High Pressure on 6x45

V

VAkritterkiller

New member
Ok im new to reloading for AR's but have rolled quite a few for my bolt guns but im running into pressure problems with my oly 6x45. The only loads it likes are the ones showing high pressure, IE flattening primers. Ive tried different powders, weights, bullets, COAL, primers, but nothing fixes it. Is there something I'm missing? Ive heard of adjustable gas blocks would this help?
 
How flat are they? If the edges are just knocked off, I'd not worry too much. If it was popping primers and such, yeah, worried.
 
Flat enought you can drag your fingernail across it and not hang it at all. Also seems to ding the mouth of the case up pretty bad too and when re priming the primers fall in.
 
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A luke-warm load with a case that is shorter than the chamber can give you very flat primers. Is your load near max by load data?
 
Im using the loads posted on here by pcammo. Ive tried backing down grain by grain but as i do, the groups open up considerably. Only difference ive found is the majority of the loads were based on a bolt, not a AR. The flat primers dont bother me as much as the loose primers.
 
First fire on cheap brass (PMC) and 2 loads out of remington and winchester brass. Another problem im having is the bullets dont seat far enough to clear my mags and im having to seat further than i would like. Any good mags out there for longer bullets? ive tried pmags, dpms metal and el cheapo plastics.
 
You will be limited to about 2.260 max length but some bullets may not need to be seated that long to touch the lands of the barrel... just depends on your chamber.
Maybe if you give an example of a load that that caused loose primers in one firing that might be helpful.
A 6X45 is usually easy to find a accurate load for with many different powders and bullets.
 
Your load would be very helpful. As others have suggested, make sure you are not setting back the shoulder during sizing and be cautious of seating the bullet into the riffling.
John
 
27.3 gn h335 cci400 and450 primer 70 gn nosler ballistic tip. Have to get ack to you on the COAL. That's the most accurate load but shows the most pressure. I've stepped down .2 gn increments to 26 but the groups open up as I go down. I've tried 70 gn sierra blitzkings and 65, 55, vmax but no luck on accuracy.
 
sounds like you might be overworking your brass during the necking up process. If you bump the shoulder back too far, you'll create an excessive headspace condition which may result in seeing the pressure signs you mentioned.

Is there any way you can measure the datum line on the shoulder to note the difference between a resized and a fired case?
 
Originally Posted By: knockemdownsounds like you might be overworking your brass during the necking up process. If you bump the shoulder back too far, you'll create an excessive headspace condition which may result in seeing the pressure signs you mentioned.

Is there any way you can measure the datum line on the shoulder to note the difference between a resized and a fired case?

Since they have the same shoulder and length I use this to check mine works great.

http://www.natchezss.com/product.cfm?con...&src=mbProd
 
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prezactly. I have those RCBS Mic gauges in almost every caliber I load for...

You really don't want to see more than .005" difference between resized & fired.
 
I went and looked up that load since I was shooting it.
You are right on with 27g H335,70g NBT, My COL was at 2.250" that just fit my magazines. This was ran about 2900 fps, 20" bbl, 1/10" twist, very accurate and not one sign of pressure, my primers were always nice & rounded.
I have since just gone to the 65g Vmax and its faster & was more accurate in my AR.
 
I checked my casings and yall was right, the dies were set to far down and pushing the shoulder back. Didnt get a chance to test a batch yet but should get back with the results next week.
 
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