6X45 (6mm-223) Load data questions

[rc109a]

I was able to try out the 80g PSP and H322 with the following results (all were only 5 shot groups)
21.5g= 1.1" groups
23g= 1.90" groups
24g= 2.62" groups

I had five rounds of 24g left and the shooter next to me wanted to see the round chrony, so here are the results (18" SS barrel with 1:9 twist):
2628.1
2656.0
2623.0
2695.4
2623.8
Average 2645.3 with a difference of 72.4 FPS
I am not sure what this other data means (If you know what that data is please let me know. I am always trying to learn something new):
SD: 31.1 (standard deviation?)
CV: 1.18%

MAD: 24.4
CV: 0.92%

I did try out the 100g Sierra BTSP with 19g H322 and got 1.4" groups.

Some of the problems I had was bumping the shoulder while seating the bullet with the 80g PSP on some of the brass. This did not stop most from chambering, but a few did. I did not have this problem with the BTSP. Not sure why this was happening. Any ideas?

I am leaning towards the BTSP at 100g, but there is a lack of data for this round. Does anyone have any that they are currently using?

Thanks...

(and yes, I have posted this same question in another boards)

 

[kaferhaus]

bullet seating die is adjusted improperly that die should never touch the shoulder of the case.

I'd try a different powder... those are pretty awful groups for such a inherently accurate cartridge.

 

[NCsmitty]

I like H322 for the 222 class cases, and it is usually a good choice for an accurate load.
Having said that, there are a half dozen powders that will give superior velocity to your 6x45 round. You should test at least another powder like H4895, which should work better with the heavier 6mm bullets.

Set your FL die so the cases fit the chamber, and if your crimping with the seating die, all the cases need to be the same length to avoid some cases bulging the neck under crimping and refusing to chamber.

Check www.hodgdon.com for powders and loads. You'll see that 24gr of H322 is a 1/2 gr over max with the 80gr bullet.



NCsmitty

 

[W.E.G.]

18-inch barrel



20-inch barrel

 

[rc109a]

WEG
Can you run that information with a 100g BTSP Sierra?

I know the 24g with the 80 PSP was too high according to the charts, I got that data as a good load from another shooter. I want to stick with th 100g and see if I can get the H322 to work, but am open to other powders (just what I need more powder since I already have over 10 pounds of H322 and 15 other powers on the shelf).

 

[rc109a]

I only got that bump when I loaded flat base rounds. I never got it with the boatails. I am not sure why...
I am sure the accuracy was more on my part. It was cold and off a bipod vice the bags with a 25kts cross wind on the target.

 

[W.E.G.]

The Quickload program lists the pressure spec for 6x45 as ~55000 PSI.
Curiously, the program lists the pressure spec for 5.56x45 as ~62000 PSI.
No explantion for why the 7000 PSI difference.

I would assume you are firing a gun that is spec'd for 5.56 pressures.
Take that juke for what its worth.

OAL is assumed to fit in AR-15 magazine.

I don't trust standard small rifle primers as pressures get near the ATOMIC level.
Seen a lot of PIERCED .223 standard small rifle primers.
My ATOMIC .223 loads all are equipped with MAGNUM primers.

 

[rc109a]

Well I played aroudnwith the seating die and realized when I tried to give it too much crimp it bumped the shoulder back. I backed it off with little to no crimp and no issues. I want to give the round some crimp, but not sure how I can do this. Will a 243 factory crimp die work with the 6x45 load?

WEG thanks for the information. Not sure about the 556 pressures, but I will assume for now until the manuf lets me know. I am using standard small rifle primers as per manuf recommendations.

 

[W.E.G.]

I am using standard small rifle primers as per manuf recommendations

Only diff between magnum and standard in small rifle primers is the cup thickness.
We got the same velocity numbers over the chronograph using each type of primer.
Being aware of that fact, if you can think of some way to figure that there is a pressure difference between the two types of primers, I'd like to hear it.

.
.
.

I want to give the round some crimp...

Why do you want to crimp the bullet?

Here is a test:
Load the round WITHOUT the crimp.
Grab the round, and push the bullet hard against a firm surface.
Did the bullet move?

If it didn't, you need to ask yourself why you are crimping those rounds.
If it did, you need to reduce the diameter of the expander ball on your sizing die.
Boat-tail bullets lend themselves wonderfully to heavy neck tension, as it is very easy to fit the boat-tail bullet into the case during the seating stage, and without "snagging" the lip of the case.

 

[rc109a]

I don't crimp any other round except those in my revolvers. Thought it might be a good idea since this is going to primarily be a hunting round. I will forgo the crimp and just do as you suggested. Since I have over 15k small rifle primers I will see how they work for now.

 

[W.E.G.]

Your standard small rifle primers should be fine if you keep your powder-charges sub-ATOMIC.

Having loaded ~20,000 rounds of AR-15 and M1A ammo without crimping, I'm comfortable with my position on the matter.

 

[rc109a]

WEG
Ok, just so I understand the reason you prefer the mag primers is to prevent the primer from getting pierced when the pressures start getting high? I have never thought about the cup hardness in this manner and am trying to educate myself.

AS far as my next load, I am going to try some of the 100g with starting loads of 19g and work my way up to a max of 21g. If I cannot get anything that works, then I will look for a different powder.

Thanks for all the help.

 

[NCsmitty]

Here's a small read on primer info.

http://www.jamescalhoon.com/primers_and_pressure.php



NCsmitty