Cavim 308 7.62 powder

iagbarrb · June 9, 2016, 01:34 PM

Hy friends,

Does anyone knows which powder uses Cavim for its 7.62 308 ammo?

**Unclenick** · June 9, 2016, 03:08 PM

Commercial ammunition plants normally use bulk grade powders which have more burn rate variation than the canister grade powders sold for reloading. Powder for handloading is usually controlled to ±3-5% of nominal burn rate, depending on the maker, while it is not uncommon for bulk grade powder to vary by more than ±10%. The ammunition manufacturers do this because controlling burn rate adds cost to the powder, and the ammunition maker has pressure test guns with which to adjust his loads to compensate for different burn rates. Handloaders normally rely on published recipes, so they cannot have their powder burn rate vary so much, or the recipes would be invalidated.

The bottom line is that there may be no exact match to that powder that is available to handloaders. I can only tell you that the standard spherical propellant used in 7.62 Ball ammunition in this country is WC846, which is available in both bulk and canister grade. The bulk grade is WC846, while the canister grade is sold by Hodgdon as BL-C(2). If you can get that powder, it would be a close comparison. For most consistent ignition you should use a magnum or a NATO specification primer with it like the KVB762 or the CCI #34.

michaeldarnold · June 9, 2016, 05:45 PM

^^^Does this stuff come out of a book, or off the top of your head? Your specifics are amazing. Good info. Thanks.

iagbarrb · June 9, 2016, 11:18 PM

Thanks for the explanation.
It means this bulk grade powder will never give me the accuracy I would like to have. I might have to search for a nice load reducing the charge dtep by step, till I find a consistent grup?

Marco Califo · June 10, 2016, 12:29 AM

iagbarrb,
What that means is that, like the rest of us, you will need to select a suitable powder that is available to you. Then you start testing loads at 90% of maximum loads and work up slowly, checking accuracy and fired cases for any signs of over-pressure (perforated primers, flattened primers, etc.). Yes, you will be able to load factory quality ammo with these cannister powders. The only advantage of bulk powders is/may be cost, not capability.

Here are some (there are a lot more) commercially available powders well suited to 308/7.62:
Ramshot: TAC
Accurate Powders: AA2230, AA2460, AA2495, AA2520
IMR: 4895, 4064, 4320

The bolded powders are explicitly endorsed for gas operated 308 rifles: "within the threshold limit for the M14 systems." ALL eight of those powders are in the same general burn rate range (#84-105 http://imrpowder.com/PDF/Burn%20Rate...02015-2016.pdf). Even if you are not shooting a gas gun, these powders and their published loads are definitely mainstream for any 308 firearm.

Go here, select your caliber, bullet weight, and they will list many loads:
http://www.hodgdonreloading.com/
Accurate and Ramshot data is available here:
http://www.accuratepowder.com/wp-con...1-2016_Web.pdf

Some of the powders listed are made in Belgium, Canada, and Australia, and may be known by different names in different countries. So, find out what you can get, and then see if you can find load data for it. Only then you are ready to purchase powder.

You original question, "what does CAVIM use?" We don't know, that info is not published. If you have some CAVIM 308 ammo, pull the bullet out, and dump the powder where you can examine it. It will be either A) tiny sticks or cylinders (extruded) or, B) tiny specs which are flattened balls (ball powder). Whatever they used will be closely equivalent to AA2495, or IMR 4895 (sticks), or TAC, or AA2520 (ball). Any of those powders will be fine, and exactly appropriate. And as Unclenick pointed out, U.S. military 7.62 uses a ball type powder available as Hodgdon BL C(2) and WC846 (surplus when available).

drobs · June 10, 2016, 06:55 AM

Completely unrelated - I always like Cavim. Worked great in STG58 and M1A.

mineralman55 · June 10, 2016, 07:04 AM

Not to start an argument, but I thought
WC 844 = BLC(2)
WC 846 = H335

T. O'Heir · June 10, 2016, 02:40 PM

Commercial and military ball ammunition makers don't publish what components they use. Both of 'em are loading to get a specific velocity and pressure range as per a 'spec'. They may not use the same powder every time at all.
"...come out of a book, or..." Started with books.

HankC1 · June 11, 2016, 09:30 PM

Quote:

Completely unrelated - I always like Cavim. Worked great in STG58 and M1A.

I thought Cavim brass is soft and have issue for reloading. I once saw a pile of Cavim brass at the range and no one pick up the brass! I took them home but set them aside!

Marco Califo · June 11, 2016, 11:03 PM

Quote:

BLC-2?
Not to start an argument, but I thought
WC 844 = BLC(2)
WC 846 = H335

Its the other way around:
"Hodgdon
BL-C (Lot 2) for full-charge loads in the .308 Winchester and .223 Remington[12] was newly manufactured by Olin in 1961 with 10 percent nitroglycerin, 10 percent diphenylamine stabilizer, and 5.75 percent dibutyl phthalate deterrent, but without the flash suppressant used in the surplus military propellant.[10] . . .
H335 was surplus Olin WC844[10] for full-charge loads in the .223 Remington and .308 Winchester.[12]"
https://en.wikipedia.org/wiki/Ball_propellant

**Unclenick** · June 12, 2016, 11:31 AM

Correct. Back in 2009, before some of the specificity requirements were dropped, I assembled the following table of equivalents from various manufacturer MSDS sheets. The current MSDS sheets no longer include the equivalent name information. For that reason, unfortunately, newer powders aren't possible to include without begging the distributors for the information, which they sometimes will and sometimes won't give.

The gas gun pressure limits was a good point to bring up. Meeting SAAMI standards means not exceeding an average maximum pressure (called Maximum Average Pressure, which I think causes some confusion) and meeting velocities for common bullet weights that are ±90 fps of SAAMI's velocity numbers for them. A powder that won't do both at the same time does not match the SAAMI standard. The military, however has not only an average maximum pressure but a tighter ±30 fps velocity for specific bullets, as fired from a test barrel (individual guns vary a good bit more), plus a gas port pressure window must be stayed within at a standard distance down the barrel. So the military spec is tighter.

Code:

Powders from 2009 MSDS sheets (some newer MSDS sheets lack the powder name information due to
changes in MSDS requirement regulations).

Note that bulk grade versions have wider burn rate specs and can vary significantly from the
canister grades, which are controlled for burn rate by blending with held back fast or slow 
lots, as needed to adjust them to within ±3% of their nominal burn rates.

     Canister      | Bulk Grade |       Canister         | Canister |      Canister        |
      Grade        |            |        Grade           |  Grade   |       Grade          |
                   | St. Marks  |                        |          |                      |
     Hodgdon       | Mil & OEM  |      Winchester        | Thales   |        IMR           |
___________________|__Numbers___|________________________|__(ADI)___|______________________|_
                   |            |                        |          |                      |
HP-38--------------|-- OBP231 --|- 231 ------------------|----------|----------------------|-
                   |   OBP124   |  AALite (WFL)          |          |                      |
Titewad            |   OBP132   |                        |          |                      |
Tightgroup --------|-- OBP242 --|------------------------|----------|----------------------|-
                   |   OBP465   |  Super-Handicap (WSH)  |          |                      |
Longshot           |   OBP473   |                        |          |                      |
Lil' Gun ----------|-- OBP516 --|------------------------|----------|----------------------|-
Hybrid 100V        |   SHP771   |                        |          |                      |
                   |   SMP224   |  AutoComp              |          |                      |
-------------------|--- WAA90 --|- WST ------------------|----------|----------------------|-
H110               |    WC296   |  296                   |          |                      |
HS-6               |    WC540   |  540                   |          |                      |
HS-7               |    WC571   |  571                   |          |                      |
-------------------|--- WC748 --|- 748 ------------------|----------|----------------------|-
H414               |    WC760   |  760                   |          |                      |
H335               |    WC844   |                        |          |                      |
BL-C(2)------------|--- WC846 --|------------------------|----------|----------------------|-
H380               |    WC852   |                        |          |                      |
US869              |    WC869   |                        |          |                      |
-------------------|-- WMR780 --|- Supreme 780 ----------|----------|----------------------|-
                   |   WXC170   |  WSF                   |          |                      |
Clays              |            |                        |  AS30N   |                      |
International Clays|------------|------------------------|- AS50N --|----------------------|-
Universal Clays    |            |                        |  AP70N   |                      |
H4227              |            |                        |  AR2205  |IMR 4227 second source|
H4198 -------------|------------|------------------------|- AR2207 -|----------------------|-
                   |            |                        |   BM1    |                      |
H322               |            |                        |  AR2219  |                      |
Benchmark          |            |                        |   BM2    |                      |
-------------------|------------|------------------------|- AR2210 -|- IMR 8208 XBR -------|-
H4895              |            |                        |  AR2206H |                      |
Varget             |            |                        |  AR2208  |                      |
H4350 -------------|------------|------------------------|- AR2209 -|----------------------|-
H4831              |            |                        |  AR2213  |                      |
H4831SC            |            |                        | AR2213SC |                      |
H1000 -------------|------------|------------------------|- AR2217 -|----------------------|-
Retumbo            |            |                        |  AR2225  |                      |
H50BMG             |            |                        |  AR2218  |                      |
-------------------|------------|------------------------|- AR2215 -|IMR 4198 second source|
                   |            |                        |  AS25BP  |IMR Trail Boss        |

iagbarrb · June 13, 2016, 02:27 PM

Thanks a lot for all the post. Very very useful. Ive learned a lot

iagbarrb · June 20, 2016, 05:14 PM

just to show some results with the ammo.

Results:
Disassambled the bullets, removed powder and tar. Primer remained.
I might have the powder information. It is brazilian CBC 102 (confirmation requiered)
Case is Brazilian CBC.
Projectile, Do not know yet, most probable also CBC.
Factory load 47 gn.
I reduced 2 gn to 45.
Results at 300 meters, ten impact group more than 10 inch wide. (For compare, I group 4 inch at 300 m with good ammo.)

Marco Califo · June 20, 2016, 07:10 PM

What does the powder look like?
Factory ammo does not need to be reduced. Accuracy may be better as issued. The reduction is from maximum when trying a new load with your own powder.
CBC owns S&B and other companies.
The tar indicates you have Milspec ammo; it is a water seal.

iagbarrb · June 21, 2016, 07:58 PM

Powder looks like round flakes. Can be described as segments of a cylinder.
Problem with the tar is that the tar remains in the barrel, and removing it from the barrel is extreme difficult. (This is not an experience I made, its other shooters experience) This is the reason why I disassembled the bullets and reassembled those.

I have never used this ammo before, and just received about 80 units as a gift from a friend.

I will use the original 47gn load and see what happens.

GeauxTide · June 23, 2016, 02:11 PM

^^^Does this stuff come out of a book, or off the top of your head? Your specifics are amazing. Good info. Thanks.

Unclenik is the Godfather of Reloading Information on this thread.

Marco Califo · June 23, 2016, 06:07 PM

Xylene will dissolve the tar.
The tar is used in U.S. military ammo used in machine guns. It seems to "burn up" when fired, else it would not be used.

June 9, 2016, 01:34 PM	#1
iagbarrb Member Join Date: May 31, 2015 Location: Bolivia Posts: 38	Cavim 308 7.62 powder Hy friends, Does anyone knows which powder uses Cavim for its 7.62 308 ammo?

June 9, 2016, 03:08 PM	#2
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,090	Commercial ammunition plants normally use bulk grade powders which have more burn rate variation than the canister grade powders sold for reloading. Powder for handloading is usually controlled to ±3-5% of nominal burn rate, depending on the maker, while it is not uncommon for bulk grade powder to vary by more than ±10%. The ammunition manufacturers do this because controlling burn rate adds cost to the powder, and the ammunition maker has pressure test guns with which to adjust his loads to compensate for different burn rates. Handloaders normally rely on published recipes, so they cannot have their powder burn rate vary so much, or the recipes would be invalidated. The bottom line is that there may be no exact match to that powder that is available to handloaders. I can only tell you that the standard spherical propellant used in 7.62 Ball ammunition in this country is WC846, which is available in both bulk and canister grade. The bulk grade is WC846, while the canister grade is sold by Hodgdon as BL-C(2). If you can get that powder, it would be a close comparison. For most consistent ignition you should use a magnum or a NATO specification primer with it like the KVB762 or the CCI #34. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

June 10, 2016, 12:29 AM	#5
Marco Califo Senior Member Join Date: April 4, 2011 Location: LA (Greater Los Angeles Area) Posts: 2,609	iagbarrb, What that means is that, like the rest of us, you will need to select a suitable powder that is available to you. Then you start testing loads at 90% of maximum loads and work up slowly, checking accuracy and fired cases for any signs of over-pressure (perforated primers, flattened primers, etc.). Yes, you will be able to load factory quality ammo with these cannister powders. The only advantage of bulk powders is/may be cost, not capability. Here are some (there are a lot more) commercially available powders well suited to 308/7.62: Ramshot: TAC Accurate Powders: AA2230, AA2460, AA2495, AA2520 IMR: 4895, 4064, 4320 The bolded powders are explicitly endorsed for gas operated 308 rifles: "within the threshold limit for the M14 systems." ALL eight of those powders are in the same general burn rate range (#84-105 http://imrpowder.com/PDF/Burn%20Rate...02015-2016.pdf). Even if you are not shooting a gas gun, these powders and their published loads are definitely mainstream for any 308 firearm. Go here, select your caliber, bullet weight, and they will list many loads: http://www.hodgdonreloading.com/ Accurate and Ramshot data is available here: http://www.accuratepowder.com/wp-con...1-2016_Web.pdf Some of the powders listed are made in Belgium, Canada, and Australia, and may be known by different names in different countries. So, find out what you can get, and then see if you can find load data for it. Only then you are ready to purchase powder. You original question, "what does CAVIM use?" We don't know, that info is not published. If you have some CAVIM 308 ammo, pull the bullet out, and dump the powder where you can examine it. It will be either A) tiny sticks or cylinders (extruded) or, B) tiny specs which are flattened balls (ball powder). Whatever they used will be closely equivalent to AA2495, or IMR 4895 (sticks), or TAC, or AA2520 (ball). Any of those powders will be fine, and exactly appropriate. And as Unclenick pointed out, U.S. military 7.62 uses a ball type powder available as Hodgdon BL C(2) and WC846 (surplus when available). __________________ ............ Last edited by Marco Califo; June 10, 2016 at 01:00 AM.

June 10, 2016, 06:55 AM	#6
drobs Senior Member Join Date: July 17, 2015 Location: South Central MO / Africa Posts: 1,111	Completely unrelated - I always like Cavim. Worked great in STG58 and M1A. __________________ NRA Life Member

June 10, 2016, 07:04 AM	#7
mineralman55 Member Join Date: September 29, 2009 Location: deep south Posts: 99	BLC-2? Not to start an argument, but I thought WC 844 = BLC(2) WC 846 = H335

June 9, 2016, 05:45 PM	#3
michaeldarnold Senior Member Join Date: April 8, 2016 Location: St. Louis Suburbs Posts: 137	^^^Does this stuff come out of a book, or off the top of your head? Your specifics are amazing. Good info. Thanks.

June 9, 2016, 11:18 PM	#4
iagbarrb Member Join Date: May 31, 2015 Location: Bolivia Posts: 38	Thanks for the explanation. It means this bulk grade powder will never give me the accuracy I would like to have. I might have to search for a nice load reducing the charge dtep by step, till I find a consistent grup?

June 10, 2016, 02:40 PM	#8
T. O'Heir Senior Member Join Date: February 13, 2002 Location: Canada Posts: 12,453	Commercial and military ball ammunition makers don't publish what components they use. Both of 'em are loading to get a specific velocity and pressure range as per a 'spec'. They may not use the same powder every time at all. "...come out of a book, or..." Started with books. __________________ Spelling and grammar count!

June 13, 2016, 02:27 PM	#12
iagbarrb Member Join Date: May 31, 2015 Location: Bolivia Posts: 38	Thanks a lot for all the post. Very very useful. Ive learned a lot

June 20, 2016, 05:14 PM	#13
iagbarrb Member Join Date: May 31, 2015 Location: Bolivia Posts: 38	just to show some results with the ammo. Results: Disassambled the bullets, removed powder and tar. Primer remained. I might have the powder information. It is brazilian CBC 102 (confirmation requiered) Case is Brazilian CBC. Projectile, Do not know yet, most probable also CBC. Factory load 47 gn. I reduced 2 gn to 45. Results at 300 meters, ten impact group more than 10 inch wide. (For compare, I group 4 inch at 300 m with good ammo.)

June 20, 2016, 07:10 PM	#14
Marco Califo Senior Member Join Date: April 4, 2011 Location: LA (Greater Los Angeles Area) Posts: 2,609	What does the powder look like? Factory ammo does not need to be reduced. Accuracy may be better as issued. The reduction is from maximum when trying a new load with your own powder. CBC owns S&B and other companies. The tar indicates you have Milspec ammo; it is a water seal. __________________ ............ Last edited by Marco Califo; June 20, 2016 at 07:15 PM.

June 21, 2016, 07:58 PM	#15
iagbarrb Member Join Date: May 31, 2015 Location: Bolivia Posts: 38	Powder looks like round flakes. Can be described as segments of a cylinder. Problem with the tar is that the tar remains in the barrel, and removing it from the barrel is extreme difficult. (This is not an experience I made, its other shooters experience) This is the reason why I disassembled the bullets and reassembled those. I have never used this ammo before, and just received about 80 units as a gift from a friend. I will use the original 47gn load and see what happens.

June 23, 2016, 02:11 PM	#16
GeauxTide Senior Member Join Date: April 20, 2009 Location: Helena, AL Posts: 4,426	^^^Does this stuff come out of a book, or off the top of your head? Your specifics are amazing. Good info. Thanks. Unclenik is the Godfather of Reloading Information on this thread. Last edited by GeauxTide; June 23, 2016 at 02:28 PM.

June 23, 2016, 06:07 PM	#17
Marco Califo Senior Member Join Date: April 4, 2011 Location: LA (Greater Los Angeles Area) Posts: 2,609	Xylene will dissolve the tar. The tar is used in U.S. military ammo used in machine guns. It seems to "burn up" when fired, else it would not be used. __________________ ............