BASS Report post Posted May 14, 2008 Alright, I've now loaded about fifty rounds of .300wm (180gr SMK, 70gr of reloader 19, federal primer) with the bullet off the lands by approx. .025. And fifty rounds with the same componets loaded right into the lands (touching, very slight resistance when locking the bolt. My question is this, so far I have not reached the maximum preasure and have yet to have any preasure signs with any of my working loads. I was talking this over with a guy I work with who does custom reloads for Barnes Bullets and he was saying to get the bullet jammed right into the lands. Now I have two trains of thought on this. One side of me thinks that this would be correct. The lack of met resistance after free movement makes sense to me IE preasure would be directly into the lands instead of slight gap between the two. But the other side of me says that this would incease the preasure very quickly. So should I load some rounds up with the bullet jammed into the lands and shoot to see how they act since I have yet to meet the preasure signs, and am a good four grains under max preasure? Or should I drop it all the way back down and start over with those again? Share this post Link to post Share on other sites
Red Rabbit Report post Posted May 14, 2008 What tools are you using to measure the distance off the lands? I also would expect pressure to increase with the bullet in the lands. I would use a chronograph to see what the velocities are (Higher vel = higher pressure). How are the two loads accuracy wise? Share this post Link to post Share on other sites
BASS Report post Posted May 14, 2008 What tools are you using to measure the distance off the lands? I also would expect pressure to increase with the bullet in the lands. I would use a chronograph to see what the velocities are (Higher vel = higher pressure). How are the two loads accuracy wise? Well, who knows if it is correct or not, but I am using the RCBS Precission Mic set, and a double checking it with a digital gauge. If I understand correctly, the RCBS mic gives you the "optimal size " for a loaded round, so backing the round off into freebore would be subtracting slightly from the Mic set reading. Again, right now I'm trying to find a perfect load for this rifle. For the most part these rounds are for blasting rocks a ways out there, or going after yotes that hold up way out there. So far the two rounds are pretty close accuracy wise, and it seems to hold true out to the longer ranges as well. For the most part I am very happy with the way the way the two loaded rounds work together, but curiosity got the better of me when I was told to load them right into the lands by a pretty expirenced reloader. I just wanted to get the thoughts of other reloaders who have been at it as long as you guys have to see if my higher presure concerns were correct. I'll have to set-up a date with my shooting partner to get some range time behind a chronograph. Share this post Link to post Share on other sites
matthewp45 Report post Posted May 14, 2008 With the bullet jammed into the lands you can run into a problem unloading the gun. I have loaded a bullet into the gun and decided not to fire the gun. The bullet was jammed into the lands and when I went to take it out of the gun the bullet stuck in the barrel and the casing pulled apart and spilled gun powder all in the action and left the bullet stuck in the barrel. Now if you were in the filed this could be a major problem. Share this post Link to post Share on other sites
hawkeye Report post Posted May 14, 2008 When reloading my 300 Ultra Mag. if I seat the bullet just off the lands, the rounds will not fit in the magazine. I had to seat where they would just fit. I was lucky they are very accurate. Sub 3/4 inch at 100 yars. I am reloading 104 grains of RL25 with 150 grain Barnes MRX. They are blazing at 3750 fps. Share this post Link to post Share on other sites
scottk Report post Posted May 14, 2008 When reloading my 300 Ultra Mag. if I seat the bullet just off the lands, the rounds will not fit in the magazine. I had to seat where they would just fit. I was lucky they are very accurate. Sub 3/4 inch at 100 yars. I am reloading 104 grains of RL25 with 150 grain Barnes MRX. They are blazing at 3750 fps. Hawkeye, Sorry I don't want to steal this thread but what is your barrel length? Thats pretty fast. My 7mm RUM is not quite that fast with a 140 gr nosler. But I was told by using the Barnes you can pick up a bit of speed. I am not questioning your numbers just curious about your combination that is getting you that kind of speed. I will have to look at my chrono numbers but I think I was shooting around 3400 fps with the 140 grn nosler ballistic tips. I am pretty sure I would have a problem loading my shells in the magazine also by increasing the over all length so that it would seat at the lands. I was always told not to seat it in the lands because like mentioned before it can pull a lead and will mark up your leads if you don't shoot the round. FWIW. Thanks, Scott Share this post Link to post Share on other sites
Benbrown Report post Posted May 14, 2008 For cup and core bullets, I start at .010" off the lands and tinker with increasing or decreasing once that distance once I reach the velocity I want with a reasonably accurate load. Seating your bullet to engage the lands will increase pressure. For instance, Barnes recommends starting .050 off the lands because their bullets do not compress like those with a lead core and seating them closer to the lands with maximum loads will produce chamber pressures that will exceed the SAAMI maximum. Weatherby rifles are made with what is called "free-bore", i.e., the bullets have to move a good bit (over 0.2" in some chamberings) before they reach the lands. This permits the factory loads to use more powder without a concommitant increase in pressure. In my .300 WSM CZ Model 3, I can seat the bullets .010" off the lands and they will still feed from the magazine. In true short action rifles such as the Model 70 Winchester, that is usually not possible. According to my "Load From a Disk" program, your load is probably generating around 60,000 CUP; warm, but well within the limits of the .300 WSM. This is probably why you are not seeing any signs of high pressure. As your powder charges approach the maximums in your reloading manuals, I would be very careful about seating the nose of the bullet in the lands. Share this post Link to post Share on other sites
BASS Report post Posted May 15, 2008 60,000? That seems high to what I've always thought the 300 wm was capible of. I thought the max preasure was closer to 54,000. I guess it was a good thing I asked this question before starting a starter load!!! Share this post Link to post Share on other sites
Benbrown Report post Posted May 15, 2008 60,000? That seems high to what I've always thought the 300 wm was capible of. I thought the max preasure was closer to 54,000. I guess it was a good thing I asked this question before starting a starter load!!! The SAAMI maximum for the .300 WSM is 65,000 CUP. The maximum for the venerable .300 Winchester Magnum is 64,000 CUP. Your load is well within the acceptable limits of maximum average pressure for either case. Ben Share this post Link to post Share on other sites
.270 Report post Posted May 15, 2008 i like to load my stuff to where it just touches the lands. paint the bullet with a magic marker, load it long and tinker with it. Lark. Share this post Link to post Share on other sites
