The Firing Line Forums

Go Back   The Firing Line Forums > The Skunkworks > The Smithy

Reply
 
Thread Tools Search this Thread
Old November 13, 2021, 10:10 AM   #26
Unclenick
Staff
 
Join Date: March 4, 2005
Location: Ohio
Posts: 19,294
MG,

M118LR is the long-range military ammunition that uses the Sierra 175-Grain MatchKing bullet. The LR (for Long Range, originally for sniper systems) distinguishes it from the original M118 Match ammunition made with the old military M72 Type FMJ match bullet of nearly the same weight (174.5 grains with - 3.0 grains tolerance, 173 grains being the midpoint value). Alliant brags that Reloader 15 was chosen for this round, so the M118LR chamber should be optimized for that bullet as far as bullet jump goes. If you want, you can buy new production by Winchester or by IMI to make comparisons to your own ammo developments.

M118LR proved to develop pressure signs in the desert temperatures in Iraq, so ATK came up with M316 Mod 0 to replace it in the M24 sniper system. This is made by Federal using their match brass and primers and is charged with a special run of the less temperature-sensitive IMR4064 with flash suppressant added. The 175-grain Sierra was still the bullet. If you buy Federal's match ammo with the 175, that will perform very close to M316 mod 0 and is another choice you can make some comparisons with.

Presumably, the Palma chamber is geared toward the Sierra 155 grain Palma bullet for fit. Their 308 Winchester will likely be a SAAMI chamber. I don't know where the F-TR (F-class Target Rifle) design comes from, but I think if you have trouble with heavier bullets getting too close to the throat of the M118 chamber, you can look for designs with longer gives. Another strategy will be using the Sierra 175-grain Tipped MatchKing, which has a higher BC than the standard 175 but has a secant ogive, so it will likely be more finicky about tuning. The new 169-grain MatchKing is no slouch (higher BC than the original 175 and can be started out faster to stay supersonic at 1000 yards). Berger's 185-grain Juggernaut is made with a longer ogive radius and may fit that chamber as well, but expect less powder space with it. It's just something you'll have to try.
__________________
Gunsite Orange Hat Family Member
CMP Certified GSM Master Instructor
NRA Certified Rifle Instructor
NRA Benefactor Member and Golden Eagle
Unclenick is offline  
Old November 15, 2021, 12:15 AM   #27
Metal god
Senior Member
 
Join Date: April 10, 2012
Location: San Diego CA
Posts: 6,050
Quote:
M118LR is the long-range military ammunition that uses the Sierra 175-Grain MatchKing bullet. The LR (for Long Range, originally for sniper systems) distinguishes it from the original M118 Match ammunition made with the old military M72 Type FMJ match bullet of nearly the same weight (174.5 grains with - 3.0 grains tolerance, 173 grains being the midpoint value). Alliant brags that Reloader 15 was chosen for this round, so the M118LR chamber should be optimized for that bullet as far as bullet jump goes. If you want, you can buy new production by Winchester or by IMI to make comparisons to your own ammo developments.
Thanks for that . The only thing I know about the chambers is what James at Northland Shooter Supply told me when making the order . He said the only difference in all the 308 chambers is the leade/throat length . Pointing out 308 Win is the shortest , M118LR is longer then standard 308Win and FT-R is longer then both of those . I chose the M118 because I want a chamber a tad longer but not to long . Even if it's still to short I can have a smith ream it out a bit but I can't add material back if the FT-R is way longer then I want .
__________________
If Jesus had a gun , he'd probably still be alive !

I almost always write my posts regardless of content in a jovial manor and intent . If that's not how you took it , please try again .
Metal god is offline  
Old November 15, 2021, 08:35 PM   #28
std7mag
Senior Member
 
Join Date: June 23, 2013
Location: Central Taxylvania..
Posts: 3,362
It all boils down to what bullet you plan to shoot.
ELD, MatchKings, Nosler RDF all like a jump.

Shoot something like a Bart's Bullets, Berger VLDs, and some other custom makes and they like to be at or close to the lands.
__________________
When our own government declares itself as "tyrannical", where does that leave us??!!
std7mag is offline  
Old November 15, 2021, 09:01 PM   #29
Metal god
Senior Member
 
Join Date: April 10, 2012
Location: San Diego CA
Posts: 6,050
Well my first thought would be something in the 190gr range . I really like the 190gr smk with N-540 but that powder and bullet have not been to plentiful . The 185gr Berger hybrid or juggernaut sounds pretty good . I have some 195gr ELD's but they were for a different purpose I gave up on so not sure If I'll be going back to them . I have enough to work up a couple loads in the new barrel so I'll do that but as of right now I think I'd rather shoot the 190gr smk over the eld . I do have about 350 to 400 - 175gr TMK that I'll try so I do have a couple different bullets on hand to try out . I even have around 700 Fed match primers to use but I told my self I was not going to get hooked on those . They were hard enough to get before the panic , now I assume they are the great white wale of primers . One good thing is that I have plenty of components to get started when ever that is .

What I've generally done with any of my match type rifles is work up a couple loads with specialty bullets and powder . Then also have a load of cheap match bullets to plink with . Right now that is the Hornady 168gr BTHP using IMR-4895 . I have a nice load that works well enough in all my 308's to plink with and let others shoot with my rifles .

This new rig will likely be more dedicated to only shoot specialty components specific to the rifle . No need wasting barrel life on cheap components but you never know .
__________________
If Jesus had a gun , he'd probably still be alive !

I almost always write my posts regardless of content in a jovial manor and intent . If that's not how you took it , please try again .

Last edited by Metal god; November 15, 2021 at 09:10 PM.
Metal god is offline  
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 10:47 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2021, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2021 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Page generated in 0.03238 seconds with 9 queries