Muzzle Velocities

[muzzlenut]

Does anybody know of a web site or have personal information on approximate or average muzzle velocities using different kinds of powder with different bullet/sabot combos? I would really like to use a chronograph on my different loads but I simply don't have the resources for that. I thought maybe somebody had a database somewhere that would give an estimate.

[Semisane]

I don't know of any such site. Some of us have velocity readings on various bullet/powder combinations. Are you looking for anything in particular?

[muzzlenut]

Well, for starters, I am using 100 gr pyrodex pellets and have been shooting 240 gr XTP & Shockwaves as well as 300 gr XTP & shockwave. Shooting all of these with harvester crushed rib sabots if that matters at all. Later this spring I will be shooting loose powder but for right now this is what I have. Thanks.

[Semisane]

I've never shot pellets. Here's the closest I can come for you.

In my Mustang, I got a five shot average of 1602 fps with 100 grains of Pyrodex RS and the 240 grain XTP in the sabot supplied by Hornady.

In general, 300 grain sabotted bullets with 100 grains of Pyrodex RS give me something in the range of 1400 to 1450 fps.

[lemoyne]

Try to give you a general idea, for 240 and 250gr bullets this is with a tight sabot it will make a differance, more with some powders than others.
Goex FF ,APP FF and the APP off brand give about 1500 fps
Pyrodex RS and Pellets about 1600 fps
777 FF ahout 1700to 1800 depending on tightness of sabot barrel length etc
Blackhorn about 1900 to 1975 depending mostly on a tight sabot [a loose sabot in some guns can cause hang fires]
With most powders your 300gr will be about 200fps slower except Blackhorn will be more like 100 fps slower.
Hope this gives you a general idea. Lee

[Semisane]

Based on my experience I would say thatLee hassummed it up perfectly.

[muzzlenut]

Thanks guys for your replies.

Lemyone, that is the kind of the formulated info I was looking for. Something to give me general idea. I know that MV isn't the most important variable in accuracy but I like to run information through a ballistics/trajectory calculator to get a better understanding of what I am shooting and to help me understand my capabilities and limitations.

I am assuming that since both of my MLs have a fairly long barrel for an inline (28") that my velocities would be toward teh upper end of that range. Also, does the fit of the sabot make a difference as long as it is tight enough that you don't lose compression. I shoot the harvesters because they are easier to load but they still give resistance when loading.

Thanks again for you help.

[lemoyne]

muzzlenut
I will say yes, the guys here will tell you that I am a bit of an accuracy nut, and they are right, that's what I enjoy.
Think about this, the tightness of the projectile be it a sabot or round ball controls how much pressure is built up before the projectile starts moving, that controls how well the powder burns and if the vibration of the barrel is the same or not both of which affects accuracy. Back when I was shooting bench competition with a round ball I found out to get it in the x ring every time every thing needs to be exactly the same; consistency is what makes it work. That's why we wipe our barrels every time and try to get a sabot with just the right amount of pressure [to much is as bad as to little] the only exception I know of is Blackhorn 209 it actually shoots better if you don't clean between shots, now its true that with some powders that you can get several reasonably accurate shot which is fine for hunting at 150 yds and under. lee

[muzzlenut]

lemoyne

I stand humbly before you and thank you for your expertise. I failed to apply the basic principles of physics to my reasoning. My thought in my previous post was that less friction would mean faster expulsion from the barrel but I didn't take into consideration that leaving the barrel earlier does not mean that the projectile is traveling faster when it leaves the barrel.