feeding long action cartridges into a short action

keokio

Private
Minuteman
Dec 1, 2019
10
4
6
this is a weird question im a noob here and im just trying to decide which custom action I need to get. I plan on running both a 6.5 creedmoor and 7 saum on a Origin action, but I would like to load the 7 saum with big 180gr bullets out to long action type lengths. If I want to stick with a short action I know the 7 saum fitting into a short action magazine is not an option, however my question is would I still be able to single feed the long 7 saum bullets by hand? I remember reading somewhere it can be done but you gotta pull out the entire bolt if you want to remove the round. Just want to make sure before I pull the trigger on a short action
 

b6graham

MMPRL
Belligerents
Jul 29, 2014
3,421
2,599
219
this is a weird question im a noob here and im just trying to decide which custom action I need to get. I plan on running both a 6.5 creedmoor and 7 saum on a Origin action, but I would like to load the 7 saum with big 180gr bullets out to long action type lengths. If I want to stick with a short action I know the 7 saum fitting into a short action magazine is not an option, however my question is would I still be able to single feed the long 7 saum bullets by hand? I remember reading somewhere it can be done but you gotta pull out the entire bolt if you want to remove the round. Just want to make sure before I pull the trigger on a short action
Youre correct

Bolt removal maybe depends on coal
 

Steel head

Stylish Ninja
Belligerents
Aug 3, 2014
3,892
3,171
219
Washington
this is a weird question im a noob here and im just trying to decide which custom action I need to get. I plan on running both a 6.5 creedmoor and 7 saum on a Origin action, but I would like to load the 7 saum with big 180gr bullets out to long action type lengths. If I want to stick with a short action I know the 7 saum fitting into a short action magazine is not an option, however my question is would I still be able to single feed the long 7 saum bullets by hand? I remember reading somewhere it can be done but you gotta pull out the entire bolt if you want to remove the round. Just want to make sure before I pull the trigger on a short action
You 100% can single feed long 7 saum in a short action.

I run my 7 saum at short action mag length through the mag easily as well with 180’s

As said you have to pull the bolt to eject a live round loaded long.
 

keokio

Private
Minuteman
Dec 1, 2019
10
4
6
You 100% can single feed long 7 saum in a short action.

I run my 7 saum at short action mag length through the mag easily as well with 180’s

As said you have to pull the bolt to eject a live round loaded long.
thanks for all the answers, guess i'm gonna get the short action for sure now.
In your experience with the 180s loaded for short mag length, what kind of fps are you getting. My goal is to get it into the 2900+ fps
 

Steel head

Stylish Ninja
Belligerents
Aug 3, 2014
3,892
3,171
219
Washington
thanks for all the answers, guess i'm gonna get the short action for sure now.
In your experience with the 180s loaded for short mag length, what kind of fps are you getting. My goal is to get it into the 2900+ fps
2940 is what it was slinging them at yesterday
28” barrel.
 

whatsupdoc

Gunny Sergeant
Belligerents
Minuteman
Dec 12, 2017
782
721
99
Maybe im wrong but doesn't bighorn have a mechanical ejector? So if a loaded cartridge is too long to eject and you need to remove the bolt, once the extractor snaps over the case rim and the manual ejector his the case it would stop.

Right? Wrong?
 

Steel head

Stylish Ninja
Belligerents
Aug 3, 2014
3,892
3,171
219
Washington
Maybe im wrong but doesn't bighorn have a mechanical ejector? So if a loaded cartridge is too long to eject and you need to remove the bolt, once the extractor snaps over the case rim and the manual ejector his the case it would stop.

Right? Wrong?
I just pushed the cartridge out of the bolt face down the mag opening with my nucleus.
 

65x55guy

Maker of bad decisions
Hessian
Belligerents
Feb 14, 2017
156
49
34
Arkansas
thanks for all the answers, guess i'm gonna get the short action for sure now.
In your experience with the 180s loaded for short mag length, what kind of fps are you getting. My goal is to get it into the 2900+ fps
2850-2900 is a range that most slower powders can hit with 180s and a 26” barrel. I recently had a 7 saum in short action that had a great node at 2890 with 59.6g of RL26. Max for me was at 2995, but the best node was lower.
 

NukeMMC

Damn Bubblehead
Online Training Access
Belligerents
Mar 3, 2009
1,161
272
189
Harrisburg, PA
FYI
USAMU used to run 300wm prone rifles built on 40x short action single feeds. Yep, they would pull the bolt to eject a live round sometimes.
 

keokio

Private
Minuteman
Dec 1, 2019
10
4
6
FYI
USAMU used to run 300wm prone rifles built on 40x short action single feeds. Yep, they would pull the bolt to eject a live round sometimes.
thats very interesting, was there a particular reason for that?
 

Steel head

Stylish Ninja
Belligerents
Aug 3, 2014
3,892
3,171
219
Washington
2850-2900 is a range that most slower powders can hit with 180s and a 26” barrel. I recently had a 7 saum in short action that had a great node at 2890 with 59.6g of RL26. Max for me was at 2995, but the best node was lower.
I had the same max with my 28” barrel and R26.
I’m actually thinking about dropping even further to 2900 ish just for more high temp safety.
 
  • Like
Reactions: 65x55guy

b6graham

MMPRL
Belligerents
Jul 29, 2014
3,421
2,599
219
I definitely can run my 7saum out of ARC short action mags, the only problem I have is to much jump. I wasn’t able to get accuracy out of it magazine feeding it. I single feed now in my Nucleus which I’m ok with.
Sounds like a freebore issue. 7 SAUM is meant for a SA though the new high weight bullets do test it
 

Steel head

Stylish Ninja
Belligerents
Aug 3, 2014
3,892
3,171
219
Washington
I definitely can run my 7saum out of ARC short action mags, the only problem I have is to much jump. I wasn’t able to get accuracy out of it magazine feeding it. I single feed now in my Nucleus which I’m ok with.
I was lucky and got good accuracy with the jump

Sounds like a freebore issue. 7 SAUM is meant for a SA though the new high weight bullets do test it
175 SMK’s can get up to the lands mag length.

180 ELDM’s aren’t even close at mag length.

A 7mm hunting game bullet(can’t remember what it was) I was able to get to the lands with room to spare in a ARC mag.

Take maybe .05-.07 off the freebore spec and your getting cozy with the lands in a 2.95ish magazine.
 

b6graham

MMPRL
Belligerents
Jul 29, 2014
3,421
2,599
219
I was lucky and got good accuracy with the jump



175 SMK’s can get up to the lands mag length.

180 ELDM’s aren’t even close at mag length.

A 7mm hunting game bullet(can’t remember what it was) I was able to get to the lands with room to spare in a ARC mag.

Take maybe .05-.07 off the freebore spec and your getting cozy with the lands in a 2.95ish magazine.
Right. Shorter freebore and 180s are in a good relationship with lands but shit relationship with the shoulder

7SS and 7SST. Just sayin 🤷‍♂️
 
  • Like
Reactions: gnochi

Steel head

Stylish Ninja
Belligerents
Aug 3, 2014
3,892
3,171
219
Washington
Right. Shorter freebore and 180s are in a good relationship with lands but shit relationship with the shoulder

7SS and 7SST. Just sayin 🤷‍♂️
With all it’s detriments I’m still absolutely loving 7 saum and don’t regret not going 7SS.

The bullets I prefer SMK’s, hybrids and Eldm’s love jump and I’ve never had aproblem finding a load that shoots in my 260 and 7SAUM.