338 lapua build

[KyCarl]

I have a MPA 338BA and if you look at just what you get for the money.I think it's a great deal! It comes with a good action and chassis TT trigger about everything I wanted 1/2 MOA claim. And it was a lot cheaper than any comparable rifle out there at about 2500 bucks (if you look) I found Barnes ammo 300Gr.OTM for about 3 bucks a round loaded in real Lapua brass (L in a shield head-stamp) I bought 200 rounds?
https://masterpiecearms.com/shop/mpa-338ba-bolt-action-rifle/

 

[VLD Pilot]

Which chassis system has 4.050" mags?
Thanks

Mirage URL TACZ X and TAC XH non bottom metal chassis systems.

 

[Bloegwta]

I am a small custom rifle shop. This is a client project. 338 Lapua shooting 300 gr Bergers to .5 MOA. COAL is 3.733 measured to the meplat. No feed problems.

Steve
Dutch Hall Rifles
402-630-2399
[email protected]

 

[VLD Pilot]

View attachment 127096 I am a small custom rifle shop. This is a client project. 338 Lapua shooting 300 gr Bergers to .5 MOA. COAL is 3.733 measured to the meplat. No feed problems.

Steve
Dutch Hall Rifles
402-630-2399
[email protected]

It's not that you can't get the 300 Berger's in a mag fed platform with standard or CIP mags. Alex was saying that to get the most performance from the 300 Berger's, you must load them to beyond 4.00 OAL. Most platforms require single feed operation with rounds that long. You'll get excellent accuracy with a 3.750 or shorter but powder capacity will be limited.

 

[Alex Wheeler]

Im not talking performance due to powder capacity. Im talking about accuracy and how seating the bullet's pressure ring (which forms at the boat tail/shank junction) deeper the the sized part of the neck effects neck tension.

 

[VLD Pilot]

Im not talking performance due to powder capacity. Im talking about accuracy and how seating the bullet's pressure ring (which forms at the boat tail/shank junction) deeper the the sized part of the neck effects neck tension.

I guess I understand your meaning somewhat.

 

[Alex Wheeler]

If you have a good micrometer, measure the shank of your bullet in different places. Its not uncommon to have a ring right at the boat tail that measures .0002-.0005 larger than the rest of the shank. This acts like an expander mandrel in the neck as you seat the bullet. You dont want to push it all the way through the sized part of the neck or you will loose neck tension. If you have ever noticed bullet seating force gets easier towards the end, thats why. The work around here if you have to seat deep is to find bullets without a pressure ring.

 

[VLD Pilot]

If you have a good micrometer, measure the shank of your bullet in different places. Its not uncommon to have a ring right at the boat tail that measures .0002-.0005 larger than the rest of the shank. This acts like an expander mandrel in the neck as you seat the bullet. You dont want to push it all the way through the sized part of the neck or you will loose neck tension. If you have ever noticed bullet seating force gets easier towards the end, thats why. The work around here if you have to seat deep is to find bullets without a pressure ring.

Yep I got it now. I know what you are talking about now. Didn't understand it the first time around. Thanks

 

[Bloegwta]

It's not that you can't get the 300 Berger's in a mag fed platform with standard or CIP mags. Alex was saying that to get the most performance from the 300 Berger's, you must load them to beyond 4.00 OAL. Most platforms require single feed operation with rounds that long. You'll get excellent accuracy with a 3.750 or shorter but powder capacity will be limited.

This rifle shoots just over 2800 fps at the muzzle. I'm not being critical or disagreeing with you, but how fast do you want to go?

 

[VLD Pilot]

This rifle shoots just over 2800 fps at the muzzle. I'm not being critical or disagreeing with you, but how fast do you want to go?

3000 fps has been my goal with the 338 LM improved. When shooting 2000 yards +, I believe that extra horsepower helps. Especially with the 300s. Keeping my barrel length at 28-30" was also my goal and going the improved route, I can achieve the 3000. Don't think a 338 LM can do it regardless of barrel length.

 

[VLD Pilot]

If you have a good micrometer, measure the shank of your bullet in different places. Its not uncommon to have a ring right at the boat tail that measures .0002-.0005 larger than the rest of the shank. This acts like an expander mandrel in the neck as you seat the bullet. You dont want to push it all the way through the sized part of the neck or you will loose neck tension. If you have ever noticed bullet seating force gets easier towards the end, thats why. The work around here if you have to seat deep is to find bullets without a pressure ring.

Just checked about 25 of my Sierra 300s and no increase in size at the shank/ boat- tail junction. Maybe on the Berger's but not noticable in SMKs. I'll pull a 300 Berger eventually once I start my load work with them.

 

[Alex Wheeler]

Bergers will have more of a pressure ring and it will vary lot to lot.

 

[VLD Pilot]

Bergers will have more of a pressure ring and it will vary lot to lot.

Ya I figured. I'll check some soon. Thanks