XM118LR questions

[LRRifleman]

I have acquired about 1000 rounds of XM118LR that I am using for the start of an F class 1000 yard rifle. This is marked as lot XM118PD, which my research suggests was released in the civilian market because it didn't meet military QC. Before bedding my rifle, I can safely say that I was able to keep all 20 record shots on the 6'x6' target at 1040 yards. When I chronographed the surplus ammo (head stamped 2011), it was pushing the Sierra 175 matching at 2765 fps out of my 26" varmint barreled Remington. I never saw any signs of excessive pressure.

My questions:
Apparently, there are two variants of XM118LR, general XM118LR in Lake City cases loaded with RE15, and SOCOM's variant known as Mk316 Mod 0 loaded with IMR4064 in "special Federal Gold Medal Match" cases.
1. Was the Mk316 version ever loaded in Lake City "11 LR" cases?
2. Was the Mk316 loaded in Federal or FCC headstamped cases?
3. How does that special Federal case compare to the LC11LR cartridge case?
4. Since both the XM118LR and SOCOM's Mk316 Mod 0 ammo exceed Sierra's load recommendations for military brass, and the RE15 recipe is way hot for commercial brass (per Sierra's manual):
a) Has anyone experienced high pressure signs with repeated reloadings?
b) If so, how many reloads did you get out of a case before you had to toss the case?
c) Has anyone experienced rifle damage from repeated use of either variant of XM118LR, such as bent bolt bodies?

Thanks in advance for your constructive advice.

Note: I wish to duplicate this particular round since it relatively insures that my 1000 yard load stays supersonic on my home thousand yard range which is realistically about 1040 yards close to sea level.

 

[Xtremegunnr]

Hello,

Glad you got some good ammo to start out with. Although I am not aware of the differences in the M118lr ammo, i do know that at 1000 yards it will work great.

You do not have to worry about a "bend bolt body" unless you figured out how to get .50 BMG in that cannon of yours. The primers will start flying before you will ever damage your gun or you person.

Although some individuals have luck shooting 1200+ with M118LR (myself included), if you plan on doing it frequently, it would be a good thing to step up from the MK to something in the 185 to 208 grain region. They tend to be more predictable with wind etc.

I have loaded LC 2011 LR brass 10+ times with no issues. That was with 43.1 grains of RL15 at about 2640 our of a 22". 4064 is darn close so i wouldnt image the two variants would be all that different.

Zero, Chroonograph, and start flinging them!

 

[Darkker]

LRRifleman,
Gotta get a few things cleared-up, to get your questions answered.
1) Powders. I have read the same crappy internet stuff telling us that those powders are what are in the various variations of that ammo; don't count on it. Both of those powders are Canister grade powders for the reloading market. NO, I repeat NO, major ammo company (certainly not a defense contractor) uses canister grade powder. We are the waste/blended market, always have been. NO cutting edge ANYTHING happens here first. Folks think CFE223 from 2 years back is magic.... General Dynamics has had SMP842(non-canister parent) in production for more than a decade already.
Other than the old A-Squared manual, NO one gives you component lot #info. Most will not publish the nominal BR/VMD's for canister grade powders. So ANY info from ANY manual is horribly vague at best, unless you use your own pressure testing equipment (Pressure Trace, etc). While we're on it, NO manufacturer loads cases by weight of powder, they use volume. Loading by volume is NOT used to get a "weight" of powder, it's used for a volume of powder, based on pressure testing done for that specific lot of powder purchased.

2) Cases. Much like the powder, there is a lot of bad info out there. Companies don't tell you what metallurgical mixture they used to build cases. IF they followed the metals handbook formula for cartridge brass only, tensile strength is 70,000psi. So by the time you "see" or measure case expansion, guess where your pressures are? There has also been some very good work done from the arsenals about nominal case variation from various production lots, in reference to case volume. Considering who actually builds their own brass, headstamps don't mean much. Volume from the same production lot can have variations as large as you have likely ever measured. The old stories about brass being "thicker" is hooey. Back to the part about what "mix" they were built with.

3) Bullet. The 175SMK was built to safely cross Trans-sonic, so you don't need to be super sonic. At those launch speeds, you are supersonic long past 1040; may want to double check your ballistic calculator.
From a very long time ago at camp Perry, it was found that the 168 SMK was not surviving transonic. The military was none to happy, and called upon Sierra to help get 'Merica's finest back at the top of the results. Just as McCoy's work showed, the POS 13° tail angle coupled with a awkward Center of Gravity/Center of Pressure ratio, gives a sexy B.C.; but won't cross safely.
From that work the 175 was born.

 

[Greg Langelius *]

Use what you have and enjoy it. But seriously, since you are planning to handload its replacement, take the time to do your own load development, specific to your own particular barrel.

I use 42.2gr IMR-4064, Rem case, Fed 210M, 175SMK, 2.815 OAL. This should put you in a reasonable ballpark. I treat that as a max load, others go considerably higher. I think that they know their own rifles, but that higher loads are also tougher on brass and rifles.

Greg

 

[stealthgoat]

FYI I have a bunch of M118LR "12" so out of curiosity I pulled one this morning. My sample has 44.0g of the mystery powder.

 

[BCP]

FYI I have a bunch of M118LR "12" so out of curiosity I pulled one this morning. My sample has 44.0g of the mystery powder.

That looks exactly like RL15 are you sure it's not 43 grains? Perhaps they upped it because of a slower lot of powder.

 

[stealthgoat]

That looks exactly like RL15 are you sure it's not 43 grains? Perhaps they upped it because of a slower lot of powder.

I also thought it looked like R15 too, but as Darkker noted above may not be exact R15 powder formulation.
This particular sample of 1 was 44.0 grains, but again that doesn't tell us much from a 'statistical probability stand-point', this was just my curiosity pulling one...

_______________________
Edit 28 July - I came up with 43.9 on my RCBS balance beam on another '12' round I pulled down tonight. Usual cautions apply - you should definitely start lower and work up on your rifle, your mileage may vary, only you can prevent forest fires etc...

 

[M40_A1]

Years back, I disassembled several FGMM 175gr. cartidges. I found each had 42.8gr. of a powder that looked like, measured the same dimensionally as, and burned like RL-15......."canister-grade powder".......(blah!blah!blah!)......sounds authoritative.....big deal.....pretty amazing coincidence......42.8gr. of RL-15 gave me the same velocities as the super-duper, secret "canister-grade"(LOL) powder in the cartridges that looked just like it...so.....whooptido....who cares......it's close enough.....just like it.....if not really just RL-15 itself (shhh! it's a secret)....use it.....or switch to 4064 like I did after Alliant abandoned us for so long.

 

[agbm]

tag

 

[rduckwor]

Hard to believe that manufacturers are going to the trouble to "blend" canister grade powders for the great unwashed masses out here when they could simply dump their milspec powder in the appropriately labeled jugs and sell it to us. I understand blending to achieve certain characteristics, but simply to keep us from getting the milspec stuff. No.

 

[918v]

Mark316Mod0 ammo uses 41.75grs of IMR4064 per the spec sheet. The "special" FC case has a harder case head than civilian FC brass. They have the same weight and internal capacity.

LCLR brass is a bit heavier than FC and has less capacity.

44grs is real heavy for that case if it is RE15.

 

[ksthomas]

The earlier (and possibly current) LC M118LR was indeed canister grade RL-15, no different than what you buy at the local shops. Earlier lots, when Olin still held the contract, used a non-canister grade powder known as WC-750. I certified hundreds of those lots, using both powders over the years, and LC never provided powder for the RL-15 loads, they just specified that this was the powder to be used, with their primed cases, as well as the characteristics of the test barrel (twist, length, etc.) in which the cert was to be shot. When I was testing or certifying M118LR while Olin had the contract, they provided the powder for those certs.

Also, there never was a specified charge weight, but rather a set of performance standards, with the charge to be adjusted by lot, in order to meet those standards.

 

[rduckwor]

" Also, there never was a specified charge weight, but rather a set of performance standards, with the charge to be adjusted by lot, in order to meet those standards. "

This would make the most sense.

Thanks,

 

[Darkker]

Hard to believe that manufacturers are going to the trouble to "blend" canister grade powders for the great unwashed masses out here when they could simply dump their milspec powder in the appropriately labeled jugs and sell it to us. I understand blending to achieve certain characteristics, but simply to keep us from getting the milspec stuff. No.

Let's talk about the manufactures. There is only one private powder mfg in the US. So who is General Dynamics? A defense contractor. Otherwise you have Thales, a French defense contractor. Or Groups SNPE a French state owned defense conglomerate. Rhinemetal is a German defense contractor. They don't blend anything for us. That comes from the resellers like Hodgdon, etc.

For another little wrench in the whole THE powder looks like... X powder... General Dynamics has testing data and approval for SMP 768 to be used in the mk316 mod0. That powder is a ball powder.

 

[M40_A1]

The "special" FC case has a harder case head than civilian FC brass.

WTH! I find this disturbing. So, civilians who are more likely to reload their brass time and time again get the soft crap that could have been harder??? If the idea is to sell more, their reputation precedes them and reloaders go to other brass. Bad marketing ploy, if that's the case.

Also, there never was a specified charge weight, but rather a set of performance standards, with the charge to be adjusted by lot, in order to meet those standards.

I knew that had to be the case. It just makes sense. How many pounds is in a typical lot of powder?

 

[918v]

WTH! I find this disturbing. So, civilians who are more likely to reload their brass time and time again get the soft crap that could have been harder??? If the idea is to sell more, their reputation precedes them and reloaders go to other brass. Bad marketing ploy, if that's the case.

Federal doesn't care about the reloadability of their brass. They use an 80/20 alloy unlike the typical 70/30 cartridge brass.

 

[M40_A1]

Federal doesn't care about the reloadability of their brass. They use an 80/20 alloy unlike the typical 70/30 cartridge brass.

Which prompts two more questions.
What is the purpose of harder bases for the military?
If they can supply harder bases, then why wouldn't they just make them all that way and solve their soft primer pocket PR debacle?

 

[Emouse]

Federal doesn't care about the reloadability of their brass. They use an 80/20 alloy unlike the typical 70/30 cartridge brass.

This has become a very interesting thread: In duplicating the M118LR load using scenar 175 and military cases I have an excellent load. As soon as I try that load using either RUAG or Lapua brass it trashes the cases fast. The commercial cases are without a doubt significantly softer spec. Again when looking at and testing RUAG and MEN brass the MEN military brass is significantly harder and lasts longer without any signs of pressure in stiff but safe loads.I have found this in 308/300 and 338LM brass.

 

[918v]

Which prompts two more questions.
What is the purpose of harder bases for the military?
If they can supply harder bases, then why wouldn't they just make them all that way and solve their soft primer pocket PR debacle?

The purpose is to meet performance standards, one if which is to function within a certain temperature window. A load developed at mild temperatures will have significantly higher pressure in hot environments. So a stronger casehead and crimped in primers are needed especially since this ammo is now being fired out of semi-auto rifles. Another way to accomplish this is to use a temperature insensitive powder, but those are few and far between and may not deliver the accuracy of IMR4064 with 175SMK.

 

[dauntedfuture]

a) Has anyone experienced high pressure signs with repeated reloading's?
- If anything on your second loading you will have a little more internal capacity even with FL dies as the factory sizing is usually smaller then you can get things back to with a FL die.
- You will likely have loose primer pockets before any other issues with repeated loadings. If your ammo is in FC cases the primer pockets will open up fast. If its MIL cases or WIN cases they will last longer.
b) If so, how many reloads did you get out of a case before you had to toss the case?
- When I was loading 45.5g VARGET with molly 175g Bergers I was getting 3 loading before the primer pockets open up with WIN COM cases
c) Has anyone experienced rifle damage from repeated use of either variant of XM118LR, such as bent bolt bodies?
- M118, M118LR and M852 are all designed to work in a variety of rifles and are on the mild to medium side of loadings in most rifles. MK316 is a more temperature insensitive version of M118LR but the velocities are all about the same.

I don't know specifically about XM118PD but there is a strong possibility that it is contract overrun ammo that's been sold on the market and is intended for PD use.

Reference 175g sierras at 1040 yds, check JBM ballistics and run your velocity numbers there. Experience tells me that when bullets go from super to sub sonic accuracy suffers even if the bullets remain stable.