Sizing before PC for beowulf

[Al_Bundy]

First time out with some pills I didnt get good accuracy. I'm thinking of trying to fatten these Lee .500s because I've read you want them to be 2-3 thousandths larger than the bore for best performance since fit is king in a barrel.

Because opening up a sizer that much was a chore and a half the last time I did it, would I be okay with just sizing before for consistency and adding PC for the addition in size?

[Conditor22]

Al, you first need to determine the bore size of your gun to know where to start.
PC can add .001 to .004 depending on the PC you use.
Yes, you can PC after you size you boolit, just make sure your size die is CLEAN so the PC will stick right.
Not knowing the PC you'll be using and how you'll be applying I'd suggest sizing the boolit .001 under the determined bore diameter and go from there.

[Al_Bundy]

so i dropped a sized .500 bullet and it fell right through. I tried with an already sized then pc boolit that measured .503 and i had to hammer it out. After measuring i believe it read .500-.501

Ill see how consistent these come out at .503.

[Onebad06vtx]

I would open your sizer up to .502 and size powder coated bullets.
I would only size once but you want to size after coating for best results

[Al_Bundy]

Yeah I'll do that, even if it's a pain in the ***

[Dragonheart]

Al, I have heard so many touting oversized bullets being more accurate, but I have yet to see any real test data to prove this theory, just opinions. As far as my testing, and I admit limited testing, but oversized bullets shot large groups.
There are so many factors that effect accuracy starting with the case, headspace and going on from there. Have you slugged your bore, measured your bullet jump, etc. Locking onto a single item and making a change without good reason is not going to get you where you want to be. I definitely would not alter my equipment until I had something concrete to go on.

[Al_Bundy]

I like to think of it as a journey. Make a ton of mistakes and keep trying till you see improvements. If it's not one thing you move on to the next. Right now is sizing consistently over the bore size to mainly avoid gas cutting, any + in accuracy would be nice. Next I'll look at casting better quality bullets, my Lee sprue plate is leaving mounds of excess lead on the bases. It's always these two hole sizes that can rarely drop clean bases. But Lee's 6 hole molds drop them perfect. I'm assuming because the two hole gets hotter quicker since theres less material for the heat to spread out. I've tried using a damp cloth on the spruce plate but it regains that heat after a few more drops. I'm working at 750-800F.

[Dragonheart]

I realize a lot of people swear by Lee Molds so I won't get into bashing, but I will say I personally have tried them, I don't like them and don't use them because Lee quality control is just not acceptable for me. There are other Lee tools I think are outstanding, just not their molds, but if it works for you so be it.

If your Lee sprue plate is leaving lead buildup on the bullet's base then you are producing bullets that are going to have accuracy problems. Any damage or deviation to a bullets base is going to alter the bullet's flight path. My guess is the sprue plate is not parallel to the mold block. If it were mine I would attempt a fix starting by sanding the underside of the sprue plate first. Using a completely flat surface like you find on a table saw, machine tool or even a piece of thick glass, lay down a sheet of wet/dry sandpaper with a 400 grit. Wet the paper with water or light oil and slide the underside of the plate across the sandpaper. Check the plate and see if there are high/low spots. If so, continue to sand until the plate is uniformly smooth. A strong bar magnet works well as a handle to hold the plate flat and maintain control. Once the plate is flat smooth out the surface with a finer grit of paper like 800-1200. The same process can be used to repair a mold block. If the problem is the screw holding down the sprue plate was not drilled completely perpendicular to the block I wouldn't waste my time on the mold.

Once you have good cast and properly coated & cured PC bullets here are some other steps to try. BTW: cooking your bullets base down will aid in creating a flat base as the powder tends to fill slight imperfections on the base.

I would suggest starting off by slugging your bore. I slug my guns by firing into a water trap with a powder charge reduced to just get the bullet clear of the barrel. From there the fired bullet gives me the barrel dimension. To get a seal one to two thousands over bore size is all that is needed. PC is a jacket and protects the inner alloy like a jacket.

I would then sort my cases and make them as uniform as possible. Since you are loading a tapered case the case headspaces off the mouth, so length makes a difference in accuracy. I don't own a 50, but your best accuracy will come from a case length that matches your headspace or just under. Unfortunately, you may find the cases to be short, meaning they are headspacing off the extractor.

Use a standard case with the mouth cut to measure the bullet jump to the lands to determine the best OAL; changing the OAL by a few thousands can make a tremendous difference in accuracy; because barrels & bullet design vary, you have to measure using your bullet of choice. Obviously the rounds have to fit in the magazine so achieving the ideal OAL probably won't be possible, but a bullet design change may get you closer.

From there it is primer, powder and the charge weight and that can take a long time. I personally make up 5 round batches as uniform as I can with the charge of each batch varying by 2 tenths of a grain.

Making accurate ammunition is a challenge I find rewarding and I hope this helps somewhat.

[Al_Bundy]

Thanks a lot of good info to take with me here. I got the summer and a fresh membership to get all this worked out.