LR-.308 Build

[cjuergs90]

I'm looking to start building an LR 308, but planned to make it in the .22-250 Rem (Don't try to change my mind on that part) and was wondering if there was anything I would need to change from a regular .308 build besides the barrel? 

Many Thanks

[308kiwi]

I looked at the 22-250 as well before settling on 243 Win for a build, I have a Rem 788 in 22-250 so already load the round.

The biggest, (potential), problem I saw was that the 22-250 case is quite tapered and does not sit well when stacked in a double column magazine that is designed to house/feed a much less tapered case, I could see this possibly causing feeding problems so binned the idea.

 

 

 

[survivalshop]

4 hours ago, 308kiwi said:

I looked at the 22-250 as well before settling on 243 Win for a build, I have a Rem 788 in 22-250 so already load the round.

The biggest, (potential), problem I saw was that the 22-250 case is quite tapered and does not sit well when stacked in a double column magazine that is designed to house/feed a much less tapered case, I could see this possibly causing feeding problems so binned the idea.

 

 

 

     The 6.5 Creedmoor has a very pronounced case in that regard & some have had to alter the feed ramp to help them feed on some builds . It goes to show you , when you build a parts rifle , you may have to do your own R&D .

      I would load some 22-250 into a Lr 308 Mag type & see how they load & strip off the mag by hand & how they sit in the mag ,as has been mentioned . any looseness or pointing at an odd angle , etc . can cause feeding issues . 

  You may also run into Buffer system issues , but a lot will not be known till you build & test .

   Good luck & please keep us informed .

[98Z5V]

Here's how Olympic Arms accomplished it - something to think about...

http://www.olyarms.com/shop/rifles/umar-rifles/umar-22250.html

[308kiwi]

8 hours ago, survivalshop said:

  I would load some 22-250 into a Lr 308 Mag type & see how they load & strip off the mag by hand & how they sit in the mag ,as has been mentioned . any looseness or pointing at an odd angle , etc . can cause feeding issues

When I did this exact test the issue I saw was that as you start loading the rounds they start to tip down at the front as the taper comes into play, much like the 7.62 x 39 round, you need a curved mag to compensate for the tapered round.

Loading 22-250 into both the 20 and 25 round Magpul 308 mags I got, (from memory), 10 to 12 rounds into the mag before the tip of the top projectile was pointing at the inside of the front of the mag, no way was it going to feed out of the mag let alone into the chamber so I took it no further.

Best of luck with your 22-250 build cjuergs90, and like SS says, please keep us all in the loop as you go.

[cjuergs90]

Ha, when I said "don't try to change my mind", I wasn't too sincere I guess because you all might've just done it with these potential problems... I'll do a little research and see if I still plan to build in the .22-250 caliber after that. Thank you all very much

[jtallen83]

41 minutes ago, cjuergs90 said:

I'll do a little research

Check out the 224 Valkyrie;

https://www.americanrifleman.org/articles/2017/10/30/the-keefe-report-224-valkyrie-rightly-the-next-big-thing/

or the 22 Nosler;

https://www.americanrifleman.org/articles/2017/1/16/the-keefe-report-go-small-or-go-home-22-nosler/

These are AR-15 pattern cartridges but then you would save some weight and get pretty darn close to the same ballistics.

Edited January 5, 2018 by jtallen83
clarity

[survivalshop]

39 minutes ago, cjuergs90 said:

Ha, when I said "don't try to change my mind", I wasn't too sincere I guess because you all might've just done it with these potential problems... I'll do a little research and see if I still plan to build in the .22-250 caliber after that. Thank you all very much

  How about the link 98 posted , I thought the 22-250 would of been too long for an AR 15 , but that link shows what looks like one , ( weight of 9.9 # is definitely in  the LR range )

[shepp]

18 hours ago, cjuergs90 said:

I'm looking to start building an LR 308, but planned to make it in the .22-250 Rem (Don't try to change my mind on that part) and was wondering if there was anything I would need to change from a regular .308 build besides the barrel? 

Many Thanks

Welcome to the forum feel free to tell us about yourself in the intro section

[shepp]

16 minutes ago, shepp said:

Welcome to the forum feel free to tell us about yourself in the intro section

Beat me to it welcome again :)

[98Z5V]

3 hours ago, survivalshop said:

  How about the link 98 posted , I thought the 22-250 would of been too long for an AR 15 , but that link shows what looks like one , ( weight of 9.9 # is definitely in  the LR range )

The Olympic Arms 22-250 has been out about 2 years, if I remember right.  I think they accomplished it by (literally) lengthening AR-15 receivers, to account for the longer loaded-bullet length.  It still uses all AR-15 parts, but I can't remember on the BCG setup.  Theres something in their 22-250 rifle information that states you can still use it for .223, by swapping a few parts.

Yep, it's right on that link I posted:

The following features are used in addtion to standard
features on the UMAR lower receiver:

1. Modified UMAR AR-15 lower receiver magazine well. Designed specifically for the UMAR magazines to accept the venerable .22-250 caliber and long WSSM loads.

2. Threaded bolt catch hole: designed for a quick and easy change of your bolt catch between standard 5.56 magazine and the UMAR magazines, (Which use different bolt catches). Swap back and forth in seconds!

3. All modified UMAR lower receivers can also readily accept every standard AR-15 upper and caliber option. The UMAR lower is applicable to all AR-15 calibers from .22 LR and 5.56 NATO, to the WSSM and .22-250 calibers. Just swap the upper, the magazine and the bolt catch (if needed).

4. UMAR magazines come in two vatieties:
.22-250 or WSSM/OSSM

Edited January 6, 2018 by 98Z5V

[survivalshop]

  Since he wants to use an LR frame size ( who knew OA has it in a Small custom Frame ) , the Mag would be the first one to tackle . A change in the Mag's Follower would probably take care of the Taper in the Case , since the Magpul is made of Polymer , so IF there was enough material on it , it could be altered for the Cases to feed .

  If you just want a 22-250 in an AR  , go with Olympic Arms , seems like they have it figured out .

[cjuergs90]

On 1/5/2018 at 2:43 PM, 308kiwi said:

Loading 22-250 into both the 20 and 25 round Magpul 308 mags I got, (from memory), 10 to 12 rounds into the mag before the tip of the top projectile was pointing at the inside of the front of the mag

So if I were to keep my options open to only lower capacity magazines such as 5 and 10 rounds would this still be a problem?

[survivalshop]

4 hours ago, cjuergs90 said:

So if I were to keep my options open to only lower capacity magazines such as 5 and 10 rounds would this still be a problem?

  Probably , only way to know for sure is to stuff a five or ten rounder with 22-250's & see how they sit in it .

  If you have a 308AR , you can seat the mag with them loaded in it & see what angle they are through the Ejection Port. Take Photo's !

 

[cjuergs90]

That's the problem, this would be my first 308AR. So I don't have any of the parts and materials to test some of these questions I have out... Might have to buy a magazine or two to try it out.

[survivalshop]

    I have no 22-250 brass or loaded ammo to check it for you , I have just about every other Caliber out there , but that one , sorry , maybe someone here does & can take some photo's of how they fit in a LR Magazine .

[308kiwi]

Here ya go....7 rounds of 22-250 loaded into a 308 Magpul P Mag.

First pic, note the gap between the underside of the feed lip and the case and the gap between the top round and the next round down in the stack, the gaps get bigger the more rounds you load into the mag.

Second pic is after I gently pushed the top round forward, simulating feeding, note how the round tips down severely at the front, the tip of the projectile hits the inside front of the mag and thats with me just quietly pushing the round forward, imagine how this would end up under the violence of normal cycling, the projectile would end up inside the case.

The issue is the taper of the case and how the cases interact with each other in the mag IMO.

Hope this is some help to you cjuergs90.

I'd be curious as to what Olympic Arms did to solve this issue.

 

 

Edited January 11, 2018 by 308kiwi

[308kiwi]

Well that's that mystery solved, Olympic Arms 22-250 mag is 5 round single stack and with quite a pronounced follower?, feed ramp?, built in, bit hard to tell from the pic.......

 

 

Edited January 11, 2018 by 308kiwi

[survivalshop]

    The Magazines follower would need to be altered for the Case difference in the 22-250 , but such a pronounced angle should not be needed if the Cartridge is aligned to feed straight in , as with Lancer 7 Mags . With such a pronounced feed angle , you could also have the round tip up & jam, of course that mag was made for a specific ( read proprietary ) Receiver set up & the way it is made may be needed .

[308kiwi]

I would also imagine that the barrel extension would need to have a single feed ramp, like the RRA design, seeing as the rounds are feeding from the middle of the mag.