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Question re: density of IMR4320 powder
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I've fallen a little behind the power curve w/my .308 reloading and am preparing to catch up. I will be using, per the Lee Second Edition reloading manual, 45 grains of IMR4320 as the max load for my rifles, both of which are semi-auto. I am using .308 commercial brass - no NATO 7.62 - and a 147gr FMJ military bullet. My question is re: the density of the 4320 powder. 45gr of this powder comes, by my eye, about one-third the way up the shoulder of my brass on the inside. There is a compressed load of 4320 on the chart, at 49.0 grains. This is considered by the manual to be at the top end of the scale, a "max" load. When measuring I've been watching each try on the scale and seeing how close I can come BELOW the charge weight before I change the setting on the power trickler from "HIGH" to "VARIABLE," so I can trickle just enough powder onto the scale pan to make goal. Every try always gets the powder charge roughly half-way up that case shoulder, which at least is 1) consistent; 2) NOT a compressed charge, since holding the intended bullet alongside the case, lining up the cannelure center with the case mouth, and looking at where the base of the bullet is compared to the top of the charge, there is an obvious gap.

Based on anyone's experience - is it normal to fill that much of a .308 case with IMR4320, with a charge of 45gr?

PS - I am using an American Weigh Scale electronic digital scale for weighing the charge.
 
Posts: 48 | Location: SE USA | Registered: 09 August 2020Reply With Quote
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Sorry everyone - I said later in the post I was going half-way up the shoulder - it's still 1/3 of the way up. Sorry in advance if that caused any confusion.
 
Posts: 48 | Location: SE USA | Registered: 09 August 2020Reply With Quote
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You would be much better off using 48 grs of 748 in an auto..WW-748 and H414 suit the auto 308 better IMO...but 4320 is OK I suppose as ImR-4064 has been a go to powder for the 308 and preferred by many..I never got the best accuracy with IMR-4320 in my 308s..


Ray Atkinson
Atkinson Hunting Adventures
10 Ward Lane,
Filer, Idaho, 83328
208-731-4120

rayatkinsonhunting@gmail.com
 
Posts: 42190 | Location: Twin Falls, Idaho | Registered: 04 June 2000Reply With Quote
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It's years since I loaded for 305s and I never used bullets heavier than 150 grains.

Like Ray said, 748 is good. Very dense and get 52 grains in without trouble. Winchester 748 has a burn rate similar to 4064 but you can get more in the case. Similar with Win 760 and 4350.

4320 is in the same general birn rate as 4064 and Varget. For wme they were too slow with 130 and 150 grain bullets. In Australia an Australian made powder (the ones sold under the Hodgdon name) called 2206 is widely used and is lie 3031, virtually indentical in burn rate. 2208 is sod in America as Varget.
 
Posts: 7046 | Location: Sydney Australia | Registered: 14 September 2015Reply With Quote
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Nothing wrong with 4320, used a lot of it in my younger years in the 243 with great results. Staying with IMR powders 4895 and 4064 are the go to powder for accuracy loads. I don't like ball powders for the fact they generally burn hotter. They sure meter nice through your powder measure. The 5.56 was originally designed to be loaded with a stick powder. The only reason they went to the ball powder was the Army wanted more velocity and the ball powder gave it.
 
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Many years ago I used a lot of 4895, 4064 and 4320 and in 100 and 110 grain in the 270 and also in th 375 H&H. Lots of other Australian shooters were the same. Also for 130 and 150 grain in the 30/06.

Generally velocities were all about the same but in some 270s the 430 put close to a 100 f/s on the other two powders. 4320 was more touchy t maximum loads. The overall best results came with 4064.

Out of the Australian made powders sold by Hodgdon as H4350 etc., the Reloader powders and the IMR powders I found the IMR powders gave the best results when taken across many different loads and bullet weight in a calibre and that was from using 3031 through to 7828. However, the very best specific load for accuracy and velocity in most calibres came with either the Ausralian powder or Reloader powder, especially the Reloader powders.
 
Posts: 7046 | Location: Sydney Australia | Registered: 14 September 2015Reply With Quote
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quote:
Originally posted by Mike McGuire:
Many years ago I used a lot of 4895, 4064 and 4320 and in 100 and 110 grain in the 270 and also in th 375 H&H. Lots of other Australian shooters were the same. Also for 130 and 150 grain in the 30/06.

Generally velocities were all about the same but in some 270s the 430 put close to a 100 f/s on the other two powders. 4320 was more touchy t maximum loads. The overall best results came with 4064.

Out of the Australian made powders sold by Hodgdon as H4350 etc., the Reloader powders and the IMR powders I found the IMR powders gave the best results when taken across many different loads and bullet weight in a calibre and that was from using 3031 through to 7828. However, the very best specific load for accuracy and velocity in most calibres came with either the Ausralian powder or Reloader powder, especially the Reloader powders.


If you've been at this reloading thing for a long time you will notice that powders switch places in loading depending in which CARTRIDGE they are loaded in. In other words one must never go by the burn rates.
 
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Thought this was interesting.

cc/gr and gr/cc.

http://www.tacticoolproducts.com/powder.pdf
 
Posts: 6510 | Location: NY, NY | Registered: 28 November 2005Reply With Quote
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quote:
Originally posted by vzerone:


If you've been at this reloading thing for a long time you will notice that powders switch places in loading depending in which CARTRIDGE they are loaded in. In other words one must never go by the burn rates.



Agree 100% with that.

Although with some it seems to b a "speed up" or a "slow down" on all powders. I had a lot to donwith 6mm/06 and 6mm/284 and in accuracy stle guns. Did not go for fast twist and very heavy bullets but mainly 1 in 12 twist and relevant bullets. Although 6mm/06 is slighly larger case capacity it was best with a faster powder.

Reloader 7 is like two diffrent powders, when comparing burn rate to her powders, when used in the 458 Winchester as compared to in the 222 and 223.
 
Posts: 7046 | Location: Sydney Australia | Registered: 14 September 2015Reply With Quote
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quote:
Originally posted by Mike McGuire:
quote:
Originally posted by vzerone:


If you've been at this reloading thing for a long time you will notice that powders switch places in loading depending in which CARTRIDGE they are loaded in. In other words one must never go by the burn rates.



Agree 100% with that.

Although with some it seems to b a "speed up" or a "slow down" on all powders. I had a lot to donwith 6mm/06 and 6mm/284 and in accuracy stle guns. Did not go for fast twist and very heavy bullets but mainly 1 in 12 twist and relevant bullets. Although 6mm/06 is slighly larger case capacity it was best with a faster powder.

Reloader 7 is like two diffrent powders, when comparing burn rate to her powders, when used in the 458 Winchester as compared to in the 222 and 223.


That RL 7 is kind of like 4198. It's not a bad powder. A lot of Alliant's powders are double based I believe.

I've seen 4895 and 4064 change places among others. Many don't understand that the burn rates are a closed bomb test and that's not exactly like the powder being in a cartridge inside rifle with a movable bullet. Then the larger the bore is the faster that volume increases. Case shape plays a big part too.

That 6mm-06 that's like a 240 Weatherby huh?
 
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Similar case capacity to the 240, maybe a couple of grains bigger.

The 240 is smaller head size because belted and with rim and belt diameter of the 30/06 at .470 so bottom of the case a bit less than .470. However, it is a more parallel case and also Wby brass is thin in the walls so it comes out with similar case capacity.

6mm/06 brass of coutse much cheaper. Super easy to make from 25.06 brass.
 
Posts: 7046 | Location: Sydney Australia | Registered: 14 September 2015Reply With Quote
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quote:
Originally posted by Mike McGuire:
Similar case capacity to the 240, maybe a couple of grains bigger.

The 240 is smaller head size because belted and with rim and belt diameter of the 30/06 at .470 so bottom of the case a bit less than .470. However, it is a more parallel case and also Wby brass is thin in the walls so it comes out with similar case capacity.

6mm/06 brass of coutse much cheaper. Super easy to make from 25.06 brass.


You are of course right about that. That's one Weatherby cartridge that didn't go over so well.
 
Posts: 662 | Registered: 15 May 2018Reply With Quote
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I'm returning after getting out (not on my own accord) in 1995. Just a little scary to see that much powder in a case. However, it's NOT a compressed load which the manual makes reference to farther up the scale, so it must be OK pressure-wise.

I remember loading the Unique powder and because of its flake characteristics it was easy to put what seemed to be a LOT in a 9mm case even though it was what was called for. 4320 is a stick or rod powder and therefore a little denser, but not like a ball powder; identical weight charges of 4320 vice a ball powder should in theory fill different interior volumes of the same case due to the difference in physical characteristics of the two powders. The ball should pack more densely than the rod or cylindrical powder you'd think - meaning a physically smaller charge. Am I guessing right?
 
Posts: 48 | Location: SE USA | Registered: 09 August 2020Reply With Quote
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quote:
Originally posted by vzerone:
quote:
Originally posted by Mike McGuire:
Similar case capacity to the 240, maybe a couple of grains bigger.

The 240 is smaller head size because belted and with rim and belt diameter of the 30/06 at .470 so bottom of the case a bit less than .470. However, it is a more parallel case and also Wby brass is thin in the walls so it comes out with similar case capacity.

6mm/06 brass of coutse much cheaper. Super easy to make from 25.06 brass.


You are of course right about that. That's one Weatherby cartridge that didn't go over so well.


Several years ago I had quite a bit with Weatherby custom shop rifles. One day I was talking to the bloke that ran their custom shop and about the 240 and he said the reason the 240 has only limited sales is because the cost of Mark Vs is such that most buyers want a calibre that is better as an all round calibre. I think the other issue is with any f the bigger 6mm cartridges a very high percenatge of shooters will want them in an accuray based rifle.

The custom shop fellow also told me that at different times of the year and I think he was referring to Elk shooting in America, the 270 Wby would outsell the 257.
 
Posts: 7046 | Location: Sydney Australia | Registered: 14 September 2015Reply With Quote
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quote:
Originally posted by SSI01:
I'm returning after getting out (not on my own accord) in 1995. Just a little scary to see that much powder in a case. However, it's NOT a compressed load which the manual makes reference to farther up the scale, so it must be OK pressure-wise.

I remember loading the Unique powder and because of its flake characteristics it was easy to put what seemed to be a LOT in a 9mm case even though it was what was called for. 4320 is a stick or rod powder and therefore a little denser, but not like a ball powder; identical weight charges of 4320 vice a ball powder should in theory fill different interior volumes of the same case due to the difference in physical characteristics of the two powders. The ball should pack more densely than the rod or cylindrical powder you'd think - meaning a physically smaller charge. Am I guessing right?


Yes. Powders like Winchester 748 and 760 will get a lot more weight of powder in the case. That is why 748 can work very well when 4064 burn rate is a bit skow as 748 is lime 4064 burn rate but youcan simply get more in the case. Same thing where 4350is a bit slow then Win 760 can be good. The 375 H&H is a good example. 4064/4895/4320 are a bit too fast burning but 4350 is a bit too slow and especially with long spitzer bullets so 760 does very well.
 
Posts: 7046 | Location: Sydney Australia | Registered: 14 September 2015Reply With Quote
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Grew up using 4350 and H4831 (old early stuff), great powder but had to weigh charges..Today Im a fan of the ball powder and short sticks that meter such as most of the RL powders, RL 15,16,17,19, and I love H414, CFR-223, H322, etc. the ones you don't have to weigh and they don't cut grains in the powder measure, and they hit the "0" mark every time..If your not comfortable with this don't do it..


Ray Atkinson
Atkinson Hunting Adventures
10 Ward Lane,
Filer, Idaho, 83328
208-731-4120

rayatkinsonhunting@gmail.com
 
Posts: 42190 | Location: Twin Falls, Idaho | Registered: 04 June 2000Reply With Quote
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quote:
Originally posted by Atkinson:
Grew up using 4350 and H4831 (old early stuff), great powder but had to weigh charges..Today Im a fan of the ball powder and short sticks that meter such as most of the RL powders, RL 15,16,17,19, and I love H414, CFR-223, H322, etc. the ones you don't have to weigh and they don't cut grains in the powder measure, and they hit the "0" mark every time..If your not comfortable with this don't do it..


My Belding & Maul powder measures will cut zero with just about any powder. It will even cut 5010 pretty good. This is of course if you know how to operate it correctly.
 
Posts: 662 | Registered: 15 May 2018Reply With Quote
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quote:
Originally posted by SSI01:
I'm returning after getting out (not on my own accord) in 1995. Just a little scary to see that much powder in a case. However, it's NOT a compressed load which the manual makes reference to farther up the scale, so it must be OK pressure-wise.

I remember loading the Unique powder and because of its flake characteristics it was easy to put what seemed to be a LOT in a 9mm case even though it was what was called for. 4320 is a stick or rod powder and therefore a little denser, but not like a ball powder; identical weight charges of 4320 vice a ball powder should in theory fill different interior volumes of the same case due to the difference in physical characteristics of the two powders. The ball should pack more densely than the rod or cylindrical powder you'd think - meaning a physically smaller charge. Am I guessing right?


Yes and no on using less ball powder. In most reloading with the fast to medium burn rate ball powder, true. But if you take something like 860, 867, 870, and 872 these are very slow burning powders and they fill the case up without being overloaded. Often kind of not enough.
 
Posts: 662 | Registered: 15 May 2018Reply With Quote
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my go to powder in 308 win. is usually RL-15
 
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