primer pocket depth

[Murray Brook]

Need some advice here. I am getting some components together for a future 6mm br build. I purchased a box of Laupa brass so as to get some measurements so I could order a custom reamer. One of the things I noticed on the new brass was that a primed case seemed to have it's primer seated somewhat low. I measured the depth with my digital vernier and got a .011 reading. Felt this was deep so I measured the depth of the Laupa brass primer pocket and came up with a depth of .126 on average. Is this excessive or acceptable , or am I seating the primers with too much force. Maybe someone with Laupa 6mm br brass could give me a reading on what their depth is.
TKS

 

[oldduc]

Need some advice here. I am getting some components together for a future 6mm br build. I purchased a box of Laupa brass so as to get some measurements so I could order a custom reamer. One of the things I noticed on the new brass was that a primed case seemed to have it's primer seated somewhat low. I measured the depth with my digital vernier and got a .011 reading. Felt this was deep so I measured the depth of the Laupa brass primer pocket and came up with a depth of .126 on average. Is this excessive or acceptable , or am I seating the primers with too much force. Maybe someone with Laupa 6mm br brass could give me a reading on what their depth is.
TKS

The primer pockets on new Lapua 6BR brass that I have averages 0.0125x. I run a pocket uniformer in them and they are then 0.1275. My seated primers are about 0.005 deep, depending on the brand (F205M, CCI450, etc.). .011 is deep, but shouldn't be an issue if they are all the same.

 

[Murray Brook]

TKS. What tool do you use to prime your cases. Maybe that is my issue.

 

[oldduc]

TKS. What tool do you use to prime your cases. Maybe that is my issue.

I use either a Holland's Perfect Primer Seater or an old Lee AutoPrime XR hand primer, depending on how bad the arthritis is in my hands. I think I'm more consistent with the Lee because I've used it for 30 years, or so, but the Holland Seater is easier on my thumbs and does an excellent job also.

 

[Murray Brook]

For over 35 yrs I've been using my Lee Ram prime unit or the RCBS hand held one. Never had and issues till now, but I've only used large rifle primers in the past.

 

[243winxb]

Saami is flush to .008" below the case head. https://www.thehighroad.org/index.php?media/saami-primers.1299/

 

[JEFFPPC]

I use either a Holland's Perfect Primer Seater or an old Lee AutoPrime XR hand primer, depending on how bad the arthritis is in my hands. I think I'm more consistent with the Lee because I've used it for 30 years, or so, but the Holland Seater is easier on my thumbs and does an excellent job also.

I have used the Lee tool for about 55 years. I have been through several of them. Two years ago I started getting misfires in my bench rifles. Long story short after much anguish my friend and gunsmith Bob Green figured out the problem. The Lee tool cam want so worn it felt like the primer seated but it was the tool bottoming out on its self. New tool ended the problem.

 

[oldduc]

I have used the Lee tool for about 55 years. I have been through several of them. Two years ago I started getting misfires in my bench rifles. Long story short after much anguish my friend and gunsmith Bob Green figured out the problem. The Lee tool cam want so worn it felt like the primer seated but it was the tool bottoming out on its self.

I've heard of that happening. Must represent a lot of rounds loaded. You probably got your moneys worth out of it. I don't think the new Lee tools are as good as the old one, but I've never actually used one. I looked at a friends and decided to keep using my old one until it dies, or my thumbs finally give out for good.

 

[JEFFPPC]

If I had a dollar for every round I could fund THE WALL.

 

[BoydAllen]

 

[Murray Brook]

View attachment 1088001

Mine ( primer pockets) are on average 0.125 deep. Do you believe this will be a problem. TKS

 

[Murray Brook]

I measured my primers and they are .116 height and my primer pocket depth at .125 This would give me .009 with the primer "feet" just touching the bottom of the pocket. How much crush is acceptable to seat the feet, or is just touching ok. TKS

 

[243winxb]

No expert here.
But i seat with an RCBS Ram prime(not 6mm br). When i feel primers bottom out, they are good to go.

If primers are .011" below the case head, i would shoot them. The firing pin protrusion should easly reach and fire the primers? Pin protrusion should be about .055" on some, not all.

My guess.

 

[243winxb]

But will the primer maintain a seal or leak gas under pressure? Its going to move back to the bolt face on firing.?

Gas leaks pock mark the bolt face.

 

[Murray Brook]

Could someone with a 6mm br Norma measure their Laupa primer pocket for me and post the #'s. TKS

 

[Ggmac]

I have used the Lee tool for about 55 years. I have been through several of them. Two years ago I started getting misfires in my bench rifles. Long story short after much anguish my friend and gunsmith Bob Green figured out the problem. The Lee tool cam want so worn it felt like the primer seated but it was the tool bottoming out on its self. New tool ended the problem.

I also still use the round primer holder Lee primer tool . I may have a good cam if you need one .

 

[Murray Brook]

@dmoran
Mine are on average .126, with some at .127-.128. There are are also some at .123 etc. My Fed 205m mike at appx .117. Seated with the anvil's seated to appx .002 crush then the primer depth below flush could be as much as ..013+. I wonder if this is to much. I do not have the rifle yet so as to test, and if the pockets would be to deep then I could get in touch with Laupa and maybe return the brass. This is why I was asking someone if they would measure one of their Laupa primer pockets for me. Thanks for the response.

 

[KenOath]

Just measured 10 for an average of .01235”..Some were .0005” deeper but that may be my measuring technique..

 

[Murray Brook]

@dmoran
Thanks for the info. I appreciate your help.Got on the Laupa site and sent off an email explaining the situation. I wasn't aware of Mr Thomas. Will update on what they say. TKS
What led me to check the pockets is I ran my primer pocket reamer in a pocket and there was zero touch anywhere. This has never happened to me before with other cases.

 

[Webster]

Need some advice here. I am getting some components together for a future 6mm br build. I purchased a box of Laupa brass so as to get some measurements so I could order a custom reamer. One of the things I noticed on the new brass was that a primed case seemed to have it's primer seated somewhat low. I measured the depth with my digital vernier and got a .011 reading. Felt this was deep so I measured the depth of the Laupa brass primer pocket and came up with a depth of .126 on average. Is this excessive or acceptable , or am I seating the primers with too much force. Maybe someone with Laupa 6mm br brass could give me a reading on what their depth is.
TKS

I use a RCBS pocket uniformer and brass is cut out of almost every 6BR Lapua case. Never measured the depth. It shouldn't matter they always go off. I set by feel, the depth shouldn't matter as long as they touch the bottom of the pocket.