LR243 Gas System Adjustment and Buffer Spring Selection

[98Z5V]

Seems to be a trend with X-Cal gasports... 

[BIGTRUCKNUT]

Youngest just recently home from college.  After today, says she wants one of her own.

[jtallen83]

Sounds like a good shooter . Too bad X-Caliber couldn't hang with us on the forum and learn a little about gas port sizing, other than that their barrels seem to be winners.

[washguy]

45 minutes ago, jtallen83 said:

Sounds like a good shooter . Too bad X-Caliber couldn't hang with us on the forum and learn a little about gas port sizing, other than that their barrels seem to be winners.

JT    man...be careful...you know that this is all secret stuff you're talkin bout       Wash

[EngrBob]

9 hours ago, jtallen83 said:

Sounds like a good shooter . Too bad X-Caliber couldn't hang with us on the forum and learn a little about gas port sizing, other than that their barrels seem to be winners.

I hope they have learned something since I am waiting for my 18" .338 Federal barrel from them.  I guess that will need to be the first thing I check!

[Sisco]

Going to be a sweet rifle for distance shooting! 

[EngrBob]

 

On 5/21/2017 at 9:46 PM, jtallen83 said:

Sounds like a good shooter . Too bad X-Caliber couldn't hang with us on the forum and learn a little about gas port sizing, other than that their barrels seem to be winners.

On 5/22/2017 at 7:18 AM, EngrBob said:

I hope they have learned something since I am waiting for my 18" .338 Federal barrel from them.  I guess that will need to be the first thing I check!

Well, perhaps they did.  It appears that the gas port on the rifle length .338 barrel is 0.09375 (3/32).  Might be just a touch small but I want to get it to the range and see whether it functions properly.  Since it is a frankengun (Aero Precision M5 upper, Blitzkreig Tactical 80% lower, Fulton Armory LPK, La Rue MBT, Tubbs flat wire sping, etc.) if it doesn't I will have a lot to triage. 

[98Z5V]

9 hours ago, EngrBob said:

Well, perhaps they did.  It appears that the gas port on the rifle length .338 barrel is 0.09375 (3/32).

That should be fine.

[EngrBob]

Wind is too high to get to the range but the .338 went together nicely.  Hope the wind drops before the weekend is over so I can do some testing.  Picture quality sucks but she does look nice and feels good.

[washguy]

SWEET!          Wash

[308kiwi]

On 19/05/2017 at 11:17 AM, BIGTRUCKNUT said:

So at 24" and rifle length gas system I guess that the suggested port size of .099" was spot on.   Can't wait to test it Saturday if the ranges on Quantico are open.

Excellent and timely info, thanks guys.

Am building a .243 upper for mine and have been scouring the net and scratching my head furiously trying to decide on an initial gas port dia for .243, still haven't decided on overall length, was going to go 22", then decided on 20", then decided I haven’t decided just yet, I guess you can always make it shorter easier than you can make it longer again.

Have a 1:8 5R .237/.243 blank on order from Bartlein at the moment, just waiting on the export paperwork from your State Dept so I can get the damn thing shipped.

[98Z5V]

1 hour ago, 308kiwi said:

Excellent and timely info, thanks guys.

Am building a .243 upper for mine and have been scouring the net and scratching my head furiously trying to decide on an initial gas port dia for .243, still haven't decided on overall length, was going to go 22", then decided on 20", then decided I haven’t decided just yet, I guess you can always make it shorter easier than you can make it longer again.

Have a 1:8 5R .237/.243 blank on order from Bartlein at the moment, just waiting on the export paperwork from your State Dept so I can get the damn thing shipped.

Start smaller than the 0.099" here, just because it's easy to go up in size. I don't know squat about the .243, but it's looking alot like standard .308 Win gas port sizes.  The 0.060" that was in this barrel (from the OP)  was WAY too small, and that was very obvious.  Big fuckup by the manufacturer, IMHO, with all their "secret gas port sizes." 

I'd start at 0.080" and see what you get, then go up from there, especially if you're cutting the barrel down.  Try it longer, see if you like it with that length, and 0.080" starting.  If you don't like the length, just cut it and leave the 0.080" and try again...etc. I wouldn't drill up until you find your preferred barrel length, then drill if needed at that length.

My opinion doesn't mean shiit, though, with zero experience on the .243... Take it for what it's worth... 

Edited May 29, 2017 by 98Z5V

[308kiwi]

Cheers 98Z5V, some sound advice, thanks.

I have a full set of number drills so yes will be starting well below .099 and working up.

Will post up some pics as it goes together.

[BIGTRUCKNUT]

Kiwi, I went around and around about the barrel length too before I finally settled on the 24" in the pictures here. That's a 24" barrel and another 2" of compensator. I'm not home to check overall weapon length for you but my LR243 as configured with the Magpul PRS stock is about 1 1/2" shorter than my Savage model 112 243 with 24" barrel.  I too figured that I could have it shortened if I didn't like it but so far I'm digging it. 

[308kiwi]

20 minutes ago, BIGTRUCKNUT said:

Kiwi, I went around and around about the barrel length too before I finally settled on the 24" in the pictures here. That's a 24" barrel and another 2" of compensator. I'm not home to check overall weapon length for you but my LR243 as configured with the Magpul PRS stock is about 1 1/2" shorter than my Savage model 112 243 with 24" barrel.  I too figured that I could have it shortened if I didn't like it but so far I'm digging it. 

Cheers, the deciding factors for me are velocity, ie making the most of the cartridge vs practicality, do I need that extra 40fps from that extra 2" of barrel. And of course it's got to look right as well, ie the ratio of hand guard length vs barrel length :-).

Just looking at your build, 24" doesn't look out of proportion at all as like you say 2" of that are actually a brake.

Probably a few more weeks before the barrel turns up so no hurry to decide.

Cheers

 

[BIGTRUCKNUT]

For reference, mine's got a 12" handguard.  I wanted to maximize my LR243 for use from 600 to 1000 yards hence the 24" length and 8 to 1 twist for heavier (95 - 107 grn) bullets.  Good luck with your choice.

[survivalshop]

  It would probably be a good idea to check the Gas Port size before assembling the Barrel , then assemble  & test fire it to see how the system reacts before drilling or cutting anything .

[308kiwi]

3 hours ago, survivalshop said:

  It would probably be a good idea to check the Gas Port size before assembling the Barrel , then assemble  & test fire it to see how the system reacts before drilling or cutting anything .

The barrel I have coming is an un-profiled, un-chambered blank, a complete blank canvas as such.

So I'll be starting from scratch and after reading this thread I think I'll be starting somewhere around .075" to .080" and fine tuning from there, your 'secret port dia list' has been very helpful SS.

Cheers

[survivalshop]

34 minutes ago, 308kiwi said:

The barrel I have coming is an un-profiled, un-chambered blank, a complete blank canvas as such.

So I'll be starting from scratch and after reading this thread I think I'll be starting somewhere around .075" to .080" and fine tuning from there, your 'secret port dia list' has been very helpful SS.

Cheers

Oh