Blown primer in .243 Ackley

[adam32]

Without any real data and because of your eagerness to argue instead of providing any, I don't have the ability to and have lost the desire to help. So carry on.

I answered your questions politely. What other real data do you want? Lets assume they are .050 off the lands, and lets also assume they were touching...what could be the issue with both? I understand jammed and touching can cause pressure spikes, but one that big is new to me.

 

[jomiba]

Maybe seated too deep?

 

[turkn8r1]

Did you happen to chronograph the round? Just asking. I know this will seem like a bad question but have you verified that you didn't grab a mag primer on accident? Do you have any H4831 SC that you have used before and have you tried that?

 

[nmbarta]

Can you easily push or drop a new bullet in the fired case? Carbon build up in the neck area of the chamber can cause major problems, it won't let the case let go of the bullet. This usually won't happen for a couple hundred+ rounds, but I've seen it happen

 

[adam32]

Did you happen to chronograph the round? Just asking. I know this will seem like a bad question but have you verified that you didn't grab a mag primer on accident? Do you have any H4831 SC that you have used before and have you tried that?

I did not chrony it, I was just gonna do a quick 5 round string to find pressure. It landed square in the bullseye at 97 yards tho lol

I'll verify the primer...I'm "pretty sure" it wasn't a Mag primer but I'll check.

I have lots of that powder but this was a new jug, I'll check Lot #'s compared to the used jugs.

 

[adam32]

Can you easily push or drop a new bullet in the fired case? Carbon build up in the neck area of the chamber can cause major problems, it won't let the case let go of the bullet. This usually won't happen for a couple hundred+ rounds, but I've seen it happen

I'll check that.

This barrel has about 450 rounds thru it.

I shot 3 of my 87gr V-Max loads out of it after and they shot fine (1/2 moa).

 

[zr600]

Yea I would say to clean the rifle very good. How many rounds are down the barrel? What are your barrel cleaning practices?

 

[adam32]

Yea I would say to clean the rifle very good. How many rounds are down the barrel? What are your barrel cleaning practices?

About 450.

Shooters Choice solvent, bore mop, brass brush, jag.

 

[lancetkenyon]

Try starting at a lower charge weight. Since there is no H4831 listed for .243 Win, you won't find max loads for the parent case to start from. I have seen some other load data for .243AI & H4831, but all I have seen is around 47.5 max with different brass. Brass content and case capacity can make a big difference in pressures. When in doubt, start low. 1.5 grains is not starting low.

 

[SealT5]

Carbon ring? They are pretty common in wildcats that shorten the over all length of the parent case. Are these fire forming loads? If so the case could be moving if you don't have a proper crush. Is this only happening with the selected bullet?

 

[just country]

morning, I shoot a 243AI and 6mmAI. 4831SC, 210fed.,
Winchester brass, neck sized and 95gr. berger. NEVER had a
problem.extremely accurate. justme gbot tum

 

[adam32]

Carbon ring? They are pretty common in wildcats that shorten the over all length of the parent case. Are these fire forming loads? If so the case could be moving if you don't have a proper crush. Is this only happening with the selected bullet?

Could be carbon ring? I'll check.

Not fire forming, these a formed rounds.

It's only happened one time. I'm going to the shop in a bit to do some more investigating on it.

 

[adam32]

Try starting at a lower charge weight. Since there is no H4831 listed for .243 Win, you won't find max loads for the parent case to start from. I have seen some other load data for .243AI & H4831, but all I have seen is around 47.5 max with different brass. Brass content and case capacity can make a big difference in pressures. When in doubt, start low. 1.5 grains is not starting low.

I run 48gr of RL22 and a 105gr Berger and get 4-5 firings per case.

I know 46 is not starting super low, but then again it's not super high to cause a blown out primer? Maybe an ejector mark or something?? I dunno, just seems weird to me.

 

[can1010]

minimum book for cup and core ( berger) is the max load for monos ( barnes )
I just checked you are maxed out for barnes
clean barrel, check reloading supplies are right, check length, and start at 42.0 H4831sc