30 338lm improved help

[wolverine99]

I had a 30 338lm improved built and everything was going great until round 101. when I shot the 101st round (now twice fired brass), the gun showed heavy bolt lift. I didn't change anything in the load that I had been using with zero bolt lift (action is a defiance ). I have talked with a few people and I guess this is not uncommon and it's due to the die not sizing enough down by the case head. On the second firing I used my full length sizer (a Redding custom die) and just bumped the shoulder I bit and the neck like I do for other guns. I am at a loss and not sure what step to try next

 

[JARHEAD1371]

It's common to see a velocity increase around 100-150 rounds, that brings increased pressures. Try backing off some on your powder charge (try .5 gr) and see if you get the same performance as before. If you chrony'ed your original load compare the velocity with what it is now, assuming it's safe to shoot again.

 

[wolverine99]

Thanks for the tip. I have shot it up to 104 grains with no pressure and settled on the current load at 101 for accuracy purposes. does anyone no what Kirby suggestss for his 300ax?

 

[RockyMtnMT]

Is the bolt hard to close with the loaded round? Did you completely clean the sizing wax off the brass? Are the primer pockets loose? Is there a fouling build up in the barrel?

You may have to bump just a bit more on the fl die.

Steve

 

[RockyMtnMT]

One more ?. Are you using Lapua brass? If not you may be too hot.


Steve

 

[wolverine99]

The loaded round closes with ease. I wipe all the cases before I chamfer deburr but possible I missed one but I don't think I would miss all of them. I am using lapua brass and the primers are still good. I am going to switch dies and see if it's as easy as that.

 

[rickiesrevenge]

Sounds like the die is too big at the base compared to your chamber. Its really quite common. Normally it takes a few firings on a BR sized case before it gets tight. Does anyone make a small base die for a Lapua sized case? There was a guy making a ring die that would size the base of cases. Don't know if he made them for 338L cases though.
Aaron

 

[wolverine99]

I just got off the phone with rcbs and they make a small base die. I have heard of people making a sizing ring, do you remember the contact name that was making them?

 

[RockyMtnMT]

Are your dies made from your reamer drawing? There are lots of 30-338 Lap Imp reamers. It is not standard like 6.5-06. They all vary just a little.

Steve

 

[wolverine99]

My die now was not made from a reamer drawing. I called one die maker and he said that even with the reamer print he couldn't ensure the fit. In my simple mind if the die is the same as the reamer it should work right?

 

[RockyMtnMT]

Your die needs to match your reamer. That way it matches your chamber.

Steve

 

[rickiesrevenge]

The guys name that made them was Paul, but I can't seem to find the thread on it. It was on accurateshooter.com

Aaron

 

[TXAoudadKlr]

Thanks for the tip. I have shot it up to 104 grains with no pressure and settled on the current load at 101 for accuracy purposes. does anyone no what Kirby suggestss for his 300ax?

I'm using 104gr rl33 no bolt issues here

 

[IdahoCTD]

I would send 3 fired cases to Whidden and get a new FL die made from your brass. Reamer prints are one thing but if it wasn't chambered correctly the back of the chamber could be over sized causing the cases to swell in front of the web. You might look into a slower powder like RL-50, 869, 872, etc.