Primer investigation – Part 1

Sometimes the day doesn’t give you what you want, but does give you what you need.

I wanted to spend the day in the garage reloading.

Instead, I spent a good portion of the day 1. cleaning the house, 2. playing Horse-opoly with Daughter, 3. napping. I got what I needed.

However, I did get some things done today, so here’s part 1.

(Updated: here’s links to part 2 and part 3 and part 4).

From my first round of .223 hunting loads, we noticed after shooting the primers were backing out of the cases. foo.c‘s hypothesis is the new brass, but he admits it’s only because he’s not worked with new brass before and isn’t sure how it would react. My hypothesis is I’m loading “short”; that is, I’m making a .223 Remington load and shooting from a 5.56x45mm NATO chamber, thus the cartridge length is a wee short when compared to the length of the chamber it’s being shot out of. I’m thinking if I can load a little longer OR if I can shoot the brass once then reload that same brass and try again (i.e. fire-formed brass) it might work out.

My Plan

I want to load up some test-specific loads and see what happens. I want to see if new brass could be the problem and/or the chamber/length might be the problem.

I’ll give the rifle a cleaning. Then I have a Hornady O.A.L. gauge and I’ll try measuring and seeing where things lie in that regard. What will I do with this data? Not sure at this point, but I think it’s worth gathering.

Loading the Barnes bullets for all this testing is rather expensive. I’ve got a bunch of 55 grain Winchester FMJBT’s, which are plentiful and cheap enough. I know it’s a different bullet and a different powder weight (vs. the 62 grain Barnes TSX), but I just can’t afford to shoot tons of the Barnes to figure this out. My approach isn’t to find the best load or most accurate load, but to examine the length issues, pressure issues, and brass issues. So as long as I keep within published data, I should be OK here.

Again I shall use new Remington brass. While we noticed the primers backing out with all the powders, it so happened we first noticed it while shooting TAC-based loads so I’ll use TAC powder for this (besides, I’ve got a lot of it). According to Ramshot’s Load Guide version 4.3, the only 55 grain .223 Rem they list is for a Sierra Blitzking (23.4 – 26.0, OAL 2.240″). On Steve’s Pages, the only thing he says about TAC for 55 grain .223 Rem is 21.5 – 26.3 grains. Some Googling turns up values like 24.5 grains behind a 55 gr Winchester FMJBT, on up to 26.0 grains and down to 23.5. I found on ar15.com:

I assume you want the higher pressure MIL loads. If not you can reduce these by 1.0 full grain for the lower SAAMI level.

Caliber: 5.56mmx45NATO. (.223 Remington)

Pressure spec: MIL <58700 Psi “Case mouth” = <62000 Psi chamber

Barrel length: 20” (For 16” barrel reduce velocities by 5 to 6% ca 150 Fps)

Powder: Ramshot – TAC.

Bullet weight: 55 grain FMJ (M-193).
Start load: 25.0 grains (2925 – 3025 Ft/p/sec)
Maximum load: 27.8 grains (3300 – 3400 Ft/p/sec). <62000 Psi

Bullet weight: 62 grain FMJ (M-855).
Start load: 24.0 grains (2850 – 2950 Ft/p/sec)
Maximum load: 26.7 grains (3100 – 3200 Ft/p/sec). <62000 Psi

Bullet weight: 68-69 grain HP.
Start load: 23.5 grains (2750 – 2850 Ft/p/sec)
Maximum load: 26.2 grains (3075 – 3175 Ft/p/sec). <62000 Psi

Bullet weight: 77 grain HP.
Start load: 22.1 grains (2525 – 2625 Ft/p/sec)
Maximum load: 24.5 grains (2750 – 2850 Ft/p/sec). <62000 Psi

NOTES:
It’ important to note that SAFETY is our prime concern therefore we strongly recommend.
1. TO ALWAYS BEGIN LOADING AT THE RECOMMENDED MINIMUM “START” LOAD.
2. If at all possible, measure the velocity and correlate with our data.

Regards

Johan Loubser
Ballistician
Ramshot/Accurate Powders
Tel: (406) 234 04 22 email: johan@ramshot.com
Western Powders Inc –– Miles City – Montana.

Given all of that, I will start at 24.0 grains and work up in 0.5 grain increments to 26.0.

I have a few other brass things I will try.

The brass used last time was new, but I did run it through my RCBS small-base full-length resizer die. This time the brass will not only be resized, but I will debur the flash hole and uniform the primer pockets. I’ll use that brass for the main load figuring.

When I did the last batch of reloads, I loaded more brass than I needed (well, more like I changed my mind and didn’t load as many rounds as I thought I would). Consequently I have some brass that was prepped the same as the first run. For grins, I’ll load this brass up as well with the FMJ’s and various levels of TAC. The difference here is this brass was not deburred or primer pocket uniformed. We’ll see if this exhibits any difference in behavior, but my guess is this at least should behave similar to the prior loads.

As well, I’ve got bunches of used .223 brass of unknown life. I will pick a median powder amount (probably 25.0) and reload various used brass. This brass will be resized, trimmed, deburred, uniformed, and if it has a military crimp I’ll swage the primer pocket too. As long as I’m going to the range, I might as well load up what I can and take it and see if any differences occur.

Furthermore, I shall take some Georgia Arms Canned Heat and shoot that too.

So as you can see, a lot to load and a lot to shoot, all to try to see what happens with regards to the primers.

Measurements

Hrm.

Provided I’m using the Hornady OAL gauge correctly, I obtained a measurement of 2.340″” with the Winchester 55gr FMJBT’s, and 2.367″ with the Barnes 62 gr TSX.

Of course, that’s way beyond the max OAL for .223 Rem, which is 2.260″. And recall, this is a 5.56 chamber which will have a longer leade; I don’t know if that will factor into the measurement here (I would think so but even then it seems too long). I can’t help but wonder if I’m measuring wrong, but by all accounts I’m doing the right thing.

Let’s measure some other ammo and see how it stacks up.

Federal P223S – about 2.170″

Hornady TAP 5.56 75 grain – about 2.237″

Hornady TAP .223 75 grain – about 2.24″

Wolf .223 55gr FMJ – about 2.24″

Georgia Arms Canned Heat .223 55gr FMJ – about 2.23″

With the Barnes manual #4 data I was loading to 2.250″ OAL.

Well, it is what it is. Given I’m within spec from the book, according to the .223 Rem publish min/max lengths, I’m in the same ballpark as other factory loads well… I can’t think that I’m having an overpressure situation due to being too long.

How long will I load my test loads? I’m going to follow what’s in the Barnes #4 manual for the Barnes bullets, and I’ll follow the Speer #14 manual data for the Winchester 55 gr FMJBT.

One other thing I shall do regarding measurements is taking the calipers with me and measuring brass after it’s been fired.

That’s what was done today: cleaning, measuring, planning. Tomorrow I intend to skip the IPSC match so I can reload.

3 thoughts on “Primer investigation – Part 1

  1. Pingback: Primer Investigation – Part 3, Results « Stuff From Hsoi

  2. Pingback: Primer investigation – Part 4, Hopefully the end. « Stuff From Hsoi

  3. Pingback: Primer Investigation – Part 2, 43 Loaded « Stuff From Hsoi

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