T/C Compass

Rounded edges of primer and no swipe on case head; I just don't think you're running pressure. I'm thinking straight walls are probably contributing to bolt lift??
 
That could very well be the case, and it also could be those rounds was just neck sized. Had been fired in the Remington then again neck sized before firing in the Compass.
Which I did check them by running through the action before pulling the trigger. Either way, I'm pretty sure I can get around it with the load, which this node I know where the upper end is. Which is still not a hard bolt lift, Just don't have the bottom end of that node so I can sit in the middle of it. Which when I get that and sit in the middle is nothing but tuning with the seating.
41.6gr is the group in the picture- runs smooth and easy
41.9grs tightened up ever so slightly but went horizonal vs the vertical of the previous load --- again smooth bolt operation
42.2grs groups opened up and bolt needed some extra persuasion to open.....
I had 42.4grs on hand but stopped at 42.2grs because of lift.

I'm thinking somewhere below 41.6gr is where I'll slip out of the node so once I find that one. Taking the upper limit of 41.9grs into account, I'll be able to sit in the middle which I'll be out of the the sticky bolt.
(yeah I do need to get a FL or a bump die now that I have two rifles chambered in that cartridge, just waiting on my hunting buddy to get a order with Midsouth Shooters supply up)

hehe now back to processing that box of .308 W brass, got the LC brass in the final tumble (I use the vibratory with walnut hulls as the last brass cleaning as it will pull any SS pins, just a quick visual check, case a pin is sitting sideway in the neck).
 
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Since we're taking brass...
How about these. Factory ammo, brand new gun. No primer flow but look at those ejector and swipe marks with leftover burrs even
1000007457.jpg
 
AR10 variant. After looking more closely, I'd say negative on the carbon but I'm half blind. I need to check the bolt face for burrs too.
 
Strange. WAG! Have you checked headspace? Primers not flattened so wondering if excess HS. Case full forward in chamber when detonated letting it slam back against bolt face???? Doesn't look like hot load, primers not flattened at all.
Have you tried other ammo/cases to see if you get same marking?
 
I would suspect headspace first.
Wonder what the cheap military 150gr loads look like from say Federal or Winchester vs the Norma?
I'm seeing what looks like ejector marks, and extractor marks.
Are any of the rims "bent"? even slightly.
 
No bent rims. I also shot the 5 rounds of your "special" load (150gr bullet & imr 4895). Cases looked the same (not norma brass) and had severe vertical dispersion.
 
crapshoot said:
No bent rims. I also shot the 5 rounds of your "special" load (150gr bullet & imr 4895). Cases looked the same (not norma brass) and had severe vertical dispersion.
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The AR family is not known for "bent" rims, but the M-14 series is, when the propellant burn rate is fast / slow. Which is the reason I asked, thinking to could be the case.
I don't know what you have for measuring tools, such as the Headspace Comparator made by Hornady, and caliper. But one could measure the unfired brass, and then the fired brass. To find the difference then set your FL dies to bump the shoulder back 0.002" (from the fired dimension), take the rim use a sharpie blacken it then fire to see if it still marks it up. Bump back the shoulder datum line just enough for reliability, you may have to go more or less than the amount I quoted which is merely a guideline /start point.

Diagnosing the AR family over the internet is painful.

Like @hm1996 alluded to I'm thinking headspace, not out. But at the upper limits. Probably at the "field" gage I'm thinking still will work fine is safe but is slipping to "nogo" .
This doesn't pose a unsafe condition, but will mark up the brass terrible.
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Military and civilians headspace the weapons system differently. BUT, they get to the exact same results in the end.
In the Military world there is three gauges used per "set" Go, Field , NoGo. One set is for weapons system such as the M-14 /AR-10ish, and then a different set for the Machine guns M60's, M240B's, M134's, etc. This last set is sloppiest in tolerances for reliability. ( here you see exactly what you showed, a bit bulged cases, etc, but still safe, why so sloppy?? dirt carbon, sand, etc, and the absolute non reuse of the fired brass. it's only a issue if it's a issue. And it isn't in that world, did it safely go boom? yes, great now move along little trooper.)
There is another set that is used but usually reserved for the boys at Benning (AMU) which is what civilians call out to the NM set. Which one can actually set the headspace to each 0.001" of a inch from min to max precisely . This last set is not available through normal supply channels. <<< usually used on the M24 SWS that in now defunct, but only in a rebuild, as Remington "normally" handles that (did) for the Army.
Now all of that is just academic discussion ^^^^ if you ever tried to resize Mil brass from a range this makes sense, especially if the brass was fired from a M249, man you really have to work it down.
Now can you buy the three Go, Field, Nogo on the civilian market yes you can absolutely. What do most "smiths" use the Go, NoGo. Some will only use the Go and then use tape on the back of the gage to check for NoGo. Stupid as it sounds does work, not a fan, but at the cost of a additional gage I do understand why some do that. Think about the different calibers the smith will service? Yeah that is a high number, thankfully the .308 .243 7mm-08, and few others use the same gage.

What's the difference in the military set and the civilian well the reference datum line is sometimes changed, but the same result in the end. There is a cutout for the ejector, so removal of a ejector is not required.

Personally if it bothered me, as I'm not thinking it's in a unsafe condition. Merely a irritant. (and not being there or having the rifle in my hand is not a good thing in this assumption)

1. I would buy another bolt stripped, dismount the barrel check it with Go, should rotate into the barrel extension, slight resistance as snug, not binding is the desired feel. No Go well it shouldn't rotate into the extension, a little as in kind of starts, but that's it is OK. You could check the existing bolt the same way, remove the ejector and the extractor though. Having the barrel dismounted allows you to use just the bolt less the carrier, so you can feel.
The advantage that a military small arms repair tech has that you don't. Is a bench full of barrels, and bolts (about 10 to 20 or so) to mate up to.

That being said "USUALLY" the civilian market does extremely well in this regard. It is rare that a new bolt won't headspace to a barrel, as in the bench of parts is simply not needed. Now barrel extensions yeah I've seen those sloppy, not often though, even still usually will headspace.

2. If the NoGo doesn't go in I would maybe polish the bolt face with crocus cloth / 1000grit sandpaper using a casing to slicken the face a bit in the rare event of burrs. I have glued the fine sandpaper to a .473" rimed case. i.e. 30-06 / .243 /.308 to do this with (here caution you can change the headspace if you apply too much pressure, just lightly and only about 2 to 4 rotations). But again here the bolt is completely stripped. Another cause could be the ejector itself being a bit long or short in the cut out for the pin to head, and they are cheap. Spring tension of the ejector spring could be it as well. Or, simply could be binding due to a burr or a bit tight inside the bolt's ejector hole, or dirty.
^^^^^^^^^^^^^
I do not like recommending this method, my intent is discussion here, some folks take this to a extreme. Use at your own risk. The 1000 grit, yeah that is the roughest I would use I'd prefer even finer, the idea of polish not metal removal is the concept. I have done leather and rouge for this vs sandpaper it is about the safest.

3. Ignore it and let it wear in, but would pay attention to laying a good oiling on the ejector when cleaning, and pushing on it with a punch to free it up a bit. If the rifle headspaces correctly this would be my preferred method and ignore the markings or simply use my dies to adjust out of it.

(dang I think I just reveled what one of the many MOS's I had over 36 yrs)
 
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hm1996 said:
Ya think? :D
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maybe... maybe...
And if we went to talking about blowing something up or, maybe a minefield, or field fortifications. blade team calculation of a tank trap . or fastest way to remove a IED. Yeah guilty as charged.
Or maybe how quickly a sounder of hogs can disappear with a m134 minigun on the side of a Huey or Blackhawk , or how to set the pods for missiles such as felchettes to hit a certain convergent point for maximum coverage .... yeah guilty again.

Did a lot of just plain fun stuff over the years... so glad my Uncle let me do that stuff
 
Haven't talked to Geno yet on the bushing the bolt on the Compass but did look up what some charge to do that. Hmmm a bit more than I paid for the rifle, not much more....
I could ignore it, but I do know at some point that I could have a condition that the primer might rupture.... badd ju ju . (I could go harder in the primer but that is only a stop gap not a fix)
So yes I'll bite the bullet so to speak, and simply fix the flaw.
Probably do that tomorrow, dog sitting today. Man Australian Shepherds are definitely "Velcro'" dogs LMAO... he is funny though, entertains me when I tell him to heard the cats.......

Also in my looking around (isn't forced retirement great, have time to do that stuff) I did find a drop in bolt handle already threaded for 5/16-24 for the Compass. And the black ball knob... wooohoo. just will need the logo (circle 8) lasered in
 
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Status of 8-Ball the International Harvester Terra Scout of Rifles... (my gunsmith fell over laughing when I referred to the Compass in that manner.)
During the discussion of what needed to be done with Geno. Tim the actual owner, and a really fine Smith/ Machinist jumped in curious. And then noted that the bolt face was slightly countersunk at the firing pin hole. Exasperating the effect. I muttered a curse against S&W. With the look torn between disbelief and you gotta be ***** kidding me on my face.
Well the need a special boring bar to tackle the problem. Which Tim used to have, but hasn't replaced the old one. Logged the gun in. Looks like April Time frame.
After that I left to go to the VA for the lung screening.
 
crapshoot said:
AR10 variant. After looking more closely, I'd say negative on the carbon but I'm half blind. I need to check the bolt face for burrs too.
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I'm late to the party here. Quick question, are you running suppressed? If not, you're waaaay over gassed imo. If so, same problem, and you can mitigate it some.

I'll share my experiences if you're interested.
 
Also wanted to add that I have a Compass in 204, very accurate and I got it because it has a ten twist. Same primer flow issue, and I just ignore it, just don't use soft/thin primers like cci 400 or you will pop holes in them. Stock fit my hands horribly so I took a sanding drum or file to it, don't remember now. Trigger was workable with some work. I really like the magazine, it's probably the best part of it lol as it allows a long oal.
 
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