Building a Shorty - now what to chamber it in?

[steffen707]

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

View attachment 267084

how did the 300wsm 18" work out? what are muzzle velocities, powder and bullet details?

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.

how is the 7SAUM going? what muzzle velocities are you getting at 20", powder and bullet details?

 

[pc3]

Just about to finish up my latest project (7 SAUM on new Defiance anTi action) and I’ve already got the gears turning for a new project.

I really want to build a super short (16” or so) rifle with a lightweight/foldable chassis. Ideally make it a very light weight compact rifle capable of hunting all over Alaska. Thinking 16” proof barrrel. Maybe another defiance anTi action if I end up liking it and the XLR Element chassis.

Now what to chamber it in??? Obvious choice would be .308 Win but is there any other cartridge I am overlooking that has decent performance out of a short barrel? Intended uses would be mountain hunting shooting sheep, caribou and goats out to 500 yds. Would like something that I could shoot moose with and also have as bear protection. I like to shoot Barnes monos. Also would shoot it suppressed at times. I reload so would be able to try different powders depending on availability.


Sent from my iPhone using Tapatalk

I have a couple of short builds, a .223 AI and a .308. Plenty of short .308 information out there. For Alaska you could look at the .338 Federal ability to use heavier pills, say a woodleigh 225 gr pill would hit hard and drive deep on some of you bigger game there.

BULLET SPECIFICATIONS, DIMENSIONS & DETAILS .338"-.375"​

	CAT No	CALIBRE		QTY /BOX	SD	BC	REC. IMPACT VELOCITY (fps)	LENGTH (inches)
	56C	338 Fed 338/06 .338"	180gr PP SN	50	.226	.361	2000-2900	1.033
	56D		200gr PP SN	50	.251	.401	2000-2900	1.113
	56E	33 Win .338"	200gr FN SN	50	.246	.234	2000-2200	1.035
	56A	338 Mag .338"	225gr PP SN	50	.281	.425	2000-2900	1.189
	56		250gr RN SN	50	.313	.332	2000-2500	1.226
	56B		250gr PP SN	50	.313	.431	2000-2500	1.288
	57		250gr FMJ	50	.313	.326		1.334
	58		300gr RN SN	50	.375	.416	2000-2500	1.430
	59		300gr FMJ	50	.375	.414		1.558

 

[steffen707]

Thinking 16” proof barrrel. ............. Also would shoot it suppressed at times.

Double check the suppressor you have/want can handle that short of a barrel. I got a thunderbeast ultra 7 and they said 18" min. Not sure if the 308 needs to be 18", but they did say my 7mmRM does.

The .30 cal ULTRA was designed around .308 for maximum flexibility and is rated up to .300 Winchester Magnum (18" barrel), but it's the ideal suppressor for the most competitive mid-sized cartridges for long-range shooting such as .243 Winchester .260 Remington, 6.5 Creedmoor, 6.5x47 Lapua, 6.5-284 Norma, and 7mm Remington Magnum & WSM.

 

[BjornF16]

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

View attachment 267084

Any update on this rig?

 

[tdbaugha]

how did the 300wsm 18" work out? what are muzzle velocities, powder and bullet details?


how is the 7SAUM going? what muzzle velocities are you getting at 20", powder and bullet details?

Threw together a quick load for hunting. I expect to get more out of it in the coming months. But here is what I am running for this year.

169 gr hammer hunter
ADG brass
3.050” COAL
55.7 gr H4350
2815 fps
~.3 MOA

 

[steffen707]

Threw together a quick load for hunting. I expect to get more out of it in the coming months. But here is what I am running for this year.

169 gr hammer hunter
ADG brass
3.050” COAL
55.7 gr H4350
2815 fps
~.3 MOA

And that's the 20" 7saum?

 

[tdbaugha]

And that's the 20" 7saum?

Yes