was going to ask in pm, but then

1
i thought maybe someone else might think this interesting or informative.

i've never had this much trouble with a rifle, and it's becoming a real confidence-buster.

i've owned my polytech m14 now for a couple of months, and i'm having issues getting it on target. it hits to the right of poa. the front sight is noticeably to the right on the flash hider, and to get the rifle to hit where i'm aiming at 50 yds, i have to set the rear sight windage 3 marks left of center.

i've replaced the rear sight assembly, op rod spring, op rod spring guide, and shimmed the gas cylinder, all of which has helped consistency, but not made poi=poa. so i'm thinking the barrel is out of index, which i believe calls for professional gunsmithing skills and tools, and then maybe headspacing, all well beyond my skillset.

or i could just drift the front sight over even further to the right,

or...

i could scope it and ignore the iron sights altogether. but that doesn't actually fix the problem

am i missing something here?
Last edited by lurker on Fri Oct 11, 2019 10:31 pm, edited 1 time in total.
i'm retired. what's your excuse?

Re: was going to ask marlene in pm, but then

4
Sights are adjustable for a reason. Seems that it’s a fair bit of adjustment to get poi=poa but if it works it works. I’d leave it and shoot it.

That said, if I was looking for things that could influence poi v poa, I’d look at the crown and alignment of the muzzle brake. After that I’d look at the solidity/tightness/evenness of the metal to stock fit.

Things related to chamber clearances/headspace would sooner make groups big than make them land far right.

The improvement in consistency from the other changes you’ve made sounds promising. If the range of available adjustment makes it land right, you’re fine if you like. If you’d rather chase after it, knowing it could get weird or expensive or both, then I’m happy to advise. The first couple places to look are pretty straightforward and reasonable. Beyond that we can be in to questions of fundamental construction like barrel straightness and concentricity and other fun subjects and elaborate fixes. Fortunately it’s easy to take the train a couple of stops and get off when one has seen as much country as suits one’s taste.

I personally find the idea of a rifle naturally inclined to hit right to be charming and convenient.
Image

Re: was going to ask marlene in pm, but then

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LOL then you’re an old pro!

In all seriousness, I just don’t know these rifles. Is it something a generic brass punch can do fine? Or is it like a bottom bracket on a bicycle, where you can use a screwdriver as a drift, but the proper tool will prevent you from buying a second bottom bracket and the tool anyway.

If it’s a punch, don’t buy it. If it’s a bottom bracket wrench, buy it.

Re: was going to ask marlene in pm, but then

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lurker wrote: Sat Sep 21, 2019 11:48 pm
bajajoaquin wrote: Sat Sep 21, 2019 11:36 pm You should absolutely buy that.
that's very helpful, thanks. when i worked on cars regularly, a new tool was always a good investment. now i have a shop full of tools, most of which i've used... once. now i have no idea what some of them are for.
Are you as bad as me? It's not just one set of tools...it's multiples, usually "strategically located" around the house. I THINK I know what most of them are for, but there are a few specialized tools for items (Like a valve opener for a 1981 Yamaha 650 Maxim--valves were adjusted by coin-like shims--got some of those, too) I haven't owned in years...Said Maxim was traded in on a 1991 Venture Royale in...1991. Venture Royale sold in 2004... I MIGHT have some tools for it...somewhere....just in case....
"Even if the bee could explain to the fly why pollen is better than shit, the fly could never understand."

Re: was going to ask marlene in pm, but then

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i need to quit thinking about this and just do it.
the more i think on it, the more wrong it seems. a post in my thread on m14 just put it over the top. i understand, it's not a high tone hunting or target rifle, it's a battle rifle, meant to be dragged through the mud by soldiers and still shoot minute-of-man. but coming from a background in software, it has the distinct aroma of a "patch" (field expedient, kludge). rather than actually fix the problem, we write a bit of code to cover up the ugly symptom, often with the full intention of coming back later to correct the code, which doesn't usually actually happen. eventually you end up with a program full of . i understand. what i think is the actual solution would cost money, and i am, after all, frugal(cheap). i may revisit this.
Last edited by lurker on Mon Sep 23, 2019 1:11 pm, edited 1 time in total.
i'm retired. what's your excuse?

Re: was going to ask marlene in pm, but then

17
today i got to the range with poly, the chinese m14. first, i set up targets at 25 yards, and shot 5 rounds each of magtech, ppu, aguila and S&B to eliminate a particular manufacturer as the problem. and i did, also noticed magtech gives the largest groups, all of them hitting low and right. the elevation adjustment went smoothly, so i got out the hex keys and hardwood dowel and used my vise-grips as a mallet to drift the front sight further over to the right, which helped. after a couple of "just a little more", i gave in and adjusted the rear sight left a notch or so and we're now all around the bull's eye. groups still bigger than i like but that might be me or cheap ammo. maybe glass would help? i'm not happy with the front sight drifted over so far, or the rear off center at all, and glass would make iron sights irrelevant. tomorrow i'll post pics.

meanwhile, a couple of asides: there were way more other shooters than i'm accustomed to, so lots of waiting for the range to go cold. mostly AR variants, in 5.56, .308 and 300blk. with muzzle brakes. i hate being down the line from muzzle brakes, and i barely suppressed a guffaw at the shooter's comments about making recoil manageable. guess he's never shot a bolt gun in 30-06? tacti-wimps.

also recovered 3 unfired light primer strike 300blk cartridges. these little things are the "latest and greatest"? wtf, 7.62x39 or 30-40 krag , even 30-30 looks like more power in .30 cal.
Last edited by lurker on Fri Oct 11, 2019 9:50 am, edited 1 time in total.
i'm retired. what's your excuse?

Re: was going to ask marlene in pm, but then

20
it's a lovely morning. light is good, got some pics.
l-r, 30 mauser, 300blk, .223, 30-40 krag, 30-06
on the plus side, i see the 300 bullet has four grooves down the length of the hollowpoint bullet, which, if it opened up, would make a HUGE wound channel. perfect for um, never mind.
and yes, one of the rifles there yesterday, in and among the annoyingly too-loud muzzle-brakes, had a suppressor
LUGO1662.JPG
Last edited by lurker on Fri Oct 11, 2019 9:52 am, edited 1 time in total.
i'm retired. what's your excuse?

Re: was going to ask marlene in pm, but then

23
shinzen wrote: Fri Oct 11, 2019 10:37 am I'd still do the first two easy things Marlene mentioned up thread- crown and muzzle brake. The large brass screw, drill, and valve lapping compound does work on the former. Probably be the first thing I'd check.
so, looked up a couple of videos on "barrel crown". didn't see a "brass screw" reference.

looks like something i could do if i had the tools, which i do not at present. no brake, i'll pull off the flash hider and look at it, see if i can see any dings in the crown.

got the FFH (Faux Flash Hider) off, no visible signs of damage to my poor untrained eye, will try for pics tomorrow.

aside: the Faux Flash Hider lacks a bayo lug, i've considered replacing it with an actual flash hider with lug. any benefit to going with an actual hider?
i'm retired. what's your excuse?

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