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Posted: 1/19/2005 8:48:20 AM EDT
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I have been considering making some MK262 like loads. Does anyone know what powder/primer combo is used? How about the load of powder? Which bullet is commercially available? I did a search, but didn't come across anything that fit. Mods, IM me if this is too close to reloading and I'll ask my question there. It just seemed that there would be more info available here. |
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There plenty ways to get there using a variety of powders, primers and brass, the key is the bullet (either the early Mod262, Nosler 77grn. OTM or the newer Mod262 Sierra 77grn. SMK) and the velocity. IIRC they (the NATO version) move at something like 2750 fps outta a 16" barrel. I used LC brass for all my loads when working toward the Mod 262, and like the military decided against the Nosler as my rifles prefer the SMK. Seems I stopped about 60 fps shy of their velocity using H335, LC brass and Remington 7.5 BR primers, (use your reloders manual for starting powder weights) as the Remy primers were showing pressure signs and I don't care for reloading experimentation involving protective gear. Mike added: btw, wth is this about? www.ar15.com/forums/topic.html?b=3&f=17&t=220248 |
Mike, Is the Nosler 77gr with cannelure available for commercial purchase? |
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Not that I know of but I purchased some 77 grn Noslers cannelured from one of the guys off the EE at the time. Mike ps - he was using a cannelure machine, they were excellently done and reasonably priced, sorry I been rackin my brain and searchin but I cannot remember his handle......dang I wish the archive server would get fixed as I saved the thread address but it does no good when ya can't get there added later: ahhhh,ha, See post below, it was jetlag that I got the cannelured Nosler 77grn. OTMs from!!! |
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Just go to a HP board and ask for what guys are using for their 75-77 grain rapid fire loads. Those are all loaded to mag length. You can also get an idea by what they're loading for 600 yd SF -- these will be laoded long for single round feeding, but you will get some insight on popular powders and max loads which you can back off some. FWIW, DocGR has stated if you are looking at 200 yds and under, SAAMI spec ammo is fine. |
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Mk262 Mod0 = 75gr Hornady no cannelure Mk262 Mod1 (test lots) = 77gr Nosler with cannelure Mk262 Mod1 (production) = 77gr Sierra MatchKing, with modified cannelure The original Mod0 worked well except for the lack of cannelure on the bullet (and lack of crimp), which allowed for bullet set-back, especially when chambering the same round more than once. This was deemed unsuitable for combat use. Hornady originally stated that they would not add a cannelure to their bullet, and end-users wanted the Sierra MK bullet anyway, due to its reputation for accuracy. However, Sierra also stated that they did not want to add a cannelure to their bullets. Nosler, who had a similar 77gr bullet, was more than happy to add a cannelure, and so the first run of Mod1 ammo used their bullet. Sierra, seeing that Nosler was about to take away a big chunk of potential business, and having fielded complaints from the field from users who preferred their bullet, relented, and as a compromise, offered to add a modified, minimal cannelure to their 77gr bullet. This was enough to satisfy everyone, and the Sierra MK bullet was formally made the standard. It should be noted that the 75gr Hornady and 77gr Nosler both had excellent wound profiles and were quite accurate, but that the Sierra bullet was somewhat more accurate and was more consistant in a larger number of rifles, which made it attractive to the end-users. Unfortunately, like all MatchKings, the Sierra 77gr bullet has a long "neck" area of the wound profile, penetrating 4-6" before beginning to yaw and fragment. Those looking to maximize terminal ballistic performance should consider the Hornady or Nosler bullets over the Sierra. -Troy |
You know what? Thank you! I had some 77gr rounds laying around with WCC brass and WCC primers, but I couldn't figure out who made them! I looked at every type of ammo I've got except the Mk262. That was driving me crazy thinking I had loaded them (but I've never bought WCC primers!) 
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To throw another curve, dont forget about the 77gr Sierra without the cannelure. |
Troy, isn't the nosler bullet a better preformer on the terminal side than the SMK bullet? I know the SMK is suposed to be more accurate, but just how much more so that they would sacrafice better terminal preformance? |
Re-read the last paragraph of my post... -Troy |
| Just use a Lee FCD and don't worry about the cannelure. Terminal performance doesn't rely on a cannelure, it was dictated by functional reliability. Lee FCD will crimp sufficiently to avoid bullet setback on handling/chambering, and it doesn't need a cannelure. |
 I think I had three people that bought some...
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I agree; the Lee Factory Crimp Dies are outstanding. -Troy |
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I have yet had the need to crimp any loads for the AR15. Neck tension is so great with dies made by the likes of RCBS, I have yet to experience any set back with any of my ARs with rounds that actually fed into the chamber. Rounds that nose dived right into the barrel extension due to using something like an exposed lead tip spire point(which my AR10 has time and again demonstrated it hates) are the only culprits for causing setback. But in those situations the entire rifle got tied up with the bullet hanging up on the barrel extension. Other people's mileage may vary but it's a step I have yet to have to rely on. |
Thats what I get.... Thanks Troy |
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Sorry Troy, not even then(with exceptions to the context of my loads in my rifle and possibly within the context of this thread which is creating a handload similar to the military round recognizing that the need to crimp may or may not exist based on the amount of neck tension the resizing button creates). Just to see if your assumption about my loaded rounds was true, I just went and chambered a single round repeatedly from the magazine. Took a measurement using my dial calipers before chambering and took a measurement again after each time it was ejected from the chamber before being reseated in the magazine. There was no appreciable change in overall length, I did manage to create a fairly nasty looking bullet due to the amount of marks that were put on the bullet from it crossing the feed ramps. But it has been my experience that RCBS dies give you mondo neck tension, enough that I have yet to bother with crimping the bullets on my 308Winchester or my 223Remington. Is this a rule of thumb for everybody, certainly not but after evaluating my loads why the hell am I going to add another step in the reloading process when it's quite clear to me there isn't any need for me to do so. Now if I was doing a neck sizing and body sizing in seperate steps for trying to only bump the neck down .002-.003 from the outside diameter of a loaded round, neck tension would be a concern for sure. Next time I'm reloading my 223Rem or 308Win I'll take note of how much work is being placed on the neck reducing it down beyond the diameter of a loaded round, from there I can compare just how much neck tension is being exerted compared to say something like a match loaded round meant for a bolt gun. Due to my own personal experiences, I've never bought into the absolute need for bullets to be crimped. Are there good arguments for it? Certainly. Is it sometimes neccesary, that is something I leave open to a case by case basis. |
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Point taken. I suppose it would be more correct to say: the military has found the need for a crimp based on their experience with non-crimped Black Hills ammo. The high-speed machines used by BH to load their ammo may proclude the neck tension you are able to achieve at home. -Troy |
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No worries :) I'm used to having to explain my position regarding crimping. Whenever people hear me talking about reloading for my AR15s and the AR10, seems they always ask if I crimp for it. And when I say "no", their eyebrow shoots for the sky as if they were Spock from StarTrek. The neck tension produced by my dies is kinda a combination between a saving grace and a pain in the ass. While loading for the 308Win with bullets like the Nosler Balistic Tips, the inner diameter of the case mouth is so undersized that as the bullet is seated a small portion of the bullet's jacket is shaven off of the bullet. Even after trying to carefully champher the case mouth I still got it to a limited degree. Guess that's a sign that neck tension is definitely "up there" and goes far to explain why I haven't found the need to crimp. But what it's doing to the bullet in terms of deforming it and potentially damaging the accuracy potential of the bullet, that's bad joo-joo. Recently I found out that Lee makes a VLD champhering tool, one at like an 18 degree angle to help make a more gentle transition for seating bullets. Got one of them on the way currently to see if I can knock that few thousandths of material from being shaven off the jacket. |
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Uglygun, The military considers the cannelure basically an insurance policy. It makes the ammo more durable ,and resistant to setback induced jambs during a rough feed. Is it actually needed in most circumstances? No. Is it desireable as a feature to help avoid problems under worst case situations, when a malfunction could kill you? Yes. The military has to feed a huge number and variety of guns, under the worst field conditions of mainainance.Extreme weather,mud,crud,sand hot weapons,sometimes bad mags,and so on.The slight drawbacks of a cannelure are outweighed by the advantages in those conditions. Jeff |
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Completely agree and I think I noted towards that end with one of my responses where I recognize that a crimp is certainly advisable or preferred in some circumstances, such as a place where you are betting your ass on your gear getting you out of a fight alive. I completely understand why the military would choose to crimp bullets, just like I understand why they would choose to crimp the primers. I've had fits with Federal ammo in my AR15s that most certainly could have benefit from a crimped primer pocket, or better yet simply having brass that was within spec. Note this isn't the Lake City XM193 under the Federal label, I'm talking about the commercial American Eagle, Gold Medal, and Premium stuff. 3 AR15s as well as an AR10 all unanimously agreed that they hate Federal's commercial ammo offerings. Gov't. specified assurances such misfit ammo such as crimped primers and crimped bullets are certainly a good idea when weighing the seriousness of the situation in which that ammo will be used. For my own purposes though I've found I can get away without that step and in some instances I may wind up benefiting from not doing it by creating more accurate ammo in the process. A lot of people think that feeding a semiauto means that crimping a bullet is absolutely mandatory when all I'm saying is that it may or may not be neccesary. The decision of whether or not to crimp is certainly something that is worth exploring and different handloaders may come to different conclusions after evaluating their loads with their rifles. I think that if somebody is going to go for a load that closely follows the MK262 loading, a person is sooner to hit a barrier with trying to duplicate the velocities seen by the MK262 load before they run into signs of pressure. Cases and primers may or may not be up to the task, long before ever getting to the issue of whether to crimp or not if it is deemed to be neccesary. |
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Somebody just stated that the cannelure does not effect terminal performance of the SMK bullets. Do we know that for a fact? I've not seen any rigorous gel testing of with/without cannelure for the Sierra's. I'm not trying to turn this thread into something that belongs in the reloading forum but let me just state that it is quite possible, with a little patience, to hand roll loads that will perform to MK262 MOD I specs, without undue pressures, using available commercial components. Search the reloading forum or IM me. I've also done a little cannelure cutting on some SMK's. I typically cut them to about twice the depth Sierra does. In a rack grade rifle, I can detect no meaningful difference in accuracy between the bullets with and without the cannelure; about 0.5 -0.6 MOA in each case. What you do get is a spectacular upgrade in the drama of shooting a melon. This is of course not the same grade of data that Tatjana, Troy, and Brouhaha turn out but it does offer up a slim sliver of hope that a cannelure might materially improve the SMK's efficiency upon arriving at the surface of a bad guy. SD |
Dr. Roberts reported that it was tested in both configurations, with identical results. This is also the case with the 69gr loads, and other OTM brands. -Troy |
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