.

 

My gun is a Winchester model 70 with the claw extractor 10-15 years old I think. I bought some accubond 150 grain to try and work up a load. Imagine my surprise when I tried to find the lands and couldn't seat the bullet out far enough to get it just off the lands and still have it secured in the neck. So I think I'll just have to work with it like this and built some test loads to take to the range.

 

When I tried to cycle them though the action to test they were way to long. What the heck? I have to seat them even deeper so they will fit the magazine. Anyone else have long freebore and short magazine? I think this might screw with accuracy.

 

This gun has been very accurate with 150 grain factory ammo so I compared my reloads with the factory and I am quite a bit longer than factory.

 

How deep must a 180 to 200 grain bullet sit in the case? I would think almost deeper than the neck length.

[Benbrown]

I have reloaded for a few post-64 classics, but have never encountered the problem you have described. Did you buy the rifle used? It might be worth doing a chamber cast to see what the dimensions really are. In Weatherbys, which have a lot of free-bore, I usually load for the longest OAL that will feed reliably from the magazine. That may be all that you can do here without setting the barrel back a thread or two and rechambering it. You probably should make the acquaintance of a good gunsmith who can help you sort this out...

[punxsutawn]

Actually, I have the same issue with a few of my rifles. I seat to max magazine length less .005" and don't have any accuracy issues once the load is developed. A pretty standard minimum seating depth is usually the caliber diameter... a 308 should be at least .308" deep. I had tried to load a 125 grain Nosler in my 300RSAUM and at magazine length, there was not enough purchase to keep the bullet from moving out of the case! I even tried a Lee factory crimp die and that did not help. Once I seated the bullet .308" , the problem went away. Also, just to make sure what works in my mind at least, I measured each round (and wrote that number on the round with a Sharpie) placed them in the magazine, fired a shot and then measured the rounds in the mag to see if the bullets moved foreward at all.

Hope that helps!

[.270]

how are you determining where the lands really are? if that's the case it sounds like a really screwed up chamber. if you determine that this is actually the case, take it to a gunsmith and have him move the barell shoulder forward a little and re-ream the chamber. i always paint the bullet in a few loaded rounds with a magic marker and see where the lands touch. they will scrape off a little of the ink. and then adjust from there. i have a rifle that sounds a lot like yours and it shot great, until i wore out the barrell. shoots even better now with a new schnieder. i shoot 165's. if you don't have enough bullet in the neck, you can have some real heartburn with bullets in the magazine coming out of the case. i'd do the magic marker deal and if you really have that much throat i'd have somebody measure it. you're gonna have some real problems with accuracy and getting loaded rounds to fit in the magazine if you have a throat that is that far outta spec. Lark.

[tontotom]

Thanks guys, I did buy the gun used. It really shoots well .8" at 100 yards with factory 150 grain federals.

 

I'm trying to find a better long range bullet than will shoot as good as possible. I measured my magazine length and it is 3.41". The overall cartridge length is 3.39".

 

I'm working up the loads right now. I have a big supply of 4350 powder so I'm hoping this will work with the combo but only the range will tell this weekend depending on the wind and rain.

 

I have a lot of time before next season.

 

My expectation is to have a 600 yard MOA gun. I shot a 300 yard group just over 4" a couple of weeks ago so hopefully I can improve on that.

 

Lark, what kind of load did you work up with you new barrel?

[.270]

i use h4831sc hogdon powder. loads a lot easier than 4831. i use hornady 165 gr btsp interlocks going 3250 fps. i don't give anybody but family powder grains because i use a lotta powder and don't want somebody using my load and having problems because of it. you'll hafta figure that out. when my kids bought me this new scope it was set up for 3250 fps so i actually had to drop my loads a little. i was spittin' em out at about 3350. there are bullets with better BC's and stuff, but i've always used the hornadys, i have never had one come apart and they have always been very accurate. my son can shoot inside an inch at 300 yards with it. you can't do much better than that. with my old eyes, wore out body and new shoulder i wobble a little after a dozen or so rounds so i get my kids to do the fine tunin'. the guy that did the barrel gave me a break in procedure and i followed it to the letter. don't know how much it had to do with it, but this is one shootin' sob. i tinkered with it in pig camp last weekend and smoked a rock less than a foot in diameter at 765 yards. just on the bypods on a camp table. no sand bags or other stuff that helps shoot better. i love it. if i would have known they were getting me this scope i might have had it set up for 180's but as it is it wouldn't make any difference. this thing is amazing. it oughta be illegal. heck, i can kill stuff so far away i hafta put salt on my bullets so the aminal don't spoil before i get to it. i still think there is something goofy with your throat. i think you may not be getting a good read on it. it can be kinda tricky to figure it out. good luck. Lark

[tontotom]

Thanks for the reply. Maybe I'm not doing it right?

 

I shot it today at 200 yards mostly to test the new loads and see if I was too hot. Turns out that the max load in my nosler book is fine in the gun with no signs of pressure. The group was 3" with 5 workup loads.

 

I'll keep working on this.

[.270]

it's been my experience that some guns are kinda tricky to figure out where the lands start. i can't imagine a rifle with a throat as long you say yours is that would hit with any kind of bullet. not saying it ain't so, it just seems odd. i'd find somebody who could get you a good measurement on it somehow, either with a borescope or just somebody that really knows what they're doing. there's a lotta stuff that can go on in that little area, and it's all real critiical to accuracy. that or just sell it and get a .270. good luck. Lark.

[DesertDiesel]

I use to load for 300 win (Tikka) My three favorite loads were:

 

 

Bullet; Powder; Velocity; Primer; 100 yrd group

180 Nosler Accubond H4350 x 66 gr 2890 CCI 200 0.359

165 Nosler Accubond H4350 x 69 gr 3010 WLRM 0.582

165 Nosler Accubond RL22 x 76.5 gr 3070 CCI 200 0.511

[roninflag]

the 300 win is one of themost forgiving easy to get accurate load for cartidges. only the .222 and 308 have i found easier. use your 4350 and either wlrm or cci 250 rpimers. try a 168 berger, 168 combined tech balistic tip or some 165 balistictip.