Colt Delta Elite 10MM -- Large Pistol Primer Shoot Out: CCI and Winchester

[mr.revolverguy]

https://www.youtube.com/watch?v=kUmZV6BeV2Y&feature=youtu.be

Recently I developed some rifle loads in 308 with two different primers and on the range notice the POA was totally different as well as the group size. I began to wonder if pistol primers would have the same effect.

10MM
155gr Hornady XTP
AA#7
CCI Large Pistol Primers No.300
Winchester Large Pistol Primers
New Starline Brass

To try and ring out the most accuracy and get the most consistency I did measure and trim 50 pieces of brass to the exact same length. The final cartridge length is a COAL of 1.255

I had a great time loading and shooting these!

[Trapper6L]

Thanks for the 17 minute vid. When I first heard your voice I thought you were my college history teacher. Fond memories of that guy but that was nearly 50 years ago.
Interesting that you decided to shoot so close. That Colt is definitely a much longer range pistol. LOL, I can only assume since I have to chase brass into the next county even with LOTS of spring mods to my Long Slide 10mm that it's just a matter of fact with the gun/round. For me, this is a very timely vid. I'm generally a Remington primer kinda guy. I got on Remington primers many years ago shooting a .261x 47 D TNT bench rifle. At that time, Remington would run the 70gr bullets thru the same hole at 100 yds. Other brands would have tiny groups but one hole beats tiny groups. So I'm looking for the next brand of primers to fill near empty holes in the armory. While it may seem like the closer the velocity is, the better the groups should be, shot to shot. If you shoot bench long range at 600yds, you'll find that doesn't work. I have no clue why but frankly, I've all but eliminated the chronograph from the equation and go by repeatable tight groups. I could care less about the spread as long as it goes to the same hole or pretty close to it. Ya know, we assume that the readings on our chronographs are correct. Most often, they aren't. There are so many variables that most chronographs are near  worthless. Doesn't take much for one to throw off a hair. Depending on the type, even a cloud can throw a chrono off. The best out there are supposed to be the ones with IR lighting. I never could afford one.

I appreciate the time you spent making the vid. You made up my mind about pistol primers anyway. Since I'm more concerned about accuracy, I'm going to be buying Winchester pistol primers. Rifle, well that one will still be up in the air. As of now, the 600yd rifle is a Remington 40X 30/338 mag setup by Bob Pease years ago. I still have a bunch of the Federal 215M for it as after I found the load, the bullet, the primer, the powder, I stocked up what has to be a lifetime supply. For my hunter class rifles, that's going to be the question as I shoot that more than anything. I shoot 6 different cartridges in the hunter class and 2 in the 200 meter offhand open sights match. It's always a hoot at the range as the guys never know what I'll show up with. Not many "match" grade 22 Hornets out there.

Again, thanks for the time making this vid. I've tried a couple of DIY vids and it takes a ton of planning and time. Your time was not wasted. Thanks.

[The_Shadow]

First of all, what load weight of AA#7 did you use in the testing?  Yes, it is good powder for 10mm.  Seeing your data at 1425-1430 adv. raises my safety concerns...

Accurate Arms shows the flowing data:
AA No.7 12.7 grains 1379 fps 37,500 psi

Hornady shows several variations for AA#7 for the 155 grain XTP
8th ed. page 961
A#7  using 12.7 grains @ 1250

6th ed. page 791 & 7th ed. 861
AA#7 using 14.6 grains @ 1400 fps
AA#7 using 15.1 grains @ 1450 fps  (Warning! This data maybe printed wrong)(Data may be for AA#9)

There was some warnings for Hornady Data, just can put my hands on it at the moment.

Here is the Accurate Arms Data Info for 10mm with pressure data
Accurate Arms Powder

[mr.revolverguy]

Shadow,

I verified data from two different manuals and have been using this load for a while now. My delta actually produces better velocity than my Long slide Para Elite.

https://www.speer-ammo.com/downloads/speer/reloading-pdfs/Handgun/40_caliber-10mm_400_dia/10mm_Auto_155.pdf

That is just one check of data but I did not go over the accurate max either.

[The_Shadow]

I'm was just interested in the load data used in the testing, while it raises some concern, I have seen where the 13.0 grains was used in older data.
BTW, truly enjoyed the video and your testing...

HORNADY 10 MM LOAD DATA
Source: Hornady 4th edition Manual

Test firearm, Colt Delta Elite, Winchester Large Pistol Primers, 1.260" COL, Hornady Brass NOTE: MAXIMUM LOADS are in RED use with Caution!
Honady, is NOT responsible for typographical errors

155 Grain XTP's
Velocity ---->>>     1050  1100  1150  1200  1250  1300  1350  1400
Powder Type
Powder weight AA#7  9.7   10.3   10.9   11.5   12.1   12.7   13.3   13.9

[Trapper6L]

Let me chime in here with the answer as given to me by the Sierra people. Not all firearms are created equal. You can take 10 308 rifles of the same barrel length and have a variable of as much as 350'ps difference by chronograph over all 10 rifles using the same load. The reason is simple, the finished barrel bore diameters can be slightly different as well as the roughness of the barrel steel, all effect the velocity of the firearm. In pistol data such as both that are shown here, one, which showed the lowest data, is a test ballistics barrel made to extreme standards. The Speer data show the test firearm as a SW1006. They will not be the same barrel dimensions as production barrels have quite a large tolerance before the manufacturing bore/rifling plug is changed(read less bullet resistance=higher velocities). That's why in rifles we have go-no go gauges. Not all chambers are the exact same. What might be fine in your gun might not be fine in mine. That's why the rule of start 10% below any max data and work up.
As an example of the data, I have a custom 6.5x 06 with an 8.75" twist barrel in 23.5" length. It's highly specified for shooting the real light bullets at extreme velocities for varmints. I can't use the max published data in any book unless I just like beating on the bolt. The chamber and barrel are very tight. If using the published data, I can get to medium loading densities but that about it. And here again is where a chronograph is near worthless, I can get about 350'ps faster from much lower charges listed in published data. There is no growth of the brass and primers are not flattened- no signs of any excessive pressure using a micrometer on the head, etc. IF I were to use the chronograph to determine my loads, I'd be running way short of the rifles capabilities. If all I wanted was a 6.5 bore rifle at mediocre velocities, the 6.5x55 would have been more than enough but it wasn't what I was looking for. If you've ever looked at the difference between a 270x06 and a 270 Winchester, you know what I'm talking about. The 270x06 is about 250-300'ps faster.

[mr.revolverguy]

I am sorry Shadow I thought I mentioned it in the video. The load is 12.5gr of AA#7. I worked up from 11.8 a couple of years ago to get to this load. This is going to sound really crazy but one of the reason I love the Delta is for testing and the lack of chamber support. In the Delta my brass will start to bulge long before I start to get flat primers, which I know is not necessarily a sign of pressure. In the Delta if I go up to 12.8gr my brass starts to bulge. Interesting enough in other 10MM's I can go up to 12.8 and not see any signs of pressure mainly due to better chamber support.

Chamber support video https://www.youtube.com/watch?v=F2AN5v7AjyI&t=2s

Interesting enough I can go all the way up to 13.2gr before I see pressure signs in the Kimber or Para, but I wanted a load I could fire in every 10MM without having to worry about pressure or battering the heck out of the firearm yet still be a 10MM load so I backed down to 12.5gr. In weighing the first 10 rounds as I do with every load I had 6 rounds come out 12.5gr and 4 rounds come out to 12.4gr's. This being weighed by a digital RCBS scale and Balance beam RCBS 5-0-5. Also in working up this load I had an overall length of 1.250. Again looking for a load that would fire in everything, on the final load and decision of going with 12.5gr I also extended the COAL to 1.255. Using quickload to help determine pressure, I took the H20 empty case capacity and plugged it in. With the COAL of 1.250 it was a little to close to SAAMI spec. We all know SAAMI spec is 37,500psi and the 1.250 load showed 37,304psi. Extending the COAL to 1.255 quickload shows maximum chamber pressure to be 36,318psi.

FOR those reading this thread it is critically important that you do your own research with multiple manuals and work up your own load for your pistol. As so wonderfully described every pistol will be different even if it came off the assembly line on the same day.

[The_Shadow]

mr.revolverguy, Thanks again for the video and the added info you explained so very well.  With the older Hornady manuals showing the amounts of AA#7, this is why I was concerned as your velocities were in the 1400+ fps results. 

In the video I noticed you were also wearing some U.S.M.C. adorned items, Thank you for your service.

[mr.revolverguy]

It was an honor to serve and always fun on the range especially with 10MM.

[SnApPyNHaPpY]

Nice video, thanks for the test.  I had already sub'd to your channel after coming upon your chamber support vid.  Keep 'em coming!

Cheers

SNH

[50BMG]

Great minds MUST think alike because I was doing the same thing this past weekend. Same brand new Starline cases, but, I was running VV3N37 powder (which is pretty darn close to AA#7) and I also tested 3 different loads with 3 different projos: 185g Montana hard cast, 180g XTP, 165g Sierra JHP.... I also shot them out of 2 different guns. A Colt Delta, and a Rock Island Ultra FS.
I won't go into all of it here, but the WLP seems to do a bit better job of igniting all the powder than the CCI300.
For an even slower powder like AA#9, I would expect this to be even more noticeable.

[Forrest]

12.6 is what I run under a 180 for #7 and it's really accurate. Hot too. I use CCI Magnum large pistol primers.