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Hot load signs

How do you decide if a load is too hot? Is it when you get primer cratering, ejector wash, or sticky bolt? In this past weekends match i was shooting what seems to be a light load compared to others and i was getting slight cratering, and ejector wash too. One round on sunday actually lost the primer, but it cld have been loose to begin with too. None of my rounds caused sticky bolt though.
 
Hey Goldy1, Here's an article that helps explain Load Density: http://stevespages.com/powderdensity.html
It might help others help you if you include Gun and load data you are using. How many firings on your cases? Is this the same load you have been using in the past? Is this your first negative experience with this gun/load? A little more background would be helpful..
Did you get the link I sent you last night?
 
Flattened primers with hard bolt extraction are the typical signs of excessive pressure but these also could be signs of some other problem.

Primer cratering, by itself, in my experience is not a good indicator of excessive pressure since it could be due to firing pin / hole issues. However when combined with other symptoms mentioned above it could mean high pressure.

What caliber are you loading? What powder are you using? Do you measure each powder charge or use a progressive loader? Are you loading near maximum? If so back off at least a grain and try a few loads.
I assume headspace and case sizing are within specs.
There could be a lot of things contributing to the conditions you described and it not be excessive pressure. The first place to check is the load itself and verify it's what you think it is.
 
Hey brad. I sure did get that article. It is very interesting, i think i've read it 3 times now just to try and remember all i can. Its the rifle i was using in the match this past weekend. the 6brx, using 32.7 varget, 107 sierra's and cci 450s. I weigh every charge and i was getting the same signs from the cases that have been fired 4-5 times as the ones that were getting final fireforming. I'm planning a trip to the range in the next few days to test a few different primers and loads to be sure im using the best load, or find a better one.
 
It doesnt sound like you are over charging them. When I started load development, I tested 105Vld's, 107MK's, and 108Vld's
Berger 105 VLD
Powder Charge 32.6 gr 32.8 gr 33 gr 33.2 gr
Berger 108 VLD
Powder Charge 33 gr 33.2 gr 33.4 gr 33.6 gr
Sierra 107 Match King
Powder Charge 33.2 gr 33.4 gr 33.6 gr 33.8 gr
Fireforming was done with 30 grains of Varget, Wolfe primers, 95 grain bullets, jammed .015. All testing was done with Varget and Wolfe primers.
I experienced small signs of pressure on the higher side with the 108's and 107's but nothing like you've explained.
Are you full length sizing your cases? Maybe you're bumping the shoulders down to far. I've found my BRX likes things to fit snug in the chamber. Watching you shoot last Saturday, it appeared that your bolt closed pretty easy and lifted hard. If the case is "loose" in the chamber, you will get false pressure signs because the primer will move back against the bolt first, flatten, and then the case will move back against the bolt. Primer cratering in my opinion is due to bolt/firing pin but usually not a problem unless it's excessive. Are you seeing any evidence of possible Case head Separation? Look for a faint line about 3/16" up from the groove at the bottom that goes all the way around the case. How are you fireforming your case's? It sounds like your problems may be starting from the time of fireforming or coming from chamber/case size issues.
 
Goldy,
if you haven't considered it yet, send the bolt to greg tannel and get the firing pin bushed. it may make this challenge disappear, never to be seen again unless you are really pushing pressure. i blame the 6brx "dynamics" for a possible source, prone to this behavior...but an AWESOME round! please keep us updated on your findings and solutions.
cheers,
doc
 
navyrad8r said:
if you haven't considered it yet, send the bolt to greg tannel and get the firing pin bushed.

This is a worthwhile suggestion, but be aware Greg just moved his operations to Colorado.

He's without doubt the bolt bushing guru - get it done & your cratered primers are history (as long as you don't go overboard in load testing!!).

Give him a shout & see if he's got his machines up & running!


Phone: 970-878-5421
Fax: 970-878-5420
E-mail: greg@gretanrifles.com
Address: Gre'-Tan Rifles LLC, 24005 Hwy. 13, Rifle, CO 81650
 
My customers and I have done extensive testing with the 6mmBRX. For Maximum case and barrel life and best accuracy loads between 31.5 and 32.5 of Varget in fire formed cases. Find a velocity between 3020 and 3080 fps where the accuracy node is best. With the 6mmRRX you have the best of all worlds. Bushing the firing pin will help with primer flow. But keeping the pressure within reason is the best thing. Some lots of Varget are hotter than others so test your loads. There is no reason one can not get 16-20 loads out of Lapua brass.
Nat Lambeth
 
Goldy, I think this article on pressure problems will be worthwhile to you: http://riflemansjournal.blogspot.com/2011/02/cartridges-long-range-reloading-safety.html

If you're blowing primers out of Lapua 6BR brass, you're definitely over pressure. With normal pressures, they will never loosen on that brass.
 
The 308 case above is almost scary!

hard bolt extraction

This is usually the first sign for me.

It happened last sunday when I was shooting my 338 Edge! Everything was going fine, then I tried the next batch which went up about .4 grains of powder! The bolt has a little resistance, first time that day. I quickly look at the case and didn't see any signs. I shot again and had a sticky bolt, now two in a row! I put my glasses on and inspected both cases. Ejector wash was present. I immediately mark the load "HOT" and didn't shoot anymore of these. I have also done the same with my 6.0x47 Lapua!

Now I always start off with the low side of powder and .050 off the lands and go from there! I have never seen a blown bolt, nor do I want to! Each gun is different. A person gave me his favorite load for the 6.0x47L, but shooting the same in my gun, the case was just about to come apart in my gun.
 
I dont think its the sizing on the brass. i only bump the shoulders back about .001, just enough to get a touch of crush when i close the bolt on empty brass. the ones i used in the match were done this way too. The one i lost the primer on may have been loose before i shot it. this weekend i'll do more testing and see what happens. i plan to test a few different primers i have to see what groups best with a given charge at 400 yards. i just hope that can translate to 1000 yards somewhat.
 
Goldy,
if you can get a couple the Wolf primers are a little thicker cup and may prove a little helpful in "looser" pockets.
cheers,
Doc
 
Wolf Small Rifle magnum primers, Remington 7 1/2, CCI 450 all work pretty well in the BRX and Dasher.

Remember your barrel is new and not broken in. This relates to tighter bore and copper fouling.

Remember to clean well to remove both copper and carbon.

Seating into and close to equates to higher pressure also.

Varget and Reloader 15 are some of the most temperature stable owders. But remember reduction of one grain when the temperature is over 80 degrees is often smart.

Nat Lambeth
 

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