Japanese Militaria at Castle-Thunder.com Forum Japanese Militaria at Castle-Thunder.com
An information board for the Collector of Nippon Militaria
 
 FAQFAQ   SearchSearch    Back to Castle-Thunder.comCastle-Thunder.com    MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
  Castle-Thunder.com ChatLive Chat    ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

shorten barrel

 
Post new topic   Reply to topic    Japanese Militaria at Castle-Thunder.com Forum -> Japanese Weapons and Militaria
View previous topic :: View next topic  
Author Message
chucksniper



Joined: Mar 09 2005
Posts: 53

PostPosted: Wed Apr 01, 2009 5:48 pm    Post subject: shorten barrel Reply with quote

If I cut down a chrome lined barrel, will the chorme seprate from the
bore?
Back to top
View user's profile Send private message
03man



Joined: Jul 30 2005
Posts: 131
Location: Denver, NC

PostPosted: Thu Apr 02, 2009 7:28 pm    Post subject: Reply with quote

NO.
_________________
03man
Back to top
View user's profile Send private message Send e-mail
chucksniper



Joined: Mar 09 2005
Posts: 53

PostPosted: Fri Apr 03, 2009 2:57 am    Post subject: Reply with quote

you're right!! Very Happy
Back to top
View user's profile Send private message
arisakadogs



Joined: Oct 05 2003
Posts: 191

PostPosted: Sun Apr 05, 2009 1:17 pm    Post subject: Reply with quote

03man wrote:
NO.

It's a shame that you know that Confused
_________________
"A woman, a dog & and a walnut tree. The more ya beat em, the better they be" (From "The Red Bagde of Courage")
Back to top
View user's profile Send private message Send e-mail
chucksniper



Joined: Mar 09 2005
Posts: 53

PostPosted: Sun Apr 05, 2009 7:34 pm    Post subject: Reply with quote

WAAA
Back to top
View user's profile Send private message
03man



Joined: Jul 30 2005
Posts: 131
Location: Denver, NC

PostPosted: Tue Apr 07, 2009 6:41 pm    Post subject: Reply with quote

Someone has to know stuff! you don't. Twisted Evil
_________________
03man
Back to top
View user's profile Send private message Send e-mail
arisakadogs



Joined: Oct 05 2003
Posts: 191

PostPosted: Tue Apr 07, 2009 7:45 pm    Post subject: Reply with quote

I don't butcher these rifles, I collect them Wink
_________________
"A woman, a dog & and a walnut tree. The more ya beat em, the better they be" (From "The Red Bagde of Courage")
Back to top
View user's profile Send private message Send e-mail
03man



Joined: Jul 30 2005
Posts: 131
Location: Denver, NC

PostPosted: Thu Apr 09, 2009 3:49 pm    Post subject: Reply with quote

Dogs,
If you are implying that I 'butcher' rifles, you are wrong and should apologize post haste. Mad

I have saved many rifles from the scrap heap by repairing them, restored some, and occasionally converted bubba's junque into unusual and fascinating fantasy carbines of the highest standard of workmanship! Razz

This carbine was made from a poorly sporterized T 38, bbl and stock had been cut and nothing there to save.


This 97 sniper had had its barrel cut, scope block gone, and no stock.
Don S fitted the replacement scope block, the stock is a modified T 38, and the lower band is a modified T 99 to replace the missing one.
A real butcher job, huh?





Last but not least, my Love of Country T 44, which arrived with me as a barreled receiver.




_________________
03man
Back to top
View user's profile Send private message Send e-mail
chucksniper



Joined: Mar 09 2005
Posts: 53

PostPosted: Thu Apr 09, 2009 3:52 pm    Post subject: Reply with quote

oh shnap Surprised
Back to top
View user's profile Send private message
arisakadogs



Joined: Oct 05 2003
Posts: 191

PostPosted: Thu Apr 09, 2009 7:38 pm    Post subject: Reply with quote

Ok, Ok, I was just kidding Embarassed
Nice work - really Shocked
_________________
"A woman, a dog & and a walnut tree. The more ya beat em, the better they be" (From "The Red Bagde of Courage")
Back to top
View user's profile Send private message Send e-mail
03man



Joined: Jul 30 2005
Posts: 131
Location: Denver, NC

PostPosted: Thu Apr 09, 2009 9:43 pm    Post subject: Reply with quote

Thanks,
a compliment from you is worth a million somethings. Shocked
_________________
03man
Back to top
View user's profile Send private message Send e-mail
chucksniper



Joined: Mar 09 2005
Posts: 53

PostPosted: Fri Apr 10, 2009 2:43 am    Post subject: Reply with quote

rrriiight dogs Rolling Eyes
Back to top
View user's profile Send private message
hottarod



Joined: Apr 02 2009
Posts: 11

PostPosted: Sun Apr 12, 2009 8:44 pm    Post subject: Reply with quote

If you plan to cut down your barrel you want it as close to perfectly straight and smooth as possible and reproduce the slight chamfer on the inside of the end of the barrel where the chrome edge has been taken down just a small amount.

Shortening your barrel length will lower the muzzle velocity of your rounds and it can get dramatic. I forget exactly what the close guesstimate is on that. Every inch is so many ft per sec on average but I don't remember the number. It adds up if you take a lot off.

I guess you could estimate it as a percentage of the whole so if you have a 24 inch barrel and take 4 inches off thats 1/6th so if you have a 2400 fps round - 1/6th you just lost 400 fps. I'm not sure if its quite that bad because the round would have some velocity with a 1 inch barrel. It can be severe though. You could make a 300 meter gun into a 100 meter gun pretty fast if you were to lop off say 6 or 8 inches. It also gets even worse because you are taking turns out of the spiraling of the barrel. These guns were made with a certain amount of spiraling for accuracy so if you wack spiralings off the bullet won't have the spin it needs to make it fly well so you may wind up going from a 3 inch pattern to a 7 inch pattern at the same distance.

The biggest accuracy downfall of my Marlin 30-30 is because it has such a short barrel but it was made that way on purpose. 4 inches more barrel would change my whole shooting neighborhood with that gun. Hornaday has helped a lot with the ballistic tipped rounds too though so I'm not limited anymore to blunt tipped ballistics.
Back to top
View user's profile Send private message
chucksniper



Joined: Mar 09 2005
Posts: 53

PostPosted: Mon Apr 13, 2009 6:34 am    Post subject: Reply with quote

The 2001 Edition of the Shooter's Bible states, in the introduction to the Centerfire Rifle Ballistics section, "Barrel length affects velocity, and at various rates depending on the load. As a rule, figure 50 fps per inch of barrel, plus or minus, if your barrel is longer or shorter than 22 inches." However, they do not say what category of load to which this 50 fps average pertains.

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.




40 max fps?........ Rolling Eyes I don't know where you got your info.
I think I go with Lyman and Remington.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    Japanese Militaria at Castle-Thunder.com Forum -> Japanese Weapons and Militaria All times are GMT - 6 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum



Powered by phpBB © 2001, 2005 phpBB Group