Core lokt data (7mm)
 

I was looking for some data for Remington core-lokts, haven't been able to find any...
Cartridge is 7mm Remington Magnum
Bullet is standard core-lokt, 140gr
Powder is Hodgdon H4831

Also interested in 140gr Sierra SBT (I know, I need to make an order for a sierra manual :D)

Thanks in advance

RE: Core lokt data (7mm)
 

My best load for the 140-grain bullet (both Sierra PSPBT and Nosler Partition) in the 7mm Rem Mag. is 71.5 grains of OLDSURPLUS H4831. MV is 3350 FPS from a 26" barrel. This load consistently groups in 0.5" - 0.6" at 100 yards. Newer H4831 may be faster, so to use this load, it must be approached from at least 5% below (68 grains), and worked up to in half-grain increments. I use mine in a Ruger 1B which has a standard-length throat-no freebore.

RE: Core lokt data (7mm)
 

Thank you
Hodgdon shows 64gr max load for partitions, but I see many people areshooting 68-70gr with non-partitioned bullets.
I have 3 batches ranging up to 64gr that I will shoot this afternoon, and if those show good performance, I may go up, but that depends on how today's shoot goes. This is for accuracy only, asI can go for power with RL22 and know that pressures will be safe without risk.

RE: Core lokt data (7mm)
 

The best groups were only about 1.25-1.5moa...21mph wind right to left I'm sure is what gave me the problems. There were no pressure signs at 64gr, accuracydidn't favor a charge that I could tell.This load will have tobe continuedwhenI can get to the range without so much wind. Overall I think I can get something good out of this soon...the wind was just messing with me.

RE: Core lokt data (7mm)
 

Well, it is possible that H4831 is alot faster now than the stuff I used, but I can't believe it is THAT much faster. I would try starting with the load you just used, and work up in half-grain increments until I reached a good accuracy level or pressures began to become obvious, but not too high!! I would be interested to hear how far you get before that happens. As a matter of interest, I have found that I can use Sierra Game Kings and Nosler Partition bullets with identical charges, and get very similar velocities and accuracy.....

RE: Core lokt data (7mm)
 

Cartridge is 7mm Remington Magnum
Bullet is standard core-lokt, 140gr
I here some say you can use the hornady loading chart for remington bullets.
I load the 308 165 grainers and the hornady chart works excellent

RE: Core lokt data (7mm)
 

I hear ya eldeguello. They show 2950fps for a max, not even a hot 280 load, and I foundthat kind of odd. I wonder what part of theload is stopping them fromshowing hotter (liability? I would hope not).
I think I'll load up some small batches of the smaller charges I've just used again and try for accuracy...I wasn't disappointed with my poor average noting all the wind, but surely they aren't that bad in 'normal' conditions :DI'll try and update this in a couple weeks with my experiences (will be gone for awile) and also we'll see how the core-lokts do with some rl22.

RE: Core lokt data (7mm)
 

For some reason, in recent years, the manual publishers (and even the ammo makers) have "wimp-ized" the 7mm Remington Magnum. For example, when the round first came out, the Remington 175-grain factory load was rated at 3070 FPS. I got mine in 1969, right after the Ruger No. 1 hit the market, and being the dummy that I am, I BELIEVED the data that the ammo makers put out, and using Norma N205 powder (now replaced by MRP1), I developed a load for the 175-grain bullet that gave the same MV as the factory load was supposed to do (3070). I had two chronographs at that time, and verified the load's performance.

Then Norma stopped making N205, but brought out MRP (now called MRP1), and it was able to do the same as N205 with a slightly different powder charge. Then, Norma powders disappeared from the market (this has happened two or three times in tha last 30 years!!), so I switched to RL 22, which was claimedto be "the same as" MRP. Well, it wasn't-RL22 would not give over 3000 FPS with a safe load! So I tried IMR 7828, and it worked OK! But I had to use 70 grains of IMR 7828 instead of the 66 grains of N205, or the 68 grains of MRP that worked before.

I use 175-grain bullets exclusively these days in the 7mm Magnum, because the 140-grain bullet at 3350 FPS is just too destructive. If I want to shoot a 140-grain bullet, I use a 7X57mm to launch them. However, today I use the 150-grain Remington Corelokt in my 7X57mm's for deer only.... When I go for elk I use the 7 Mag.and 175-grain Nosler Partition bullets.

RE: Core lokt data (7mm)
 

My idea behind the 140gr core-lokts in a 7mm RM was formedium-power loads (such as those I believe I've already tried) similar to a 280 on deer,and just plain fun target shooting for not a lot of money. I don't really deer hunt with my 7mmRM much with my 25-06 and muzzleloaders around, and tend to use heavier bullets when I do. I appreciate the insight, I've been reloading myself for about 2yrs and am glad tohear from more experienced reloaders.