having powder compression concerns loading the 535 Postell bullet.

[Road_Clam]

So today I loaded up 10 of the 535 gr Postell bullets. I calculated my chamber's max AOL and I can load out to 2.974 and I just start to see rifling marks on the ogive. So I decided to start with 65 gr by volume, which equals 63.9 by weight. I'm also loading new Starline brass. My concern is the necessary amount of force I need to exert on my compression die to get my powder to compress enough to set the bullet. I'm really having to force my press to what I think to be excessive force on my press. (I'm using Goex FFG). From what I observed today, I dont think there is any way I can load 70 gr and get my seating depth to 2.974. I used a drop tube and I vibrated to get the powder to settle as much as possible. Is it normal to need a fair amount of force to compress the powder ? The seating depths as you can see vary. I learned that if you force too much on the bullet nose it distorts the ogive diameter.

https://preview.ibb.co/i4cONm/DSCF0426_1.jpg (https://ibb.co/dnGuTR)

[Themoose]

Every rifle is different... I used the Postell in a C. Sharps and found my accuracy load was 62.5 grains by weight Goex cartridge grade... worked quite well on rams out to 500 yds... when compressed, you definitely used some pressure... 70 grains would not work in my rifle with that bullet.

[Road_Clam]

I'm currently using .060 poly wads, and I ordered some .030's from BACO to gain me a bit more needed space.

[country gent]

My load with the lyman postell is 62 grns of 1 1/2F Olde Ensford for right around 1200 fps. I weigh the charge. Drop thru a 3 ft drop tube with a slow trickle in charge. add my .060 rubber fiber wad and compress. This is in fired Starline Brass. I only size the neck in a bushing die so that may add a little more capacity also/ New brass that hasn't been expanded to the chamber my have a little less capacity. New brass can be on the small side and need a load to get it out to size.
You want a 15-20 second trickle into the drop tube to let the powder drop into the case. It does make a difference.

[Road_Clam]

My load with the lyman postell is 62 grns of 1 1/2F Olde Ensford for right around 1200 fps. I weigh the charge. Drop thru a 3 ft drop tube with a slow trickle in charge. add my .060 rubber fiber wad and compress. This is in fired Starline Brass. I only size the neck in a bushing die so that may add a little more capacity also/ New brass that hasn't been expanded to the chamber my have a little less capacity. New brass can be on the small side and need a load to get it out to size.
You want a 15-20 second trickle into the drop tube to let the powder drop into the case. It does make a difference.

Thanks country gent for the load data. I loaded up 63 gr and 64 gr by weight and my end results were much better. I learned a LOT of unique to my rifle information yesterday so even with my first batch being poor i'm happy with the gained knowledge. Seems the lead in rifling on my Pedersoli Sharps is tapered as I can gently push the round into the chamber and feel some slight resistance for about .125" of depth. All my modern smokeless rifles have a definitive "hard stop" when touching the rifling. Did a lot of reading and seems the pedersoli sharps chambers are throated specifically for the 500+ grain match bullets. On the 64 gr load that last grease groove on the Postell bullet was almost completely covered by the casing. The 63 gr load was slightly past the last grease groove. By my experiences with a hefty amount of press force on my compression die my Goex FFG has the capability to compress about .63 max from a vibrated state of case fill. I was concerned about case bulge after compression, but all my casings chambered excellent so seems i'm ok.

[Kevin Rohrer]

Did you use a powder compression die beforehand?

[kokomokid]

Are you using the bullets to compress the powder? Some of the nose look flat. Once you fire form the starline brass it will hold a little more powder.

[Road_Clam]

Are you using the bullets to compress the powder? Some of the nose look flat. Once you fire form the starline brass it will hold a little more powder.

I initially used a compression die. From my total lack of experience I would seat the bullet and add some pressure to the seating die which is a no-no. As you can see a few of the bullets are malformed. I know now to gently seat and as soon as I feel the bullet stop, do just that STOP.

[kokomokid]

I always have a reduced dia bullet that I can drop in my charged case to measure oal. Run a bullet through a smaller sizer die and sand off the base to same length as the bullets you are using or sand down the whole dia to slip in and out of the case. Loaded oal is the starting point for me. I load five to jump .010 and five touching rifling and five seated .010 into rifling. The gun will tell you what it likes.
Adding a few grains of powder may not increase your vel very much.

[MT Chambers]

How much are you compressing the charge? Not measured in "effort" but in inches.

[Road_Clam]

How much are you compressing the charge? Not measured in "effort" but in inches.

68 gr charge by weight = approx a .460" compress using Goex FFG, .060" wad, drop tubed and vibrated to settle. This is required to seat the Postell bullet to cover the last grease groove with the casing. This is about the max compression I can get. I think my next batch I will try the 68 gr load again, and compress and seat with the last grease groove showing. I tried the 68 gr load today and it shot excellent. About 2 moa @ 50 yds with cheap irons, and my pi$$ poor eyesight. I'm also waiting on some .030" wads from BACO. Once I establish my ideal bullet jump and compression depth i'm thinking of machining a shouldered compression die specifically calculated to get me the perfect depth.

https://preview.ibb.co/ia14V6/DSCF0427_1.jpg (https://ibb.co/cKfbcm)

[MT Chambers]

If compression required is too much, like I believe it is in this case (1/2"), you either have to try a diff. powder or reduce your charge so that there is 1/4" or less comp. to start with.

[Wayne Smith]

And remember that the original 70 gr load was with balloon head cases, more room in them than in our present solid head cases.