Bullet seating depth issues

the books col is what they used in their equipment. it really means nothing to your rifles. seat short of the lands with a safe load .

Yeah start by getting a bullet length that will work in that particular rifle. THEN start 10% below max and work up your load looking for pressure signs. The lower case volume will slightly raise pressures but with working up (as you are supposed to do with new loads and component changes ) you have a safety margin to work in and also I bet you will find an accurate load before you hit max anyway. Chances you are using a different bullet profile that requires a different OAL and may still be able to use their other OAL if you were using the same bullet they were.

philip brousseau said:

the books col is what they used in their equipment. it really means nothing to your rifles. seat short of the lands with a safe load .

Click to expand...

Yes, what he said.
Actually, 0.010" will not make a noticeable difference in either .30-06 or .280 Rem. It might be measurable with the sophisticated equipment used in a ballistics lab. Maybe.

You should actually count yourself lucky! It's not unusual to not be able to seat a bullet far enough out to reach the lands and still have enough bullet in the case to have a secure grip on it.

0.010" off the lands is a good lace to start with your COAL and is where I, personally, like to start my testing for OCW. Then I adjust COAL to find the absolute sweet spot for that particulr load. The bad news is, I almost always believe I can do better, so I try a different bullet weight, bullet mfr, powder, brand of brass or primer and do all the testing all over again!
It is a hobby afterall, isn't it?

Depending on the particular bullet, some actually shoot better seated away form the lands.

I had a similar issue with a Browning A-Bolt 280 and speer bullets I used to shoot. I started at SAAMI length, and tested one it chambered fine, so I loaded about 15 to test different powder charges, I found some wouldn't chamber so I stopped shooting them. I got home and checked them with the calipers, thinking maybe the die wasn't set or moved, but the length was the same on all of them. I attributed this to variances in the bullets. I seated slightly deeper, and never had any problems after that.

I have started shooting Swift Scirocco bullets recently in the same 280, and have had better luck on grouping getting further away from the lands. I am still in load development, so don't have any final numbers on length yet, but am getting closer to where I want to be. My shortest length I tried on Saturday had the best group, about 0.75" at 100 yds, so pretty good. I am going to go a bit shorter on a couple of test batches just to see if it gets better.

Different bullets behave differently in guns.

I also had to seat deeper on a 22-250 I have in order to use the magazine. During load development, I found a load I liked, but was only shooting single shot at the range. Once I loaded a few more and went back, I found they wouldn't clear the magazine properly, so again went slightly deeper to remedy this. I should have checked magazine clearance before the first batch of test loads, but I failed to do so.

Good luck on the reloading! Every rifle and bullet is a little different, so trial and error on reloading can be frustrating, but once you get to the sweet spot, it is time well spent.