Shortening an M305 barrel

Wallaback

Wallaback

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Hey guys,

I was wondering whether it's legal to shorten the barrel of an M305 to the point where it is roughly 8cm shorter, but doesn't cross the Restricted-length yet. So, before I do anything stupid, I have a couple of questions:

1) The obvious one: Is it legal?

2) If it is legal, how much do you think a gunsmith would ask for that? I would much like it if it was possible to still have a flash-hider (or at least a dummy) attached to it.

3) How much would the rifle's accuracy suffer from such a shortened barrel?

Thanks a lot in advance everybody!
 
1) Yes it is legal

2) There are people here who have done it themselves as well as many competent gunsmiths that can shorten your rifle for you. I do not know the price. Flash hiders and muzzle brakes would be attached the the threading your gunsmith would put on the end of your shortened barrel.

3) Though I have no practical experience with a shortened barrel I have read that the accuracy is not negatively effected and occasionally increases the accuracy. The shortened barrel will slightly reduce the muzzle velocity of the projectile.
 
Yes, it is legal (mine is 18 3/4"). About $60. Accuracy does not suffer. Dlask Arms. I just did mine last week. Waiting on a couple of parts from Marstar now.

DSCN2680.jpg
 
Thanks for the reply, NavyCuda.


LTR308:
Very nice, how much did it cost you? Also, did it increase the muzzle flash, or does the flash hider compensate sufficiently?
 
Wallaback said:
LTR308: Very nice, how much did it cost you?
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Around $60, but it might be more for individuals. I brought mine in with 4 other rifles (friends): sort of a group buy.

Wallaback said:
Also, did it increase the muzzle flash, or does the flash hider compensate sufficiently?
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I don't know yet, I am waiting on my Vortex, my Marstar OPRSG and Gas Lock Front Sight! I have 200 rounds of IMI ammo, going to do some runnin' 'n gunnin' as soon as I get my gear.
 
do you need to open up the gas port at all or will it cycle fine cut to 18.75?? and how do you measure the barrel starting at the receiver or inside?
ill be doing mine soon with a pepper boyds and arms 18:dancingbanana:
 
For chopped M14 barrels, the flash suppressor thread is 1/2"-28, which is standard for .223 units. This means that you will have to have a .223 muzzle device reamed out to .308.

The standard M14 barrel is too thin to take the 5/8"-24 thread for .308 muzzle devices.
 
tjhaile said:
For chopped M14 barrels, the flash suppressor thread is 1/2"-28, which is standard for .223 units. This means that you will have to have a .223 muzzle device reamed out to .308.

The standard M14 barrel is too thin to take the 5/8"-24 thread for .308 muzzle devices.
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Something doesn't add up in these numbers, it could be me :confused:
 
tjhaile said:
What do you mean?
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I am not trying to diss you, but rather I am confused.

You mentionned using 1/2" x 28 rather than 5/8" x 24 because the barrel is too thin, that being the case I would reverse that and use the 5/8" since it is thicker!! The measurements as I understand them seem contradictory to the explanation (ie reversed) :confused: or do I understand the numbers wrong.
 
furet said:
I am not trying to diss you, but rather I am confused.

You mentionned using 1/2" x 28 rather than 5/8" x 24 because the barrel is too thin, that being the case I would reverse that and use the 5/8" since it is thicker!! The measurements as I understand them seem contradictory to the explanation (ie reversed) :confused: or do I understand the numbers wrong.
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You are misunderstanding I believe.

A 5/8" diameter threading is going to require a larger outside diameter of the source material, in this case the barrel. From what has been said here, the outside diameter of the "stock" m14 barrel is not sufficent to allow a 5/8" diameter threading. A 1/2" threading requires a smaller outside diameter of the barrel than the 5/8".

Now, personally... I f**king hate standard. So when I get my lathe setup I'm going to thread my barrel in a metric thread pitch... why? It is the only logical method of measurement and anyone who would argue against it... well... you are incorrect.
 
Ok, I got the 1/2" 5/8" thing right, as in 5/8" leaves more barrel... here is where I am mistaken, the "thin" explanation to me meant that the material left behind would make the barrel too thin, thus the 5/8" would be best, but the thin issue refers to the thread material being too thin (ie not enough bit from the FH) thus the 1/2" would be best.... Am I correct ??
 
No offence taken, furet.

The barrel of my M14 ranges in OD from .585" in front of the gas cylinder to .565" just before the flash suppressor splines. It just isn't big enough around to take a 5/8" thread. You would indeed end up with shallow threads if you tried to use a 5/8" tap.

Some people might argue that the wall thickness of the barrel is too thin at the bottom of the 1/2" threads, but many M14s have been so modified without issues. Besides which, the metal of the flash suppressor should provide some reinforcement.
 
For years I have been hearing about the the barrel too thin issue and thought it meant the threaded barrel would be too thin and fail under fire. All makes sense now. Thanks for clearing that up.

I will have too look towards Dlask for this, I wanted to get mine cut at ValleygunSmith last year but never got a response after a few tries.

For the OP, a link to Valley for reference material.

ww w.smithtac.com/Customgunsmithing.html
 
As a registered dealer here on CGN , we also offer full cut crown thread services for the m14 platform and carry .308 bore 1/2 x 28 vortex flash hiders as well.

see the link below for pricing or email attn Thomas , to m14doctor@hotmail.com

I'm still away hunting and using a friend's computer but i'll be back in town in a week to get the shop open and back up and running. ;)
our price for this service is 65.00 plus applicable shipping.
 
The Chinese M14 outside barrel diameter at the 18" to 19" cutoff point varies + or - .10".

SOME of these [ the heavier barrels ] might take a 9/16" OR 5/8" fine THREAD,
but,
ALL of the barrels WILL take a 1/2" x 28 TPI thread, which coincidentally is the correct size for any one oif hundreds of AR 15 muzzle brake/flash hiders.
 
LAZ hit it on the head....
there has been much debate in the past on this topic of using the standard 5/8 thread on the chinese barrels. "some" have sufficient diameter at the 18.5 to 18.75 mark on the barrel..... most unfortunately do not. I have recently seen a very professionally finished SAK usgi barrel, cut to 18.75, original flash hider splineways cut , shouldered and the standard usgi spec threads machined. It mic's out correctly and a standard m14 flash hider attaches tightly using the original g.i. castlenut. It would be great if this job could be performed on the norc barrels for those wanting to remount an m14 type flash hider or smith enterprise type , all having front dovetail mounts for original front sights. Misanthropist posted a great thread on modifying and remounting his norc flash hiders to the 1/2 x 28 shorty barrels. For those with the ability and a shop to perform this modification of the flash hider, it's a plausable solution for the front sight BUT due to hardness variations, with most hardened almost to tool steel specs , the norc flash hiders are extremely hard on the tooling.... it's why I do not facilitate that service anymore. Taps were exploding, flash hiders where cracking hehehe , but some worked well....

long and short, the 1/2 x 28, as LAZ stated, is compatable with ALL norc barrels, so it's the most commonly, and safely applied thread.
 
My last two shorties, I used a couple of different ideas, both using the original Chinese flashider.

1] A brand new /unfired Poly/BELL 2009 - on this one I used Misanthropist's great idea for threading the original Norc flashider to 1/2X28 TPI, and reinstalling it with an AR 15 crush washer. This is a nice, neat, almost original looking mod, and as a bonus, if the barrel is slightly out of index, the flashider can be rotated a few degrees to fix.
Blue loctite and a crush washer are used to hold this one in place.
NOTE: some of these Chinese flashiders are way too hard, and will ruin your tap if you don't anneal the flash hider first.
When the tap starts to squeal like a piggy in heat,
it is time to stop and re-evaluate the project.

2.] While option 1 is a nice simple fix, the original M14 flashider looks too long to me for on a shorty, and it doesn't offer any braking/compensating.

So, I played around with the ORIGINAL FLASH HIDER, turning it into ONLY a front sight base, ending up with a TWO piece front sight/FH design.
First, I threaded the FH 1/2" X 28. Then I reamed out the three internal splines, and chopped off all of the flashider in front of the front sight base.

So basically, all we have now is a front sight base that turns on the LONGER 1/2"X28 x 7/8" long thread at the muzzle of the 14 barrel.

Crush washer and blue loctite to index it, a day to set up, then I screwed on a YHM combination flashider/compensater, on to the remaining 1/2" inch or so of threads left over.

The only downside is that the threads on the barrel are longer by about 1/8" than the usual AR 15 threads, which is why the barrel was cut to 19" instead of my usual 18 3/4".

If it doesn't work out, I can always shorten the threads to standard AR 15 length, or else just double up on the crush washers, and got back to a clamp on front sight base, or a gas ring front sight.

I'll post some pics tomorrow, but so far this looks to me like the nicest way to go for shorties.

34.] I am still playing around with the concept of a clamp on front sight base, but with tgat wide variation in barrel OD on the Chinese 14s, the clamp would have to accept about .020" variations. When I tried to get Joe Dlask interested in this project, he suggested extending the flashider/brake about 1/2" in length, and with the standardised OD of the extension, using a FSB that clamps on to the flashider extension instead of the barrel [ simnialar to the YHM design .
Or,
threading the outside of the FH, and turning a FSB on there.

More to come ... eventually.
[;{()
LAZ 1
 
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