I have done a lot of reloading since the late 90's but I haven't had to work up a new gun since 2005 I may have gotten a little rusty on pressure signs. So I need some opinions.

I purchased a new Browning X Bolt .308 win with 22" barrel. I am using new Lapua brass and Winchester large rifle primers.

I loaded 9 rounds of 150 grain Nosler accubonds using OAL of 2.810 same as in the book. Loaded RL 15 powder in measurements of 44 grains with average speed of 2780. Then 45 grains with average speed of 2840. Then 46 grains recommended max in Nolser manual with average speed of 2905.

I loaded 9 rounds of 150 grain Nosler accubonds using OAL of .02 off the lands. I used the stoney point measuring tools with 5 different bullets averaging the 5. I loaded Varget 44.5 grains with average speed of 2800. Loaded 45.5 grains with an average speed of 2858. Then loaded 46.5 grains recommended max in Nosler Manual with average speed 2915. High speed was 2919, lowest 2910, and middle 2916. This load gave a .591" group.

I loaded 9 rounds of 165 grain Hornady Interbonds Using OAL of .02 off the lands measured the same way with stoney point measuring tool. Hornady does not give online information so I got my information from Hodgen. I Loaded 44 grains of Varget with average speed 2750. Then loaded 45 grains of Varget with average speed of 2805. Then loaded 46 grains Varget recommended max by Hodgen with average speed of 2860.

After I got home and had mixed all the brass together, I got looking at it a little closer and some of the primers looked like they were flattening. So I separated them and 9 looked normal and 18 looked slightly flattened.

So my guess is the 9 that looked normal were the ones loaded with an OAL of 2.810 and RL 15. The ones that looked slightly flattened were the ones loaded .20 of the lands and shot with Varget. Just a guess.

I have attached a link. In the picture the 9 normal primers looked like the case on the left. The other 18 looked like the case in the middle.

http://www.massreloading.com/images/flattened.jpg

What are your thoughts?

Thanks Adaams

Slightly flattened primers in themselves are only one sign of raised pressure and if not accompanied by other signs such as ejector pin indent on the case head or slightly sticky bolt lift, then that load maybe approaching maximum in your rifle but perfectly usable when accompanied by good velocity and accuracy.

Recently on our online auction site someone was selling three pots of AR2208 powder at a good price. This Aussie made powder is renamed as Varget and supplied to Hodgdon for his American market. The person added a caution to his auction that this batch of powder seemed quite a bit hotter than the previous batch he had worked up a top load for and he didn't want to use it anymore. Obviously other aspects of his reloading may have contributed to this although by his comments he seemed credible.

Hodgdon's published loading data for Varget and his H series powders are straight from ADI in Australia who manufactures these powders for Hodgdon. We know these as the AR rifle powders here down under although Hodgdon's Varget and H powders are also imported and sold here too, after a round about journey I presume.

the link is of HOT loaded 357mag cases, and the center and far right one are over pressure, the far right looks dangerously over pressure to me\

Flattened primers don't mean over pressure by themselves.
Just a note: When I am approaching max loads I never increase loads in 1gr increments. In a case of similar volume to a 308 my increments would be .5gr and then adjust from there. 1gr gives too much velocity/pressure increase.

Forget about what the primers look like for now. How did the brass eject, and how tight/loose are the primer pockets? Those are better determinants of pressure.
Our M256 Tank cannon operates at 100 thousand PSI with no problems. How? Screwed in electric steel primers, and steel case heads. So go by all the data; not just one point.

quote:

Originally posted by dpcd:
Forget about what the primers look like for now. How did the brass eject, and how tight/loose are the primer pockets? Those are better determinants of pressure.
Our M256 Tank cannon operates at 100 thousand PSI with no problems. How? Screwed in electric steel primers, and steel case heads. So go by all the data; not just one point.

Agree. One of the reasons I like to prime my cases by hand is that I can feel how tight the primer pocket is.

If the primer is too loose, I discard that case. This is very rare.

If the primer seems a bit looser than I'd prefer, I mark the primer with a Sharpie and discard that piece of brass after having fired it one last time. This too is rare.

I keep almost all my loads ½ to 1 grain below whatever the published maximum for that cartridge is, I neck size and I've loaded some cases well over a dozen times.

We only use published data as a guide.

Newer loading data is very conservative, and we have no problems exceeding published maximum data.

It all depends on the rifle in question.

We have had some rifles that will not digest even starting loads!

Thanks for the replies. When I got the brass I did use a primer pocket uniformer. After testing a few cases some were much tighter than others. However I was careful while doing this not to over ream them and to make sure the uniformer wasn't being tilted. But am now questioning if I should have done that. When seating the primers though all of them felt tight to seat. I'm using an RCBS single stage to prime. I am still loading new brass so I have not tried resizing any brass and then putting another primer in the brass.

Tonight I'm going to check to see if the shoulder got pushed out more on the primers with slight flattening.

There were no signs of a tight bolt it opened as if there wasn't a case in there. Cases ejected well with no marks on the cases. I thought where the firing pin struck the primer looked normal.

I need to figure out how to get picture on this site so can actually show you the exactly what I am trying to explain in words.

Primers vary in cup hardness and your head clearance can cause them to flatted more.

Measuring the base diameter just above the extractor groove is a good way to know the strength of the case.

Simple Trick for Monitoring Pressure of Your Rifle Reloads

http://www.hodgdonreloading.co...e-your-rifle-reloads

I went and measured all my brass. Using Stoney Point Head & Shoulders measuring tools everything was very very close. I didn't expect them to all measure the same as I was using different amounts of powder on virgin brass. I also did a measurement taken just ahead of the extractor groove on the case head and all measured identical. So I am still sort of baffled.

So I decided I would start completely over working from minimum to maximum. As I was priming my brass I noticed (again) that the primers are just not seeming to seat as deep as they should. I noticed this the other times when seating primers in this brass. I also reload for another .308 win I have and I use Winchester brass in that rifle and every rifle I load for. The reason I choose Lapua brass for this rifle is because I don't want to mix up the brass between the two rifles. So I pulled some loaded rounds from the other .308 out and noticed a huge difference in how far the primers were seated into the Winchester brass compared to the Lapua. The top of the primer in the Lapua brass is seating so close to the top of the casing that I keep questioning if it is actually above of the top of the case. I keep putting them on a flat surface to see if they wobble and I can't tell. However, I am wondering if this is giving me the perception of flattening brass because it is not what I am used to looking at. It would make since because the top of the primer after shooting is level with the top of the case. It looks very close to the middle brass in the the above picture.

Is this possibly what I'm seeing?

Thanks Again,
Adams

I did a search for fired Lapua brass and found this picture. My brass does look like the brass in the middle picture of the is link. Only difference the brass in the picture looks to be seated a little further into the casing. So I may not be seeing flattening brass at all. But am still unsure. I'll figure out how to post some picture out here to get your opinions.

Again Thanks,
Adams

http://www.sniperforums.com/fo...-pressure-signs.html

adams,
I noticed you are priming with an RCBS single stage press. IME this method of priming does not have much mechanical advantage and you really have to push the ram hard to get good seating. You may want to try a different tool for seating or try a softer primer.

Sniper picture: Two cases on the L show slight cratering.

I'd say to load three of each the same way you did before and make sure the primers are all the way in hard.

Mark each case with the loads using a marker so you'll know. Keep each set seperate. I put fired cases heads up in the ammo box. For test loads I put a strip of paper above each giving the load details and keep them that way. Fire one at a time and inspect as they eject. I also shoot all test loads over a chronograph and watch the vel's close.

when you go over the guns max, most times the vel drops off or stays the same as a lighter charge.
You might try shooting a few known loads from the other gun/s and compare.

Good luck, stay safe is the main thing.

George

Just wanted to give an update. First off this was an optical illusion for me as I am not having flattening primers. I've reloaded 1000's of rounds but have always used Winchester brass. The Winchester brass lets me seat the primers deeper into the head by a ways. I still do question why I am not able to seat deeper with the lapua brass but they are below the level of the case head.

I worked up from minimum to maximum with no pressure signs. All primers looked identical throughout the loads so I'm confident I am not having any increased pressure.

Since my gun liked max the best in my last testing I loaded 3 different sets of 3 loads using different distances off the lands. First set was .05 2nd .06 3rd .07. I found a sweet spot for the gun. The .05 shot a 1.2" group. The .06 shot a .445" group. The .07 shot a 1.1" group.

So after all of this concern things turned as good as could be expected.

I want to thank all of you for commenting as it made me aware of things I really haven't needed to deal with since 2005. I will be working up another new gun in the spring and am looking forward to the process. I hope the results are as good as I got out of this rifle.

Thanks,
Adams

You are using new virgin brass and will have varying head clearance. The greater the head clearance the further the primer can back out of the case and flatten the primer edges when reseated when the rear of the case contacts the bolt face.



After you fire form your cases the head clearance will be uniform with minimum shoulder bump. After this the primers should look normal and not looked mushroomed because of excess head clearance.