Much difference between M305 22" and 18.5"?

Ah, I changed it up, just ordered two (Opted the thrid one for cheap ammo instead... Took me a long time to decide, but there are more guns coming that I need to save room for :D), one shorty socom for the blackfeather and one full size for an Archangel stock and use the M14.ca scope mount. Unless the USGI glass stock is a better option? Opinions?
 
Mauser GDog said:
Then you sir, have nothing to worry about! :)
You will need:
1x full length to put in nice boyds or USGI wood stock for your traditional look.
1x full length to put in a USGI glass stock, trust me you NEED this.
1x shorty to put in your blackfeather to fill the "little ass-kicker" slot in your arsenal.

You will also need 3x cans of brake cleaner and a nice sunday afternoon outside on what will be an epic cosmoline party!
And of course, we can assume you are picking yourself up 3x crates of the dirty old Norc steel cased ammo, these rifles don't like to share.

Have fun!
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LOL, great reply man, just one can for now, should be hitting the road for a bit, so there is always time for more in the future. So brake cleaner and a garbage can will be the necessary cleaning tools I suppose? I paid to have my SKS's cleaned, this is going to be my first time cleaning this #### off a rifle. I am not looking forward to it.
 
Brake cleaner has some nasty stuff in it. I would suggest something less carcinogenic. Years ago we cleaned everything with varsol, carb and brake cleaner using our bare hands and I won't lie to you the stuff works and has no equal. Now we know better. If you are going to make physical contact with your cleaner use something non toxic.
 
johNTO said:
Be careful with the brake clean. Buy the one that won't leave it with white residue all over it! Then oil it down.
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Seafury said:
Brake cleaner has some nasty stuff in it. I would suggest something less carcinogenic. Years ago we cleaned everything with varsol, carb and brake cleaner using our bare hands and I won't lie to you the stuff works and has no equal. Now we know better. If you are going to make physical contact with your cleaner use something non toxic.
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Oh yeah, I have used it for cleaning guns before painting, and on cars/bikes, just never had to clean cosmoline off of anything before. I am going to get two more SKS's as well and I always do searches and read about using all kinds of different #### for cleaning cosmoline off, so brake cleaner is the best for it then?
 
brake cleaner= overkill.

milsurp fans know simple green is the best- just basic degreasing dishwashing soap. Dissasemble parts, put in container, agitate and leave for a bit. scrub, rinse, dry n done.
 
Seafury said:
Yeah actually 100 fps per inch is a fairly common estimate of velocity change.
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A vastly overblown estimate at that. I was being generous at 50fps per inch, this info says way less than my estimate:

Jack O'Connor wrote in The Rifle Book that, "The barrel shorter than standard has a velocity loss which averages about 25 foot-seconds for every inch cut off the barrel. Likewise, there is a velocity gain with a longer barrel." He went on to illustrate this using a .30-06 rifle shooting 180 grain bullets as an example, so his estimate was obviously for rifles in that general performance class.

Other authorities have tried to take into account the different velocity ranges within which modern cartridges operate. The Remington Catalog 2003 includes a "Centerfire Rifle Velocity Vs. Barrel Length" table that shows the following velocity changes for barrels shorter or longer than the test barrel length:

  • MV 2000-2500 fps, the approximate change in MV per 1" change in barrel length is 10 fps.
    MV 2500-3000 fps, the approximate change in MV per 1" change in barrel length is 20 fps.
    MV 3000-3500 fps, the approximate change in MV per 1" change in barrel length is 30 fps.
    MV 3500-4000 fps, the approximate change in MV per 1" change in barrel length is 40 fps.

The 45th Edition of the Lyman Reloading Handbook also has a table showing Center Fire Rifle Velocity Vs. Barrel Length. Their figures apply to barrels between 20 and 26 inches in length and agree with the Remington figures. The Lyman table shows the following approximate velocity changes:

  • For rifles with muzzle velocities in the 1000-2000 fps range, the change in velocity for each 1" change in barrel length is 5 fps.
    For rifles with muzzle velocities in the 2001-2500 fps range, the change in velocity for each 1" change in barrel length is 10 fps.
    For rifles with muzzle velocities in the 2501-3000 fps range, the change in velocity for each 1" change in barrel length is 20 fps.
    For rifles with muzzle velocities in the 3001-3500 fps range, the change in velocity for each 1" change in barrel length is 30 fps.
    For rifles with muzzle velocities in the 3501-4000 fps range, the change in velocity for each 1" change in barrel length is 40 fps.

The 43rd edition of the Lyman reloading Handbook gave some concrete examples of velocity loss for specific calibers and loads. The Lyman technicians chronographed some high velocity cartridges in rifles with barrels ranging in length from 26 inches down to 22 inches with the following results:

  • The average loss for the .243 Win./100 grain bullet was 29 fps per inch.
    The average loss for the .264 Win. Mag./140 grain bullet was 32 fps per inch.
    The average loss for the .300 H&H Mag./220 grain bullet was 25 fps per inch.

For standard high intensity cartridges in the same test, the Lyman technicians chronographed the cartridges in barrel lengths ranging in length from 24 inches down to 20 inches with the following results:

  • The average loss for the .270 Win./130 grain bullet was 37 fps per inch.
    The average loss for the .270 Win./150 grain bullet was 32 fps per inch.
    The average loss for the .300 Sav./180 grain bullet was 17 fps per inch.
    The average loss for the .30-06/180 grain bullet was 15 fps per inch.
    The average loss for the .35 Rem./200 grain bullet was 11 fps per inch.
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http://www.chuckhawks.com/rifle_barrel.htm

I am not really a fan of a lot of Chuck Hawk's stuff, but this isn't his opinion, it is the work of some very notable authorities on rifles and ammo. Based on this info, I would estimate the velocity loss for the 18.5" to be ~100fps.


Mark
 
simple green ... spray that sh-t on everything and works goooooood ... except on the bathroom mirror... ! friggin turned the glass smudgy .. but for guns, its the stuff
 
buckbrush said:
simple green eats aluminum.
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Aluminum - Is it safe to use Simple Green® on aluminum?

When used with caution and according to the instructions, Simple Green All-Purpose Cleaner has been safely and successfully used to clean aluminum. Simple Green All-Purpose Cleaner, Crystal Simple Green® Cleaner/Degreaser, Simple Green Pressure Washer Concentrates, and Pro Series™ Simple Green® Automotive Cleaner have been used on aircraft, automotive, industrial and consumer aluminum items for over 20 years. However, caution and common sense must be used: aluminum is a soft metal that easily corrodes with unprotected exposure to water.

The aqueous-base and alkalinity of Simple Green All-Purpose Cleaner can accelerate the corrosion process. Therefore, contact times for unprotected or unpainted aluminum surfaces should be kept as brief as the job will allow - never for more than 10 minutes. Large cleaning jobs should be conducted in smaller-area stages to achieve lower contact time. Rinsing after cleaning should always be extremely thorough - paying special attention to flush out cracks and crevices to remove all Simple Green® product residues.

Unfinished, uncoated or unpainted aluminum cleaned with Simple Green products should receive some sort of protectant after cleaning to prevent oxidation.
 
A bud of mine has a custom EBR is 22" and hand loads his ammo... I have a slightly custom M305 shorty both of us have the same scope (Redfeild Revenge 3-9x42 4plex) I don't remember what rings we have he has the 3 screw version of the two screw version rings I have. I hit inside the same pattern he dose at 600 meters.

P.S. I shoot S&B 147grn
 
Before this muzzle velocity stuff gets out of hand: http://m14forum.com/modern-m14/94083-chronogragh-18-18-5-barrels-questions.html

Post #9 states actual measurements from a 22 and 16 inch barrel.

147gr from 22": 2846 fps
147gr from 16": 2726 fps
Difference of 120 fps.

168gr from 22": 2601 fps
168gr from 16": 2430 fps
Difference of 171 fps.

From these numbers, I highly doubt you would lose more than 100-150 fps going from the 22" to the 18.5" (depending on projo weight. If you're slinging 170gr+ you might get into the higher end of MV loss).
 
Accuracy has nothing to do with barrel length. Barrel length only affects velocity. A short barrel does seriously affect the muzzle flash and blast though. Way more of both. In any case, an 18.5" barrel on an M305/M1A is a marketing thing that was started by Springfield Armory.
"...Other then bayonet lug..." When? The bayonet lug is on the flash hider. If you want one on a short barrel, put one on. It's no crazier than putting one on a 20" shotgun. Mossberg did it, long ago. 8 shots, 20" barrel, bead sighted, M500, that took an M16 bayonet. We sold a bunch of 'em.
 
No noticeable difference, if you are talking about both lengths with the factory flash hider. At least not that I can differentiate.
 
sunray said:
"...Other then bayonet lug..." When? The bayonet lug is on the flash hider. If you want one on a short barrel, put one on. It's no crazier than putting one on a 20" shotgun. Mossberg did it, long ago. 8 shots, 20" barrel, bead sighted, M500, that took an M16 bayonet. We sold a bunch of 'em.
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I do not know why you asked "When?" In regards to the bayonet lug, but I would love to see some pics of the shorty with a bayonet on it, because I think its to short to support a bayonet, I have never seen a shorty (Not even M14's) with one on it, the handle of the knife would be hitting the front of the gas block. I do not own an M305 yet, so I cannot say any of that from experince, got two coming as we speak, but from pics, it always looked like to me they were too short for them... That said, I asked "What are the benefits" Other then it having a bayonet lug, as apposed to : Not having one.


Mossberg does it now too, the Mossberg 590's bayonet lug sits under the barrel band and the loop of the bayonet is attached to the tube, plenty of space for it there, as crazy or not crazy as it is, you still need a bayonet lug and enough space for the handle of the bayonet, hence why it only comes on the full length 20" tubes and the full length M305/M14 barrels. You can't just throw one onto any old shotgun.

And I guess as far as velocity is concerned, more velocity = a flatter trajectory which in turn would equal better accuracy(Or less bullet drop estimation)? What I was wondering more or less, does it affect it enough to make a big difference between the two :D Either way, I got one of each lol. I will be scoping the long barrel. The short barrel socom wannabe is going into a blackfeather stock.
 
Thanks cowboy, all the numbers I have seen are pretty minor, minor enough that it wont affect my current effective range anyway.


Before this muzzle velocity stuff gets out of hand: http://m14forum.com/modern-m14/94083-chronogragh-18-18-5-barrels-questions.html

Post #9 states actual measurements from a 22 and 16 inch barrel.

147gr from 22": 2846 fps
147gr from 16": 2726 fps
Difference of 120 fps.

168gr from 22": 2601 fps
168gr from 16": 2430 fps
Difference of 171 fps.

From these numbers, I highly doubt you would lose more than 100-150 fps going from the 22" to the 18.5" (depending on projo weight. If you're slinging 170gr+ you might get into the higher end of MV loss).[/QUOTE]
 
yomomma said:
The gas plug needs to be replaced or ground off a bit,IIRC. Other then that your good to go.
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Thanks Yomomma, but before the thread starts to be about the bayonet lug , let me squash it, one comes with one, and you don't have to grind anything. The other does not come with one, so you have to buy it , then alter your rifle so it fits . As I pointed out, I asked what are the benefits of the long version (Other then the bayonet lug)
 
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