Load Development for 7mm & .338

[Kurt82]

I just recently started reloading. My first loads I am work on are for a 7mm Rem Mag and .338 Win Mag. I decided to go with 162gr SST for the 7mm and 225gr SST for the .338. I picked these because both rifles liked and shot Hornady SST's very well. I measured the bullet seating depth 4 or 5 times and felt good with the measurement I was getting and then decreased it by .022 and went with that. What i don't understand is why manufacturers make bullets with that ribbed ring around the bullet if your not going to seat it deep enough to get into it and does it effect anything by not seating it that deep. I am only asking because when compared to the factory Hornady SST load the bullet is seated just above the ring. It would seem the ring is there to allow better grip between the bullet and case. What's you thoughts? Thanks for any advise.
I am blown away by how much the factory load jump before hitting the lands compared to the reloads I worked up. The .338 is a Savage 116 Bear Hunter. Honestly I am kind of scared to shoot the loads...lol I think the first shot will go in the lead sled with a string on the trigger! It wouldn't be the first time I have done that (crazy old rifles and unknown AR builds, etc)

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[osprey]

Factory rifle ammo has to be manufactured to a shorter oal to work in many different weapons and bullet makers place the crimp groove accordingly. Many bullet makers offer bullets to handloaders with no groove at all and this is my preference for most all my bolt guns as I do not crimp for them. Proper neck tension keeps bullets in place fine for all but the hardest recoiling bolt guns. If it has a crimp groove just ignore it and seat bullets where you achieve max accuracy and proper feeding. Crimping is not needed in most bolt gun applications.

 

[P7M13]

Factory jump because both calibers, like all magnums based on the 375 H&H parent case, are headspaced off the ring. Manufacturers cannot account for chamber differences, so build to SAAMI specs which will encompass 99% + of the guns made out there, so they produce for the minimum size specs.
One thing you may not want to do is "full size" the 7 mag and 338 mag brass that was fire-formed to your chamber. Instead, neck size and shoulder bump. I don't do this, so others on this forum may have suggestions.
As far as the cannelure, I don't claim to know the purpose of it, though cannot imagine roll- or taper-crimping a bottle-necked case, except for MG rounds. The neck has enough tension to hold the bullet.
However, there is a rule of thumb, the neck and bullet seating should be at least as long/deep as the bullet caliber.
Look at the SAAMI SPECS for 7mm Rem and 338 Win Mag cartridges, and your bullets should seat at least the full length of the neck.

 

[osprey]

I have played with just neck sizing but for hunting rifles I prefer full length resizing for reliability. I really did not see enough accuracy gains with just neck sizing to warrant it. I do however set my dies to minimally set the shoulder back.

 

[jordanka16]

Everything sounds fine with what you did, .020 is the usual starting point for the jump into the rifling. Like the others said the cannelure is just there to provide a crimping spot for factory ammo or people that think a crimp might be needed. You will probably get better accuracy by choosing a bullet without one, but it won't hurt anything.

 

[Kurt82]

Awesome! Thanks so much for everyone's quick reply's. I did do full length resizing as thats the only one my rcbs die came with. My concerns were answered and I feel more comfortable about the load.

 

[osprey]

Hornady sst's will always have this crimp groove because the were derived from the original interlock bullet that has this interlock crimp that protrudes into the lead inner portion of the bullet to help control expansion and promote penetration. I use Nosler partitions and accubonds to great effect and they are provided to reloaders sans crimp groove. You may want to give them a try in your rifles. GL

 

[Kurt82]

I almost went with Partitions. I was buying some DoubleTap specialty ammo loaded with Partitions. I shot a few bears and a deer with them years ago, but then of course they stopped making the ammo, so I went over to Hornady just because I have been shooting factory SST's for the last couple years now. Depending on how the load development goes with these I may end up going back to the partitions.

 

[jordanka16]

I almost went with Partitions. I was buying some DoubleTap specialty ammo loaded with Partitions. I shot a few bears and a deer with them years ago, but then of course they stopped making the ammo, so I went over to Hornady just because I have been shooting factory SST's for the last couple years now. Depending on how the load development goes with these I may end up going back to the partitions.

The ELD-X is also an excellent bullet to try, and more affordable than the noslers.

 

[pharmseller]

The ELD-X is also an excellent bullet to try, and more affordable than the noslers.

Unless, of course, you frequent shooter's pro shop online and buy the cosmetic blems. They're all I use. Close to BOGO pricing.



P

 

[v0lcom13sn0w]

a buddy and i load for 338 win mag.

love the 225gr sst over some h4350!!

2850-2900fps.

 

[Colts4me]

a buddy and i load for 338 win mag.

love the 225gr sst over some h4350!!

2850-2900fps.

Yup, I shoot over chronograph and try to duplicate factory loads.

 

[v0lcom13sn0w]

Yup, I shoot over chronograph and try to duplicate factory loads.

that load we use for 338wm is a little over maximum published data from hodgdons website. no pressure signs either.

 

[Crohnos01]

I have been shooting 65 grains of H4831 pushing 162 grain Noslers down range for years. I get fantastic accuracy with this load and took an antelope at 800 yards with it. I think this load may be over max in many of the new manuals, but was max load years ago. As always, YMMV and work up loads slowly checking for pressure signs.