muzzle velocity using bh209

I read today where someone is getting 2050 approx. fps using 84gr of bh209 weighted. In my Remington ultimate mzl I get 1940 with 84gr and 2050 with 95gr. can anybody out there tell me why that happens ? guy ps I don't doubt others numbers .

Different:
Ignition source
Twist rate
Bullet fit

These items will effect velocity..

Were Bullet weights the same? Same Primer?

Bullet weights the same. ignition different . guy

Id say faster velocity was from a federal209A primer and 1-28 twist.
Yours large rifle primer and faster twist will be slower.
Then bullet fit?

One of the variables that will produce noticeable difference in velocities is the fit of your sabot bullet combination. Muzzleloaders have a wide tolerance in bore diameter this causes a tighter or looser fit Blackhorn is a progressive burning powder and just right fit will give more velocity so will a longer barrel. Your ignition can change it some but usually is not a major factor unless you use those weak 209's designed to keep the curd ring down when using 777.

That MV is quite a bit different than what RW has posted with his RUML.

gmstack said:

I read today where someone is getting 2050 approx. fps using 84gr of bh209 weighted. In my Remington ultimate mzl I get 1940 with 84gr and 2050 with 95gr. can anybody out there tell me why that happens ? guy ps I don't doubt others numbers .

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I guess my first thought was, what weight projectile were used in the two comparisons? Were these projectiles using sabots and were the sabots the same? Also was the other rifle a RU?

Bestill and others have suggested that the primers may have been the difference. With the that I would have to add they especially Bestill has more experience than I in this area.

I have tried to prove to myself that primers can effect velocity a few of times. I have never been able to show this difference.

This is one of the attempts I made to verify the effects of different primers.

That's funny Mike. It looks like CCI mag primers shoot to the left and the CCI regular primers shoot to the right. The Fed primers shoot straight.

Glad i'm using the straight shooting primers.

Original post stated Remington ultimate which would have large rifle primer and comparison was made to unknown gun primer velocity.

Imo federal209A with blackhorn will produce more velocity than lrp and blackhorn.

If we had details about gun and velocity being compared in original post could my give better feedback.
Primer type?
Twist rate?

bestill said:

Original post stated Remington ultimate which would have large rifle primer and comparison was made to unknown gun primer velocity.

Imo federal209A with blackhorn will produce more velocity than lrp and blackhorn.

If we had details about gun and velocity being compared in original post could my give better feedback.
Primer type?
Twist rate?

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Even his choice of CF primers could make a difference. LR vs Magnum Match.
I believe the CF magnum primer is hotter, the 209M/A has more pressure.
His twist is 1:26 in the RU, same as the BP Xpress.
I know you guys shooting sabotless say different but, IMO the bullet needs to be seated forcefully on BH209 in his RU, with a fairly tight fitting sabot/bullet. I've shot it before as you know and if that bullet wasn't seated hard, you could feel the ignition difference.
Just my 2¢..........

RW claims 136gr of BH209 by volume and a 300gr bullet is good for 2125fps from the RUML. Thats roughly 95gr by weight.


Knowing your exact bullet and sabot used would be helpful. Ive seen close to a 50fps difference just by changing a sabot in my ULA.

Near 1950 fps with a 250 grain saboted bullet in a 50 cal is a nice, ballpark average, 115-120 grains B209 powder by volume.

muskrat30 said:

Near 1950 fps with a 250 grain saboted bullet in a 50 cal is a nice, ballpark average, 115-120 grains B209 powder by volume.

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Maybe depending on the bullet, but shooting the Barnes 250gr TMZ's with the supplied sabots, I was getting just over 2,000fps using 107grs volume. My targets coincided with my ballistics programs.

I used 84gr measured bh209, 300gr hornady sst, Harvester H5045lb, cci 250 large rifle magnum primer. thus 1940 fps. the same components with 95gr measured yielded 2050fps.

Sorry, in my last post the charges were weighted NOT MEASURED. 84gr and 95gr weighted.

gmstack said:

Sorry, in my last post the charges were weighted NOT MEASURED. 84gr and 95gr weighted.

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How did that combination work?

Ii shot very well . quite accurate at 100yds.

Im surprised that sabot shot well in that bore. Ive heard they run a little large. I use the Harvester "short black" in the ULA and 275gr .4505 bullets (old Parker BEs). My ULA has a .500 land to land and the sabot loads kinda easy but still snug. It is the sabot that i get close to 50fps faster than the MMP Short which is tighter.

I would suggest trying the MMP HPH-24 and HPH-12. The HPH-12 will be noticeably tighter. The HPH-24 will be just slightly tighter, maybe not even enough to really feel a difference.

It is possible with BH209 a tighter fit could give you a higher MV.

good idea I have those also next trip I shall try them. guy