Rifle case fill percentage

4T4MAG · May 21, 2015, 03:57 PM

Is there a benefit to achieving a case fill rate of %100? I'm wanting to load some 338 win mag with Varget, of which Nosler and Barnes show load date. However the fill rate is about %85, where some other powders are %105 full. Does a case only %85 full still burn well? The use will be mainly hunting. I know I could go out and test each load to find out myself, I figure the knowledge is already out there. I tried searching but did not find much.

Thanks.

jwrowland77 · May 21, 2015, 04:04 PM

I personally like powders where I get full cases. My best match loads are slightly compressed loads. I get a lot more consistent numbers with slightly compressed loads.

flashhole · May 21, 2015, 08:02 PM

I echo what he said

Clark · May 21, 2015, 11:23 PM

I seem to get away with 105% per quickload with stick powder.
Ball powder does not compress enough to notice.

nemesiss45 · May 22, 2015, 02:00 PM

Accuracy aside, i have never had any problem with cases filled slightly less than full... you can expect perfectly reliable ignition with an 85% fill, and if that gets you to an accurate MV for your gun, it may be better than a 105% fill of another powder.

243winxb · May 22, 2015, 04:23 PM

Use a magnum primer.

**Unclenick** · May 22, 2015, 05:00 PM

4T4 Mag,

The slower bullets give the muzzle more time to rise, so some velocity variation doesn't usually affect shot placement much. The old M72 National Match load in .30-06 always ran on about 80-85% case fill, depending on the lot of 4895, and it could stay in the 10 ring at 600 yards (about 12" circle). So, for hunting accuracy that isn't at extreme ranges, I would not be too concerned.

FrankenMauser · May 22, 2015, 05:30 PM

I try to stay as close to 100% as possible with some cartridges and powders. But, the choice seems pretty arbitrary, when you look at the particular cartridges and powders where I do such.

Generally, I try to stay with 95% or better, but some loads are down as far as 80% fill (.30-06, .270 Win).

My most consistent loads have always been compressed extruded powders. (Up to 110% case fill .... necessitating a long drop tube.)

Mobuck · May 23, 2015, 08:02 AM

I choose powders which provide 80%(85% is better) to 105% load density.

black mamba · May 25, 2015, 09:35 AM

It is kind of a self-correcting situation. The reason you only get 85% case fill is because the Varget is a little too fast for the 338 mag, but faster powders ignite more easily than slower powders so should not be a problem. If the load you are using to get the 85% fill is within the start to max published loads, then it should work well. You wouldn't want to go with an 85% fill load with a slower powder like RL22, but I doubt the books would have such a load listed.

May 21, 2015, 03:57 PM	#1
4T4MAG Senior Member Join Date: April 28, 2009 Posts: 162	Rifle case fill percentage Is there a benefit to achieving a case fill rate of %100? I'm wanting to load some 338 win mag with Varget, of which Nosler and Barnes show load date. However the fill rate is about %85, where some other powders are %105 full. Does a case only %85 full still burn well? The use will be mainly hunting. I know I could go out and test each load to find out myself, I figure the knowledge is already out there. I tried searching but did not find much. Thanks.

May 21, 2015, 08:02 PM	#3
flashhole Senior Member Join Date: February 9, 2005 Location: Owego, NY Posts: 2,000	I echo what he said __________________ ,,, stupidity comes to some people very easily. 8/22/2017 my wife in a discussion about Liberals. Are you ready for civil war?

May 21, 2015, 11:23 PM	#4
Clark Senior Member Join Date: December 4, 1999 Location: WA, the ever blue state Posts: 4,678	I seem to get away with 105% per quickload with stick powder. Ball powder does not compress enough to notice. __________________ The word 'forum" does not mean "not criticizing books." "Ad hominem fallacy" is not the same as point by point criticism of books. If you bought the book, and believe it all, it may FEEL like an ad hominem attack, but you might strive to accept other points of view may exist. Are we a nation of competing ideas, or a nation of forced conformity of thought?

May 22, 2015, 05:00 PM	#7
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	4T4 Mag, The slower bullets give the muzzle more time to rise, so some velocity variation doesn't usually affect shot placement much. The old M72 National Match load in .30-06 always ran on about 80-85% case fill, depending on the lot of 4895, and it could stay in the 10 ring at 600 yards (about 12" circle). So, for hunting accuracy that isn't at extreme ranges, I would not be too concerned. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

May 22, 2015, 05:30 PM	#8
FrankenMauser Senior Member Join Date: August 25, 2008 Location: In the valley above the plain Posts: 13,424	I try to stay as close to 100% as possible with some cartridges and powders. But, the choice seems pretty arbitrary, when you look at the particular cartridges and powders where I do such. Generally, I try to stay with 95% or better, but some loads are down as far as 80% fill (.30-06, .270 Win). My most consistent loads have always been compressed extruded powders. (Up to 110% case fill .... necessitating a long drop tube.) __________________ Don't even try it. It's even worse than the internet would lead you to believe.

May 21, 2015, 04:04 PM	#2
jwrowland77 Senior Member Join Date: March 23, 2012 Location: Conway, Arkansas Posts: 1,398	I personally like powders where I get full cases. My best match loads are slightly compressed loads. I get a lot more consistent numbers with slightly compressed loads.

May 22, 2015, 02:00 PM	#5
nemesiss45 Senior Member Join Date: February 6, 2014 Posts: 526	Accuracy aside, i have never had any problem with cases filled slightly less than full... you can expect perfectly reliable ignition with an 85% fill, and if that gets you to an accurate MV for your gun, it may be better than a 105% fill of another powder.

May 22, 2015, 04:23 PM	#6
243winxb Senior Member Join Date: July 26, 2011 Location: USA Posts: 1,730	Use a magnum primer.

May 23, 2015, 08:02 AM	#9
Mobuck Junior member Join Date: February 2, 2010 Posts: 6,846	I choose powders which provide 80%(85% is better) to 105% load density.

May 25, 2015, 09:35 AM	#10
black mamba Senior Member Join Date: September 13, 2011 Location: SW Florida Posts: 890	It is kind of a self-correcting situation. The reason you only get 85% case fill is because the Varget is a little too fast for the 338 mag, but faster powders ignite more easily than slower powders so should not be a problem. If the load you are using to get the 85% fill is within the start to max published loads, then it should work well. You wouldn't want to go with an 85% fill load with a slower powder like RL22, but I doubt the books would have such a load listed.