ORIGINAL: shawn_st
I'm fairly new to reloading and I need a good (excellent)recipe for my Winchester 7mm Rem Mag (26" Barrel). Any suggestions?
One problem I'm having is that the cheap, store bought, Remington "Core Lokt" shoots the lights out and I can't even come close to a reload that shoots as well. This off-the-shelf stuff will shoot a 1/2" group @ 100 yd (and that's good for my skill level) and it seems like I should be able to find a recipe that shoots at least as good. I've followed a few of the recommended loads but have had pretty bad results (2" group @ 100 yd).
I've been using the following materials:
- 160 gr Sierra spbt
- Reloader #19 or IMR 4350 powders
- Federal #215 primers
- Remmington and Federal once fired brass
- Overall length 3.26"
I've been restingthe bullet directly on the rifling. I know it because I have to work a little harder to close the bolt action. Remmington factory loads have an overall legth of 3.16", could this be a culprit? Also, the recipes I've followed are for a 24" barrel and I have a 26" barrel, could this affect things? Any help would be appreciated...
Hello Shawn. Part 1. You have many things going on here and I need more info to help you. First, why are you loading such heavy bullets? Are you Elk hunting? Second, what grain bullet are the factory shells you shot such good groups with? Third, the reason you are having problems closing the bolt is not because you are jamming the bullet into the lands. The reason here is that a 7 Mag is a powerful belted magnum that requires full resizing after each shooting. The shoulders of your brass is being restricted in the chamber. Then the brass must be trimmed to 2.490. Try this with an empty and see how easy they chamber. My guess is that your OAL of 3.26 is not into the lands although that would explain the wild groups to some extent.
Part 2. My experience of 40 odd years monkeying with the big 7 has been filled with a mix of the agony of defeat and the thrill of victory. It wasn't until I became a serious reloader that the mystery was revealed. First, the 140 gr bullet is king in the big 7. When you consider the extremely long bullets available ie the Nosler Accubonds and BT's, these bullets are extremely accurate and efficient. The problem is when you get in the heavier bullets, they get so long and have to be seated so deep as to keep the bullet off the lands, they will not stabalize in many rifles. You are also in most cases compressing the powder which is not good for most powders. Second, you need an OAL gague. They are cheap and they take all the guesswork out of the equation.
Part 3. The OAL with a 140 gr Nosler BT is 3.370 in my Tikka. I have found this rifles likes to jump a bit and seat the bullet 45 thousandths off the lands which equates to an OAL of 3.325.I have used nearly every powder and bullet combination in the books and have settled on one. I use 70gr RL22 and push the bullet at 3160'/sec. Groups are very consistent 1/2 inch at 100, 1 3/4 at 200 and 3 1/4 at 400 yards. This is a deer load. If you want to hunt Elk, just stick a new accubond in there and you are set. The 140 gr Game Kings should work just as good....maybe better. I go with the Noslers as they have a better BC and I need a 400 yard gun. If you aren't shooting super long distances, the 140gr Sierra Pro Hunter is also a great bullet.
Part4. Safety. Never jam a bullet into the lands....very dangerous chamber pressures will happen. Don't compress the powder unless the receipe says it's ok.
I hope this helps you and wish you good luck with your rifle. Regards, Rick.