This is a discussion on Polytech Accuracy Question within the The M14 forums, part of the M14 M1A Forum category; How accurate should a stock Polytech be at 100 yards? I shot mine with some Spanish surplus 7.62X51 and the accuracy was less than stellar....about ...
There's never been any question as to the accuracy of the chrome lined barrels that came on the preban Polytech's or for that matter their excellent forged receivers and one piece forged op rods.
The consensus is that their accuracy will be on par with a chrome lined, rack grade USGI M-14 which will be around 2-3 inches with decent milsurp such as Portugese 7.62x51 that Midway used to sell for $135.00 per 1K round case.
I don't have any experience with Spanish milsurp, however Portugese has a good reputation for accuracy in M-14's with many claiming that it's almost as accurate as match 7.62 NATO. You may need to do a little fine tuning on your weapon to achieve these results such as shimming your M-14's gas tube assembly which is no big deal.
There's even a member here who sells excellent M-14 gas tube shim kits. See link...
after messing around with literally hundreds of Chinese rifles,
AND LITERALLY THOUSANDS OF ROUNDS OF ALL SORTS OF AMMO,
I can state from that experience that, if you find the ammo your Chinese M14 likes best,
it should shoot under 2",
unless something is wrong some where.
This is for five shot, 100 yd groups, fired off the bench.
The vast majority of Chinese M14 rifles I've shot would do 1 1/2 - 2", after a bit of basic tweaking and tightening, and WITH A TRIGGER JOB AND A NICE BIG SCOPE.
I've seen a few that would do under 1", but these were rare, and usually involved a GI stock and GI bolt swap. My last major range testing, for the R&D involved with the Blackfeather stock, I shot three sub-moa grouips from a basically stock Chinese m14, with a trigger job, a round op rod spring guide, and a decent scope on a CASM mount.
The free floating of the Blackfeather and the SAGE stocks can make for a bit better accuracy.
My poly was shooting 4.5" groups when i got it with unknown manufacter copper washed milsurp...shimmed it and it shot just under 4". With south african R1M1 groups went to 3". When i put it in a GI stock groups shrank to 2.25". I then put it in a glass bedded E2 stock..groups were 1.5"...tried some old Hornady 168gr BTHP and it became almost 1 moa... then some Fed match made it sub moa. You have to be sure you have a tight scope mount for sure. I shot it in windy conditions today out to 700 yds. I couldn't hit the target every time until i used the fed match. 5 shot groups were under 14". For whatever reason i've found my poly does best with 168gr 308 vs. any 7.62x51 so far but i've not had any LC to try. I had another poly that only liked 308 ammo. Go figure.
Finding the ammo your 14 likes best is the most cost effective accurising you can do with any M14 rifle.
PS: if you try the Lake City match ammo and get vertical stringing, before firing run the ammo through your press and seat the bullets a few thou deeper. Much of the LCM ammo is VERY OLD so the sealant around the bullet dries out (erratically). Cracking the sealant in the press gives a more consistent release from the neck of the case on firing.
PPS: on average, through many different M14 type rifles, the cheap Walmart available Federal Blue box Powershock 150 gr hunting ammo shoots quite well. And yes, I have also seen some M14s that would shoot this cheap ammo as well as MATCH ammo ( with occasional fliers due to quality control not being as consistent with the cheap ammo). It really pays to try many different factry loads in your 14 BEFORE investing time and money in "accurising" and/or custom reloads.
Mine seems to like 168gr Sierra Matchkings over H or imr4895 powder shooting about 2560fps. My poly's POI or zero is pretty speed sensitive, with slower loads hitting higher. Anyone else notice that in their Polytech or M14?
Mine loves 168 grain like others here but is currently under the knife as it gets a glass bedding, camo paint job for the stock and new parkerizing of the metal parts, new Fulton parts (most cosmetic, nothing responsible for bolt operation) and a trigger job. It recently received a Leatherwood M1000 scope and a Fulton Armory mount. Once I get it all together I'll let you know what kind of groups we get (good or bad).
Shot my rifle again this morning and tried several different makes and weights of bullets. BlackHills 168 Gr. Match shot the best. Now I will be looking around for some different 168 gr. loads to try. Thanks for the help.