338 Lapua Improved 40 degree with print. Which design is better?

[Despotes]

I sent my custom print to JGS. I settled on a Lead of .215 since I'll be using a variety of 300gr or 285gr bullets. I hope that was a good estimate. I'll have to load around that lead length and hope the bullet doesn't take up much space in the case.

 

[Pdvdh]

I sent my custom print to JGS. I settled on a Lead of .215 since I'll be using a variety of 300gr or 285gr bullets. I hope that was a good estimate. I'll have to load around that lead length and hope the bullet doesn't take up much space in the case.

I think you're in the ballpark. I went back and forth on Lead length. I think I settled on 0.225" for my .338 Lapua 37*. Which is essentially the same as what you decided to go with. A difference of 0.010" is insignificant when it comes to LEAD length.

Curious; did JGS have any comments on the shoulder diameter and case body taper on your reamer spec? Were they good with the 0.08805" taper/20 inches? Good luck on your rifle project!

 

[Despotes]

I think you're in the ballpark. I went back and forth on Lead length. I think I settled on 0.225" for my .338 Lapua 37*. Which is essentially the same as what you decided to go with. A difference of 0.010" is insignificant when it comes to LEAD length.

Curious; did JGS have any comments on the shoulder diameter and case body taper on your reamer spec? Were they good with the 0.08805" taper/20 inches? Good luck on your rifle project!

The tech is going to contact me after checking out the print. I'll keep you posted.
This is what I sent:

 

[Despotes]

The tech sent the print back for my review. He didn't mention anything about the body taper.

 

[TXTrained]

I would at least change the design to reduce dimensions G and I from 0.3398" to 0.3385". No sense allowing the excess gas to excape around the bullet as it travels thru the "LEAD".
If you're going to outside neck turn the necks of your brass casings, you may want to reduce the dimension H from 0.372 to 0.370".
And as yorke-1 stated, determine your preferred cartidge overall length (COAL) with the bullet you intend to shoot, and then match the "LEAD" length to be compatible with your preferred COAL. Your "LEAD" dimension is shown as 0.130". I went with 0.225" "LEAD"
on my reamer design, intending to load the Berger 300gr OTM to a COAL of ~3.945".

 

[fruitnut]

Did you want to add something? This thread is 10 years old.

 

[Left Hand Dave]

Since I am curious I will ask a few questions.
@Despotes did you finish your .338 Lapua Improved project and if so how did everything turn out?
What did you do for dies?

@Pdvdh what did you do about dies for your version?