M118LR too long for my LR-308??


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Baron
February 3, 2008, 11:00 PM
Hi all - I've got an LR-308 that is absolutely beautiful and shoots incredibly, but I've got a big problem with the magazines. When I get about 10 rounds of Lake City M118LR in the mag, they seem to bind as if they're too long. If I turn the mag over, several rounds simply fall out as there's no spring tension to keep them pushed tight against the feed lips. I've disassembled and thoroughly cleaned both mags and even slightly filed the followers to be sure they weren't binding. There are two bronze streaks down the inside of the front wall of the mag, indicating that the tips of the bullets are dragging. You can imagine the reliability problems this causes. I called DPMS and they told me that M118LR was crap and I should only use domestically produced, non-lacquer coated ammunition. I tried to explain to the kid that that's exactly what M118LR is, but he wouldn't budge. I'm going to try and call them again in the morning.

I seem to recall reading that others had used M118LR in LR-308s with no problems - anybody have any great ideas?

Thanks,

Gerry

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Eightball
February 4, 2008, 02:28 AM
If they mistook Wolf/Laquer coated for LC ammo, that's just special.

Take two, and call them in the morning?

Baron
February 4, 2008, 07:47 PM
I tried posing my question in the industry forum over at ar15.com, hoping that to save face they'd respond well, but no reply yet. Shucks. They wouldn't post something like that crap about LC M118LR being junk ammo; here's to hoping.

GunTech
February 4, 2008, 07:48 PM
Did you measure OAL of the cartridge? Is it less than or equal to 2.800?

USSR
February 4, 2008, 08:03 PM
I believe LC M118 LR is loaded to an OAL of 2.810".

Don

Baron
February 4, 2008, 11:59 PM
Wish I had calipers - I'm about to dive into reloading, and may just seat all 400 of my M118LRs deeper. Kinda wish they would just work - I may look into what other mags work in LR-308s. It's a shame, really - the DPMS mags are solid and well made. Too bad they don't work for M118LR. Oh well - time to make friends with a reloader until I buy all my stuff...

TexasRifleman
February 5, 2008, 12:04 AM
Wish I had calipers - I'm about to dive into reloading, and may just seat all 400 of my M118LRs deeper.

Be careful just randomly shoving bullets deeper into the case. That's generally not advisable. There's a reason the OAL is what it is. You can conceivably increase the pressure to dangerous levels doing that kind of thing.

Proceed carefully if you decide to go down that path.

DnPRK
February 5, 2008, 12:36 AM
If you examine the point of each SMK bullet, you'll notice they are all different. The point sets up the shock wave the bullet flies behind. The aerodynamic theory is the irregular points set up the shock in a different place for each bullet and since each bullet has different aerodynamics due to shock placement, they will hit the target in different places (i.e. larger group size). The product below will make sure every point is the same. It also slightly reduces overall length which may help your magazine feeding issue.

Tubb meplat uniformer (http://www.midwayusa.com/eproductpage.exe/showproduct?saleitemid=432976)

dmftoy1
February 5, 2008, 08:28 AM
Wish I had calipers - I'm about to dive into reloading, and may just seat all 400 of my M118LRs deeper. Kinda wish they would just work - I may look into what other mags work in LR-308s. It's a shame, really - the DPMS mags are solid and well made. Too bad they don't work for M118LR. Oh well - time to make friends with a reloader until I buy all my stuff...

FWIW - you can get a cheap set of digital calipers that will work for reloading at most home improvement stores for less than $20. Just take a look at Midwayusa.com for the frankford arsenal calipers and you'll see something branded differently at every home improvement store I've been in lately.

Zak Smith
February 5, 2008, 11:14 AM
A few comments--

* Seating them 0.010" deeper (from 2.810 ro 2.800) will probably be safe, but approach such a change like you would any reloading experiment.

* In a good bolt gun, I found M118LR to be underpowered and noticably less accurate than the common commercial match loads, and my reloads. It shot more like the Aus F4 surplus than good match ammo. YMMV.

-z

30Cal
February 5, 2008, 03:22 PM
If you examine the point of each SMK bullet, you'll notice they are all different. The point sets up the shock wave the bullet flies behind. The aerodynamic theory is the irregular points set up the shock in a different place for each bullet and since each bullet has different aerodynamics due to shock placement, they will hit the target in different places (i.e. larger group size). The product below will make sure every point is the same. It also slightly reduces overall length which may help your magazine feeding issue.

Tubb meplat uniformer

Proof? Because everything I've ever seen on a target says that the condition of the tip makes virtually no difference. Take 5rds and bash the tips on 3 of them. They'll shoot just as well as 5 virgin ones. You've got to pretty much mangle a tip beyond recognition before it shows up on paper.

Bitmap
February 5, 2008, 03:29 PM
Because everything I've ever seen on a target says that the condition of the tip makes virtually no difference. Take 5rds and bash the tips on 3 of them. They'll shoot just as well as 5 virgin ones. You've got to pretty much mangle a tip beyond recognition before it shows up on paper.

That is true at 100 yards. I'm not so sure it's true at 1000 yards.

Richard.Howe
February 5, 2008, 05:44 PM
That is true at 100 yards. I'm not so sure it's true at 1000 yards.

MOA is MOA, whether at 100 or 1000.

The most accurate load in my M70 6.5x55 is standard Federal blue box -- .4" 3-shot groups. The nose profile of each bullet is always different, and some just look truly mangled.

At 500yds, tested last weekend, I was able to hold 4-5" groups with a VXIII scope set at 10x.

Zak Smith
February 5, 2008, 05:46 PM
MOA is MOA, whether at 100 or 1000.
True, but a difference in BC due to nose profile difference won't expose itself at 100 yards.. but probably will at long range.

Richard.Howe
February 5, 2008, 05:51 PM
Yep on BC -- great point. The difference would then manifest itself in some kind of vertical stringing. Up to 800m though, I haven't seen it too much in either .308 or the 6.5. I guess you'd really have to get out there for it to become a significant contributor.

30Cal
February 5, 2008, 07:24 PM
True, but a difference in BC due to nose profile difference won't expose itself at 100 yards.. but probably will at long range.


I'd buy that with respect to really badly beaten tips. But I'm not really convinced the normal bullet to bullet variation matters.

Zak Smith
February 5, 2008, 07:29 PM
A 1% difference in BC will cause 2.6" of elevation dispersion in a common 308 load, at 1000 yards.

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