.223 5/8" group but...

[Shanghai McCoy]

Took out my latest batch of reloads for my Savage Model 11 this afternoon. A slight cross wind and assorted bullet weights, 55-63 grain but all using 24gr of H335 and CCI 400 primers. The best group was the Sierra SMP 63gr soft points. I mean 4 shots touching and the fifth just outside the other 4 shots amking it 5/8".

The "but" is that the primers were showing up pierced from those rounds ...
So, maybe 24 grains of 335 is too much for that bullet weight, but Dang, it sure was accurate.

 

[<*(((><]

I ran into the same problem with my Mossberg MVP, I've been trying to duplicate Hornady's 55gr. SP ammo as it is .75 MOA or better in my 5 shot groups if I'm on my game and was getting some good accuracy but had pierced primers and had to drop back down and lost the accuracy. Back to square one.

I was frustrated after that with it and took a break and bought some more Hornady ammo and shot some more whistle pigs, that eased my frustration.

 

[murf]

25 grains is max for that bullet and powder according to the hogdon manual. sure your cases aren't too long, or something?

luck,

murf

p.s. found this: https://www.24hourcampfire.com/ubbthreads/ubbthreads.php/topics/2745999

 

[Shanghai McCoy]

Nope, the cases have all been trimmed to spec but it might be the elusive "or something" causing the problem.
That campfire thread was interesting, it sounds like these 63gr SMP bullets are pretty effective.

 

[murf]

Nope, the cases have all been trimmed to spec but it might be the elusive "or something" causing the problem.
That campfire thread was interesting, it sounds like these 63gr SMP bullets are pretty effective.

yah, you shouldn't be piercing primers with that load. have you chronographed that load to see if it's going way too fast? something is going on here that is not right.

luck,

murf

p.s. maybe the c.o.l. is too short, or too long?

 

[Shanghai McCoy]

I don't have a chrono to check them with but there are 8 rounds left so I'm going to check their specs and pull the bullets and check the charge weight.
Could have been the old "pilot error".
But dang, they sure were accurate.

 

[HankC]

Do you have standard firing pin spring or light weight spring? May not have sufficient support under pressure.

 

[<*(((><]

What primers are you using, I had more piercing problems when using Remington 6-1/2's than I do with Remington 7-1/2's. The 6-1/2's have thinner cups.

 

[Shanghai McCoy]

^^^
The firing pin spring is what ever the standard Savage spring must be. Have not messed with anything in the bolt.

The primers are CCI small rifle primers.

C.O.A.L. on these is/was 2.235" so maybe I need to seat the bullets out more with this powder...?

 

[243winxb]

The quick fix is, dont use CCI 400 or Rem 6 1/2 primers in the 5.56/223. Unless pressure is kept below 40,000 PSI .

Use a magnum primer or Rem 7 1/2.

 

[Shanghai McCoy]

The quick fix is, dont use CCI 400 or Rem 6 1/2 primers in the 5.56/223. Unless pressure is kept below 40,000 PSI .

I'll have to watch the load and pressures on the charts more carefully then cause I've still got about 800 of the CCI's still left. They worked fine with the 4895 powder.
How about Winchester small rifle primers? I picked up some of them recently as well as a couple flats of the 71/2 Remingtons.

 

[243winxb]

Winchester small rifle primers

Have not used them.

The CCI 400 primers were flowing into the firing pin hole for me using mid-range loads. Loading IMR 4198 powder. Having 5000 of them, i still use them. Luckyfor me, no piercings.

I do control shoulder bump when fl sizing in my Savage Axis.

 

[Blue68f100]

Use the CCI #41 for the high pressure 5.56. I have not had any problems with Rem 7 1/2 either, which are Bench rest primers.