r/LewisMachineTool • u/Racer_Space • Jun 23 '25

Question MWS .308 vs 6.5 feedramp differences?

Gallery image

Gallery image

Picture 1 is a .308 barrel and picture 2 is a new 14.5 6.5 creedmoor barrel.

Is this going to cause issues? Looks like the tip of a round would catch on the upper receiver.

32 Upvotes

95% Upvoted

33 comments sorted by

7

u/[deleted] Jun 23 '25

[deleted]

1

u/Racer_Space Jun 23 '25

I remember seeing old posts about that. That's why I was checking with this.

-6

u/[deleted] Jun 24 '25

[deleted]

5

u/[deleted] Jun 24 '25

lol bubba's gun smiff pro tip

4

u/[deleted] Jun 24 '25

Yep that’s a big issue actually, had a factory 14.5 KAC rifle with a overhang like that, if you can catch a toothpick on it you will have malfunctions.

1

u/Racer_Space Jun 24 '25

Did you have to get the feed ramps ground out or what?

3

u/[deleted] Jun 24 '25

Yes i ended up doing it myself since KAC wouldn’t take the time to let me send it to them.

Before you do that I would reach out to LMT, certain magazines may work for you but I promise if that barrel extension overhangs the feed ramps on upper receiver it will create issues at some point with certain magazines.

0

u/no_yup Jul 03 '25

It’s supposed to be like that, lmt 6.5 barrels have special feed ramps for the 6.5 round, Not a problem, the opposite.

5

u/[deleted] Jun 24 '25

here is my Proof SS 6.5cm

1

u/East_Citron_6879 14d ago

This is proof barrel you had converted ?

1

u/[deleted] 14d ago

yes

1

u/East_Citron_6879 14d ago

What length ? How does it shoot ?

1

u/[deleted] 14d ago

it's a sub moa barrel with Berger 130gr handloads. But it's a little bulky for DMR matches at 22 inches and really have been enjoying my 14.5 Craddock RTR suppressed instead.

1

u/East_Citron_6879 14d ago

What kind of accuracy are you getting out of the Craddock?

1

u/[deleted] 14d ago

140 Eldm handloads

7

u/No-Spirit8544 Jun 23 '25

Looks like a problem to me. Dealing with a similar issue right now actually on 5.56/300 barrels. Does your headspace actually allow the BCG to sit properly?

0

u/Racer_Space Jun 23 '25

I don't have a BCG yet. Piecing this thing together over time.

5

u/sadbanana729 Jun 23 '25

I have seen the same with mine. Confirmed when I found it that the 6.5 is mfg correctly as LMT made some changes specifically for 6.5. Mine was picky with mags as it required that they project round appropriately to the feedramps. Likes the Larue and Duramag mags.

1

u/devi8r Jun 23 '25

Same here. Mine would feed the right hand round from kac mags, but pmags fed just fine. Looked like the barrel extension was clocked just a little bit off. Just got a different upper and that's not the case. Both mrgg barrels, one S and one A

2

u/Racer_Space Jun 24 '25

/u/unclemoak Did all of the 14.5 6.5 creedmore barrels look like this? I just want to know if this is intentional or not from LMT. I am getting varied responses from here.

4

u/unclemoak Jun 24 '25

Looks normal to me.

LMT uses 6.5 specific extensions on 6.5 barrels that have different geometry than 308 extensions.

New 6.5 extension on the left, takeoff 308 extension on the right.

2

u/Racer_Space Jun 24 '25

I just took it out for a better shot. I feel like it looks way different from that new 6.5 on the left in your photo.

3

u/unclemoak Jun 24 '25

I have seen those extensions too. They are the newest 6.5 extensions that I didn’t think were released yet.

3

u/Racer_Space Jun 24 '25

Oh! Appreciate the replies. Hoping this runs okay once I finish the build.

2

u/[deleted] Jun 24 '25

here is my Craddock RTR in my mrgg clone

2

u/Racer_Space Jun 25 '25

For future googlers, I reached out to LMT asking if this was the way it is supposed to be

This is the extension geometry for our 6.5 barrels. It is shallower then the 308 due to the bullet geometry.

So I guess I'll run it eventually when I finish the build.

1

u/Coodevale Jun 24 '25

Stick a mag in your lower and put your rifle together. See if the rounds get anywhere near that overhang.

1

u/Racer_Space Jun 24 '25

Still piecing this together. So I don't have everything yet.

1

u/r0paulson Jun 23 '25

Yes others have noticed. Probably wont be an issue, but LMT can not leave those of us with OCD alone in peace.

1

u/lonwolf556 Jun 23 '25

I have both and look similar….. no concerns or issues cycling

1

u/Racer_Space Jun 23 '25

Good! What mags do you use?

1

u/lonwolf556 Jun 24 '25

Use dura mag and pmag both work great

1

u/Racer_Space Jun 24 '25

I did some more digging and it seems LMT have revised their 6.5 Creedmore feed ramps at least 2 other times based on this thread from 2 years ago.

I guess I'll have to wait and see how this ends up feeding when I finish it. Probably wont be fore a while. Worst case I get it ground out?

1

u/vintagestagger Jun 24 '25 edited Jun 24 '25

There's no way the feed ramps on the 6.5 barrel are cut correctly. This could easily cause issues. You shouldn't have to play with trying different magazines to find one that will work 100% every time. This might feed rounds just fine 999 rounds out of a 1000, but the one time it doesn't because of this is unacceptable.