powder for 308 auto (Win 100)

goose

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Dec 26, 2008
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I've decided to see what I can do with my grandfather's Winchester model 100 in 308. Like many, we have had reliability problems with factory ammo. One loading manual said to stick to medium burn rate powders and not to go too fast or slow. I will be shooting lighter bullets, 125 and 150 mostly for varmints and targets.

I gave it a good cleaning and brushed out the chamber which helped the failure to extract cases, and think a stiffer magazine spring would help failure to load the last round in the magazine. Should I crimp the bullets when using standard sizing die? I will start with standard sizing dies, and maybe go to a small base die if required.

I don't have much of medium to fast burning powder on hand, I'm thinking of getting some W748, H4895 or reloader 15. The 4895 might be good for the 45-70 as well.
 
For an all round powder for the 308 I really like IMR 4895. 46 grs with 125 Nosler BT is a tack driver in my bolt rifle and a deer killer. 43 grs with 150s is also a tack driver. You may solve some of your problems by just going straight to the small base dies and really FL size them. I know this solved a many a trouble with Rem. 742 rifles. I have found that in many cases the Lee Factory Crimp Die improves accuracy and you don't need bullets with crimp grooves to use it. Just leave your cases 5 thousands longer than the trim to length so you have enough case to get a bite on.
 
I wouldn't recommend win ball powders like 748 with 125-150grn pills RE15 is your best bet for speed and accuracy. If not that I'd go for Varget or Imr4064 they will be very accurate as well just not as fast.
 
Thanks, I've got some 4064 to get started. Any more thoughts on weather to crimp or not?
 
If you've got adequate neck tension you won't need to crimp, even for semi-autos. Might be worth trying the Lee FC die, simply because it's a variable. The recommendation to take a look at SB dies is worthwhile, too. They standard FL dies may do just fine, but you'll always want to FL size for an auto, and if there's an issue at that point, then try the SB dies.

Just remember that reloading for semi-autos is substantially more complicated than loading for a bolt gun, and you really do need to approach it diffrently. You need to consider and check things that would never have a bearing in reloading bolt guns, and that's just the nature of the beast. If you're not already using one, I'd also strongly suggest that you get yourself a headspace gage like the Wilson chamber type or something like an RCBS Precision Mic, and use it when setting your dies up to load for this rifle. You want ot allow for a shoulder bump of .003"-.005" with autos, not the .001" you'd use with bolt guns. Check your primers and make sure they're seated below flush in the case head, to ensure there's no slamfire issues. You get the idea.
 
You can try 38gr of tac,an a150gr anything, see what it likes,an pay attention to col an Have fun, SLOAN.....
 
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