I just bought some of the 55gr Vmax bullets. When I checked the max charge with Hornady, they list 23.7 gr H335. Hogdon list the max charge as 25.3 gr H335. Why the difference, I Hornady playing CYA?

Maby that hornady uses actual rifles in most of thier tests and hodgdon uses "test barrels".You have a bullet mfgr. that is giving data that they feel did fairly and safely well using thier product in an actual firearm,,,and a powder mfgr.that is just giving you data for the maximum charge weight they consider safe for a certain weight bullet class in whatever cartridge you're looking at,not posting any accuracy comments at all. The more of thier powder you burn when you pull the trigger,the sooner you'll be buying more.The bullet mfgrs.[all of them]make the same money on every round you send through the air regardless if you use 1 gr. of powder or 500 gr. Comparing hornady and lyman data,,,the loads darn near mirror each other,if you feel that it is'nt enough powder in the case,you can resort to the powder mfgrs.data and usually be able to stuff a couple more grains in,according to them. Be Carefull and Good Shooting!!!! P.S somewhere in the front of the hornady manual they mention thier criteria on selecting powders and charge wieghts

EL VIEJO,
The difference in the loads may well be due to the difference in the length of barrel used to develope the loads. The barrel length is indicated in the manuals. It also may just be the difference between the rifle used in one manual opposed to the rifle used in the other manual. I hope that this is of some help. Good luck.

If you read (5) loading manuals, you'll find they all very quite a bit. There are just too many variables to be able to duplicate published data. Chambers, barrels, cases even the dies used can all change pressures & velocities. I have at least (3)CURRENT manuals & take the average of the max. loads listed as my working max. Start 5% below that & work up. Some carts. like the .280, 7X57. etc. are usually shown under loaded. Be safe, have fun!

I think everyone but Speer publishes velocities from test barrels.

However, when there are big differences in charges you might want to look at the OAL the different manuals used. Often there will be a lower max charge if someone seated the bullet a lot deeper.

When OALs and barrel lengths are similar the differences will be remarkably small. Check out .375 H&H loads with the 270 Hornady SP using RL-15 and IMR 4064 in the Hornady, Alliant and Accurate manuals for a good example.

Barrel length can't have anything to do with what amount of powder a case can take.

Are both manuals using the same primer? Are they using the same lot or batch of powder? Seated to the same distance off the lands? All these things will affect the "max" load.

The day when you find identical charge recommendations in two different manuals for the same bullet in a given cartridge is when you need ask questions!! There are so many variables at play in reloading that it is a wonder that so many recommended loads are even similar!! This is why they always tell you that your loads HAVE TO BE DEVELOPED INDIVIDUALLY IN YOUR INDIVIDUAL GUN!! Reloading manuals are a guide only, so one must start with the lowest powder charges published in them!!

Ditto Eldequello!

Today, I shot the bullets I loaded last week. I got some interesting results.

Gun: Rock River 5.56m 16car 1 in 9 twist
Bullet: Hornady A Max 52gr
Powder: WC844, new, not pulldown
Charge Weights: 23.5 to 25.5 in .5gr increments.
Each charge hand weighed on a digital scale to exact weight.

The velocities on the AMax loads ranged from 2800fps for the light charge, to 3100fps for the heavier charge.

None of these loads gave groups as good as the Remmington 55gr PSP I loaded on the Dillon progressive press (which has a .2grain variation).
This load gave the best groups of all, although still leaving something to be desired. Also, the Remmington 55gr PSP are .0005 wider at the base than the AMax bullets are.

I am thinking that what I need is a heavier bullet, 62 gr.

The oddest thing is that I had a 32 fps std deviation. The brass was from the same lot, and weighed. The primer was Winchester small rifle(standard, not match) and each powder charge was weighed to the exact same weight on a digital scale. Anybody got any ideas as to what is going on?

[ 08-04-2002, 06:07: Message edited by: El Viejo ]

Do not be afraid to send an e-mail to the manufacturers Tech section. I do this all the time whenever I need something explained and they have always been eager to answer my questions in a timely manner, that 's what why they are there.

http://www.hodgdon.com/

http://www.hornady.com/

[ 08-04-2002, 20:12: Message edited by: raamw ]

Thanks, I will.