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After FL Sizing - Cartridge is VERY Tight - Please help

2K views 23 replies 7 participants last post by  Don Fischer 
#1 ·
Loading for a buddy's 7MMRem Mag. After sizing, the cartridge is very tight. You have to force the bolt down, in most cases. The same FL Sized cases fit fine in my 7mm. Factory ammo and new brass chamber perfect....but I have never had this problem in his rifle. I have been loading for about 8 years, so I'm not as seasoned as most hand loaders. Does this make any sense? Thanks to all.
 
#3 ·
Hey Mak, thanks much for your reply. They are trimmed, not a full .010" though. Factory new brass works fine. 7MM max length is 2.500", I trimmed to about 2.493". My buddy's rifle is an older S&W Model 1500, mine is a Sako Finlight (much newer) and my loads chamber smooth as silk. I just can't understand it. Thinking about screwing the die down another 1/8 turn?
 
#13 ·
I got an idea there's your answer. Sounds like you set your sizing die for your own rifle using partial sizing. Often the same die will do just as your saying, your rubbing the shoulder. Screw the die all the way down to the shell holder and size one and see if it works. Set properly to factory spec's you shouldn't gain a thing by turning down another 1/8 turn.
 
#9 ·
I'd bet the problem is in the re-size operation. The case shoulder isn't being set-back enough. While the 7mm Mag headspaces on the case belt, it still has a case shoulder, and when it is fired - and the case expands to seal the breach - the shoulder is likely expanded forward. It needs to be re-set to chamber again, especially in another rifle.

As to 'why the cases chamber easy in YOUR rifle and you have to force the bolt in HIS rifle'? The answer is that your chambers are not identical. Firearms are like finger prints - each one is slightly different from the others. Yours might have a wee-bit more tolerance than his.
 
#10 ·
Jim...I think that you're on to something...I'm not sure what you mean when you say
"It needs to be re-set to chamber again, especially in another rifle"

Your suggestions here are valuable ! What should be my next step?
I'm very careful to measure the throats to get a good bullet seating depth, but the loaded bullet isn't the case here. I'm chambering just brass this morning.
I'm in the process of taking my sizing di apart and starting all over, but I'm a bit pessimistic.
 
#12 ·
My first question is did you use a Sharpie as a spotting compound and find where the interference is rather than guessing? Color the shoulder, a few places along the case body down to the belt and try it. Something should show up.

Obviously a fella can only screw a die in so far. With your shell holder in the ram screw the die down until it touches the shell holder. USUALLY you can get up to another 1/4 turn in, pick up just a few thousandths more when the ram overcenters and sometimes that's enough. That's reloading 101.
 
#15 ·
Just touch's and then back off the ran and another 1/4 turn. After the ammo has been fired in the rifle it's for then partial size. Before partial sizing, neck size and let it push the shoulder out to where you can't close the bolt without difficulty. At that point then size the czse down 1/8 to 1/4 turn until the case chamber's easily. You'll in efect move the head space to the shoulder. I'm not sure about the newer Magnun rifles but the S$W 1500 is an older one and the chambers can be pretty sloppy. That's why the were/are prone to head desperation after just a few reload's. Cure is to move the shoulder forward for min stretch there. Your rifle is nothing to judge whats happening by, the 1500 is a whole new game, any other rifle in 7mm mag regardless of make, is a whole new game unless you FL size. In that case, after relatively few reloading's you'll likely notice a bright ring around the case in front of the belt, that's case head separation in later stage's.
 
#16 ·
Hey Don...That's exactly what I am seeing...a bright ring around the case in front of the belt.
So, if I understand:
1. Set the sizing die to a level where it just touches the shell holder (at the top of the stroke)
2. Keep FL sizing the case (in 1/4 turns) until it chambers without difficulty
 
#18 ·
Yes, the rifle has a sloppy chamber. I would start over with fresh brass
First time loading, neck size only. That is only size the brass minimal looking at the case neck for the die mark, you will be able to see it. One more firing, maybe two and the case won't chamber, it then need the shoulder set back. Move the FL die down about 1/8th turn at a time and after each, try it in the chamber. It will get to where it will close but you'll still feel the shoulder rub. Lot of guy's stop there and doesn't hurt anything. But I like hunting ammo to feed freely so at that point I keep going down until I can no longer feel the shoulder.

What it sound's liken is happening to you is the case is expanding to the shoulder, as it should but the chamber is sloppy and the case is expanding to far. The firing is pulling the case from right in front of the belt and that is now the weak spot with the case's, keep shooting and they will separate. Best that you lock that die in place with the lock ring when your done and dedicate it to that rifle. I think you said it was a friends rifle? Have him get you a new FL die and use the new one on your rifle and the one you have on his.
 
#17 ·
That shiny spot above the belt can cause so many handloaders to lose their mind lol. There's no getting rid of that. That's where the case is no longer being touched by the sizing die, nothing more. That can cause people to think the cases are bulged, a head separation is going to happen on the next firing, that's why the case won't chamber properly......you get the picture. The truth is, that part of the case is so thick that if you're actually bulging the case there, you've got some serious pressure or chamber issues.
 
#19 ·
The 5 belted magnums I load. 7 rem mag, 308 Norma mag, 300 win mag, 338 win mag and 416 Taylor. As the picture shows, each case shows a shiny ring just above the belt. It's not caused from a sloppy chamber, nor is a head separation in the near future. The cases aren't hard to chamber. It's simply because the sizing die doesn't touch there.
Ammunition Bullet Gun accessory Brass Metal
 
#20 ·
Don and Slayer...Thanks for staying with me on this!!
So...I started with fresh brass and after the first firing, the brass became "junk" for this rifle.

I'm sorry, I don't understand how to just neck size the case.. Unless I use a Neck Sizing die?
Also, when you say "Move the FL die down about 1/8th turn at a time and after each, try it in the chamber. It will get to where it will close but you'll still feel the shoulder rub"

Move it down from "just touching the shell holder"...I guess I can only turn the die down 1/4 to 1/2 turn the most?...The travel in the loader will just stop...?
 
#21 ·
What kind of rifle are you dealing with?

Will a case that's just been fired from the rifle chamber easily?

I bought a 7 Rem mag that I rebarreled to 416 Taylor. I shot it a few times before the barrel swap. No matter how I sized those cases, they were extremely difficult. The conclusion I came to was that the chamber was too tight. I broke out my dremel and some polishing compound and polished the chamber. There was no more difficulty chambering the rounds.
 
#22 ·
The rifle that I'm struggling with is a 1980's S & W Model 1500...don't think S & W has made rifle since...I don't think my buddy has been too careful bout caring for it, so I kind of " adopted" it as a project. I have never been so frustrated!! I wonder if the chamber is the problem. I have just positioned the sizing die DOWN closer to the shell holder, and ran a cartridge through, almost to the point of breaking the press...and the cartridge seem to chamber better...or maybe it's just wishful thinking....all of the cases chamber in my Sako perfectly.
 
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