Best dies for 7mm mag?

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BunnMan

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I'm ordering my new 7mm mag bolt gun today. Goind to Dick's to get a Tikka T3 Laminated stainless bolt gun on the way. Before ti arrives I'd like to have a good diet of handloads to feed it. The goal here is pinpoint accuracy for fun on the bench but I will also need to develop a good hunting load for medium sized (deer/elk) game by next fall. I plan on only neck sizing as it's a bolt gun, the first bolt gun I have loaded for yet. I do hear some horror stories about loading for 7mm mag, or any belted mag for that matter. Helo suggested in another forum to maybe bump the shoulder so the rifle head spaces off that instead of the belt. I know die choice is going to matter here. I read alot of positives on the Lee collet dies for neck sizing..good choice in 7mm? How would I set up dies to bump the shoulder per the suggestion? Special die for that? What's the most consisten seating die for this caliber? Should I also have a full length die on the bench even though I plan on siimpyl neck sizing?

Sorry to sound like such a noob...but I am :)

Thanks a ton folks!!

-BunnMan
 
My old Rem 7mm Mag has been a tack driver since day one with my reloads. Back in the 70's ammo was not near as good as it is today. Factory best was only 1MOA. This was the second caliber I learned how to reload in the 70s, FL sizing using RCBS dies. I purchased a neck sizer (RCBS, non bushing) this last year since this is only a hunting rifle. To do the bushing sizing right you need to turn your necks to get a even wall thickness, then pick your bushing. You will need to bump the shoulder back with a FL sizer every 3 firing, and anneal. Use the Imperial Sizing Wax here and save your self some problems. I only bump it back the bare min 0.002". Unless your shooting out past 300yrds your not going to see any difference. I like the 160gr BTSP Matchkings or 168gr BTHP Matchkings, these will shoot 1 ragged hole at 100 yrds. I don't have a place where I can shoot past 100 yrds anymore. My gun is zeroed in for 250yrds. I use the IMR 4350 at the upper end, Mag primer. You will find if you don't put good optics and mount on this caliber it will shake the internals loose on the cheap ones.
 
I load for 7mm RM mag. as well and even though I neck my brass, i still have to use a FL die between neckings to maintain shoulder position. If you don't bump the shoulders back when necessary, the shoulders will eventually prevent the brass from chambering.

I use a set of RCBS comp. dies and RCBS neck die. Keep your brass trimmied to length, shoulders properly bumped, and you'll get a good life span from your brass. I average from 12-15 reloads from my brass, but that will differ from chamber to chamber, and load types too.
 
Before ti arrives I'd like to have a good diet of handloads to feed it.
Click to expand...

This is bass-ackwards from how I've ever done it.

It's perfectly fine to go ahead and get some dies/components before the rifle gets to you. I'd personally start with a normal die set from any of the major manufacturers (Hornady usually being my poison of first choice), but if you want to get fancy pickup a seating die w/ a micrometer adjuster.

Grab some factory loads for it too... that way you have some sort of baseline for that rifle. Shoot the factory loads to get some empty cases. Pay attention to what it does and does not like. Maybe keep a notebook just for this rifle.

Have at least 2 up to date reloading books available to you (as in on your reloading bench) to cross-reference. Supplement these with the bullet and/or powder manufacturer's loading data first and random internet data last.

NOW you can get crazy with the cheez-wiz and different parameters... degree of case re-sizing, seating depth, primers (manufacturer and type), powder (manufacturer, type, charge weight), projectile (manufacturer, core/jacket material, weight, construction/configuration, tipped/non, homogenous/non, boat-tail vs flat base, ogive shape... ). and so on and on.

Luck! (probably really don't need that w/ a Tikka though... )
 
You can use your full legnth sizing die as a neck sizing die as well.
Set it up to size just enough to easily chamber a case in the rifle. Just slowly increase the ammount of sizing on a case till the bolt will close easily instead of full legnth sizing the case. This will help to extend the life of the case by not over working the brass.
Keep in mind that these cases will likely not chamber in a different rifle.
Have fun with your new toy.
T
 
I load on almost all Lee dies, accuracy has been good in all my gun. My prefered load for the 7mm is a 162gr amax over retumbo in necksized only cases.
 
You can use the FL set or get a neck sizer only. For at least 30 years I use a FL set to neck size with and had no problems . Just in last few years bought a neck sizer die (RCBS) that seems to work good also. I just neck size and keep an eye on the web of the case. I trim once and then I usually toss those cases if they need any more trimming. My pet load is a 160 gr. Accubond with 62.5 or 63. grns of IMR 7828 with Rem brass and Fed gold medal 215M primers. This load shot very well in several 7mm mags I've loaded it in and is nowhere near a max load. I've taken a least 55 or 60 whitetails with that load and all have been one shot kills. My friend has taken Caribou and Grizzilies also with one shot kills.
 
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Sky,

Outstanding results!! That's the prime purpose behind this purchase..well, that and I need to check into a clinic to get through the DT's if I don't buy a new firearm at least once a year, lol. Really though...I want a tack driver bolt gun to build for so I can develop a load that does THAT!! I only hope I can achieve a similar result in my work ups. What rifle and what rifling did you fire those groups through? I only have one bolt gun in the safe as it is, and old Enfield .303 that went through a poor sporterizing/cut down job at the hands of the previous owner. I picked it up for next to nothing with an old Lyman American peg scope. The stock is awful but the action is sound, it groups OK considering it only has two lands 180deg apart for rifling..probably 2-3 MOA. I grab it when I'm going somewhere I don't want to take anything else...lol.


Null,

You outlined my plan almost to the "T". Thanks for the run down...allows me to confirm my reasoning. I will probably have a box or so of factory loads to establish a benchmark as you suggest but mostly prefer to roll my own. Not that I'm any better at building ammo than the big boys, I just enjoy the hell out of the whole process. Typically when I'm doing work ups I'll build in 5 charge levels depending on the difference between starting and NE. I have gone 6 on occasion when dead reasoning said the steps were to big and the magic number might lay between the 5. I usually build 10 rounds in each stage, fire two 5 shot groups, and take the best one of the two as the representative performance for that step. My thought is 5 rounds gets me away from simply "getting lucky" and two groups rescues me from myself if I happen to pull one due to going cross eyed staring in the scope too long, getting excited and rushing the result because my group is shaping up good and firing on a hot barrel, of course all my trigger presses are rock solid so I would never flinch and pull one...:uhoh: I usually take me some time to meter through the 50 round in a given work up allowing a minute or two between shots so I figured maybe I might burn the candle at both ends and do a littlle combo of load research and barrel break in if I had some handloads worked up for her arrival.

Unfortunately though...the folks at Dick's F'd me! I called them as soon as they openned to get a price on the model in my OP. They quoted me a number AND an avaiblility of about a week. I show up to buy the thing and get it on order and now they can't find it in their catalogue. I went through the whole song and dance with the counter rep...who left out that he was the same guy I talked to in the morning. Then I asked for the manager and the counter guy disappeared, the manager is the one who told me I had talked to that guy earlier. Now they're saying they don't know what he was looking at or where he got the price from and that they can't even get a laminated Tikka to sell or order. I can't find any Tikka laminates in the US anywhere and Beretta doesn't list them on the BerettaUSA site...so I'm guessing they don't import that model anymore. I'm going to contact Beretta tomorrow morning but it sure looks like I'm back rifle shopping after thinking I had my mind made up.


Looks like the general consensus is for RCBS so far. I use RCBS for 9mm and 10mm and while they tend to sink pretty low in my LNL bushings they're not as bad as the Lee's. I thought I would hear more about the Lee Collet though...I have seen many reloaders sing it's praises in other calbers. For economy's sake I guess an RCBS 2 die set if I can use the FL sizer to neck size only as well. What grade dies would you recommend with hopes of working up a group like Sky's? The competition series are very pricey and I'm not sure I'd notice the difference between the micrometer adjustable seating die and a seating die I set with a separate micrometer?

Thanks folks...

-BunnMan
 
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I personally like the Lee collet dies and Forster FL, neck and seating dies. But I don't load belted mags. That shouldn't matter, though. Treat it just like a normal bottleneck case and the belt becomes irrelevant. Make sure it headspaces off the shoulder after the first firing and it should present you zero issues.
 
Noobness showing in full glory...

How do I know it's headspacing off the neck and not the belt once I close the bolt?
 
BunnMan said:
Sky,

Outstanding results!! That's the prime purpose behind this purchase..well, that and I need to check into a clinic to get through the DT's if I don't buy a new firearm at least once a year, lol. Really though...I want a tack driver bolt gun to build for so I can develop a load that does THAT!! I only hope I can achieve a similar result in my work ups. What rifle and what rifling did you fire those groups through? I only have one bolt gun in the safe as it is, and old Enfield .303 that went through a poor sporterizing/cut down job at the hands of the previous owner. I picked it up for next to nothing with an old Lyman American peg scope. The stock is awful but the action is sound, it groups OK considering it only has two lands 180deg apart for rifling..probably 2-3 MOA. I grab it when I'm going somewhere I don't want to take anything else...lol.


Null,

You outlined my plan almost to the "T". Thanks for the run down...allows me to confirm my reasoning. I will probably have a box or so of factory loads to establish a benchmark as you suggest but mostly prefer to roll my own. Not that I'm any better at building ammo than the big boys, I just enjoy the hell out of the whole process. Typically when I'm doing work ups I'll build in 5 charge levels depending on the difference between starting and NE. I have gone 6 on occasion when dead reasoning said the steps were to big and the magic number might lay between the 5. I usually build 10 rounds in each stage, fire two 5 shot groups, and take the best one of the two as the representative performance for that step. My thought is 5 rounds gets me away from simply "getting lucky" and two groups rescues me from myself if I happen to pull one due to going cross eyed staring in the scope too long, getting excited and rushing the result because my group is shaping up good and firing on a hot barrel, of course all my trigger presses are rock solid so I would never flinch and pull one...:uhoh: I usually take me some time to meter through the 50 round in a given work up allowing a minute or two between shots so I figured maybe I might burn the candle at both ends and do a littlle combo of load research and barrel break in if I had some handloads worked up for her arrival.

Unfortunately though...the folks at Dick's F'd me! I called them as soon as they openned to get a price on the model in my OP. They quoted me a number AND an avaiblility of about a week. I show up to buy the thing and get it on order and now they can't find it in their catalogue. I went through the whole song and dance with the counter rep...who left out that he was the same guy I talked to in the morning. Then I asked for the manager and the counter guy disappeared, the manager is the one who told me I had talked to that guy earlier. Now they're saying they don't know what he was looking at or where he got the price from and that they can't even get a laminated Tikka to sell or order. I can't find any Tikka laminates in the US anywhere and Beretta doesn't list them on the BerettaUSA site...so I'm guessing they don't import that model anymore. I'm going to contact Beretta tomorrow morning but it sure looks like I'm back rifle shopping after thinking I had my mind made up.


Looks like the general consensus is for RCBS so far. I use RCBS for 9mm and 10mm and while they tend to sink pretty low in my LNL bushings they're not as bad as the Lee's. I thought I would hear more about the Lee Collet though...I have seen many reloaders sing it's praises in other calbers. For economy's sake I guess an RCBS 2 die set if I can use the FL sizer to neck size only as well. What grade dies would you recommend with hopes of working up a group like Sky's? The competition series are very pricey and I'm not sure I'd notice the difference between the micrometer adjustable seating die and a seating die I set with a separate micrometer?

Thanks folks...

-BunnMan
Click to expand...
The rifle that shot those groups with was a Model 700 Rem BDL deluxe I purchased back in 1973 with I believe is a 1:9.25 twist and a 24 inch barrel. Still shooting the factory barrel. The gun is mostly stock. I have had the bolt squared and lugs lapped, the action is bedded to 1& 1/2 inch above the recoil lug. Also the bedding is taperd into a V wedge above the lug. This seems to work well with wood stocks only! I have a Hollands firing pin and spring in the bolt. Trigger is at 1 lb.
 
I have loaded some really accurate ammo with both RCBS neck sizing dies and Lee collet dies. Due to the price difference, I haven't bought anything but Lee in years.
 
BunnMan said:
Noobness showing in full glory...

How do I know it's headspacing off the neck and not the belt once I close the bolt?
Click to expand...
You're headspacing off the shoulder not the neck. When you buy new brass, see if it chambers in your rifle with ease. If it does all need to do is get enough neck tension to hold the bullet securely. So your not needing to even FL size the new cases. Load some at a starting charge and fire them. Those cases are now fireformed to your exact chamber deminsions. Thats it. For once fired cases, again check to see how they chamber in the rifle first, before loading them. If they are stiff, your gonna need to FL size them, if not then all you need to do is neck size them. If you can find a midlle of the road load that shoots good in your rifle, you can get some long case life as well as long barrel life. And of course if you have to have max loads they're not gonna last as long either.
 
To expand on what rcmodel said...

If the fired case is difficult to chamber, then you need to move the shoulder of the case back, but you want to move it back the minimum amount required to allow it to chamber in the rifle. If you push the shoulder back too far, the belt will hit the index in the chamber before the shoulder hits the front of the chamber. The next time that case is fired, the case will expand to fill the chamber again each time the case is sized and stretched in this manner, the case thins just forward of the belt and it will quickly crack and separate there. Keeping the shoulder as far forward as possible, minimizes this.
 
Ahhh!! I totally get it!! ...and that was my bad, I did mean to ask about headspacing off the shoulder not the neck. It would be rather diificult to space off of a plane at 90deg to the bolt face., looks super silly now that I read it again...just tripped over terms there. So, if I'm understanding it all just right, starting with new brass or a once fired case I methodically attempt to close the bolt on it. If it goes to battery with ease, resize the neck and load 'er up. If I meet with any resistance run it into a FL sizing die but not set to the shell plate per instructions. I guess I would put the case in the holder and run it up to top dead then screw the FL die down until it touches the shoulder then run the case down, screw in the die in 1/2 turn increments until it chambers properly then lock down the nut and label it for THAT chamber...right?

When it comes to COL I've been thinking I should seat a bullet out too far, chamber it, and slam the bolt to battery a few times on it to let the rifling seat the bullet then seat my seating die to go .001" or so less than this and label the die for THAT chamber...that cool? Any advantage to dojng this for auto pistols too?
 
My 1980 700 BDL likes the Sierra 160 gr bullets loaded through my RCBS neck-sizing die.....with 4350, 7828, or similar, three shot clover leafs at 100 yards is the norm and the 160 is excellent for deer/elk size game. The Nosler partition is another excellent bullet and my group sizes were not that much bigger - not big enough to worry about

I set the length to just off the lands and loaded to mid-range to midrange + a little - NEVER to max as the accuracy went all to hell

Good luck
 
Brass life is determined by an inspection of the brass after firing, and after resizing and tumbling. I would never just toss my brass without impending evidense of case failure.

When it comes time to reposition the shoulders I carefully adjust my FL die in very small increments, certainly not by using a fixed number of tunrs, 1/4 turn or what ever. When it will chamber without obvious unusual resistence, the shoulder is where it needs to be.

Seating to the lands, or just off them, is very easy to get right if you hand chamber the first one until it will fall out of the chamber by gravity alone. This is done with the bolt removed form the action so you can actually feel the olgive making contact. You'll feel them stcik in the lands if the aren't seated deep enough.
 
In 7mmRemMag I have dies:
Forster
Bonanza
Lee
RCBS
Lyman
Wilson

The best die is a Lee Collet neck die.

For 7mmRM I also like FL dies with the neck honed out to 0.307". Stock FL dies can be 0.302" and really neck down the brass too far.

A big problem is the chamber. 7mmRM SAAMI headspace is 0.220" minimum, and yet almost all brass is 0.215" or less from the head to the end of the belt.
When I cut my own chambers I can headspace to .215" and give my brass less lengthwise stretch on the first firing.

I have the 7mmRM SAAMI reamer, which is a 0.317" neck. My chambers stretch out the neck radially.
If I were not such a cheapskate, I should have ordered a custom "no turn" .312" neck reamer.

I like the sliding sleeve seater die, like Forster sells. It is off patent now, so others offer this feature for some extra dollars.

If you have more than one 7mmRemMag, keep each rifle's brass segregated to that rifle, and life will be better.

What does it all mean?
I can get 1" groups with the cheapest RCBS die set, just by removing the expander ball and seating in steps while rotating the cartridge.
I gave some fine points that may be down in the noise.
 
I settled on a rifle today, should have it Weds. I'll pick up the Lee collet die and likely a set of RCBS dies as well. I'll look for the sliding sleeve I think my Hornady 223 set does that...not sure. Thanks for all the help folks, yall gave me a wealth of 7mm mag education here!
 
I have hornady dies for my 7mm. No complaints whatsoever. On the other hand I have RCBS and lee dies as well for other calibers. No problems with any of them. Hope this helps!
 
I ordered the Lee 2 die collet set (couldn't get the collet die alone) as well as the Hornady 2 die FL set. So I can resize necks with the collet, bump shoulders with the Hornady FL sizer then decide which seater I prefer. Thanks for all the help! Now I just need to pick up the rifle and head to the range to make some custom brass :)
 
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