My rifle doesn't like Lupua brass

[bozo699]

10 year old post. The problem was a incorrectly cut chamber. The bbl is history.I now shoot 6mm Creedmoor,no looking back.

It’s been so many years I can’t even remember for sure what I did but if I remember correctly I tossed the brass started over and went to 4831, finished the season and retired it! I still have it but haven’t shot it in years I went 6brx and Dasher. Same as you I have recently been playing with 6 creedmoor
Wayne

 

[Field_2_Fork]

10 year old post. The problem was a incorrectly cut chamber. The bbl is history.I now shoot 6mm Creedmoor,no looking back.

I'm experiencing the same issue with a Cooper 6.5-284 I recently bought, used, just had a new barrel installed on it before I got it. New Lapua brass.

Trying to work up loads and got the clickers, a first for me. Really worried there's a chamber issue as I can't afford to replace it. Wondering if it can be opened up possibly?

 

[bozo699]

I'm experiencing the same issue with a Cooper 6.5-284 I recently bought, used, just had a new barrel installed on it before I got it. New Lapua brass.

Trying to work up loads and got the clickers, a first for me. Really worried there's a chamber issue as I can't afford to replace it. Wondering if it can be opened up possibly?

Make sure your die is sizing the base enough
Wayne

 

[Field_2_Fork]

Make sure your die is sizing the base enough
Wayne

I've been working my way through a box of new brass, nothing has been resized yet.

I've tried measuring once fired to new and nothing jumps out as having grown at all. I'm measuring with a 1" Mitutoyo micrometer that reads .001, borrowed it from work, best I can get for now.

I recently cleaned the rifle as thorough as possible, definitely looks better in the chamber/neck area, there was a carbon ring I believe. Maybe that will help.

I'm a hunter, this level is quite new to me.

 

[Capt. Oblivious]

Try shooting a couple of pieces of virgin brass at 90% of your planned full power load and then on the second go you can step it up to 100%. I had a rifle that did the same in a different caliber with new brass and that solved the problem for me

 

[Uncle Ed]

Lapua brass is harder in the base and will spring back more after sizing.

Simple cure, pause at the top of the ram stroke for 4 or 5 seconds. This greatly reduces brass spring back after sizing.

I buy bulk once fired Lake City brass and the 7.62 cases need sizing twice with pausing to get them back to proper diameter.

Also chambers and dies vary in size and your die might be at the max diameter tolerance.

Example I have a standard Lee .223 FL die that will reduce the case body diameter more than my RCBS small base die does.

You could also send three fired cases to Whidden and have them make a custom die. Or buy another die and cut the top off so the shoulder is not touched. Then lap a shell holder to push the case further into the modified die to size the base more. And as much as you may dislike this, there is also a reason why they make small base dies. Nothing is written in stone when it comes to chambers and dies.

How Hard is Your Brass? 5.56 and .223 Rem Base Hardness Tests​

How Hard is Your Brass? 5.56 and .223 Rem Base Hardness Tests « Daily Bulletin (accurateshooter.com)

 

[457ciSBC]

I'm experiencing the same issue with a Cooper 6.5-284 I recently bought, used, just had a new barrel installed on it before I got it. New Lapua brass.

Trying to work up loads and got the clickers, a first for me. Really worried there's a chamber issue as I can't afford to replace it. Wondering if it can be opened up possibly?

Lapua; this was an issue ages ago when 6.5-284 was the hot ticket and the Lapua brass came on the scene. Simply put, the Lapua brass is too big towards the base. By the same token, smaller brass like Win developed a slight bulge at the base in chambers that were cut with the new reamers conducive to the Lapua brass.
Not sure if I have any of the Lapua, but I do have some virgin first and second gen 6.5-284 Norma brass that I could take some measurements for reference.

 

[Field_2_Fork]

Lapua; this was an issue ages ago when 6.5-284 was the hot ticket and the Lapua brass came on the scene. Simply put, the Lapua brass is too big towards the base. By the same token, smaller brass like Win developed a slight bulge at the base in chambers that were cut with the new reamers conducive to the Lapua brass.
Not sure if I have any of the Lapua, but I do have some virgin first and second gen 6.5-284 Norma brass that I could take some measurements for reference.

That would be very helpful, if you are able.

 

[457ciSBC]

That would be very helpful, if you are able.

This is from Norma brass that I got from Bill Shehane in Apr 2001 or 2002, I believe it’s first gen and measures approximately .499 + a few .0000’s @ the .200 point.
Here’s reamer print for Win brass supposedly.IIRC, Win straight 284 brass was in the .497 range.

SAAMI specs attached as well.

 

[Field_2_Fork]

This is from Norma brass that I got from Bill Shehane in Apr 2001 or 2002, I believe it’s first gen and measures approximately .499 + a few .0000’s @ the .200 point.
Here’s reamer print for Win brass supposedly.IIRC, Win straight 284 brass was in the .497 range.

SAAMI specs attached as well.

Thank you. I have a mitutoyo micrometer but it only measures to .001, and has flat faced anvil, is this accurate enough to use? Seems to me the edge of the anvil on the 'high side' of the measurement would be an accurate number.

I also just bought a set of mitutoyo digimatic/absolute calipers that read to ten thou.

I guess I'll do some experimenting. Thanks again.

 

[Ironworker]

No no ,take the rifle to a gunsmith and have them insert go and no go gauges to rule out if the chamber was cut wrong .

 

[Dusty Stevens]

The main issue with a 6x284 is a lot of the reamers floating around are for winchester brass. They were made before lapua brass was even on the scene. A gunsmith says sure i have a 6x284 reamer in that box of stuff i bought from that guy’s estate in the 90’s. Youll never know from a go/no go gage

 

[chkunz]

I am late to get on this thread so someone may have already said this. I had a stickey bolt problem on my 260 Remington with lapua brass. Stiff load but not a over max load. After two times fired with full lenght sizing the extraction was difficult and distracting shooting from the prone position. I changed to a small base sizing die and the problem was solved.

 

[McStocks]

I think I know the cause of the problem! The base needs to be sized more than a conventional die can do. You must make a push-through die and size the base about .002". I had the same problem with my 6.5/284, and this fixed it! I used a .284 die and whacked it off until I got the correct diameter. You must lube the crap out of it and go fast, or it will stick!
Steve McGee