Federal 45 acp brass primer hole size

[pistol champ]

I was going through my brass and observed that I have two sizes of primer holes in my large primer pocket brass.
Does anyone know why?
I have noticed that my brass from Federal 185 gr Match ammo has small holes.
What effect does the hole size have on the ballistics?
Should the brass be separated?

[Rover]

I haven't checked hole sizes since I was a young guy.

If I were really concerned, I would drill them out to a uniform diameter.

[GunRunner]

yes this cost me many points last season, federal has three kinds of 45 brass, the old stuff with the large primer w/standard flash hole, the newer large primer large primer hole and the newer small primer large flash hole, the last two are basically indoor range w/ no lead primers. These all loaded the exact same will shoot to a different point at 50 yards, you might not notice any difference at 25. I would shoot a ten or a x at 50yds and then call another and it would be a 8 or a 9 took me months to figure out what the problem was. If you shoot federal just be sure its all the same kind and once zeroed your good.

[Isabel1130]

Many bullseye shooters who reload, always use the same new, or once fired brass for their long line loads. I prefer Starline, but any good brass will do.

[pistol champ]

I looked into this a little more. I got 10k new Federal brass cases and they are all large primer with small holes. It seems that the only large primer large holes that I have mixed in have come from some cheap Federal ball ammo I was practicing with. I'll sort and toss out the ones with big holes.

[oldcaster]

All with mixed brass.

http://www.magnusbullets.com/test_targets.htm

[GunRunner]

All with mixed brass.

http://www.magnusbullets.com/test_targets.htm

but all the brass back then had the same size flash holes thats not the case(pardon the pun) these days. mixed up brass with different size flash holes will shoot to different points.

[oldcaster]

Some of these groups have appeared in the last few years. I would suggest you write an Email to Magnus to see what they think. To me this all goes back to what an old Benchrest shooter said to me when I asked if a certain thing he was doing was indeed necessary and his comment back was "I don't know but I can't take the chance." All of my recent experience with Ransom Rest 45 ACP the latest being 2 years ago was with mixed brass and it can be so different in length that you would be sure that it will shoot different but when shot in the Ransom Rest they aren't. I would expect that by this time I have every brand of brass made in the last 50 years and some of them are annoying to use because of tight primer pockets, (not crimped) but otherwise I see no difference in how they shoot. Do you have any Ransom Rest targets where you shot both size primer pockets and they are obviously in different groups because saying you called a shot and it wasn't there can't be definitive. I think I did that today as a matter of fact.

[GunRunner]

Terry Labbe is the owner of magnus bullets and a good friend of mine, i shoot with him regularly ive never seen him shoot anything but starline brass. But ive discussed the newer large flash hole issue with him in the past and know he is aware of it. id suggest someone taking mixed up Winchester, federal small and large flash hole brass and doing a test so we can see the exact result.

[mr alexander]

Here's my solution to this whole problem. It is one I have been using for

decades, even before this issue cropped up in the past few years. Right

before heading off to the range, I run a black "Sharpie" marking pen

across the back of my live rounds while they are positioned nose-down

in a plastic cartridge box. After my session, I only pick up the brass that

has a single black stripe on the back of the case. I do not retrieve

any strays that someone else left behind as I do not know their

history. However, if a someone who just got through shooting factory

ammo happens to offer me their now once-fired, brand-new empties, I

will gladly accept them. Once home, I do run all of these "donations"

through the Lyman Decapping Die that is mounted in my RCBS Single

Stage Press. Each is then inspected to see if the primer and flash hole

size are the same as all of the other ones I have in reserve. The point is

I find it most convenient to mark, save and use the brass that is only

mine and whose history is known to me. This prevents a lot of problems

down the road!

[Rupert]

To my fellow .45 shooters. I saw this discussion and experienced the same frustration. I created a gage where you can visually look and instantly see the difference between small and large primer casings.

Here is my website, please visit as it will explain far better than I can in a forum.

Primergage.michaelhahn.com

Thanks,
Rupert

[DLS]

This is nothing new, I can well remember flash hole size discussions back in the late '70s when I first started shooing BE. Even within the same "brand and stock number" you would have different sized flash-holes, it depended upon which machinery the round was built.

I saw this variation with military arsenal loaded rounds as well as civilian fodder.

The debate raged, but there was never any empirical evidence that it made a measurable difference. Primer lot variation and the cases brisance will cause many times greater shot to shot variation.

I still have never seen any empirical evidence that it makes enough difference to matter, even at 50 yards.

If you are worried, just uniform the flash holes and be done with it. Sinclair makes a great little multi-caliber tool or you can use a hand held drill bit. Get the tool, less blisters on your fingers. You probably need to pop the tumbler media out of the hole anyway, and the tool does this quite nicely.

In actuality I suspect it's much like the Bench Rest mentality ... "I don't know if it works or not ..., but can't afford no to". Most that I know that state this will admit that they like to play around with these type of details for their own sakes and would do it even if the results don't show on the target.

I know there will be those who disagree on this one <ducking>