M118 Match vs Mexican Match

[pbcaster45]

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.

[rjtfroggy]

Considering IMR 4895 was developed for 30cal military rounds, what you found doesn't suprise me at all.
I have found loads for everything I shoot with it and now that is all I use. Yes I loose some velocity but my accuracy more than makes up for it out to 200yards, that is the furthest I can shoot around here. I would love to find a place to shoot further but none is available.No I take that back there is a 350 range but no openings for new members and the guys there don't like quest.

[dcloco]

Target #6 was the tightest group...sans one flyer.

Redo the test at 200 or 300 yards....THEN pick the winner.

[Eric in NC]

Didn't know that match ammo had neck sealant...

Learn something new every day.

[pbcaster45]

No doubt substituting the Sierra HPBT is the most accurate way to go... but the time involved? I'll stick with breaking the neck sealant. If I can find the rest of my stash I will test it at 200 yards and chronograph it too.

Eric, it's military match ammunition - you won't find neck sealant on the regular commercial stuff.

[Eric in NC]

Oh I knew that - just never noticed neck sealant on my 06 FA match ammo - guess they started putting it on the 308 stuff (why?).

[Hutch]

Why? The rigours of war, that's why.



Hutch

[Balljoint]

I was using the same match ammo to break in my F/TR when i first got it had the same accuracy with it as you did.

[earl39]

No doubt substituting the Sierra HPBT is the most accurate way to go... but the time involved? I'll stick with breaking the neck sealant. If I can find the rest of my stash I will test it at 200 yards and chronograph it too.

Eric, it's military match ammunition - you won't find neck sealant on the regular commercial stuff.


The new M118 LR has no sealant nor crimped primers and uses the 175 SMK. so i don't think mexican match would do you any good at all if using newer ammo.

Gary

[pbcaster45]

Yep, all just for fun and to learn a little history!