Lyman 535 Postell speed.

[DangerousDrummer]

I know that speed is a relative thing, but I will ask anyway.

I dropped the charge in my 45-90 from 80 grains to 70 grains in order to reduce my purple shoulder the day after shooting. My bullet speed was avg ~1235 fps and has now dropped to ~1135 fps. I was surprised that I only gave up 100 fps but wonder if my speed is still enough to relate correctly to my Baldwin sights? (while getting help with the initial use of my sights I was told that my bullet speed was in the correct range).

I did have to correct my vertical adjustment for 200 yds from 55 to 62 which brings up anither question. Will I be able to add 7 to my previous settings for longer distances and still be close enough to fine tune, or will I have to step up to get back where I can hit at 300 400 and 600?

This was my third outing with my new BPCR and I gotta say, DANG!

[Don McDowell]

Any time you cut the velocity you're going to experience a change in points on the sight. Yes your 7 minute difference is the place to start, altho it may vary.

[upnorthwis]

Get the "Shooter's Friend" recoil pad. It's the best shooting accessory ever made. I shoot my 45-90 with 85 grains of Swiss 1-1/2, same 535 grain Postel boolit at 1350 fps. Shoot two day matches with only minor discomfort.

[kokomokid]

Might try 60 grains. Several master shooters I shoot with only use 60 grains with a 540 grain Jones bullet and shoot very close to sub sonic with 45-70. They have no trouble at the ram line. I try to guess t mate 2-3 moa high on a new load and let my spotter bring me down the berm , usually on target with 3 rounds. I like the shooters friend pad but it does add a to the LOP. LB

[DangerousDrummer]

Might try 60 grains. Several master shooters I shoot with only use 60 grains with a 540 grain Jones bullet and shoot very close to sub sonic with 45-70. They have no trouble at the ram line. I try to guess t mate 2-3 moa high on a new load and let my spotter bring me down the berm , usually on target with 3 rounds. I like the shooters friend pad but it does add a to the LOP. LB

I ordered the LOP 1 " shorter than I usually shoot just in case this was an issue. I can deal with a little shorter, but not too long. Hmmmm, 60 grains. So does anybody use two different (or 3) loads? One for shorter range (chickens, pigs, turkeys and rams), and one (or two) for long (600 & 1000 paper), or is it just too much to keep up with? Sixty grains running subsonic could reduce leading and at the same time reduce recoil. I would need to use some thick veggie cards for wads to replace the void. Hmmmmm.

[John in PA]

If you have a copy of the Lyman Blackpowder Handbook (or the Cast Bullet Handbook?) , I believe there's some external ballistics info for many common Lyman cast bullets. Don't recollect how far out the range data goes but o\if you happen to have one or both books in your library, you might check to see if there's anything helpful there. Slowing the muzzle velocity will have more of an effect on drop at distance than at closer to the muzzle. The bullet path is not a perfect parabola, due to the fall-off in velocity through it's travel, If you look at the curve from the side, it's kind of slumped at the far end.(if that makes sense) The margin of error in sighting decreases due to the rapid drop of the bullet. The 1880's army used a term called "Dangerous Space" to describe the distance from where the front rank of troops would be hit in the head and the rearmost man would be hit in the foot. In other words the distance over which a bullet drops 6 feet at a given range. This was studied intensively for the .45-70, and charts can be found in the book "Instructions in Rifle and Carbine Firing for the United States Army" by Stanhope Blunt. It's available free in Google Books either as a PDF or to read online. LOTS of really interesting info on the .45-70 external ballistics. (Which is essentially what you're shooting) http://books.google.com/books?id=BdVCAAAAYAAJ&pg=PA92&dq=rifle+and+carbine+firing&hl=en&sa=X&ei=CjDMU4ihPMayyATg4IH4DQ&ved=0CB4Q6AEwAA#v=onepage&q=rifle%20and%20carbine%20firing&f=false

[Bullshop]

I think the newest Lyman book gives a BC for each cast boolit used in that book. I am not sure if that boolit is in it or not though. If you have the BC there are several programs to run the numbers out to about any range you want.

[upnorthwis]

Concerning using a couple of different loads for long range. The range that I shoot 1000 yard paper matches specifies the minimum bullet weight and velocity allowed. This is done for safety reasons so that the trajectory doesn't have boolits being lobbed into the pits. These numbers are only from my memory but they were about a 500 gr. boolit at 1215 fps.

[country gent]

The Luman 4th edition Cast bullets handBook gives 457132 ( I believe thats the postell at 535 grns) to be .402.

[kokomokid]

I had best reduced loads in a 2.6 by using cork wad stack of .060 each. This was gasket material from tractor supply. Never got consistent moa groups but did not work with it that much either. When I look back now I think fouling control was the main problem. LB

[John Boy]

Lyman's 49th Handbook lists for each bullet tested the BC & SD and only the velocities for smokeless powders used for testing. Like any powder used to load a specific bullet of a given weight, increase or decrease the powder charge and the velocity will change - more so at long range also on the grade of powder used and the brand ... buy a chronograph!

[Bullshop]

When I assemble less than 100% density loads I stuff the case with styrofoam packing popcorn and compress it with the boolit. Never a problem. Long ago near the beginning of my learning curve I did ring the chamber of a trapdoor by placing a wad on a reduced powder charge without filling the remainder of the case. With whatever filler you choose to use the key word to filler is """FILL""".
I like the packing popcorn because it is basically weightless so has no effect of changing the pressure of the load. It works the same as a compressible shotgun wad filling the empty space but cushioning the blow to the base of the boolit .

[country gent]

Another quick way to get zeros close to what you want. Make a tall target 2 ft wide and 8 - 10 ft tall. Place a aiming point at the bottom. At 200 yds with your original load shoot a group to its known zeros for each range. Now with the new load shoot to those groups always aiming at the same bull you will come out pretty close. We made up a few of these targets and plotted the hieght above line of sight for 300 500 600 800 900 and 1000 yards at 200 yds marked with a colored labeled line across the targets. One color was .223 one was 243 one was 308. club members going to thier first high power match could set the target up and get the rough 300 and 600 yd sight settings all from 200 yds. For us that shot long range the 800 900 and 1000 yards were a big plus before a match. These targets at our club get sed alot and most claim 10 ring hits with the zeros obtained. Plugging numbers into a good ballistics program with an accurate bc ussually gets you very close also. I had sierras infinity program on a lap top and at the state match stats would send new shooters out to me and if they had no 1000 yd zero we would crunch numbers velocity BC and some others required by the program. As long as they gave me accurate velocities I could give them how much to come up from 200 yd zero for 1000 accurately. On my 243 with 115 bergers first shot at 1000 yds was a 10 at 3 oclock. Should work as good with black powder rounds as long as numbers are accurate.