I worked up a load for my Rem 700P using (you can skip the data and go to the conundrum if you like):

Nosler 168gr CC BTHP bullets
IMR 4064
WLR primers
Non mil-spec brass (I think -- TAA06 head stamp)
OAL 2.80

Starting at 41.0 gr and shooting at half grain intervals to 44gr. I chrony'd these loads and they ranged from 2585 - 2763 fps
As controls, I chrony'd PP 168 match (2618 fps) and American Eagle 168gr OTM (2633 fps).
It was cold at around 30 degrees.

***The Conundrum****
Despite starting at a low end load, I noted flat-ish primers and even a bit of sticky bolt right from the start with load of these rounds, but reassured by the velocities I shot through them.

My rifle likes 42.5 and shoots it at right about 1/2 MOA.

I loaded up a bunch from 42.4 to 42.6 and the 42.5 ones are consistently around 1/2 MOA from sandbags.

But, the primers still look like pancakes and the bolt sometimes needs a gentle 'pop' to eject them. No shallow or cratered pin strikes. No ejector marks.

I cleaned and dried the chamber and commercial ammo ejects without sticking.

They Chrony right around the AA 168 OTM at 1643 2643 fps (at 30 degrees).

So, besides being a bit tough on the brass, are they safe?

It kind of sucks if they are not as dropping the velocity will make them unfit for distance and the accuracy will suffer as well.

Your experience is appreciated.

4 shots:



Factory PP on right

I don't see anything wrong with those primers

They are flat. I'll post a pic next to the factory round when the internet comes back online (can't seem to work photobucket from my phone).

So flat and bolt sticks some at low-mid range loads. Do I start over?

I agree that the primers look fine.

Is the brass known to be soft?

How far off the lands does your OAL place the bullet?

What was the OAL of the control rounds?  


Is it important to be able to easily and rapidly cycle the bolt?  

Are you concerned about damaging the bolt after repeatedly tapping the bolt to open it?  Remington bolt handles are silver soldered to the bolt body and it is possible for the handle to break off if you fatigue the solder joint by tapping it to open a sticky bolt.  <-- don't ask how I know this.

Are they flat or are they mushroomed?

Thanks for the heads up about the bolt (yikes)

The brass is from Tiawan but NATO spec according to dr. Google.

But FWIW LC brass also sticks at these loads (and shoot like crap, I assume because the volume is a bit different).

I don't know, I guess I can yank on he bolt if it safe, but a couple signs of over pressure make me squirm.

You're 3.5 gr below max, the primers in the pic still have a radius edge.  I don't see a problem.

I wonder if my sizing is off. These are 1x brass from Wideners that I full-length resized (RCBS) and trimmed.

No trouble at all closing the bolt on them but I suppose I need a case gauge.

Right, hence the confusion. Sorry the picture is bad. I'll get a better one next to the commercial brass, but they are flat. And the bolt sticks. Over pressure signs.

The question is why at such a low load.

Back to head space?

IF there is a problem (still doesn't look like it to me) try some commercial brass with the same load.

I'll take the general lack of concern that I'm at risk of a kaboom or serious harm to my rifle and try more brass at this load.

Thanks for the input!!


BTW, the added pict still doesn't do the flattening justice.

Are they flat or are they mushroomed?

Answer the OAL questions I asked.

Do you have a head space gage?  If not, get a Hornady Head & Shoulders gage set.  How much headspace do you have?

I think your velocity must be a typo. I'm sure you mean 2643 not 1643. The primers look fine to me but I question the reading of primers anyway. The sticky bolt would concern me. If factory ammo doesn't exhibit any sticky bolt issues, you need to find out why your handloads are doing it.

Your primers look just fine to me.

Reading primers tells you less than nothing.  Nine times out of nine a slightly flattened primer like the ones in your picture are caused by bumping the shoulder back to far causing excess headspace.

Check the internal case capacity of that brass in grains of H20.

Weigh a fired case unsized case, fill it with H20, weigh it again and subtract.

Do the same with a fired factory 308 case and compare.

Comcast back up. Sorry to post right as our internet was going down overnight.

An example of Prvi partizan measures 2.785"
One of the  AA 168 OTM is 2.796"
I tried out about 6-8 other factory rounds without the bolt sticking.

Not sure where this puts it off the lands but doesn't seem to be an OAL problem.

I will get a case gauge ordered. The only time I had under re-sized 223 I had trouble getting the bolt to close, not opening it (the one time a case gauge for 223 has proven useful for me).

Not sure what the difference between mushroomed primers and flat ones are, but I'll look into it. [ETA: I guess I need to pop some primers and look at them? Will do.]

Sounds like consensus is that my primers are fine. Flat primers are not the best sign of overpressure to follow anyway, but combined with the sticky bolt….

I'll post up when I figure it out.

Thanks again!

Nothing wrong with those primers.  Press on.

I'll do that.

Measuring the TAA06 brass I have ready, they are all 0.469". After shooting they are 0.470" (measured three each).

LC brass pre/post are exactly the same, so seems like I'm up 1 thousandth.

But, the PP factory (three rounds) new measure 0.467 or 0.468" and they end up 0.469".  Smaller but still up a thousanth…

I'll measure actual rounds pre and post.

Thanks!

"flat" primers show what looks like small/thin crack between the primer and primer pocket.  I've seen factory .308 and 30.06 brass/primers look way worse than yours in some rifles.

Those don't look bad to me at all.  And yes, sometimes soft shoulders/necks will lead to sticky extraction, till they are loaded/reloaded a few times and the brass gets a little harder.

Mine are more like the middle, so I stand corrected. Mine are 'flat-ish' but not full-flat.

I measured the cases with a digital micrometer that reads to the 0.0001.

If growing by 0.001 is typical (like with the factory PP) then I'm ok?

You have military surplus brass. NATO head stamps never appears on commercial brass. Weigh your empty, unprimed, resized and trimmed brass. I suspect it weighs close to 179 grains +/-.

Maximum pressure is reached in military brass using IMR-4064 and 168 grain Sierra Match Kings seated @ 2.800" at around 2600 to no more than 2625 fps when fired from a 24" barrel. This is usually 41.5 grain of IMR-4064. Virtually every reloading manual uses commercial brass which weighs significantly less and have higher internal volume than any military brass. Online reloading sources and the various manuals published by the various bullet manufacturer's data needs to ne reduced 2.0 full grains when substituting military cases for commercial cases.

Over 2750 fps with a 168 SMK  is too hot by at least 2.0 grains if your empty cases weigh close to 179 grains empty. You are close to 3.0 grains over max in my opinion. Look for good accuracy between 2550 fps and 2625 fps and be happy. Because the outside temperature is so cold it is likely masking pressure problems that are almost sure to come next summer.

If you want to flirt with 2700 fps with a 168 SMK and IMR-4064 buy some commercial Winchester .308 brass. It has the most internal capacity and can hold the extra powder without spiking pressure. While your primers don't look bad (at 30 degrees F) your velocity is too high. By the time primers show pressure signs a person has been over the top for some time as they were increasing the powder charge. Proof loads usually create close to 70,000 psi and rarely show pressure symptoms. That fact alone should scare anyone that is seeing flat primers, ejector marks or blown primers. These things indicate pressures in excess of 70,000 psi.

I think your looking for a solution to a problem that does not exist. Your chronograph info confirms you are within specs.

V

Primers look good.

My only concern would be the temperature. You are shooting in 30 degree weather. When it warms up, you will want to revaluate  that load... to be on the safe side.

I'm not familiar with your powder choice or if it's temperature sensitive

Thanks
To be clear though, my velocity is 2643 fps with the 42.5 grain loads. The over 2750 was at 44.0gr. Those primers looked exactly the same (and interestingly, I don't think the bolt stuck with those(?)).

Concern over the temperature sensitivity of IMR 4064 is partly why I was worried enough to start the thread. Hoping to have temps here in the 50's this weekend and I can try again then.

If your jug of IMR4064 shows it to be an "Extreme" powder, it is not temperature sensitive.  If it just says "IMR 4064" without reference to "Extreme" it will be mildly temperature sensitive.  None of the extruded powders are particularly sensitive but always be safe.

Punch out some primers and see if they are mushroomed.  The "flat" primer in the photo above is a 357 pistol primer that is way beyond what I would call flat.  



We are asking lots of questions about your load but also about the brass.  A case gage may help but the Hornady gage I mentioned is better.  Not all brass is optimal for reloading.  It is still possible your TA brass is soft and flowing at pressures which the other, harder, brass is fine.  Not having ever used that brass, I don't know about its properties.  

Your 42.5 grain load is too hot in military brass, Look at 2600 fps as a working maximum with 24" barrels when using Lake City or any other surplus case that weighs close to 180 grains empty and unprimed. This velocity applies to 24" barrels. If yours is shorter than 24" the charge has to be reduced even more. In your case 41.8 grains should get you close to 2600 fps.

What should I shoot for with a 26" barrel (mine is 26")? I guess I was feeling safe near the factory velocities.

I can't expect to get as much velocity from military brass as I can from commercial brass? Would have thought just the opposite (even if it was with less powder I would have thought they would take more pressure and give higher velocity?)

I'll pop out some primers when I get home, but given the bolt stick, I'll work up the military brass again at lower load with chrony and hope to find good accuracy again.

Looks like a bit of a 'mushrooming' compared to the Prvi control (right). Not sure if this is much.

Interestingly, the TAA06 brass weight is similar to Prvi Partizan. May explain why it shoots differently (better) than the LC (weights w/o primer in grains):

TAA06:
175.8
176.2
176.0

Prvi:
176.8
175.8
175.0

LC:
179.0
181.0
179.5

Are you assuming that "case weight" is an indication of "case Capacity"?  

Bad Idea.

In what way is it not an indicator of case capacity?  <-- meant as an honest question for discussion

Given a fixed size chamber, and a uniform density (homogeneity) of brass, the case weight determines the total unfilled volume of the chamber.  Something like this:

Volume of brass = case mass/density of brass

Unfilled volume = volume of chamber - volume of brass

No matter how you aggregate or smear the brass around in the chamber, it's volume does not change.

Weighing resized, unprimed and trimmed cases will give you an idea regarding where your brass sits in relation to other types. This method is not as accurate as actually conducting a H2O capacity test, but it is expedient and you won't get surprised by a new brand of brass. I have never found heavier brass to have greater internal capacity than lighter brass.

The comparisons shown above with two brands being nearly identical to each other and only 3 grains lighter than Lake City brass tells me to load them like Lake City.  176 grains vs. 179 grains are close enough to be loaded the same way using the heavier brass's data to be safe.

The OP's 26" barrel should allow a safe maximum velocity of somewhere close to 2640 fps +/-  with a maximum charge of IMR-4064 when loading 168 grain Sierra Match Kings @ 2.800". Again, the maximum charge based on your chronograph data is very close to 41.5 to 42.0 grains in warmer weather. 42.5 grains is getting you maximum velocity at 30 degrees F. when fired from your 26" barrel. Higher temperatures generally increase pressure and velocity when the ammo is fired from the same rifle.

Since this load (42.5) has performed best for you on target I would suggest you not exceed it. Slightly lower powder charges will probably work just as well without pushing the envelope. Good Luck.

Thanks for that 'wrap up' and clarification of velocity for my 26" barrel.

I have already loaded up some new TAA06 loads between 41 and 42 to see if I can maintain accuracy with a velocity close to the PP 168 factory ammo (which shoots right around 1 MOA from this rifle) so I may be able to use the same zero and hold overs (?).

Hoping the bolt-stick will go away for those loads as well. I'll post follow up to that.

Thanks all

I wanted to add a clarification to my comment regarding case weight and case volume.

Case weight will reflect case volume AFTER it has been fire-formed to your chamber.  After fire-forming, and possibly after subsequent resizing, all the cases should have the same external dimensions.  Given that, then case weight reflects the internal capacity of the case.

I haven't done the mathematical proof of this but have considered the relationships and believe it to be true.

I've made that load before using WIN, REM, FED and Lapua brass except I use 42.8 grain of IMR 4064. Nosler CC 168's. Another difference for me is I seat them to 2.93 and use as single shot only. I've never had an issue with pressure.