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...

stubblejumper

To start with you have only tried a single bullet.Perhaps your gun simply does not like that bullet.Trying others could improve things dramatically.The same goes for the overall length.Try varying it to see if the accuracy changes.You might also find that other powders work better.In short you may simply need to try more variables until you find the right combination.I do hope that you are not mixing federal and remington brass as doing so certainly will not help accuracy.

Vapodog

exactly.....try different bullets.....such as Hornady interlocks and Speer's hot core

I'd also try some ballistic tips.

LITTLE MAGNUM

I would try H4831 powder, Nosler B.tip 150gr bullet, with your Federal 215. I would seat .010 of the rifling. I use a Lee crimp die with 1/2 turn crimp. This $8.00
crimp die is well worth it. Both IMR and Hodgdon 4831 are good go to powders for the 7mm mag. H4831 meters better then IMR 4831 through the powder measure.Seating bullets in a hunting rifle on the Rifling is asking for problem with max loads. You don't need a case getting stuck in the chamber from high pressure in the woods. I have great results in my 7mm rem mag with nosler 150gr B.tips....hope that helps.

Solitary Man

You've been given some good advice. Definitely try some different bullets and powders. I've had good success with IMR 4831 and 7828. H4831 has worked pretty well too. The 150 gr. Nosler ballistic tip has been superbly accurate in my rifle and so has the 140 gr. Barnes TSX. Currently I'm loading the 160 gr. Nosler Accubond and it shows promise too.

If I were you I would NOT seat the bullets out to where they jam into the rifling when you chamber a round. You need to measure the actual distance to the rifling and then seat the bullet at least .010" less and really, .030" would be my preference.To measure the distance to the rifling take a fired case and very lightly squeeze the neck with a pair of pliers, just enough to lightly hold a bullet in place.Now, takea bullet and place it into the empty caseabout 1/8" or so and then chamber this round. As you chamber it, the bullet will contact the rifling and will be pushed back into the case.Carefully extract it and then measure the length. This will be the OAL to the lands.Take another 8 or 10 bullets from the same exact batch and do the same thing with them. After you've measured the length of these dummy rounds you can arrive at an average, which will be a more reliablefigure than just measuring one or two.Subtract .030" or so from that figure and this will give you the OAL you should start with. If you're using Barnes bullets you need to subtract .050". Keep in mind that any time you change bullets you'll need to recalculate the OAL since different types of bullets will not measure the same distance to the lands.

eldeguello

RE 19 and 4350 are both too fast for optimim results in the 7mm Mag. You reach max pressures with these before your loading density is high enough for the most consistent ignition.

You should try IMR 7828, Re 22, Norma MRP,H4831, or other powders with comparable (slow) burning ratesfor best results.

shawn_st

Excellent advice from all- If you think of anything else, let me know. Thanks Solitary Man for the OAL measuring procedure, I've always wondered how to do that...

One more thing; I use an RCBS 2-die set and a #4 shell holder/extractor. I've been neck only sizing the brass (I think). When I set the die so that the shell holder comes in contact with the bottom of the resizing die, the shoulder of the case will dimple. So I have had to back outthe die so that the neck is the only thing thatgets resized at the top of the press handle stroke, but the die does not come in contact with the shell holder. Is this right?Sometimes when I extract the cases from the sizing die, the rim of the seat will bend down slightly, like it's having to much friction when being pulled back out. I've tried playing with the amount of case lube, but nothing seems to help. I'm a mess...

Solitary Man

You're quite welcome. There are other methods for measuring OAL to the rifling, but the one I described above is the one I've settled on and it seems to work okay. There are also tools you can buy for this purpose, but I haven't seen a need to buy one.

I don't know if I can answer your other question. I don't useconventional full length dies.If you're satisfied you're using enough lube on the cases (outside and insidethe neck)then maybe the die itself is at fault.The interior surface of the die could berough and in needof polishing if the cases arethat hard to extract. Hopefully someoneelse can offer some better advice on this.

Solitary Man

I just thought of something: if you're seeing dents in the caseshoulder when you try to full length size then you may have a buildup of lube inside the die. Make sure you clean out the die, especially in the area where it contacts the shoulder.

dvdegeorge

All good advice,but don't over look the rifle itself,you may have a bedding issue.As for a load H4831sc,Federal 215 M primer and 154gr. Hornady interlock SP bullets.