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Gunsmithing .338 lapua chamber/reamer help

SPAK

Stupid can be fixed
Full Member
Minuteman
Apr 3, 2009
2,257
112
Alaska
Hey guys,

I'm looking for some input on reamer dimensions for a possible .338 lapua build...

I'd like to throat it for 300gr bergers using lapua brass to maximize case capacity while maintaining appropriate amount of bullet still in the neck of the case and leave room to chase the lands as the barrel wears..

I don't have any components yet but someone told me new lapua brass neck thickness is about .015-.016" thick.. I will probably turn the necks to .015" to have a finished loaded round neck OD of .368" and have the reamer set at .371"

I don't have any other dimensions of new lapua brass so any info there would be helpful.

What I don't have are the following:

Freebore
Freebore diameter
Base diameter
Leade angle
Total chamber length (I was thinking about just having it cut .005" longer than saami max length)

Any thoughts or input is most welcome.

Thanks in advance!
 
Re: .338 lapua chamber/reamer help

Call dave at PTG and tell him you want the 338 Lapua match. It is made for Lapua brass and 300gr bullets. OAL will be around 3.880 with 300gr Bergers seated .005 off.
 
Re: .338 lapua chamber/reamer help

I forgot to mention rifle will be magazine fed.. Will the rounds still fit in the mag at 3.880" oal?
 
Re: .338 lapua chamber/reamer help

I have the 338 Lapua Tactical Match from PTG and with Berger 300's I am at 3.900" at .025" off the lands. Base of bearing surface is right at the neck shoulder junction. I leave the reamer designing up to the reamer makers. Pretty easy to out fox yourself and end up with a very specialized hard to load for wildcat. Simple can work.

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Re: .338 lapua chamber/reamer help

At 3.900" are single feeding or mag fed?? What magazine if you are??

Thanks!!
 
Re: .338 lapua chamber/reamer help

This one would be a single shot. I wish all my rifles were single shots. These are all 3 shot groups with different powder charge levels in 1 grain increments. We were shooting in the rain and the big group the paper was so wet it started to blow bigger holes. After Elk season next weekend we will bring it back in for Cerakote.

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