pbcaster45
04-15-2010, 12:55 AM
I've always been curious to see if the old trick of replacing a military bullet with match grade one was worth all the effort. And I wanted to see for myself if breaking the neck sealant on military ammo really improves accuracy. So I did a small test - and I learned a few things.
I still have a few rounds of M118 Match 68 (7.62X51MM NATO) and that's what I used for my test. Test Rifle was my Savage 10FLP (straight from the factory except for the McMillan HTG stock). This was not an exhaustive, meticulous test by any definition - just for fun.
When I started pulling the original Lake City bullets I ran into a problem. I had deep seated twenty rounds last year and never gotten around to shooting them. I was using ten of those for my Mexican Match. When I started pulling the bullets I noticed a few were really tough to pull and it looked like the sealant had seized up again. These rounds needed a second seating to break the seal again. The other ten were probably the same way and I'm pretty sure it had an effect on the results. I didn't want to seat the bullets any deeper so I left them alone. All groups fired at 100 yards.
http://i218.photobucket.com/albums/cc265/pbcaster45/Savage10FLP308-1.jpg
Sierra 168 gr HPBT on left and Lake City 173 gr FMJBT on right.
http://i218.photobucket.com/albums/cc265/pbcaster45/MexicanMatchM118.jpg
Here's how the test went.
Group #1 Foulers with Mexican Match (from a clean, de-coppered barrel)
Group #2&4 Unaltered M118 Match.
Group #3&5 Deep Seated M118 Match.
Group #6 Five rounds of Mexican Match.
http://i218.photobucket.com/albums/cc265/pbcaster45/MixedGroups.jpg
http://i218.photobucket.com/albums/cc265/pbcaster45/MexicanMatch.jpg
With this lot of ammo (in this rifle) it looks like Mexican Match is a waste of time. I do think deep seating improved accuracy and consistency. Now if I can just find that last 50 rounds of M118 I will run the test again with freshly broken neck sealant.
**Note** The powder in the M118 Match looked just like IMR-4895 and weighed an average of 41.8 grs.
I still have a few rounds of M118 Match 68 (7.62X51MM NATO) and that's what I used for my test. Test Rifle was my Savage 10FLP (straight from the factory except for the McMillan HTG stock). This was not an exhaustive, meticulous test by any definition - just for fun.
When I started pulling the original Lake City bullets I ran into a problem. I had deep seated twenty rounds last year and never gotten around to shooting them. I was using ten of those for my Mexican Match. When I started pulling the bullets I noticed a few were really tough to pull and it looked like the sealant had seized up again. These rounds needed a second seating to break the seal again. The other ten were probably the same way and I'm pretty sure it had an effect on the results. I didn't want to seat the bullets any deeper so I left them alone. All groups fired at 100 yards.
http://i218.photobucket.com/albums/cc265/pbcaster45/Savage10FLP308-1.jpg
Sierra 168 gr HPBT on left and Lake City 173 gr FMJBT on right.
http://i218.photobucket.com/albums/cc265/pbcaster45/MexicanMatchM118.jpg
Here's how the test went.
Group #1 Foulers with Mexican Match (from a clean, de-coppered barrel)
Group #2&4 Unaltered M118 Match.
Group #3&5 Deep Seated M118 Match.
Group #6 Five rounds of Mexican Match.
http://i218.photobucket.com/albums/cc265/pbcaster45/MixedGroups.jpg
http://i218.photobucket.com/albums/cc265/pbcaster45/MexicanMatch.jpg
With this lot of ammo (in this rifle) it looks like Mexican Match is a waste of time. I do think deep seating improved accuracy and consistency. Now if I can just find that last 50 rounds of M118 I will run the test again with freshly broken neck sealant.
**Note** The powder in the M118 Match looked just like IMR-4895 and weighed an average of 41.8 grs.