I have to ask...Large vs small Primers

First topic message reminder :

I really enjoy loading Small Primer 45 acp brass.  Reason is I don't have to change out my Dillon 650 priming system.  Is there any benefit to loading large primers vs small?  Accuracy?  Reliability?

I'm all ears Gents

Joe

Jayhawk already posted test results. They show what I have found shooting mixed primer pockets. Look at the accuracy results of the bullets with the lowest velocity. The small primers hold their own at full loads but lose out in the lower (closer to bullseye) loads. In particular check out the 700x load. This test didn't really get down to our reduced loads but the results do show a loss of accuracy with one of my favorite powders.

Len
http://www.shootingtimes.com/ammo/small-vs-large-pistol-primers-45-acp/

OldMaster65 wrote:Jayhawk already posted test results. They show what I have found shooting mixed primer pockets. Look at the accuracy results of the bullets with the lowest velocity. The small primers hold their own at full loads but lose out in the lower (closer to bullseye) loads. In particular check out the 700x load. This test didn't really get down to our reduced loads but the results do show a loss of accuracy with one of my favorite powders.

Len
http://www.shootingtimes.com/ammo/small-vs-large-pistol-primers-45-acp/

Results for the small primer are far better for VV310 which is comparable to Bullseye. The test as I see it the SPP came out equal or better EXCEPT for 700X.

Results
http://www.shootingtimes.com/files/2014/08/small_or_large_pistol_primer_45_acp_1.jpg

Agreed.  Here's a nice chart showing the relative burn rate between powders for reference.

http://www.lapua.com/upload/reloading/reloadingburningratechart2011.pdf

Fastest to slowest:

1.  N310
2.  W231, Titegroup, and Bullseye (roughly equivalent)
3.  Clays
4.  700X

I have and use 231 and 700X. I don't have or use the other powders. So I guess for me the chart shows that large primers are better for the powders I use. It will be interesting when Rob publishes his test results. I suspect that instead of the zero difference that he is expecting he will find that the results are very different for different powders. I would point out that even the biggest difference at 25yds between primers is the difference between hitting the center of the X or hitting the edge of the X ring. Which would make Rob right.. For our shooting that is pretty much no difference. That's just my interpretation of the chart YMMV.

Len

I see by the Lapua chart, they never got the memo on WW231 and HP38 being one and the same powders.

I personally like the ADI one better, as they are a true powder manufacturer.

ADI Powder Equivalents

ive gone thru all of the charts i can find
and Lapua chart seems to represent the real world better than the rest
and i keep a printed copy of the ADI equivalent chart on the desk

okay i pulled 50 of the SPP rounds that went  pppffffttttt and slung the bullet REAL SLOW down range

i see the proper amount of powder in each and every one
so SPP low volume,low weight charges = not so good
now im going to put those back together and run them to see what else they will do

i forgot i found this down on the berm
so i bet everyone of them made it down there

primer fails with low charge of fast powder

In addition to all the tests, take a drill and open up the flash hole to large primer size...

report back...

darn... i already rebelled and put the divited bullets back in

ill bet at 25yds  those wont bother a bit

yup i run SOFT lead

I don't see a crimp line. I actually see a gap. That could cause psssst.

well they havent been reseated
and thusly not crimped

Let's keep this in perspective.  The OP said that he was enjoying the small primer brass and he wondered if there was an advantage or a disadvantage.

There were opinions, but not much testing--just the previous chart that says it was tested on sandbags.  Boooo sandbags.

I made a batch with no changes from my normal load other than the SPP brass.

My range upgraded the benches at my club so I couldn't use my rest yet. I'm going to need some different clamps.


I did shoot some of them:
It's my opinion that there isn't a difference between SPP and LPP.  I was able to lay a few into the middle with my hardball gun.  Machine rest testing will reveal more data soon, but here's what I shot today:

Rob what was your powder charge?

Back to keeping it in perspective. Guncheese had a legitimate response to the OP. He ran a batch of bullets with small primers and bullseye powder and had failure to ignite problems. If the problem is purely the small primers then the answer is "Yes" there is a problem with small primers. I asked about his crimp to narrow it down to the primers being the problem. I don't see how it could be more in perspective then that.
 I see vertical stringing in the test target but until it is machine tested there could be lots of reasons for that.

Len

Guncheese,
This load was 4.2 gr BE under Zero 185JHPs

I wish this was it's own thread because I don't believe your problem has anything to do with SPPs.

There are several things that need to be checked before we can conclude that the problem is the SPP cases:
1. Your 3.4gr charge is really low.  There are some classic loads that low but they didn't use powdercoated projectiles
2.  The bullet that you recovered doesn't have any marks from the grooves--just the lands.  Are these bullets undersized and not sealing to the bore?  What were these bullets sized to? What do they measure now with the powdercoating on it?
3.  What sort of powder measure are you using?  Are you sure you have consistent charge weights?  It's hard to tell visually that you are consistent when you are cooking a 3.4gr recipe.


I want to figure out why the bullets don't look like they obturate.

Vertical stringing?  I'm not Brian Zins and I was shooting irons with sweat running in my eyes....

Yea, I'd like to be able to shoot that group  

I have no experience with small primered .45 ACP brass. That being said, the quality of the bullet combined with a powder and charge that make it fly accurately is paramount in gaining 50 yard accuracy. Of course that is assuming that your pistol is capable and the gun/ ammo combo is reliable. These powder coated bullets are gaining traction in the plinking world, but I haven't seen any machine rest tests at 50 yards to show that they are ready for prime time on the line. All the online hype about these bullets and gun rag tests are not convincing for a bullseye pistol shooter. Claims of accuracy can vary from shooting at 5, 7, 10, 15 or 25 yards. None of these are useful for us.

Remember why they were introduced.  It was for using lead free primers in indoor ranges.  They weren't intended for 50:yards.  They may work, but we need more testing.

Rob Kovach wrote:Guncheese,


I wish this was it's own thread because I don't believe your problem has anything to do with SPPs

and so it shall be!!