44 Mag help, what am I missing.

[Hogpauls]

Here is the run down:
S&W 4" 629
MBC 240 grn. RNFP Smasher
7.0 grns of Titegroup
1.567" OAL
939.1 FPS

Another member here is getting 965 FPS with 6.2 grns of Titegroup under a 240grn LSWC at 1.654" OAL out of a Ruger Redhawk 7 3/8" barrel.

What am I missing? I'm using .8 grns more with a much shorter OAL shouldn't my load be traveling a bit faster? I know barrel length, elevation, temperature etc. has some play in how fast the bullet travels, but this much?

Please enlighten me.

 

[blarby]

You are missing, most likely, BC

IF these are out of the same weapon, and you are chronoing them on the same day, in the same hours worth of weather and temp.

I know that the BC of a RNFP differs from a SWC.... all things being the same ( which they aren't) I'd offer up that as a possible cause.

Also, the bearing length could be different on the bullet...but I'd go with bullet type, not just weight, being your issue.

 

[sugarmaker]

I think you're probably missing some barrel length. a 4" 44 carrys well but you're in the 50FPS per inch category between 4 and 6 inches, then something like 30fps per inch so I'd expect to loose 150FPS or so from 7.5 to 4". Cylinder gap can affect this also.

 

[Walkalong]

Big difference between 4" and 7 3/8".

Cylinder gaps vary quite a bit, and that can make a big difference. I have 6" guns that barely outrun 4" guns with the same load.

I have 5" 1911 barrels that vary 50+ FPS with the same load.

The BC has not come into play at that distance.

 

[newfalguy101]

I dunno, looks to me like you are within about 30FPS with half the barrel length.

It could be as simple as one barrel is "faster" than the other.

By the way, its immpossible to accurately compare data between different guns with any meaningful results, there are simply too many variables

 

[Hogpauls]

I dunno, looks to me like you are within about 30FPS with half the barrel length.

It could be as simple as one barrel is "faster" than the other.

By the way, its immpossible to accurately compare data between different guns with any meaningful results, there are simply too many variables

Thanks guys it is one of those things that make you go Hmmmmm.

 

[James2]

Any given load will perform a little differently in different guns. Nothing to worry about. Load for your guns.

 

[dirtengineer]

My dad and I both have Taurus model 44 with the same barrel length. Mine is stainless and his is blue. Mine is almost 100 fps faster with identical loads. Not sure why, but it is.

 

[elwoodm]

a big thing i noticed is profile of bullet. some hit the forcing cone of the barrel and there is a big distance from the end of the case to the end of the bullet a large space of no resistance these have a little more fps than bullets that hit the forcing cone with less distance from end of bullet to end of case. i think it means more of the bullet is in the barrel before it meets resistance less bearing load on lands and grooves.

 

[gamestalker]

There is more than one element at play here. First, longer barrels generally produce higher velocity. In terms of pistol barrels, 3-3/8" is a lot more barrel.

And then there is bullet profile. Two different bullets profiles, possibly two different bullet diameters, possibly two different lead qualities, two different barrels, and two different cylinders. There is also the variable of how much internal space is occupied by each bullet. Cylinder gap, forcing cones variables too.

Powder lot numbers are also a factor. And the fact that the other firearm is running .6 grs. more powder doesn't automatically mean more velocity. Powders react differently in regard to load density, and can actually produce faster or slower velocities. When I'm workng up a load it isn't unusual to see my velocities decrease at the upper end of the powder charge and visa versa.

You didn't indicate whether or not the same primers and brass were being used. This to can effect velcoities.

The variance in velocity you are concerned about is a pretty insignificant amount. I have various firearms that shoot significantly faster / slower than each other.

These are only some of the variables that exist between your comparisons.

 

[cactus02]

welcome to the world of chronographing. I have been doing this for forty years and and can tell you 25 fps difference is a rounding error with different bullets different guns at seperate times. Speer manual 10 lists different velocities for H110 and ww296 wich is the same powder. If Speer gets different data for different lots of the same powder and same barrel in labratory conditions why would you think you would get more consistent loads from your reloading room with used brass, different barrels, and different primers.

 

[Walkalong]

Yep, 25 FPS difference is mathematically insignificant.

 

[bluetopper]

Personally, I would be very leary of using Titegroup in a 44 Magnum unless the charge weights were very low.

 

[Hogpauls]

Yeah, I've come to the end of my Titegroup testing. I'm stopping at .3 grns short of max. I really had no intentions on using it as a load, I just had some on hand and for grins and giggles I wanted to get my own data on some loads with it.

 

[Mike Sr.]

Hi HP

I FEEL your pain....

I will gladly suffer the acceptance of your 629, 4" barrels suck....that's all there is 2 it....

Please let me know what dash model this, nasty 629 has attached to it.

Once it leaves you, you will no longer have to worry about inconsequential elements....I will inherit this indignity...knowing that my spot in heaven will now be secure...

PM details and I will forward my dealr's FFL and morturary address

regrds, take care, relief from this burden is just an MO away...

mike sr.

 

[floydster]

Titegroup and cast bullets do not mix, this is my experiecne after much testing.

 

[Hogpauls]

Mike, 629-5 V-Comp. I appreciate your offer and genuine regard for my pain but I think I'll hang on to it for awhile.

 

[Hondo 60]

Tite Group, cast bullets & 44 Magnums do not mix, this is my experience after much testing.

I think you're defeating the purpose of a 44 magnum by using Tite Group.
I've used several pound of it, but not in a 44.

To get the true 44 Magnum experience you need a slower powder.
W296 as mentioned above, H-110 (same as w296), Lil Gun, 2400, AA9, would all be good choices.

I usually use Lil Gun, but just made up a few with W296.

the preferred way to split a gallon water jug just like a banana