I have just gotten into reloading and started figuring out the acceptable OAL for my rifle in 300 Winchester Magnum. Not the short mag. I'm coming up with a length of 3.518 with the bullet just touching the lands. This gives me a length of 3.488 when I've seated the 180gr Nosler Partition .030 deeper into the case. However, when I chamber the dummy round at this OAL, it feels tight, especially compared to a factory load. The factory load I'm comparing it to has an OAL of 3.310" but it is a 200gr Swift A-frame.
I used the method in the Nosler Manual to determine bullet seating depth.
Rifle is a semi-custom based on a Model 70 action.
Well, you are trying to do the same thing I did starting out reloading. If I would have it to do over, I would have started loading to the Max COL that is recommended or even to the COL recommended by handbooks would be even better or match the COL of factory loads. Then slowly work seeing the difference. You might be surprised as I was with the deeper seatings. I had trouble loading way out. I went thru 200 shots and a few pounds of powder before I started loading deeper. You want to match the harmonics of your barrel. Sitting 1/1000" away from the rifling ain't always the best place.
Your reply makes sense as my rifle likes the factory load described above. I guess I thought I had to do it like the manual described. Maybe I'll try some loads at that setting and the SAAMI max setting.
Well I will tell ya, I spent forever trying to get my bullets seated as close as possible to the rifling to shoot well out of my 300RUM. Finally, a shooter told me he had the best luck out of a simular rifle seated really deep. Well, I was shocked find great groups at deep settings.
I went through the same issue with my 300 WM and ended up at 3.500" OAL. This worked in my Sako without touching the lans or being hard to close the bolt. Luckily, the Sako has a long magazine so this size still fits okay with room to spare. Some rifle magazines don't have this much space to work with.
If you can't get the regular 180 grain Nosler Partition to work for you, try some 180 grain Protected Point Partitions....they were developed for the 300 WM.
quote:Originally posted by Ben S: Newbie question here.
I have just gotten into reloading and started figuring out the acceptable OAL for my rifle in 300 Winchester Magnum. Not the short mag. I'm coming up with a length of 3.518 with the bullet just touching the lands. This gives me a length of 3.488 when I've seated the 180gr Nosler Partition .030 deeper into the case. However, when I chamber the dummy round at this OAL, it feels tight, especially compared to a factory load. The factory load I'm comparing it to has an OAL of 3.310" but it is a 200gr Swift A-frame.
I used the method in the Nosler Manual to determine bullet seating depth.
Rifle is a semi-custom based on a Model 70 action.
