GAP10/Southwest 175 SMK MV

[tnichols]

What kind of MV you guys getting with your GAP10's running SW175's? I chronoed mine today and I thought they seemed a little slow.

Rifle: GAP10
Barrel Legnth: 20" Badger brake
Ammo: Southwest 175 SMK's new Win. brass
Temp: 65 F
Humidity: 38%
BP: 30.29
MV: Avg. of 5 = 2513fps
ES: 22
SD: 8
Chrono: CED M2

 

[Pusher591]

Re: GAP10/Southwest 175 SMK MV

That seems a little slow but not that bad for a gas gun. ES and SD are impressive. I would rather have that then the extra velocity. Consistency is the key to accuracy.

 

[tnichols]

Re: GAP10/Southwest 175 SMK MV

Tag.

 

[Patrick Morris]

Re: GAP10/Southwest 175 SMK MV

It depends on how many rounds are through it. If it's brand new then you can expect it to gain some velocity over the next couple hundred rounds.

 

[Chris K]

Re: GAP10/Southwest 175 SMK MV

That's about right for what I've seen for most gassers that are about that length. Like Pusher said: I'd rather have the consistency that you're rifle is displaying than a few hundred FPS, that SD/ ES will give you splendid results at distance and sow very consistent groups. It says a whole helluva lot about SW ammo's care and craftsmanship as well.

On another note, 65*, 38%RH, 30.2 BP sounds glorious, its time to come back home to a nice climate and start shooting things on MY terms, not their terms.

C_K

 

[tnichols]

Re: GAP10/Southwest 175 SMK MV

Chris, I hope you get to come home safe and get some shooting in. We've had a nice spring, but windy as hell.

Just had a chance to stretch the GAP10/SW175 combo for the first time at 650 yards. They might be a little on the slow side, but this combo is a absolute hammer. 20 MOA come up, 4 MOA right for the wind...send it.

 

[JSTARSZ]

Re: GAP10/Southwest 175 SMK MV

That is some interesting data. I have found through Chronying loads that my Bolt rifles using the same type barrel (Bartlein) and length run about 110 fps slower than my semi's. I wonder what they would run in a bolt rifle of the same barrel type and length?

 

[T2CH]

Re: GAP10/Southwest 175 SMK MV

Thats close I'd say. I was running the SW 175 in the FC brass and had 5.1 mils elevation at 660 yds. That equals 17.5 MOA.
My GAP-10 has an 18" barrel and the avg MV on these was 2570 when I crono'd the load. I think the crono I was using was reading on the low side though.

 

[tnichols]

Re: GAP10/Southwest 175 SMK MV

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JSTARSZ</div><div class="ubbcode-body">That is some interesting data. I have found through Chronying loads that my Bolt rifles using the same type barrel (Bartlein) and length run about 110 fps slower than my semi's. I wonder what they would run in a bolt rifle of the same barrel type and length? </div></div>

That seems kind of weird to me too. You'd think the bolt would run higher, at least in my simple mind and limited experience. Next time I have the chrono set up, I'll run some through my bolt gun just for grins. My bolt is a 26" barrel.

 

[tnichols]

Re: GAP10/Southwest 175 SMK MV

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: T2CH</div><div class="ubbcode-body">Thats close I'd say. I was running the SW 175 in the FC brass and had 5.1 mils elevation at 660 yds. That equals 17.5 MOA.
My GAP-10 has an 18" barrel and the avg MV on these was 2570 when I crono'd the load. I think the crono I was using was reading on the low side though. </div></div>

It was chilly this morning when I was shooting with high BP so the air was pretty hard. The day I chronoed, I ran the numbers on that target, I want to say it was asking for 19.25 MOA at 68F. This morning it was 40F with a BP of 30.20 and 57% RH.

Fun rifle!

 

[JSTARSZ]

Re: GAP10/Southwest 175 SMK MV

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: tnichols</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JSTARSZ</div><div class="ubbcode-body">That is some interesting data. I have found through Chronying loads that my Bolt rifles using the same type barrel (Bartlein) and length run about 110 fps slower than my semi's. I wonder what they would run in a bolt rifle of the same barrel type and length? </div></div>

That seems kind of weird to me too. You'd think the bolt would run higher, at least in my simple mind and limited experience. Next time I have the chrono set up, I'll run some through my bolt gun just for grins. My bolt is a 26" barrel.</div></div>
I have had the situation on two different rifles:

DPMS Mini-SASS with 18" barrel running 2810 fps
Remington 700 - with 18" Bartein Barrel at 2685 with the exact same bullet set-up - 77 SMK with 24.5 grains of AA 2460

I have a GAP SASS with a 20" Bartlein Barrel that ran 2635 fps with a 178 AMAX - under 44 grains of Win 748.

I have a Bolt Rifle - Underground Skunkworks Perseus with a 20" Bartlein Barrel and it ran 2535 fps.

I always thought that the bolts were faster too but at least in these two occurrences it was not the case.

 

[TexasClassIII]

Re: GAP10/Southwest 175 SMK MV

Anyone else have chrono data for these loads? I have a 20" barrel and would love to know what others are getting...

Parker

 

[Jethro3898]

Re: GAP10/Southwest 175 SMK MV

I don't have a GAP-10, but I do have a DPMS SASS (18" barrel, not 20") and just chrono'd the 175 stuff on Saturday that I purchased from the recent SW group buy.

2,554
2,569
2,564
2,544
2,544
Avg = 2,555 fps

Hope this helps you somewhat.