"That'll do pig, that'll do."

Pr589 said:
You are largely going to be limited by the COAL that will fit in the magazine. Mine tops out at about 2.83", well short of the lands. I've experimented with various COAL but have not found a significant effect. I just leave it at 2.82" for my 168 gn loads and about 2.75" for 155s and lighter.
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Thanks again! Gotcha on the max case length for mag limit, I wont worry so much about loading off the lands then. Question about the bolded part, do you have different overall lengths for the two different bullet weights just for powder compaction? That's a fair bit of difference in length between the two... Or am I missing something here? I'm sorry if these are stupid questions, I just wanna be careful. Guess I'll take the plunge with some mellow charges, and keep an eye on my brass.

I love seeing these types of threads come up, always cool to see what kind of tricks people come up with to get the most out of these rifles and it surely helps us with less experience. Please keep us updated on this project Pop, very interested in what handloads do for you.
 
Google scott duff, glen zediker, jerry kunhaussen and there's a few other's. They offer extremely valuable info on reloading for the M1A and M14. And we have a good group of guys here with a lot of experience with reloading for the M305's.
 
Awesome, I did book mark a page from Zediker the other day, I'll start digging into it. Thanks again for all the help and info guys, it's really appreciated.

Welp, that does it. This thread has inspired me to try and wring some more accuracy out of the m305s. I have a bone stock shorty with about 20 rounds thru it, gonna start tearing it down tonight and see if I can learn anything.
 
UPDATE: 1.5-MOA Challenge Run #1 (not as easy as I thought)

Well I couldn't stand waiting for the weekend so I booked the morning off work, picked up two more boxes of Remington Premier Match (ouch$), made up a 5-group target and hit the range to try for the 1.5-MOA Challenge. Turns out it wasn't so simple to do.

I figured that the spirit of the thing should be 25 shots only, so no warmup or fouling shots, I dove right in. All shots were from a front bag at the bench, fed from the magazine with the gas system on.

My first group started out well, a solid 1 1/4" with two shots in nearly the same hole.

Group #2 opened up a little to 1 1/2" but I was still in the running.

Group #3 was another 1 1/4" group and I was starting to feel pretty confident (cue foreshadowing).

Group #4 was where it all went off the rails. I put the top two shots in, and then on my third shot (the upper of the two bottom-left holes) the rifle tripled on me. I'd been trying to keep a relaxed grip and steady light pressure on the trigger, and I guess I got a little too light and relaxed. Neither of the extra two shots hit paper, but they startled the hell out of me (and the guy a couple of benches over). I cleared it and ran a function test to rule out a mechanical issue and carried on.

Unfortunately I think the triple-fire messed with my concentration, afterwards I was so focused on keeping the stock firmly in my shoulder and following through on the trigger pull that I kept accidentally jerking the trigger instead of squeezing it. Groups #5 and #6 were well out of the running, and the two extra shots I put into group #4 to finish it off were off in the weeds too. I guess I'll give it another of the ol' college tries when I get some handloads developed this summer, 'cause if I keep buying box after box of Remington Premier Match any thoughts of this being a "budget" build will go completely out the window ;)

Here's the pictorial evidence of this morning's sordid tale, complete with sad-face:

 
Not too shabby at all for " POS " Norc eh.. LOL

Nice try and I wish I was there to see your face when it tripled LOL. No shame in turning the gas off when your trying for groups, especially at 2 bucks a bang.

Your going to be pleasantly surprised when you work up a sweet load.

Good luck Pop
 
Yeah that triple really surprised me, I've had a couple of doubles before when I got sloppy with grip and trigger follow through but this was my first triple. Just to be sure I'm going to strip it down tonight and take a keen look at the trigger group et al, I want to make sure there's not some excess wear on the sear or something else amiss beyond my bad form.

In other news, I was looking at getting a couple of USGI firing pins but it doesn't look like either treelinem14 or Brownells has them even listed on their sites now, supply must be drying up.
 
Yup... And there we have another common myth amongst forum members busted :D
Keep up the good shootin with that excellent rifle
 
Thanks for the update, sorry to hear about the triple... Is your hammer following the bolt? I started on my m305 last night, trying to accomplish the same thing and found after installing my action and trigger group into a different stock I had that the hammer was following the bolt. With a different trigger group it's fine, and when it's out of the stock it doesn't do it either. I tried the action and trigger group in the stock the rifle came in and no problems. As well the trigger group is tight to slide down once it reaches the bottom of the action. So I know it's in the one stock anyways, gonna have to measure my length between the trigger group and bottom of the receiver when it's out of the stock and start looking at places in the stock to whittle down.

Maybe this is the cause for your issue Pop? I read if the trigger is sitting low in relation to the action that this sear bug can develop.
 
It's a good idea but I double checked for hammer-follow right after it happened and it was working fine. Last night I tore it down and checked for anything odd and it all seems fine, lots of bearing surface at the hammer/sear connection, no bedding gunk in places it shouldn't be. If you're looking for the spot to whittle, it's right under the spot where the rear tang from the trigger group nestles into the stock. There's a groove about 1/2" wide with a smaller, deeper groove in the middle. Take off very small amounts from the two "shelves" and test often, sand paper is probably your best bet, it usually doesn't take much to make the difference.
 
" looking at places in the stock to whittle down. "


Had the same prob with a Boyds walnut.
Had to remove small amount from under the receiver on one side and a small amount from under the trigger thingy feet.
Nothing dramatic, but it proved the need to do the hammer test..everytime.
 
Hmmm that's weird that it's not a consistent problem, then again I guess the recommendation of doing the hammer test a bunch of times in a row is for a reason? Maybe someone more knowledgable can chime in... Do you by chance have another trigger group to test with? I know last night if I didn't have another trigger to test with I would've been stuck with where to look at next.

One thing I noticed when comparing my trigger groups is that the one that's giving me grief has had a bit of grinder work done to the mag latch, a bevel on the edge that catches and holds the mag. This rifle only has 20 rounds thru it and during that time I did have one magazine drop while firing. I attributed this to a half arsed seating of the mag by yours truly, but now I'm wondering if the grinding done to the mag release was a attempt to get the mags to seat and get the rifle in the box and out the door. I don't need a micrometer to see big differences between my trigger groups.

Anyways just a thought, like I say having a second trigger group to test with eliminated a bunch of head scratching and cussing. Hope you can determine the problem and glad to hear you made it back home safe.
 
I'm positive it's not mechanical, I think it was just bad form on my part for holding the rifle too loosely and not following through on the trigger pull. Essentially what I did was an unintentional bump-firing. The funny part was that there were a bunch of city police at the next range over and they didn't seem the least interested in or concerned about my "3-round burst", lol.
 
Pop, I've kinda decided to back off on my giving of knowledge/experience but in times like these, and for lack of any other "experts" chiming in... I have this to offer.
You should test the hammer hook hand off with the sear/disconnect.
Remove trigger group
Engage the rear hammer hooks with the disconnect, holding trigger to rear
Now very slowly allow trigger to move forward and observe the point where the disconnect releases rear hammer hooks and "hands off" to front hammer hooks/sears
At the precise moment of transfer, you should see NO LESS than 40% enagement with front hammer hooks.
Less than 40% and your rifle can start giving you accidental doubles and triples and Lord help you if she slam fires.

A new hammer may be in order IF the scenario I am describing shows a failure during inspection.
 
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Much appreciated advice, I'll try that tonight. If it seems borderline would you mind if I PM'd you a photo or two for your opinion?
 
Yup, fire away ;)
I always welcome questions and such by pm or email. There's a lot of folks not comfortable posting their rifle issues.
I think I give more advice by messages than posts.
allwaysfishin@hotmail.com for pics.
I'm off to catch the evening bite with my fly rods n tin boat , draggin my m305 shorty along in case I see a nice black bear along the way. :rockOn:
 
45ACPKING said:
Yup, fire away ;)
I always welcome questions and such by pm or email. There's a lot of folks not comfortable posting their rifle issues.
I think I give more advice by messages than posts.
allwaysfishin@hotmail.com for pics.
I'm off to catch the evening bite with my fly rods n tin boat , draggin my m305 shorty along in case I see a nice black bear along the way. :rockOn:
Click to expand...

I hope they're biting tonight, I checked the engagement right at the point of reset and it looks to be about 2/3 engaged so I'm breathing easy again - thanks for the tip!
 
I like the UMC, specifically because it's cheap. Mine did pretty damn good with it.

I'm curious what it could do with other brands.
 
UPDATE: Reloading and the Headspace dilemma...

UPDATE: Reloading and the Headspace dilemma...

Updated List of Parts:
- Norinco M305 with 22" barrel & plastic stock, bought for a decent price off the EE
- Fulton Gen II bolt lapped in to ~1.632"
- USGI firing pin
- M14.ca Black Arrow op-rod spring guide
- M14.ca CASM II mount
- Bushnell Elite 10x fixed scope (mil-dot)
- Burris Zee Standard 1" rings
- Tac-Pro cheek riser
- Butler Creek flip up scope covers
- cheap bubba'd flash hider to replace the one I broke while removing it (I was planning on getting a USGI replacement eventually, but I'm not sure I should change it now)
- Krylon paint, liberally applied
- Vortex 1" bubble level
- Harris LMS 9-13" swivel/notched bipod

List of Modifications:
- crown polished with a brass screw, drill and grinding compound
- gas lock flipped to tighten at 4:00 (love it when this works)
- ferrule removed and ground down to provide about 1/16" clearance from the plate, then JB Welded back on
- hand guard trimmed to clear the forestock without contact
- op-rod guide peened and red-loctited in proper position
- hammer/sear finger-f***ed smooth with toothpaste
- hollow area of stock behind the action filled with epoxy putty to provide a solid bedding base
- action bedded into the stock with JB Weld, using the coat-hanger trick to align and tension the barrel/forestock and Kiwi polish for a release agent

So far I've been really happy with how this rifle has turned out. A couple of little "comfort mods" have made it a little nicer to shoot, specifically a Harris 9-13" bipod and a Vortex anti-cant bubble level. I've grown tired of paying for factory match ammo though, and decided that I'd rather put that money towards some reloading gear and see if I can tighten the groups up a little more than <1.5 MOA.

That's where my headspace dilemma came in. I'm usually reluctant to mess with a winning combination, but if I was going to go to the trouble of buying and sorting decent brass I wanted to be able to get a few iterations out of it. Unfortunately, with the combination of a 1.645 headspace and small-base resizing dies, I didn't feel comfortable risking more than two or three re-loadings. Either I was going to go through a lot of brass, or I needed to tighten up that headspace.

The most practical option would have been a new barrel, but the one I had was really working for me. Instead, and despite much online advice to the contrary, I ordered a stripped Fulton Gen II bolt from treelinem14.com with the intention of lapping it to fit. While waiting for it I picked up some 240, 320 and 600-grit lapping compound and built a jig out of a resized case and an old 1911 recoil spring.

Predictably, when the bolt arrived it didn't just drop right in. I had about 3 thousandths worth of barrel protrusion that had to be carefully filed down to relieve binding on the front of the left lug, but that was a fairly straightforward fix. Once the bolt was able to close freely I found that I was sitting at about 1.624, based on being a hair short of closing on a resized case mic'd at -0.005. I wanted a comfortable 1.632-1.633 so I was looking at a LOT of lapping. If Fulton's claim of meeting mil-spec are accurate, the case-hardening layer should extend between 0.012 to 0.018, and taking 0.008 off of that sounded like a pretty bad idea. Lapping wears down both the bolt and receiver lugs though, and if they both wore at the same rate I should be left with a hardened layer that was still a minimum of 0.008 thick. Maybe not so bad. Worst case scenario is I'd ruin both the bolt and the receiver so what the hell, I figured I'd give it a shot.

Keeping track of how much was wearing off the bolt's lugs was easy, I just measured them before I started and kept re-measuring every time I stopped to try the GO gauge. I couldn't figure out a way to measure the wear on the receiver lugs, so I had to wait for the GO gauge to chamber and extrapolate by subtracting the bolt lug measurements from the overall change in headspace. When the bolt finally closed on the GO gauge I'd lost about 0.0033 from both bolt lugs so that meant I'd only lost about 0.0027 from the reveiver, but that was close enough to even wear for my book. I lapped a little more until I'd removed as close to exactly 0.004 from the bolt lugs as possible and checked the headspace gauges again. The bolt closed on the GO gauge (1.630) just by tilting it shut but hung up with about 2/3 bolt engagement on the NO-GO (1.634). Hopefully it was right around 1.632. I tried some Winchester White Box 147gr .308 in the chamber and the stripped bolt closed easily on them.

I stripped my old bolt and fit the parts onto the new one with no trouble. The firing pin protrusion measured at 0.056, which was high but still within spec. Using my thumb to keep the firing pin protruded on a closed bolt I tried lifting the bolt roller and the safety bridge stopped it at about 60% lug engagement - not great, but slightly better than the old bolt when I compared them. My next upgrade will be to order a USGI firing pin and see if the source of the problem is the pin geometry or a sloppy safety bridge.

I greased her all up and put everything back together and she passed the tilt and function tests smoothly. Now the only thing left to do was light off 55,000 or so PSI and see what happened.

Yesterday morning was cold and miserably windy, so I didn't plan on being out long. Just enough time to fire off that box of WWB and see if everything was still intact afterwards. A single round to start chambered and fired fine, then two more, then five more - all cycled and ejected properly and went pretty much where I was aiming at the back of the berm. As I was also using my new AIA mag for the first time I filled it with ten shots and cycled through them without a hiccup. For the last two I turned off the gas system and cycled them by hand, they mic'd at just under 1.632 and just over 1.632 respectively. Nice! Now I just have to see if I've changed the accuracy mojo for better or worse, but that's going to have to wait for a warmer day. For now, I'm content to stay warm and read through my brand new reloading manuals for a while ;)

A caveat for anyone thinking of doing the same thing: the experts all tend to agree that it is FAR better and safer to cut a chamber deeper than to try to lap a bolt significantly for headspace. A new barrel tends to pay much greater dividends in terms of accuracy as well. If you still decide to try what I did, then I strongly suggest that you regularly re-check your headspace to make sure that you haven't worn the case-hardening layer too thin. I'll be checking mine pretty anally for a good while until I'm certain I'm in the clear - probably for at least the next 1000-1500 rounds. If the headspace starts to open up I'm going to need to either chuck the bolt and/or receiver or send them off to be melonited or something.
 
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