Peterson Brass FYI and Question

Squaregrouper · Jun 15, 2018

I finally got around to shooting some 6.5 Creedmoor loads with my Peterson nickel plated brass. Their brass is known to be thicker with less case volume, so I loaded accordingly. My developed load with Hornady brass is 42.8gr RL16, 140gr ELD-M, Win lg rifle primers, 2.870 oal (.020 off the lands) and no crimp. This gives me .5MOA and 2800fps

Anywho... Using Peterson brass and 41.7gr, I was getting flattened primers, slap marks on the cases and >3000fps (2 shots fired). The velocities with 41.1gr, 41.3 and 41.5gr were ~2760-2780fps.
I have no idea how or why my velocity jumped by 200fps by increasing the powder by .2gr more. Compressed powder?

Thoughts???

PS- The remaining loads @ 41.7, 41.9 and 42.1 are all being pulled.

Squaregrouper · Jun 15, 2018

Quoted from another forum...
"I am also working with Peterson brass, but I am using RE16 and the small rifle primer version with CCI 450s. I am breaking in a new 23.5" Bartlein on my Tikka CTR that was a 260. I am going by Alliant data with Hornady brass, so I started at 40.5 gr and have worked up to 42.2. RE16 is bulkier than H4350, but I am getting 2813 with 41.6 and a 140 Amax. I am at 70 rounds and my barrel is still speeding up."

Doco Overboard · Jun 15, 2018

How does your new brass add up to your chamber? I read 1.541 for a minimum.Max 1.551 SAAMI chamber and CHS minimum at 1.5438-007. that could explain flattened primers. I don't know what slapped cases are and I also do not consider reading primers an exact science. I do believe in measuring the case head with a micrometer and starting with a published load at the bottom of the chart. Is your developed load a starting load or did you start somewhere in the middle? Did you develop a load with large primers and then switch to a case with small ones with less internal volume maybe?
Just a few of my thoughts. Hope you figure it out.

Squaregrouper · Jun 15, 2018

Doco Overboard said:
How does your new brass add up to your chamber? I read 1.630 for a minimum SAAMI chamber and CHS minimum reference at 1.634-007. that could explain flattened primers. I don't know what slapped cases are and I also do not consider reading primers an exact science. I do believe in measuring the case head with a micrometer and starting with a published load at the bottom of the chart. Is your developed load a starting load or did you start somewhere in the middle? Did you develop a load with large primers and then switch to a case with small ones with less internal volume maybe?
Just a few of my thoughts. Hope you figure it out.

I'm getting 1.635-1.637 to the taper and brass OAL is 1.920".
All brass uses large primers.
The Peterson brass is thicker and holds less powder than my "go to" load with Hornady brass.. I knew this, thus starting with nearly 2gr less than my established Hornady brass load.
What I called a "slapped case" was an obvious mark on the brass from the bolt face. The load was clearly over pressure due to: flat primer, tough to open bolt, "slapped case" and a sudden 200fps jump.

**What has me stumped is how everything was fine with each .2gr increase until BAM, a huge jump going from 41.5gr to 41.7gr. I'm not a reloading wizard, but was taught to slowly work up a load and inspect the brass and primer after each shot- which I was doing. I'm making up numbers, but it acted like I increased the load by 2.0gr, not 0.2gr. Why would a .2gr increase be that drastic? Clarifying I shot two rounds and they both did the same thing. I highly doubt I screwed up on the powder measurement, as I hand trickle each charge onto a Lee balance scale and am consistent to <.05gr with each charge.

Doco Overboard · Jun 15, 2018

I see what you mean now, you won't need a mike to see that.
Did you single load, from a mag or something that may have moved the bullet into the case without you knowing maybe.
Necks in spec? Thinking out loud. Maybe you just found the max load in the cartridge rifle combination.
I don't load for the 6.5 yet so I don't have a good understanding of components/ powders to select but if your bolts getting sticky now' the time to find out.
Somebody here will know soon.

Squaregrouper · Jun 15, 2018

Doco Overboard said:
I see what you mean now, you won't need a mike to see that.
Did you single load, from a mag or something that may have moved the bullet into the case without you knowing maybe.
Necks in spec? Thinking out loud. Maybe you just found the max load in the cartridge rifle combination.
I don't load for the 6.5 yet so I don't have a good understanding of components/ powders to select but if your bolts getting sticky now' the time to find out.
Somebody here will know soon.

I loaded it (TC Compass bolt gun) from a magazine, and did it the exact same way I have for the past ~100 handloads in that rifle.
I crimp my .300 Blackout loads, as the chances of the projectile getting set back from a semi auto feed ramp is much greater than a gentle chambering in my bolt guns.

outrider58 · Jun 16, 2018

squaregrouper said:
I loaded it (TC Compass bolt gun) from a magazine, and did it the exact same way I have for the past ~100 handloads in that rifle.
I crimp my .300 Blackout loads, as the chances of the projectile getting set back from a semi auto feed ramp is much greater than a gentle chambering in my bolt guns.

Case gauging/checking the headspace?

As for the 300 Blk, are your feed ramps "clinkers"? If you run a fine point ball point pen up the M4 feed ramp from the aluminum receiver onto the M4 ramps on the barrel extension, does it hang up between the two ramps? That can and should be fixed easily enough. You should not have to worry about bullet set-back in a properly mounted barrel/receiver junction.

Squaregrouper · Jun 16, 2018

outrider58 said:
[/B]
Case gauging/checking the headspace?

As for the 300 Blk, are your feed ramps "clinkers"? If you run a fine point ball point pen up the M4 feed ramp from the aluminum receiver onto the M4 ramps on the barrel extension, does it hang up between the two ramps? That can and should be fixed easily enough. You should not have to worry about bullet set-back in a properly mounted barrel/receiver junction.

I have not checked the headspace. Subsequent factory loads and my confirmed reloads (Hornady brass) shot fine after the sketchy handloads.
I have made loads that started to show pressure signs, but nothing like this- especially for such a small charge increase.

The .300AAC feed ramps are fine. I crimp those as an added precaution. It is the only semi auto round I load.

outrider58 · Jun 16, 2018

squaregrouper said:
I have not checked the headspace. Subsequent factory loads and my confirmed reloads (Hornady brass) shot fine after the sketchy handloads.
I have made loads that started to show pressure signs, but nothing like this- especially for such a small charge increase.

The .300AAC feed ramps are fine. I crimp those as an added precaution. It is the only semi auto round I load.

I lightly crimp my PC loads just to get rid of the flare. That's about it.

Sent from my SM-G965U using Tapatalk

Doco Overboard · Jun 17, 2018

I see rl16 loads as being discussed at 42.7 as at or past peak pressure in some users testing. Even being identified as caution do not use. I also see reports of others who have achieved excellent accuracy who have developed loads with 3-4 grains less than the load you have developed with 140 gr. bullets.
When you developed your loads where did you start? Just because someone advertises a load doesn't mean its safe for your rifle. Every time you switch a component you should work up from the bottom again checking for pressure signs.
Even if you reduce charges in your thicker brass by as much as 3% from a max load that doesn't mean you may not experience signs of pressure at an even lower starting charge due to just changing components.

Squaregrouper · Jul 5, 2018

I think I may have found what the problem was...
Some of my necks on the pulled rounds had diameters slightly over max tolerance (.295.5-.296). Is it possible that bullet depth just off the lands and "stuffed into chamber" necks would prevent any case expansion and significantly increase pressure?

Speed3 · Jul 5, 2018

Yes for sure.....if the bullet was being seated further in the lands you will certainly have increased pressure. Think of it like a bigger combustion chamber.

Bullets is .264 plus average neck thickness of.14(one side) plus .14(other side)= .292

.295 or larger would allow bullet to be pushed around rather easy.

Doco Overboard · Jul 5, 2018

Yes. Especially if the case mouth has begun to enter the leade and the bullet is seated to a longer overall length pressures will surely increase. Seating the bullets deeper, reducing the powder charge may help if your sure OAL is good and everything measures out.
I load for a .270 that did the same thing and found once I reduced the charge and crept out towards the leade velocity didn't fall off that much. I get slightly flattened primers but no hard bolt lift.
I will shoot the same ammo in another rifle (Remington pump) and see a normal primer with clearly pronounced rounded edges but a significant point of impact change in elevation. It has a longer throat which allows the bullet to get a good start before it engages the rifling with less signs of pressure. And less accuracy for that matter at 250 yds but plenty good for deer hunting with a 150 gr bullet.

Squaregrouper · Jul 22, 2018

Delayed OP update...
I'm either throwing away or giving away this brass to someone who wants it. I mic-ed every single case after sizing and after loading each round. Last Sunday, I was at Peacemaker (with ToolAA) and had 3/30rds still give me issues when trying to chamber them.
As stated in another thread, my go-to load is Hornady brass w/42.8gr of H4350 @~2775fps. I cannot get past 2650fps with the Peterson brass without seeing pressure signs. Add to that, my powder charge is really different than with any other brass. I'm done experimenting with it.

If anyone wants "match grade" twice fired brass, let me know. Otherwise it is going in the trash.

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