Hi All,
I am having built a .308 sniper rifle for an Army Veteran friend of the Vietnam War that was a sniper for SE Asia (Vietnam, Cambodia, Laos), and was wanting a "nostalgic" bolt action rifle like he used to use. I have acquired for him a Green Mountain .308 stainless 1:10" twist, 24" length, 4 groove, in Fluted M24 contour (.835 diameter at muzzle) with JT Brake that has been chambered...but I need to provide final throat dimensions to finish the machining. My Veteran friend lives in another state (across the country), and while I'll be working up loads for him so he has the most accurate rounds possible for the rifle (planning on finding one or two bullets for optimal loads from the following: 155gr Sierra MK Palmas, 168gr Sierra MK's, 175gr MK's, 168 Berger VLD Hybrids, or 170gr Lapua Scenars all shot off of Hodgdon powder in Lapua brass. I plan on working up loads from book mins across 3 burn rates to determine the best loads for his barrel's liking.
Now for the question...while I'll be cooking up his recipe for the reloads, he feels he may need on occasion to use factory ammo in a pinch. Originally, based on the 155 SMK Palmas and 170 Lapua Scenars optimal bullet depth in the neck of the casing, I settled on an ogive measurement of 2.222 ...so a suggested throat depth of 2.242 or 20 thousands over the ogive length. IF he shoots factory ammo in the rifle of 175 grain or less, is there a likelihood of excessive pressures based on the throat depth from the factory loads? I have been suggested to go .080 or 80 thousands over the 2.222 to keep the pressures in the green with factory loads...but is this depth excessive? I could always seat the reloads longer, but not optimal to the case neck depth... What throat depth would you go with and why? And don't worry - whoever provides their advice or opinion is completely exonerated from any form of liability...it's my decision, and mine alone and I accept full responsibility for my final decision...so don't hold back on an answer.
Any recommendations/advice that you could provide would be most appreciated!!
I am having built a .308 sniper rifle for an Army Veteran friend of the Vietnam War that was a sniper for SE Asia (Vietnam, Cambodia, Laos), and was wanting a "nostalgic" bolt action rifle like he used to use. I have acquired for him a Green Mountain .308 stainless 1:10" twist, 24" length, 4 groove, in Fluted M24 contour (.835 diameter at muzzle) with JT Brake that has been chambered...but I need to provide final throat dimensions to finish the machining. My Veteran friend lives in another state (across the country), and while I'll be working up loads for him so he has the most accurate rounds possible for the rifle (planning on finding one or two bullets for optimal loads from the following: 155gr Sierra MK Palmas, 168gr Sierra MK's, 175gr MK's, 168 Berger VLD Hybrids, or 170gr Lapua Scenars all shot off of Hodgdon powder in Lapua brass. I plan on working up loads from book mins across 3 burn rates to determine the best loads for his barrel's liking.
Now for the question...while I'll be cooking up his recipe for the reloads, he feels he may need on occasion to use factory ammo in a pinch. Originally, based on the 155 SMK Palmas and 170 Lapua Scenars optimal bullet depth in the neck of the casing, I settled on an ogive measurement of 2.222 ...so a suggested throat depth of 2.242 or 20 thousands over the ogive length. IF he shoots factory ammo in the rifle of 175 grain or less, is there a likelihood of excessive pressures based on the throat depth from the factory loads? I have been suggested to go .080 or 80 thousands over the 2.222 to keep the pressures in the green with factory loads...but is this depth excessive? I could always seat the reloads longer, but not optimal to the case neck depth... What throat depth would you go with and why? And don't worry - whoever provides their advice or opinion is completely exonerated from any form of liability...it's my decision, and mine alone and I accept full responsibility for my final decision...so don't hold back on an answer.
Any recommendations/advice that you could provide would be most appreciated!!
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