How to load for an extra long chamber

[joshchase]

Rifle reloading neophyte here, so please be patient.

I have a Howa 1500 chambered for .308 Winchester and I found that the total chamber length (base to lands) was 2.9045". In theory, the COL with a .018" jump would be 2.8865". The SAAMI spec defines the COL to be between 2.490" and 2.810" which means that my COL would be 0.0765" over the maximum defined COL.

Case: Hornady Match .308 Win
Bullet: Hornady .308 SST 165gr (Model #30452)

I assume that if I were to load to the defined COL spec (2.750") accuracy would suffer because my actual jump would be 0.1545" (or, put another way, 8.6x a "usual" jump.) However, if I were to load to my calculated COL I am concerned about what that would mean. With the bullet being seated so far forward is premature release an issue (less bullet in the neck?) Would there be any potential safety issues?

 

[expiper]

Josh,,that ctg overall length is so that they will fit in a mag box ...(short action) ...find what shoots best in your rifle and if they are longer than the mag box ...load some that will be your first shot in a hunting situ'ation or if single loading they will be no problem,,,then if hunting make some that will fit in the magazine..Roger

 

[joshchase]

Apologies on the bullet:

Bullet: Hornady .308" SST 165gr (Model #30452)

(Edited original post to reflect correct bullet.)

 

[joshchase]

Josh,,that ctg overall length is so that they will fit in a mag box ...(short action) ...find what shoots best in your rifle and if they are longer than the mag box ...load some that will be your first shot in a hunting situ'ation or if single loading they will be no problem,,,then if hunting make some that will fit in the magazine..Roger

Ah, that makes sense. I worked one up to my calculated COL and, luckily, it fits in the mag just fine. Thank you for your insight!

 

[gsg5pk]

How to determine the number of bullet left in the shank?

What is the minimum number of bullet left in neck for proper grip the bullet.


For example ;

Lapua Brass with trim to 2.005"

Berger 168 Hybrid
Berger 175 LRBT


Can someone suggest the maximum COAL to seat this bullet with proper grip from case nk?

 

[expiper]

gsg??..to answer your inquiry...in just about any cal. the min. shank or grip on the bullet that I have found to work is .050"....any thing less and you have to handle the ctgs like eggs...and once you get around .080 there is no worry if you have adequate neck tension (.003 +/- a lil'),,and once you get past .100 of bullet shank your absolutely perfect,,,you just have to see if you need to jam or jump and how much... the old wives tale of 1 cal of grip/engagement is not necessary and in some cases impossible with a ctg with a short neck (Dasher for example)....you have to do the math and take the measurements for your self with your particular combo of ctg case/bullet/FB...hope this helps..Roger

 

[gsg5pk]

Many thanks for your kindly information in detail.

gsg??..to answer your inquiry...in just about any cal. the min. shank or grip on the bullet that I have found to work is .050"....any thing less and you have to handle the ctgs like eggs...and once you get around .080 there is no worry if you have adequate neck tension (.003 +/- a lil'),,and once you get past .100 of bullet shank your absolutely perfect,,,you just have to see if you need to jam or jump and how much... the old wives tale of 1 cal of grip/engagement is not necessary and in some cases impossible with a ctg with a short neck (Dasher for example)....you have to do the math and take the measurements for your self with your particular combo of ctg case/bullet/FB...hope this helps..Roger

 

[jpretle]

joshchase, are you talking a long chamber or a long throat? In a long chamber you are dealing head space issues. In a long throat, w/ seating depth of the bullet. 2 completely different subjects.
Your question is on a long chamber and the responses reference a long throat.

 

[joshchase]

joshchase, are you talking a long chamber or a long throat? In a long chamber you are dealing head space issues. In a long throat, w/ seating depth of the bullet. 2 completely different subjects.
Your question is on a long chamber and the responses reference a long throat.

I guess it would be more accurate to say it is a long throat. I checked it with go/no-go gauges and everything checked out. As I said, I am quite the neophyte on this topic Thank you for the correction/clarification.

Apologies on the response time: had a wedding to go to (and the reception) Saturday and then an ATA shoot today.

Thank you everyone for your help on this topic!