Bullet Diameter

[ArtP]

I currently reload for rifle cartridges and am going to start reloading handgun cartridges. When choosing rifle bullets the choices have been straight forward, i.e., .277 bullets for 270 cal and .243 bullets for .243 caliber. For loading 44 mag I have found .429 & .430 bullets available from reputable manufacturers, both jacketed, both stated they are intended for 44 mag.

After searching the question, I am not 100% positive of the answer, but it looks like it doesn't matter. But shouldn't it? Is there a rule, such as .429 for jacketed and .430 for cast? If the gun matters, I will be loading for Marlin 1894 & Ruger SBH - both modern.

Second, because some components are still hard to find, can I use bullets designated for one caliber for another caliber? Example; Speer GDHP are available in a .355/125gr bullet but are designated .357 Sig. Could I use those as a substitute for .355/124gr which are designated 9mm? I would never substituted diameter, only weight. I would also only substitute auto fed to auto fed or revolver to revolver, thinking the bullet shape plays a role.

One more, while I'm at it... What is the difference in a pistol vs. rifle primer? The hardness of the cup? The amount of charge? Using modern, strong arms with reletively hard pin strikes, like the arms mentioned above, could I use large rifle primers in the 44 mag cartridges?

Assume for all of the scenarios mentioned that I would be working my way up from 90% of max load and never switch a component without working back up.

 

[rcmodel]

.44 Cal jacketed bullets are normally .429". Hornady for one makes them .430", and their XTP line is uniformly very accurate in all calibers.
Bottom line is, .001" doesn't make enough difference in pressure to matter.

Lead bullets are commonly sized .430", but in fact will give better results in some revolvers if even larger. They need to fit the chamber throats, regardless of what the bore diameter is.

Rifle primers are harder, and have more brisance, or flame then pistol primers.
In the case of your .44 Magnum, you should not use LG rifle primers because .44 Mag primer pockets are designed for LG Pistol primers.

There is a slight difference in cup height between LG Pistol and LG Rifle primers.
A Lg Rifle primer is taller, and may not seat fully in a pistol case, and high primers will result.

SAAMI allows .125" to .132" for large rifle pockets but only .117" to .123" for large pistol.

In a tube magazine like your Marlin, that may leave the bullet noses setting on the protruding primers.
Which could result in a Series of Unfortunate Events.

rc

 

[918v]

You need to measure the cylinder throats and slug the bore. If your cylinder throats are smaller than your barrel groove diameter (as is sometimes the case with Ruger revolvers) send the cylinder off to be honed to .0005" over your groove diameter, then buy appropriate size cast bullets.

 

[ArtP]

RC -

Now twice you have come to my aid and answered for me. Many thanks.

Making sure to get the right diameter, does the designation, i.e., 44 mag or 444 marlin matter (in a hornady round, both state .430)?

 

[rcmodel]

I think some premium .444 Marlin hunting bullets may in fact be more heavily constructed, and fail to expand at .44 Mag velocity. But certainly not all .444 mag bullets.

Given a choice, get .44 Mag bullets for .44 Mag, and .444 Marlin bullets for .444 Marlin.

rc

 

[moxie]

FWIW, brisance has nothing to do with flame, even though it is sometimes associated with the speed of an explosive's "flame front." It's actually a measure of relative shattering effect or shock of an explosive. It has to do with the speed with which an explosive detonates. As examples, RDX and PETN have higher brisance than TNT. You can literally feel the greater "snap" of high brisance explosives detonating compared to the tamer stuff.

 

[rcmodel]

Thanks for correcting me!

But I might point out that primer strength is commonly measured and referred too as the brisance. It is used by the manufactures as a measure of primer strength (flame size & duration).

http://findarticles.com/p/articles/mi_m0BQY/is_5_55/ai_n31480080/

http://www.castingstuff.com/primer_testing_reference.htm

I was trying to keep my reply to ArtP's question on a level sufficient to answer his question.
I didn't intend for it to turn into a high explosive/chemistry definition thread.

rc

 

[moxie]

Simply striving for accuracy, please don't take offense.

The first article's statement "Primer brisance mostly depends on the length of the flame that leaps out of the flash-hole" is simply incorrect. The second article is harmless, I guess.

Do any of the manufacturers themselves actually use the term brisance as a measure of primer strength? I haven't seen this personally. It's simply a loose use of the term and is incorrect.

(23 years, AF munitions officer)