Short barrel 7 Rem Mag loads?
You are Unregistered, please register to use all of the features of FirearmsTalk.com!    


Firearm & Gun Forum - FireArmsTalk.com > Gear & Accessories > Ammunition & Reloading >

Short barrel 7 Rem Mag loads?


Reply
 
LinkBack Thread Tools Display Modes
Old 06-15-2014, 07:00 PM   #1
FTF_SUPPORTER.png
Feedback Score: 0 reviews
 
McX358's Avatar
 
Join Date: Oct 2009
Location: Southern United States
Posts: 204
Liked 65 Times on 48 Posts
Likes Given: 58

Default Short barrel 7 Rem Mag loads?

I have a customer, and a friend who recently purchased a S&W 1500 in 7 Rem Mag; what is interesting is the barrel length, of 20"! I told him there was a formula {we are rebuilding/revamping so its awol } which used bore dia. to case size ratio. I used this in building a couple .358 WCF's with 19" Bbls, and lost very few FPS from a 22 or 24". I told him, the std 7-Mag is based on a 24", and some go with a 26" to get max use of all the powder. If he was going to get best benefit, he should try a faster powder, so combustion is complete. I would appreciate any help with this matter, so I can help him out.


__________________
"seas an fód"
McX358 is offline  
 
Reply With Quote

Join FirearmsTalk.com Today - It's Free!

Are you a firearms enthusiast? Then we hope you will join the community. You will gain access to post, create threads, private message, upload images, join groups and more.

Firearms Talk is owned and operated by fellow firearms enthusiasts. We strive to offer a non-commercial community to learn and share information.

Join FirearmsTalk.com Today! - Click Here


Old 06-15-2014, 08:48 PM   #2
Feedback Score: 0 reviews
 
Join Date: Aug 2011
Posts: 2,586
Liked 331 Times on 263 Posts
Likes Given: 37

Default

I believe it will be a trial and error and a dangerous process to find a reduced load of faster powder that works and does not over pressure the rifle. I can't understand why a person would want 7rem mag in a 20" barrel. Bet it was damaged and cut down from 24". Try some minumim loads and see how it chrony's. See it it gets 280 velocity or 7-08. Far better to rebarrel or re chamber to a shorter cartridge but with a .512 base diameter it does not leave many short options. A 7rem saum maybe , a 22" barrel is standard?? There still some brass out there.

7mm rem mag reloads ! Maybe a 120gr nosler ballistic tip and 4831 minimum loads. You may want to look at how some of these powder deal with below minimum load levels and look at some burn charts and find the faster powder for 7RMM. . Compare 280 to 7mm mag . The max load for a 280 would be a just below minimum for a 7mm rem mag with 4831. but that still wants a 22 to 24" barrel.

Good luck.


hardluk1 is offline  
McX358 Likes This 
Reply With Quote
Old 06-15-2014, 09:39 PM   #3
FTF_SUPPORTER.png
Feedback Score: 0 reviews
 
McX358's Avatar
 
Join Date: Oct 2009
Location: Southern United States
Posts: 204
Liked 65 Times on 48 Posts
Likes Given: 58

Default Short barrel 7 Rem Mag loads?

hardluk1,

That was my original take right off the git-go; why a 20" Bbl? I haven't examined the rifle, he is suppose to bring it over Monday. The short barrel large magnum syndrome came much later after these 1500's were built; I think your correct, someone cut the Bbl. I honestly don't get the short barrel large magnum syndrome; the Savage 111- Hog Hunter in .338 Win Mag is an example of ..why??? My little Rem 788 in .358 WCF rolls them over on the spot, measured 180 Barnes @ 2700 FPS; what more do you need? Except for Barnes to make the 180 again..Which bring's me to your point....you need a CHRONY to build loads; especially for morpho guns like this one. I have one; but I do not lend it out, I'll shoot across the screens; so if I put a slug through the ye, it's my fault...I believe a trip to the range is in order to help my friend out. Good suggestion on caliber, with the longer action, bullets could be seated out....already building in a 6.5X55...I'll put a bug in his ear..Thanks for your help.
__________________
"seas an fód"
McX358 is offline  
 
Reply With Quote
Old 06-15-2014, 10:05 PM   #4
The Apocalypse Is Coming.....
Feedback Score: 0 reviews
 
Join Date: Aug 2011
Posts: 7
Liked 22314 Times on 12477 Posts
Likes Given: 53672

Default

here are my thoughts on this.

quite possible a person cut off the barrel to make a more easily carried rifle. possibly someone maybe trying to duplicate a light and easily carried rifle in the design of of the short mag rifles that were the rage once.

most 7mm Magnums usually have 24-26" barrels and some even as much as 28" in length. my 7mm Ma. has a Magnum contour and is 26" in length. most of them need that barel length to completely burn the powder to gain the velocity the magnums are known for.

the short mag and super short mag rifles were pretty much designed to get the results of the older magnum cartridges from a shorter and fatter case, using less powder, using a short action and a shorter barrel, and getting the same or near the same results in performance, velocity and accuracy as the older and larger magnum cartridges were capable of.

is it possible to make this short 20" barreled magnum perform well? possible. but it's going to take a lot of load working to find out. with that 20" barrel, i think if it were me, i would also look at the faster powders and start at he minimum loads and chronograph them and just work up to see what works well. this may mean trying different powder and bullet combinations to see what works in that particular rifle. as a general rule, the shorter the barrel, there is a loss in velocity compared to the same cartridge in a longer barrel and it can vary from load to load as to how much variance there is.
Axxe55 is offline  
McX358 Likes This 
Reply With Quote
Old 06-15-2014, 10:38 PM   #5
Feedback Score: 0 reviews
 
Join Date: Nov 2012
Location: North Carolina
Posts: 6,624
Liked 2220 Times on 1525 Posts
Likes Given: 820

Default

A friend has a 7mm mag with a 20" barrel. The way the rifle is set up with buckhorn sights like many lever actions it is a gun to fend off bear or moose. The 20" barrel has no effect on the accuracy of the rifle. Every deer he kills is shot in the head or the neck. I saw him shoot a deer way across a field it went down first shot right below the ear. Honestly I thought he was wasting ammo. It is hard to estimate the range he shot the deer. I was about 500 yards away from him.
John_Deer is offline  
 
Reply With Quote
Old 06-16-2014, 11:35 AM   #6
FTF_SUPPORTER.png
Feedback Score: 0 reviews
 
Join Date: Mar 2013
Posts: 1,841
Liked 1435 Times on 777 Posts
Likes Given: 804

Default

Here is a discussion on how powder burns. These gun writers and balistic guys agree that the powder that is going to burn is burned up in the first few inches of the barrel. It does not continue to burn it's way down the bore.

http://www.24hourcampfire.com/ubbthreads/ubbthreads.php/topics/7851943/The_Article_How_Smokeless_Burn#Post7851943
mseric is offline  
 
Reply With Quote
Old 06-17-2014, 12:55 AM   #7
FTF_SUPPORTER.png
Feedback Score: 0 reviews
 
McX358's Avatar
 
Join Date: Oct 2009
Location: Southern United States
Posts: 204
Liked 65 Times on 48 Posts
Likes Given: 58

Default

When he bring the rifle over, I will give a very hard look over to see of the barrel has been shortened. As far as I'm concern the rifle as it is; is just a platform for a proper length barrel for a magnum size cartridge. He had been talking about going to a 300; but I told him, unless he just likes to collect, jump too the .338 or .375; he already has a moa 30/06. But hey what do I know...I have everything from a .17 too .45 in rifles..my dream was to take game with every one of them; an't going to happen running out of time, and the collection is still growing. Thanks for the input.
__________________
"seas an fód"
McX358 is offline  
 
Reply With Quote
Old 06-17-2014, 06:52 PM   #8
Feedback Score: 0 reviews
 
Join Date: Aug 2011
Posts: 2,586
Liked 331 Times on 263 Posts
Likes Given: 37

Default

McX358 The 375ruger would be an interesting cartridge too. There are concern with changing or modifying the mag box's

mseric Powder may not need 20" to burn but it expands for beyond 20"

I have a 788 to but in 308 21" barrel version. Love that ole rifle and a custom 27" barreled 7RM and I can tell you at still making velocity over a 24" barrel
hardluk1 is offline  
McX358 Likes This 
Reply With Quote
Old 06-18-2014, 11:51 AM   #9
FTF_SUPPORTER.png
Feedback Score: 0 reviews
 
Join Date: Mar 2013
Posts: 1,841
Liked 1435 Times on 777 Posts
Likes Given: 804

Default

Velocity is a result of the gases produced by the "Burned" powder pushing the bullet down the bore. The longer the barrel the more barrel time, the more barrel time the greater the acceleration. it has nothing to do with powder burning it's way down the bore.


mseric is offline  
 
Reply With Quote
Reply

Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Firearms Forum Replies Last Post
H&R long or short barrel eight225588 General Shotgun Discussion 3 12-09-2012 04:54 PM
Short barrel AR czwicky AR-15 Discussion 4 03-01-2012 11:28 PM
short barrel shooter88 General Shotgun Discussion 1 11-27-2011 11:40 PM
Carbine/Short Barrel for me tCan General Rifle Discussion 12 09-18-2011 03:47 PM
Short Barrel benjandpurge AR-15 Discussion 9 02-24-2010 01:07 AM



Newest Threads