Primers - magnum or not?

Is there any advantage in using a magnum primer in a 270 win? If using them how much do I need to lower the charge weight?

[4ked Horn]

What temperature conditions are you expecting to shoot in?

What type of powder do you use?

Right now I am using IMR 4350 but am thinking of switching to H4350 or 4831. Shoot in temp range of -30 C - +30 C. Most shooting done in +20 C weather.

[Lee in OH]

This was not a .270, but my experience may help you decide.

The cartridge used is a .264 Winchester Magnum. I began by using Magnum primers because I thought I needed to.

I decided to experiment with H50BMG powder to get the case more full and maintain safe pressure. I had a trip to the range planned and found I had no Magnum primers left. What the heck, I'll try the standard primers just to see if it goes off. I didn't note the temperature, but it was on Jan. 4th of this year and it was cold (in the mid 20's if I remember correctly). I just wanted to get some velocity measurements to see what the powder would do. I had loaded from 65.0 grains (83.8% capacity to base of neck) to 77.0 grains (100% capacity to base of neck, some compression by bullet boattail) in one grain increments. I fully expected the more dense loads not to go off.

Guess what, they all went off just fine. And there were no slouches in the velocity department. with a 140 grain naked SMK, 65 grains returned 2950 fps while 77 grains returned 3269 fps. Faster than I had expected. I'm going to try moly coated bullets as I want about 95% density to return 2950-3100 fps.

Long story short, I think you're probably just fine with standard primers. That's all I ever used in my .270 years ago and I never had a misfire in any weather. Will you get better groups with mag. primers??? The only way to know for sure is to try them.

[LDO]

i load alot of .270win [especially this winter,and its been cold]and havent had a misfire yet using standard primers.my buddy used them once but i saw no practical advantage when standards were working just fine.my-2-dave

[4ked Horn]

Hi again Harv.

I have to go strongly with the safety advice given above.

Also I would add that the Speer reloading manual reccomends that I use a mag primers with H335, BLC-2 and H380 but I use regular primers for .243, .223 and .308 win (all loaded with H335, my favorite) and I experience NO ignition problems. Even in 20 degree temps.

I have it from a source that satisfies my needs that federal primers are the hottest standard primers so that is what I use. Period.

Lastly I have heard (take it for what it is worth)that Mr Elmer Keith, the father of the .44 mag, did not believe that magnum primers were necessary at all for any (pistol?) round.

Thanks for all the posts guys. I have used, for many years, federal primers (not magnum) and was just wondering if the magnum primers would help accuracy. I have reloaded for the 270 for over 10 years and over 10000 rounds and had only 1 not fire. Primer didn't go off even after removing the primer and hitting it with a hammer. Will stick with the non mag primers. Thanks