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Stretch 16 barrel info please


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I finally got my new Stretch 16 build (non-fluted, cerakote) out to a match this past weekend. Although I built it last fall, I had some issues with the ammo I was planning to run through it, then I hibernated for the winter, and so forth...

So, I had zeroed it at 50 yards a couple of weeks back. For its first match outing, I shot in in the rain, sleet, and snow out at Peacemaker on Saturday. On the very first stage I hit 400yd and 460yd flashers with little trouble (69gr SMK Gorilla ammo). After that was plenty of fast close paper. Also, there was an off-hand plate rack at around 70 yards. For the close stuff I used Atlanta Arms 55gr reman.

The gun shot great and it achieved my main goal in building it—giving me a light rifle that made off-hand precision work easier without sacrificing at long range. One of the things I like about the Gorilla ammo is that they load their SMKs a little hot; I get the same muzzle velocity out of the Stretch 16 with Gorilla 69gr as I did out of my 18" Carbon-Wilson with Black Hills 69gr, around 2725fps.

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I'm not thinking my accuracy issue is due to my ammo anymore... I just realized that my KMR has about a CH of distance between it and the gas block. I'm using the supplied stretch 16 gas block and the screws are about to get dremeled!

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  • 2 weeks later...

So would it be a gutted rifle buffer for a full stock, or still use a carbine one. Would a hydraulic carbine buffer be any different? I have one laying around.

For a full stock, I use a gutted carbine buffer with a spacer. Hydraulics stretch out the recoil impulse, exactly the opposite of what we want for speed.

what kind of spacer are you using?
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So would it be a gutted rifle buffer for a full stock, or still use a carbine one. Would a hydraulic carbine buffer be any different? I have one laying around.

For a full stock, I use a gutted carbine buffer with a spacer. Hydraulics stretch out the recoil impulse, exactly the opposite of what we want for speed.

what kind of spacer are you using?

Polymer one sold at Brownells.

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  • 3 weeks later...

Has anyone used a set screw style gas block with the Stretch 16? I have decided that my SLR Solo UltraLite is not quite as free-floated as I would like it to be with the included Stretch 16 gas block, so I either need to grind on the screws or replace the gas block with something low profile enough to give me decent clearance. For anyone not familiar with the SLR, the internal diameter is 1.3 inches, so slightly smaller than the 1.5-inch ID Midwest Industries forearms.

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Has anyone used a set screw style gas block with the Stretch 16? I have decided that my SLR Solo UltraLite is not quite as free-floated as I would like it to be with the included Stretch 16 gas block, so I either need to grind on the screws or replace the gas block with something low profile enough to give me decent clearance. For anyone not familiar with the SLR, the internal diameter is 1.3 inches, so slightly smaller than the 1.5-inch ID Midwest Industries forearms.

If you have a Cerakoted version a set screw version won't fit. Grind away or go with an SLR clamping block
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Has anyone used a set screw style gas block with the Stretch 16? I have decided that my SLR Solo UltraLite is not quite as free-floated as I would like it to be with the included Stretch 16 gas block, so I either need to grind on the screws or replace the gas block with something low profile enough to give me decent clearance. For anyone not familiar with the SLR, the internal diameter is 1.3 inches, so slightly smaller than the 1.5-inch ID Midwest Industries forearms.

If you have a Cerakoted version a set screw version won't fit. Grind away or go with an SLR clamping block

Sniper Gray Cerakote... Alas, I don't care to run an adjustable gas block on this gun, and SLR only seems to make pinned non-adjustable gas blocks. Grinding may be my best bet.

Out of curiosity, why do you say a set screw block won't fit—shouldn't it still fit any .750" barrel?

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I didn't plan on Adj gas either, but tried it and it makes a nice difference. My wife's build still has the fixed block.

I tried a set screw on mine when looking for clearance and the Cerakote adds just enough thickness to prevent it sliding on

Edited by IntenseImage
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Has anyone used a set screw style gas block with the Stretch 16? I have decided that my SLR Solo UltraLite is not quite as free-floated as I would like it to be with the included Stretch 16 gas block, so I either need to grind on the screws or replace the gas block with something low profile enough to give me decent clearance. For anyone not familiar with the SLR, the internal diameter is 1.3 inches, so slightly smaller than the 1.5-inch ID Midwest Industries forearms.

If you have a Cerakoted version a set screw version won't fit. Grind away or go with an SLR clamping block

Sniper Gray Cerakote... Alas, I don't care to run an adjustable gas block on this gun, and SLR only seems to make pinned non-adjustable gas blocks. Grinding may be my best bet.

Out of curiosity, why do you say a set screw block won't fitshouldn't it still fit any .750" barrel?

The thickness of the cerakote can remove the clearance needed to slide on a set screw gas block. A clamp on gas block can be pried apart enough to slide it over.

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  • 2 weeks later...

Anyone seeing unusual velocities from the Stretch? I was tinkering with the Hornady 68gr BTHP over Ramshot Tac a while back and looking at my notes the other day I realized that before I gave up on the bullet (never got the accuracy I wanted) I made it up to 25.5 grains (5.56 NATO max is listed as 26 grains) and I had an average velocity of 2920fps with only occasional slightly flattened primers. Is it just me or does that seem excessively fast for a 16" barrel?

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The Stretch16 barrels are a little faster than most of the others. Melonite is a tad faster.

Also, the 68g Hornady's have never given acceptable accuracy for me in any barrel. The other weights from Hornady, yes.

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Good to know! I'll be trying the Hornady 75's next weekend, hopefully they shoot better. What speeds have you been able to get out of them? Feel free to PM me if you don't want to post data here.

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  • 2 months later...

Well I finally figured out why my Stretch-16 barrel wasn't shooting so great.

First I thermal mated the barrel and shimmed it to the upper. Wow, that even made PMC 55gr look almost like match ammo.

It took groups of about 2.5 MOA down to about 1.5 MOA. From what I have seen out of other rifles 2.5 MOA is standard for factory 55g ammo.

The second part I stumbled onto.

Apparently my barrel's head space is a little tighter than I expected and very well might be the reason with FGMM 77SMK shot like crap.

Using my head space comparator, I noted that the fired head space of a PMC round was the exact same head space of the un-fired FGMM 77s.

The difference between a fired 55g and 77 gr un-fired head space is .003.

Now that I have started moving the shoulder back an additional .003 on my re-loads, which matches most factory loads, it shoots much much better.

Has anyone else noticed this on their Stretch-16?

Is this normal or did I get a one-off barrel?

Edited by fedupflyer
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  • 1 month later...
On 7/24/2016 at 4:48 PM, fedupflyer said:

Well I finally figured out why my Stretch-16 barrel wasn't shooting so great.

First I thermal mated the barrel and shimmed it to the upper. Wow, that even made PMC 55gr look almost like match ammo.

It took groups of about 2.5 MOA down to about 1.5 MOA. From what I have seen out of other rifles 2.5 MOA is standard for factory 55g ammo.

The second part I stumbled onto.

Apparently my barrel's head space is a little tighter than I expected and very well might be the reason with FGMM 77SMK shot like crap.

Using my head space comparator, I noted that the fired head space of a PMC round was the exact same head space of the un-fired FGMM 77s.

The difference between a fired 55g and 77 gr un-fired head space is .003.

Now that I have started moving the shoulder back an additional .003 on my re-loads, which matches most factory loads, it shoots much much better.

Has anyone else noticed this on their Stretch-16?

Is this normal or did I get a one-off barrel?

I am trying to get some accurate 55 grain loads.  The one I have shoot amazing with 69 grain but sucks with 55's  Like 3-4 moa sucks I am shooting H335 with 55grn hdy bullets and magnum primers.  I really want to only shoot 55's...

IMG_1402.JPG

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On 5/8/2016 at 9:42 PM, TonytheTiger said:

Good to know! I'll be trying the Hornady 75's next weekend, hopefully they shoot better. What speeds have you been able to get out of them? Feel free to PM me if you don't want to post data here.

Sorry Tony, I must have missed your question.  I don't shoot a lot of 75s/77s, but my velocity with TAC is right around 2700 fps.

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