Off-season project - 7mm Rem Mag

[perma]

On the other hand, I think I found the issue. When I was loading a new set tonight, I found that the rim of the shell where the bullet seats seemed to be kind of rolled. I’m thinking the ribs on the Barnes are causing that, so maybe it’s loosening the bullet somehow when I seat it. If this doesn’t work out, I’m switching bullets.

 

[RevJim]

If you had chamfered the inside case mouth ( a one time deal way back) that should not be happening. Barnes are like match bullets, if any bullet is going to shoot, they have about at 95% of shooting well. Sometimes your "group" is as tight as its going to get until you seat your bullet further out. I have never had to run a Barnes more than 100 thousandths off the lands. 50-70 thou is more common than 20 thousandths off. I used IMR 4350 with the 150 Nosler when I had a 7mm RM.

 

[RevJim]

Could it be that you have your die screwed so far down that you are putting a "crimp" on the case's mouth? I run a trimmed MT case to the top of the ram stroke. I screw my FL die down until it "touched" the crimp shoulder. I then just unscrew it a half turn. That allows them to grow to trim length. If you have some cases that are longer than others, the degree of crimp is inconsistent and definitely will cause accuracy problems.

 

[perma]

Could it be that you have your die screwed so far down that you are putting a "crimp" on the case's mouth? I run a trimmed MT case to the top of the ram stroke. I screw my FL die down until it "touched" the crimp shoulder. I then just unscrew it a half turn. That allows them to grow to trim length. If you have some cases that are longer than others, the degree of crimp is inconsistent and definitely will cause accuracy problems.

I backed my die about a turn out before I tightened it to the bushing so I don’t think it’s that. I can probably do another turn but I’m pretty sure the neck is just tight.

 

[RevJim]

You bet, a full turn should be way plenty. I hope you get it sorted out, have some fun while your at it!

 

[perma]

The triple shocks came through!

I made too many changes to the process so I’m not sure what fixed it. My guess is retorquing my screws or cleaning the gun. I changed the brass too but I doubt that’s what fixed it.

Also learned that 0.5g of powder made small differences in the ladder test at 100 yards. Had one flyer because I flinched for some stupid reason, but I have a recipe that I’ll load a few rounds with, or maybe stretch the seat a bit. Upper right is 64.5g. Truth be told, I probably flinched a bit or the wind took the stand for a ride.

 

[RevJim]

That looks wonderful! Stop and consider that very few can hold right/shoot well any magnum off the bench! That's alot of blast, boot n beller going on each time that trigger is pulled. You are doing Jim Dandy my friend!

 

[Sheltowee]

The triple shocks came through!

I made too many changes to the process so I’m not sure what fixed it. My guess is retorquing my screws or cleaning the gun. I changed the brass too but I doubt that’s what fixed it.

Also learned that 0.5g of powder made small differences in the ladder test at 100 yards. Had one flyer because I flinched for some stupid reason, but I have a recipe that I’ll load a few rounds with, or maybe stretch the seat a bit. Upper right is 64.5g. Truth be told, I probably flinched a bit or the wind took the stand for a ride.

View attachment 317477

And accomplishing that with a notoriously finnicky projectile. WTG man.

 

[std7mag]

If you had chamfered the inside case mouth ( a one time deal way back) that should not be happening. Barnes are like match bullets, if any bullet is going to shoot, they have about at 95% of shooting well. Sometimes your "group" is as tight as its going to get until you seat your bullet further out. I have never had to run a Barnes more than 100 thousandths off the lands. 50-70 thou is more common than 20 thousandths off. I used IMR 4350 with the 150 Nosler when I had a 7mm RM.

Chamfering is a "one time deal" until you trim.

Barnes manual states to START at 0.050" off the lands.

Die manuals suggest to tighten the die 1 turn past touch. Not loosen. (Full length sizer)
If you loosen your full length sizing die by 1 turn after touch, you are essentially turning it into a neck sizing die.
I know, shoulder bump. Yada yada yada....
But @perma is not there yet. Let him get some experience under his belt before we go on from there!
At his stage, the KISS rule applies.
(Keep It Simple, Stupid)
I still follow that rule.

And holding a casing in a candle flame until you burn your fingers the dropping it into a damp towel is doing nothing but burning your fingers.
It takes 600-800°f to anneal brass.
Believe me when I say your NOT holding on to a casing at 600°f!!!

 

[perma]

Well something’s wrong but idk what yet. I decided to take the 7 mag out to a 300 yard range. Made sure my 0 was good at 100, spot on. Next few shots at 300 didn’t hit, were too high. To my idiocy, I assumed my FPS based on how much powder I have in each cartridge. Every shot seemed high on my gong. I dropped it down quite a bit and still didn’t hit it. Maybe I was a bad shot that day but I was whiffing.

Time for a chronograph….

 

[RevJim]

Chamfering is a "one time deal" until you trim.

Barnes manual states to START at 0.050" off the lands.

Die manuals suggest to tighten the die 1 turn past touch. Not loosen. (Full length sizer)
If you loosen your full length sizing die by 1 turn after touch, you are essentially turning it into a neck sizing die.
I know, shoulder bump. Yada yada yada....
But @perma is not there yet. Let him get some experience under his belt before we go on from there!
At his stage, the KISS rule applies.
(Keep It Simple, Stupid)
I still follow that rule.

And holding a casing in a candle flame until you burn your fingers the dropping it into a damp towel is doing nothing but burning your fingers.
It takes 600-800°f to anneal brass.
Believe me when I say your NOT holding on to a casing at 600°f!!!

I thought that was a good way to anneal? I suppose not. I have never seriously done it anyhow, but the "annealing Machines", etc are pretty expensive. My othe rSmith friend is planning on buying a set-up, think I'll let anneal all my fired brass for me, ha. I was just passing on to Perma that Charlie Sisk article about annealing his 7mm RM brass "before" load workup". He claimed it tightened his groups significantly.

 

[Deer$layer]

Seems like every year I trade in a gun and get a new one. I've shot a lot of guns in my life and some were better than others, but I really wanted to find a 'perfect' gun. Or maybe I just am bored and want to build up a new gun.

I had a 300 Weatherby that I really like. Only issue I have is getting ammo without having it shipped to me. I thought my custom 30-06 was it, but I wanted more juice.

After mowing over the idea for a few months, I think I have found the solution that fits me. When I first started, my first two guns were a .270 and a 7 mag. Both are great cartridges, and while my favorite is the .270, I opted for the 7 mag, almost from scratch.

Pieces I'm putting together:
Weatherby Vanguard Sportsman's Edition. Picked it because it's fluted (I like the way it looked), 2" shorter than the standard mag barrel length and it's cerakoted. I will remove the weird paint job on the floor plate and find someone that can put a custom paint job on it. I'm a Weatherby frog, I know.
Stockey Stocks M50 carbon fiber stock. It's a raw stock with sponge paint. I will clear coat it after I'm done cleaning it. It came from my first build. Has the upgraded limbsaver recoil pad.
Timney trigger. Nuff said.
Vortex Viper 4x16x50 HSLR. It's been a reliable scope for me. I may swap this and put it on my 300 WBY and replace it with a Leica or Zeiss. Or do nothing. Bubble level and switch lever installed
Warne rings and pic rails. Had good luck with them and Talley, so I'll just reuse them.
Haven't decided on the rifle sling yet, but probably something narrow and rubbery that prevents slip. I have a Quake but it's not my favorite.
Debating on a muzzle break but would prefer not to use one if I don't need to. I'll have to field test it all once it's bedded.
Wayne's Dog cheek rise. Dont ask, I found it on amazon and it seemed to fit the bill. The inserts it came with dont fit the stock, so I put scope lens rags underneath to raise it.

Love the tried and true 7 mag! That should be a solid setup when it’s done. Zeiss optics all the way!

 

[std7mag]

I thought that was a good way to anneal? I suppose not. I have never seriously done it anyhow, but the "annealing Machines", etc are pretty expensive. My othe rSmith friend is planning on buying a set-up, think I'll let anneal all my fired brass for me, ha. I was just passing on to Perma that Charlie Sisk article about annealing his 7mm RM brass "before" load workup". He claimed it tightened his groups significantly.

If you put a deep 1/4" drive socket on an adapter for a cordless drill, you can spin the case while you heat it with a propane torch.
Socket needs to be loose on the case.
Spin the case neck in the flame until it turns red.
Then tip the case over into a pan of water.

 

[Alpine01]

I thought that was a good way to anneal? I suppose not. I have never seriously done it anyhow, but the "annealing Machines", etc are pretty expensive. My othe rSmith friend is planning on buying a set-up, think I'll let anneal all my fired brass for me, ha. I was just passing on to Perma that Charlie Sisk article about annealing his 7mm RM brass "before" load workup". He claimed it tightened his groups significantly.

Suggest you watch this video on annealing.

 

[RevJim]

Seems like I read somewhere that if you heat it until its red its too hot, so brass becomes too soft? I know there is a "paint" for the neck/shoulder or something that will turn a different color at the "right temp"?. Ever use that? Midway lists a cartridge specific case holder you put in a drill and you can heat it with a torch.

 

[p_ham]

Seems like I read somewhere that if you heat it until its red its too hot, so brass becomes too soft? I know there is a "paint" for the neck/shoulder or something that will turn a different color at the "right temp"?. Ever use that? Midway lists a cartridge specific case holder you put in a drill and you can heat it with a torch.

Dull red. Low light conditions are best to gauge temp. Your heat zone should go just below the shoulder.

 

[Nick87]

Man, after thumbing some of these threads I'm regretting not reloading. Tons of info from helpful hunttalkers I feel like I'm wasting it by not using some of it to my advantage.

 

[perma]

Man, after thumbing some of these threads I'm regretting not reloading. Tons of info from helpful hunttalkers I feel like I'm wasting it by not using some of it to my advantage.

Welcome to my world.

 

[Jbotto]

Man, after thumbing some of these threads I'm regretting not reloading. Tons of info from helpful hunttalkers I feel like I'm wasting it by not using some of it to my advantage.

We can be helpful and enablers at the same time…. I’ve got a press I’d sell ya!

 

[Nick87]

We can be helpful and enablers at the same time…. I’ve got a press I’d sell ya!

Rockchucker?