Anyone with a GAP10 .308 16.5"?

[mavrick10_2000]

I'm curious as to the speed/peformance with 168's or 175's of the shorter setup. I keep going back and forth from 16.5 to 20" barrel.

20" would obviously have some advantages of keeping the speed up a little better and regulating pressure when suppressed, as well as a closer representation of another upper I'll eventually have built in 6 CM with a 22 or 23" barrel.

Anyone?

 

[Switchblade]

Re: Anyone with a GAP10 .308 16.5"?

I have a different 308 with a 17" barrel. I get 2550 with 46.5g Varget and a 147, and 2560 with a 175 over the same load. I have switched to 147's in that rifle just because they work better

 

[taseal]

Re: Anyone with a GAP10 .308 16.5"?

I'm kind of in the same boat. I want smaller because I want something bit more compact, yet I want the extra speed of that 20 inch barrel.

 

[tomthebaker]

Re: Anyone with a GAP10 .308 16.5"?

I have a POF in 308, 16.5", which is a very handy size. Sorry, no chrono data. I just picked up a GAP 20" upper, so I guess my solution is:

Get both!

 

[taseal]

Re: Anyone with a GAP10 .308 16.5"?

Someone needs to invent telescopic barrels!

 

[RyeDaddy]

Re: Anyone with a GAP10 .308 16.5"?

My 16.5" POF 308 gets around 2500 FPS with 168 SMK's and around 2450 <span style="text-decoration: underline">MAX</span> with the 175 SMK. This is using Varget, and I can't get to book max without seeing issues with carrier velocity due to excessive port pressures from slow powder and heavy bullets.

I decided on the 155 Amax, it gets around 2600 comfortably sith Varget and eventually I'll get around to trying a new powder for it.

I don't regret going with the shorter barrel, it is handier if you're planing to carry it around or shoot offhand. It makes your drop and wind more, but practice can overcome a slight velocity disadvantage.

With some help from Google you will find some velocity info that POF had put out a while ago with different barrel lengths, it's somewhere on their web site. It gives some info on what factory loads get in shorter barrels, my info may not be as much use to you if you don't handload.

 

[taseal]

Re: Anyone with a GAP10 .308 16.5"?

I just plugged the average numbers from the pof website for 14.5 16.5 amd

it looks like translucent at 800 850 amd 950 respectively

so you gain about 100 yards more for 20 vs a 16.5

with transmission stable bullets like berger 175s you might be ok...

 

[taseal]

Re: Anyone with a GAP10 .308 16.5"?

Here is a screenshot showing ya the differences

http://db.tt/UK6qbH7R

 

[mavrick10_2000]

Re: Anyone with a GAP10 .308 16.5"?

I'm probably going to go with at least an 18.5 then because i mostly shoot suppressed and i need some barrel length to dissipate pressure as much as possible to keep speed up.

 

[ggmanning]

Re: Anyone with a GAP10 .308 16.5"?

My POF 16" runs the 155 Bergers at 2575 over 45gr Varget and the 175's in the 2400's but don't remember the grains. The 155 load had room for a little more velocity but I stopped at that accuracy node. It shoots good to 800yds and then loses steam fairly fast. At 0-450 DA it will remain supersonic to 1000 and would do better for you higher elevation guys.

 

[LineofDeparture]

Re: Anyone with a GAP10 .308 16.5"?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mavrick10_2000</div><div class="ubbcode-body">I'm probably going to go with at least an 18.5 then because i mostly shoot suppressed and i need some barrel length to dissipate pressure as much as possible to keep speed up.</div></div>
I have this setup coming....18.5 gap-10.... almost 4 months now so i should be getting a call soon.. Ill let you know how she performs...