I need your advice, I need your help

[Greg Duerr]

I was fire forming some loads this morning in my .243 AI I was shooting New Nosler Cases and 40gr of RL 22 and the 105 Berger. The accuracy I was getting was super. Three shot groups at 100 yds. .309, .251, .286, and one five shot group that was .441 I was impressed until I started shooting Some starting loads in the Ackley formed cases. RL 22 105 berger same seating deapth, starting at 45.0gr.
The first 3 shot group went 1.546. 45.5gr 1.423, 46.0gr. 1.389, and 46.5gr 1.254 however I was getting High pressure issues at 46.0gr
The berger manual shows a max load in the standard .243 RL22 at 43.9

The Hornady Manual shows 43.5 with a 105 A Max

Nosler Manual shows 42.0gr and the 105

So are my starting loads in Ackley way to high, as it appears??


ON the way home I Chronograhphed the 46.5gr load and It read an average of 3375fps.
The Smith that built the rifle told me that you might get 3300fps
Here's the stange thing that threw me so far off.................
The Smith sent me a Proof load. Five shots at 100yds .438 His max load with his lot of RL 22 was 49.0gr...................His brothers Max load in his .243AI was 48.2 shooting the 105 Berger.
With my lot of RL 22 my max load is 45.0gr

Is there that MUCH difference in powder lots ????

I will try again at the range with a starting load of 40.0gr in the Ackley cases and work up from there....................If I don't get the accuracy as I did Fire Forming then MY hunting load this Deer season will be with a standard .243

G

 

[MudRunner2005]

You might wanna start lower and work your way up.

 

[CogburnR]

I have some old WXR(RL22 marketed by Winchester) that shoots exactly the same as my current RL22. It can vary, sounds like the lot you have is pretty fast.

Are you pushing the shoulder back any? One of my buddies did an AI and had similar problems and it was the dies pushing the shoulders back excessively, ruined groups and made pressure signs. Probably from the primer backing out then getting squished.

3300 with a 105 is pretty good...I might have to have one reamed out.!

 

[MudRunner2005]

Rooster, that's exactly why once I get all my brass fire-formed, I neck-size only. That way I don't bump anything or move it, and resize only the neck.

 

[CogburnR]

I have pretty much gone to bumping the shoulder back .002" I don't know if it is right, but I know where it is.

 

[FearNoWind]

I doubt that you'd find that much difference from lot to lot in powder. How does your CBTO compare with what your smith loaded?

 

[Greg Duerr]

Cbto ??

 

[FEENIX]

Cbto ??

Cartridge Base To Ogive (CBTO)

http://www.bergerbullets.com/effect...coal-and-cartridge-base-to-ogive-cbto-part-1/

http://www.bergerbullets.com/effect...coal-and-cartridge-base-to-ogive-cbto-part-2/

 

[Greg Duerr]

The CBTO is the same from the Smiths Dummy round that was fire formed in my rifle to the CBTO that I load, same bullet..........................His lot of RL 22 and Mine Fired from the same rifle is 6gr difference from is accuracy load to mine at 44gr Im blowing the Primer Pockets

That is just poor quality control from Alliant.

 

[FearNoWind]

...His lot of RL 22 and Mine Fired from the same rifle is 6gr difference from is accuracy load to mine at 44gr Im blowing the Primer Pockets

That is just poor quality control from Alliant.

It is highly improbable that a load would vary 6gr from one powder lot to another. 6 grains is a lot of powder. I don't know what's wrong here but if it's related to powder I'm certain that it's not a variation between lots.
Things that affect pressure:
Bullet weight
Bullet bearing surface
Bullet length
Bullet seating depth
Neck Tension
Head Space
Incorrect primer
Dirty or otherwise restricted chamber/barrel
If you're blowing "primer pockets" and not just primers whatever it is that's wrong is VERY wrong. The web is the strongest part of the cartridge.
If you're just blowing primers, pressure may not be the cause. It may be a firing pin issue.

 

[SteveBurton]

Forgive me if this is a dumb question but I did not see you mention what case the builder used for his load workup. Was he also using Hornady? I don't know if a different case manufacturer would have a 6 grain difference in volume but thought it was worth asking. I like the primer pockets of Lapua brass the best.

 

[Michael Courtney]

RL22 can give some great velocities, but the price is temp sensitivity and lot to lot variations.

Eventually we decided it was not worth the hassle every time we bought a new lot and decided to stick with H4831, H1000, and H4350.

 

[Greg Duerr]

The Smith Fire formed Winchester Brass in my rifles Chamber Using 40gr of H4350 He then worked up to the Load of 49.0gr of RL 22 and sent me the proof showing a five shot group of .441 Other than the fact that he was using Winchester brass and I was using Lapua brass everything was the same.................Same Primer same bullet same seating depth.

The Berger Manual shows a Max load in the .243 using RL 22 and the 105 at 43.9gr..................In the .243 AI cases I was enlarging the primer pockets using 44.0gr..........................enough that I could push the primers in with my finger with no pressure at all. I would assume that that means they are done ..........

I purchased some new RL 22 different Lot and loaded up one case at 40gr and went up .5gr .......I will run these through the Chronograph and check them out.....I loaded one case all the way up to 47.0gr.

We will see................................