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Compressed load?
Posted: Sat Apr 08, 2017 9:48 pm
by Lammi
Hi guy's, at 44gn of 2208 I can hear the powder crunch a little when seating a 215gn berger to an oal of around 3.100" (.003" off the lands). Note that I am using a micrometer die that uses the ogive to seat. I am only getting very minor pressure signs on this load, and want to go hotter, only to see if I find a more accurate load. I am getting around 2500fps on this current load out of a 24" factory barrel with a 10" twist. First question is- when do you guy's stop? What is the absolute pressure sign you do not want? 2nd question, is it better to run a quicker powder than an (albeit) slight compressed load? Thanks.
Re: Compressed load?
Posted: Sat Apr 08, 2017 10:35 pm
by BATattack
44gr of 2208 behind a 215. . . . I'd say your pretty close to your limit especially if you have a short enough throat to be giving a compressed load in a factory rifle. 2500fps is pretty fast in a 24" barrel!
how many times can you fire a case before the primer becomes loose?
Re: Compressed load?
Posted: Sun Apr 09, 2017 9:42 am
by KHGS
Proceed with higher loads with that combination at your own peril!!!! Considering that a "normal" load of 2208/155gr bullet is around 46 grains I would think you are at, or past a reasonable limit!!!!
Keith H.
Re: Compressed load?
Posted: Sun Apr 09, 2017 11:13 am
by ShaneG
That is a load i would consider in a Barnard with a long throat, Palma cases and tight headspace.
A factory rifle and barrel - no way.
As an aside compressed loads are always a problem maintaining overall length unless excessive neck tension is used.
Re: Compressed load?
Posted: Mon Apr 10, 2017 9:21 am
by Lammi
how many times can you fire a case before the primer becomes loose?[/quote]
I'm still using virgin brass so I can't tell. Measuring the pockets, the once fired has maybe .5 thou difference.
Re: Compressed load?
Posted: Mon Apr 10, 2017 9:24 am
by Lammi
KHGS wrote:Proceed with higher loads with that combination at your own peril!!!! Considering that a "normal" load of 2208/155gr bullet is around 46 grains I would think you are at, or past a reasonable limit!!!!
Keith H.
Thanks for your input. The primers aren't cratering yet, only indented, no raised edges however they are flattening out a little, but not quite square yet. Would you be able to provide more info on pressure signs that YOU stop at? Or the other questions I asked in the OP?
Re: Compressed load?
Posted: Mon Apr 10, 2017 8:00 pm
by plumbs7
Once the primers start flattening out , that is a real good sign to back of ! 2500 fps out of a "24 factory rig with 215's is bloody fast ! Be careful!
Re: Compressed load?
Posted: Mon Apr 10, 2017 10:19 pm
by KHGS
Lammi wrote:KHGS wrote:Proceed with higher loads with that combination at your own peril!!!! Considering that a "normal" load of 2208/155gr bullet is around 46 grains I would think you are at, or past a reasonable limit!!!!
Keith H.
Thanks for your input. The primers aren't cratering yet, only indented, no raised edges however they are flattening out a little, but not quite square yet. Would you be able to provide more info on pressure signs that YOU stop at? Or the other questions I asked in the OP?
If you are compressing 44 grains of 2208 your chamber is short throated for the 215grn bullets. This reduces the case capacity & will push the pressure up. What Shane G says in his post is quite correct. Primer cratering or lack of is not a reliable pressure indicator, nor is primer flattening, theses are used as comparative indicators. The better semi custom actions will not crater primers up to case failure. Some actions will crater primers with moderate loads. The most accurate method is to use a blade micrometer to measure the head of the case across the extractor groove. This requires a special micrometer & the "touch" to measure to .0001" of an inch, if you get an expansion of .0002" you better back off. I do use known primers & one brand only to gauge an indication of pressure as I develop loads upward. So many shooters use scary loads, judging pressure signs is an acquired skill & takes experience to learn.
I once inadvertently loaded a 210grn bullet with a 190grn bullet powder charge, when I fired it there was no indication that anything was wrong except that I found a spent primer on my shooting mat after the stage, on checking my cases I found a case with an expanded primer pocket. The spent primer looked perfectly "normal", a testimony to Barnard actions. It took some detective work to figure out what had occurred. Be careful, I have seen some nasty incidents due to incorrect loading procedures!!!
Keith H.
Re: Compressed load?
Posted: Tue Apr 11, 2017 1:12 pm
by Winston
Just had a play with your specifics in quickload. Assuming 56gr of h20 case capacity (bang on what my fired lapua brass measures), the load you're using calculates at 68k psi. Don't try any higher! Interestingly it does say you're very close to an OBT node (a little over it). 2206h will get you the same fps for less case fill (according to quickload), but it's still way too hot.
Re: Compressed load?
Posted: Mon Oct 09, 2017 11:23 am
by Lammi
Thanks to everyone. There is so much bogus information out there on the web. I have taken note and will adjust. Thanks for the constructive advice lads.