Building a Shorty - now what to chamber it in?

[Formidilosus]

Fair enough, I sit and type corrected.

So I’m assuming there’s a reason why you can buy a factory 18” 308 vs an 18” 300 RUM. Is that due to the amount of potential energy lost vs a longer barrel? Or simply because people don’t want to be struck instantly deaf?

Because they don’t know any better. Myths, old wives tales, ignorance, and advertising. The older generation were brought up on magnums- muzzle velocity and “energy”. The longer the barrel the higher the MV- and when you’re pushing MV as a selling point, it matters.
People chase MV like it’s magic. It mattered a whole lot more before rangefinders, now it mainly just applies to range of terminal performance.

 

[762 ULTRAMAGA]

I don’t know if you can call 2 rounds a “group” haha but we would all be snipers if you could.

I shoot 2 round groups all the time, it's all about cold bore hits with LR shooting.
I shot 5 consecutive 2 round "groups" at 800 yards with my wsm last month does that count??

 

[fatbacks]

Good choice man!
Get some RL26 and I think you'll be amazed at the velocity.

I’ve been looking for RL26 for a year or two and can’t seem to find it ever. Too bad we can’t order powder in Alaska, I’ve really wanted to try it in my 300 wsms, 7 Saum and 6.5 PRC.

Like your build!


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[Ram94]

I shoot 2 round groups all the time, it's all about cold bore hits with LR shooting.
I shot 5 consecutive 2 round "groups" at 800 yards with my wsm last month does that count??

From a definition standpoint, no.

Haha what matters is that you are practicing shooting. With hunting rifles, one shot where you were aiming beats a group where you weren’t.

 

[cubdriver84d]

Just put my shorty together. 308 win and comes in right at 6 pounds with the suppressor. Swfa 3-9 in Hawkins rings going on next.

 

[madcalfe]

Just put my shorty together. 308 win and comes in right at 6 pounds with the suppressor. Swfa 3-9 in Hawkins rings going on next.

what barrel size is that 18"?

 

[cubdriver84d]

what barrel size is that 18"?

16

 

[fwafwow]

Subscribed - great thread.

 

[awildswanger]

Lets say a friend lost all of his firearms in a boating accident, a true tragedy. If he was wanting to do something like this without reloading (currently), would a 16”-18” .308/6.5 Creed/.338 Fed be more advisable? Which would you pick?

 

[fwafwow]

@awildswanger - I'm very sorry for your friend's loss.

I did a brief search for a bolt action upper that could be used with an AR lower. Not much to choose from (and definitely not a short or even a 16" barrel), but if one had an SBR lower, that could be a pretty short package. Just not sure if legit, or how practical.

 

[Trapperkid]

@awildswanger - I'm very sorry for your friend's loss.

I did a brief search for a bolt action upper that could be used with an AR lower. Not much to choose from (and definitely not a short or even a 16" barrel), but if one had an SBR lower, that could be a pretty short package. Just not sure if legit, or how practical.

I’ve looked for those when I had my ar and to say your options are thin is an understatement. But it would be really cool.

 

[fwafwow]

I’ve looked for those when I had my ar and to say your options are thin is an understatement. But it would be really cool.

Glad that at least one person had the same idea. I'm sure there are plenty of reasons why there are few options (I only found one), and probably several more as to why it doesn't make sense to go that route.

 

[fatbacks]

Everything compiled and off the gunsmith for chambering, cerekote and a stock... Should have my 18" 300 WSM back in time for summer.

 

[tdbaugha]

Because they don’t know any better. Myths, old wives tales, ignorance, and advertising. The older generation were brought up on magnums- muzzle velocity and “energy”. The longer the barrel the higher the MV- and when you’re pushing MV as a selling point, it matters.
People chase MV like it’s magic. It mattered a whole lot more before rangefinders, now it mainly just applies to range of terminal performance.

I’m building a shorty custom rifle as well. Two pieces of information that I found very compelling:

1) Unknown Munitions just did a test with a 20” RUM. They were stepping up the powder charge to see where the velocity gain would level off, indicating any additional powder was being wasted. They got to 100 grains and stopped the test. Even at 100 grains they were still getting velocity increases with more and more powder. This was with N570.

2) Gunwerks has a podcast on short barrels where they go through the statistics on different chambers with different barrel lengths. The 7 SAUM was the best in their testing. Velocity difference between a 24” barrel and a 18” barrel was only 100 FPS. Most intermediate cartridges lost around 200 FPS and the stuff like a 28 nosler was closer to 300 FPS in that 6” difference.

Ultimately I ended up pulling the trigger on a 7 SAUM custom. 20” proof barrel, AnTi XM action, Axial Precision Stock. I have a Nomad Ti in jail for it as well. I’m kinda wishing I went with the 18” barrel, but ended up playing it safe and with the 20”. Can’t wait to get it done.

 

[fwafwow]

I’m building a shorty custom rifle as well. Two pieces of information that I found very compelling:

1) Unknown Munitions just did a test with a 20” RUM. They were stepping up the powder charge to see where the velocity gain would level off, indicating any additional powder was being wasted. They got to 100 grains and stopped the test. Even at 100 grains they were still getting velocity increases with more and more powder. This was with N570.

2) Gunwerks has a podcast on short barrels where they go through the statistics on different chambers with different barrel lengths. The 7 SAUM was the best in their testing. Velocity difference between a 24” barrel and a 18” barrel was only 100 FPS. Most intermediate cartridges lost around 200 FPS and the stuff like a 28 nosler was closer to 300 FPS in that 6” difference.

Ultimately I ended up pulling the trigger on a 7 SAUM custom. 20” proof barrel, AnTi XM action, Axial Precision Stock. I have a Nomad Ti in jail for it as well. I’m kinda wishing I went with the 18” barrel, but ended up playing it safe and with the 20”. Can’t wait to get it done.

Pls post pics when you get it!

 

[22Conch]

Interesting. Putting together a 16" .308. Looking at chassis options with folding stock.

 

[fwafwow]

Interesting. Putting together a 16" .308. Looking at chassis options with folding stock.

Anyone consider the Fix Side Chick Chassis?

 

[cubdriver84d]

Interesting. Putting together a 16" .308. Looking at chassis options with folding stock.

I went with the proof stock on my 16” 308 because of the weight savings, but that new mdt chassis looks pretty rad. Might go that route on a tikka build.

 

[gabenzeke]

I've been considering doing something really similar. I like the 7 saum because it seems like a good balance of power with the ability to run a short barrel. I'd be (sadly) using my 300 RUM as a donor action. Love that caliber, but a 26 inch barrel plus suppressor on an already heavy rifle makes for a lot of weight and length being carried.

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[fatbacks]

I’m building a shorty custom rifle as well. Two pieces of information that I found very compelling:

1) Unknown Munitions just did a test with a 20” RUM. They were stepping up the powder charge to see where the velocity gain would level off, indicating any additional powder was being wasted. They got to 100 grains and stopped the test. Even at 100 grains they were still getting velocity increases with more and more powder. This was with N570.

2) Gunwerks has a podcast on short barrels where they go through the statistics on different chambers with different barrel lengths. The 7 SAUM was the best in their testing. Velocity difference between a 24” barrel and a 18” barrel was only 100 FPS. Most intermediate cartridges lost around 200 FPS and the stuff like a 28 nosler was closer to 300 FPS in that 6” difference.

Ultimately I ended up pulling the trigger on a 7 SAUM custom. 20” proof barrel, AnTi XM action, Axial Precision Stock. I have a Nomad Ti in jail for it as well. I’m kinda wishing I went with the 18” barrel, but ended up playing it safe and with the 20”. Can’t wait to get it done.

You’ll be stoked with the Nomad Ti. Mine got out of jail two weeks ago and I’m pumped about how light and compact it feels compared to my other cans.

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