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Posted: 12/30/2004 4:45:13 PM EDT
| I have 2 questions about the SAM-R barrel. The first is does anyone know how the profile was decided apon and second what is the profile (diamentions) of the barrel used by the USMC? |
| It's a "match heavy barrel" which I believe is even heavier than an HBAR. As to the why, maybe you can find it in here: SAM-R |
The source mentioned above and other sources, which I can't find or recall right now state the barrel of choice was a heavy match barrel, which has a 1.0"+ OD under the handguards and standard profile forward of the 0.750" gas block. The DCM/CMP profile barrels are very close, if not the same, and I chose a Bushmaster 1/8 DCM barrel to build my SAM-R clone with. It seems to be a quality barrel, somewhat cheaper than the Douglas/Kreigers that are out there. When the Bushmaster gets shot out, I'll upgrade. Bushmaster DCM Barrel |
Mongo, I went with a KG coated White Oak NM, 1:7 twist, barrel from ADCO and I'm very pleased with it so far. It's heavy but is a sweet shooter. I only have it dialed in at 50 at this point but I'm very please with the results. |
The Bushmaster's OK. I'm trying to work up a 77gr SMK load for it, but haven't found the sweet spot of the barrel yet. When/if I ever shoot this Bushy barrel out, I was contemplating getting a short chambered Kreiger and finishing the chamber myself. Something about the challenge of making it accurate with your own hands intrigues me. |
Its is a standard SS 1:7 Krieger NM Service Rifle barrel with an M4 barrel extension KG Koted black. I have one if you are interested 
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I don't think the "profile was decided on", it was just the same barrel the Team was using at Perry, so it was a known performer. Then (CWO-5 Ken Davis, the "father of SAM" and a Camp Pery level marksman who was OIC of the Marines Precision Rifle Office) simply took the path of least resistance when they evolved into the inital SAM's. Later, when they wanted to build 113 more, they stuck with what they knew worked, even though Ken had retired by then. |
Some of the pics I have seen of the SAM-R in action showed the barrel as having the plain SS finish, not black coated. Did they do it both ways? Also what gas block is on this rifle> It has a flip up and bayonet lug, I can't seem to find one like this for my build. Here is one pic...... 
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That's a KAC front flip sight/gas block, installed with taper pins just like standard FSBs. It is not presently offered to the public by KAC. |
That figures.....typical KAC!  I did find the GG&G one that is similar but it comes with a side sling mount, which I guess I could just take off. I hate buying stuff that has extra shit on it that you don't need. |
Is that front sight a danger to the public? Why whould they not sell a machined piece of metal to the public, and make more money? I don't quite understand. -g |
That's not the only item they don't offer. Their URX rail system is another one that many here want, but can't have, unless you buy one of their complete rifles with one installed. |
I have one of the GG&G one and you can remove the sling mount. I plan to but I just haven't gotten around to it yet. It's just two allen bolts and it's off. |
YHM now has one...................................... www.bravocompanyusa.com/IronSights.html
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YHMs in OK and easy to install, but there is a HUGE difference in stability and durability between the KAC/GG&G models, which are installed with taper pins and the YHM, which is held on with setscrews. |
That's why I won't buy the YHM one. I will probably go with the GG&G because it is the closest to the KAC and installs with taper pins. |
So by your logic the "set screws" that hold all scopes in place are unstable and not durable.............................................................
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I'm sure a FSB held in place with set screws would hold up real well with a bayonet attached to it. Yeah Right Not to mention the fact that it is mounted directly to the end of the barrel and that the rifles high pressure gasses pass through it. If the SHTF and your scope rings fail because the set screws come loose then you take it off and flip up you BUIS's, if your gas block fails because it loosens and your rifle will not cycle then you are FUCKED.
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Which scopes are you using that are held in place with two setscrews? I'm certainly not using any and wouldn't use any. I'm even leary of the PRI sights I use and have a mod in mind to setscrew those in place in addition to the clamping force that holds it in place (which, BTW, the YHM has ZERO clamping force holding it in place).
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That's a better design, because it incorporates clamping force into the mix of it staying put, but two tiny setscrews don't cut it for stablility and durability. And it has the bayonet lug that everybody "needs". YMMV. |
For most float tube installations, the FSB must be removed. It isn't too hard to knock out the two taper pins and tap the FSB off the barrel. |
You guys crack me up. So, you are going to take a prescision rifle with an $800 optic on it and run up and stick some guy in the gut with a bayonet on it? Oh, that's some deep thinking! |
I think everyone here is just interested in building a clone that accurately reflects the features of the Marine Corps' SAM-R. It has a bayonet lug. Unfortunately, KAC is not willing to sell their gas block/front sight with bayonet lug to the public, so everyone is just interested in finding a worthwhile substitute. And yes, if neccessary, that Marine rifleman will fix his bayonet and use his SAM-R to stick someone if he has to, optics and all. It's not a matter of "shallow thinking;" more like necessity in combat to keep oneself or buddies alive. |
Yes absolutely........at that point it's time to just give up and put your sidearm in your mouth and...............hey wait a minute........................... 
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My concern was never about it holding in a bayonet attack, but just holding up in the genaral rigors of combat. Think about it. In and out of armored vehicles. Running to position, diving prone. Possibly in and out of buildings, although I feel sorry for the guy that has to hump this long and heavy rifle that way, but I'm sure it's done. You don't think that FSB takes some pretty good whacks during this. Not is it only about holding zero, but if you twist the FSB around enough, you can cover up the gas port and now you have a long, heavy, single shot rifle. For 100 round per year, sterile bench shooting, safe queen owning shooters, the YHM FSB with the two setscrews will do just fine. Their newer, clamp-on sytle with the coveted bayonet lug will hold up even better. I'm not a safe queen shooter or a combat person, just somewhere in the middle, but I overbuild my stuff and after putting around $1500 or so of high quality items in my clone upper build, I'm not going to skimp on the FSB. YMMV. |
Thanks for the link. It's a good, brief description of the concept. |
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interesting comments on FSB w/set screws................. www.ar15.com/forums/topic.html?b=3&f=12&t=216740 |
Oh, here we go.  That FSB is installed with four setscrews, two on each side of the FSB, opposing each other. The barrel also has flats milled into it for the setscrews to land on. It's installed by a military armorer for military use.Here's an example of the flats on the barrel: The YHM one, which was referred to above, has two setscrews holding it on the bottom of the FSB. There is a world of difference between the two. It's simple mechanics. If you must go with YHM, go with their newer, clamp on style FSB with the bayonet lug. At least you have the clamping force working for you, rather than just the tip of two small setscrews. |
The Barrel was blued you can still see some of it around the gas block, high wear area. Coldblue ??? Dave. |
Made it hot for all to enjoy. |
I'm kind of curious about this as well. The GG&G seems like the best bet for a SAM-R clone but I'm curious about those taper holes. Do any of you actually have one? Did it come pre-drilled? It was my understanding that not all barrels have their taper pin holes drilled in the exact same location? Unless that is wrong then I would think\hope the GG&G comes undrilled and would need to be installed by someone with the right tools\knowlege for the install? Who carries the the GG&G flip up and what is the average street price? |
I have the GG&G front sight on my SAM-R but I bought it from ADCO and had him install it when I built the upper. I don't even remember how much it cost but if you email Steve or Eric I'm sure they can give you the skinny. |
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