Custom .243 dangerous to shoot?

[rbseagle]

My uncle had a custom rifle built chambered for the .243 on a K98 Mauser action with a heavy contoured Sheilen barrel back in 1964. He fought the gun for years trying to get to shoot well, until he found out that it liked light bullets. He has got where he was shooting groups in the .2 range before is back trouble forced him to give up shooting. I have no idea what the round count is, but I know the barrel's throat is gone, because when I used my Hornady gauge to try and find the lands I could not get a measurement with the bullet would still in the modified case. I went all the way up to a 95gr Sierra mk with no luck. I did not realize that the barrel was that far gone when I told him I thought I could get to shoot better with all the new gauges and measuring tools that are out there now. So I loaded some full length cases with the 55 gr Nosler bullets and went to the range just because it has been years since I have been able to shoot the rifle. After the first shot when taken out the case I noticed a black powder residue down the entire length of the case about 3/16" wide just on one side. I was using 38gr of IMR-8208 XBR. I have never used this powder or seen this happen when my uncle and I shoot together a lot. I was still able to get 5/8" groups at a 100 and around 3.25" at 300. I am thinking that if I just neck size the cases that this might not happen. These where cases giving to me so I had to shoot them first of course. My question is this thing safe to shoot or I should wait until the gun is mine and re barrel it before shooting again?

 

[jds holler]

Maybe time for a chamber cast?? jd

 

[dkhunt14]

Sounds like the load is maybe a bit too light. I have never shot that powder though. I just looked it up and the starting load is 40 grains. Matt

 

[rbseagle]

Thanks I will take a look at that

 

[Cold Bore]

Sounds like the load is maybe a bit too light. I have never shot that powder though. I just looked it up and the starting load is 40 grains. Matt

Was my first thought as well.

You are concerned about safety, so it may seem counterintuitive, but in this case MORE powder will likely give better results, with a better "seal".

 

[rbseagle]

Thank you makes me feel a lot better. I will double check my load data.

 

[Zero333]

QuickLoad shows your load generates around 41,000psi, much to little and considering the fact that the freebore of the chamber is extremely long, it's more likely a lot less pressure than 41k.

Work up to 43gr with that powder/bullet. QL shows 43gr generates 58,432psi.

 

[rbseagle]

Is there a better powder suited for the .243 like say IMR-4064 I have some of it or IMR-3031.

 

[Zero333]

Is there a better powder suited for the .243 like say IMR-4064 I have some of it or IMR-3031.

For light 243 bullets, Varget/H-4895/4064/RL-15/4320 are popular, Can't go wrong with 4064.

For the heavies 4350/4831/RL-19/RL-22/H1000/RL-25. H-4350 being the most popular but I prefer H-4831.