16” 6.5 Creedmoor barrel worth it?

[turnburglar]

With today’s political climate I decided to start my journey by ordering a Stag10 blem lower in FDE, and a matching FDE upper. I’m still leaning toward a 16” barrel, but may go 18” depending on pricing and availability.

Get an 18" rifle gas. 6.5 CM is a very gassy round and the extended gas system is noticeable. I ONLY went with a 16" because I am waiting on a can in jail and wanted a shorter OAL.

To all the dudes who think a short 6.5 CM isn't worth it compared to a 308.... YOU are behind the curve. Sorry, but I dont spend a ton of time reading and extrapolating internet posts to figure out what gun is best. I go out and shoot. I have noticed a trend in large frame gas gun shooters all migrating away from 308. I even had a 308 for a little bit. So glad I shoot a 6.5 now. Sorry you just dont 'get it'.

[markm]

Get an 18" rifle gas. 6.5 CM is a very gassy round and the extended gas system is noticeable.

Are you seeing that yours is already gassy BEFORE adding the can? Or have you shot other set ups?

Neither of the 2 gas guns (Colt and LMT) we shoot seem very gassy, but they're definitely not 16" barrels. (both are suppressed)

[Todd.K]

Smaller bore, slower burning powder. It’s going to have more pressure at the same distance down the bore than 308 does, and at the muzzle it’s more apparent than a short 308.

[turnburglar]

Thanks Todd thats a good explanation.

Mark: I have a Savage MSR10 so its small frame which has all kinds of proprietary parts. Mainly of note is that the BCG is lighter than a regular AR10 so it has less reciprocating mass compared to a standard large frame. Factory configuration is an 18" barrel with rifle length gas. I shot mine like this for 1,000 rounds maybe a little more. When I switched to the Wilson Combat barrel that is a 16" with intermediate gas, I started having failure to extracts that where caused by too weak of an extractor. So I had to beef up (double O ring) the extractor to make it reliable again. Also I added an Odin works adjustable buffer and filled it with tungsten to weigh 7.5 Oz. When I did this Im pretty sure my BCG mass is now in line with a regular AR10. I had to do all of this 'over gas' fixing even though the wilson gas port is a small 0.076". To me, it confirms my theory of 6.5 being "Gassy". When my can gets out of jail, I will see how it affects the gun. Im getting a Vox S which aren't known to be high in back pressure. If it adds even more gas my last option is to add an adjustable gas block, which I didn't want to do but its now a very likely reality. I honestly never thought shortening the barrel 2" would require so much adjustment to the rest of the gun. I still have my 18" factory barrel, and am now wondering if I should get the tube shortened down to 16.5". That should be the best of all worlds. Realistically though I got my 16" running solid now and will probably be shooting it like this for the next couple years.

[markm]

Pappabear bought a COLT 6.5 gas gun that was actually under-gassed by manufacturing/spec error. It wouldn't run good without a can. It actually was a perfect set up for suppressor however.

But yeah... I could see that lighter BCG needing some beef to tame.

[turnburglar]

Pappabear bought a COLT 6.5 gas gun that was actually under-gassed by manufacturing/spec error. It wouldn't run good without a can. It actually was a perfect set up for suppressor however.

But yeah... I could see that lighter BCG needing some beef to tame.

Yea I remember reading about that and thought it was the most serendipitous 'flaw/feature' ever. I really like those Colt small frames and probably would have bought one instead of the MSR10 but IIRC they where unobtanium when I was on the market. Either way the MSR10 is sorted now. Gonna shoot it this weekend and burn off the last of my 140's.

Mark, what do you load in 6.5 CM? Currently I have been putting Hornady 140 BTHP's over a max load of IMR4350 and it's a solid clone of Hornady American Gunner. I have some 95 v max in the mail and gonna put those over some Varget. Also have some 123's to try over Varget. Got some Load D infront of me. I was playing around with strelok the other night and it looks like the 95 - 120gr bullets fly really well from short creed moors.

[Pappabear]

Why are you switching to Varget? We run mostly ELD’s and 140’s are our most consistent.

PB

[markm]

Mark, what do you load in 6.5 CM? Currently I have been putting Hornady 140 BTHP's over a max load of IMR4350 and it's a solid clone of Hornady American Gunner.

Same... except 140 ELDMs. My lot of IMR 4350 is hot. Max Load is definitely at Max for us. Same powder for 147 ELDMs. I batch up all the Hornady brass with Fed LR primers, and it's a good load.

I also have an H4350 load for Lapua Small rifle primer brass for 140s too. Not sure on the exact charges for each off the top of my head... but it'd be unique to our powder lots anyway. That IMR powder really worked better for me. It was a fluke that I tried it, and we bought 10 more pounds to pad the inventory after shooting it.

The OTHER load I finally figured out (just as we ran out of the bullets) is the 150 gr Sierra HPBT Match. The IMR made that bullet sing too! Oddly one of Pappabear's 2 Bergaras HATES that bullet to the tune of 3 MOA. But the other 6.5s do good with the load.

Why are you switching to Varget? We run mostly ELD’s and 140’s are our most consistent.

With a light bullet and short barrel. Varget might be a good fit. It's faster, but the lighter bullet would allow for it. I'd be interested to read how it works out.

[turnburglar]

Why are you switching to Varget? We run mostly ELD’s and 140’s are our most consistent.

PB

IMR4350 has been a very accurate powder for me, but I have noticed a 50 FPS swing from 70* - 105*+. This swing caused me to want to look for a new load. I can always go back to an old load, but I think its good to have a few for each gun. Running the numbers through strelok I came up with the following:

All loads are posted in Mrad for the 600 yard and 1000 yard hold.

140 ELDM: 3.9/9.0

140 BTHP: 4.1/9.8

123 BTHP: 3.7/9.1

108 Lapua: 3.4/8.5

95 V max: 3.5/9.9


Most of my shooting is done at 600 - 700 yards, so i figure the 95 Vmax is the flattest shooting and cheaper bullet for what I do. I also figure the 95gr will be lighter recoil than a 140gr. This is honestly a gamer load for a very specific match that runs against 556 shooters. If I wanted a GP round Id probably get a 120 for price/performance/recoil.

[pointblank4445]

All loads are posted in Mrad for the 600 yard and 1000 yard hold.

140 ELDM: 3.9/9.0

Putting this into context
The data I still have on my 20" MWS for FACTORY Hornady 140ELDM is 4.0/9.3 with today's atmospherics plugged in (85F, 55% humidity, 735ft).

Which factors in the context of reloading to the equation. You're able to make up ground at the bench that others who don't reload can not...case in point, you're producing better ballistics (with the assumption of similar atmospherics) despite 4" less of barrel length (though I'm guessing suppressed).

I remember a grand time where factory 6.5CM was a good $0.50 per round cheaper than its 308 counterpart, now in the factory realm that has flip-flopped. Just thought I would add that to context for those that might be so busy that they're unaware.