.308 and barrel length

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B Gordon

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Something else you might consider.
I have a 20" Remington LTR.
When I shoot it side by side with a longer barreled 308 I notice a whole bunch more muzzle jump during recoil out of the shorter barrel.
The extra jump makes it slower / harder to get back on target for a follow up shot.
My presumption is that the extra barrel weight up front helps out during the recoil movement.

On a similar note I had an AR-15 in 6.5 Grendel caliber with a 24" barrel.
The whole thing was a bit longer than I liked so I had the barrel cut back to 20".
Much nicer to shoot with the shorter barrel and accuracy is better.
Not sure if it is the shorter barrel or something the gunsmith did during the assembly process.
Because the recoil of the 6.5 Grendel is half of what a 308 would be I have no issues with getting back on target quickly for follow up shots.
 

swampratt

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I considered the extra muzzle jump with the lighter barrel..
This barrel is .840" now at the muzzle and will be .860" when cut to 20.5" give or take a little.

It should still jump less and recoil less than my skinny 22" barrel 30-06 and i have no issues with that and a quick follow up shot.
I had 2 deer running at me with that 30-06 rifle in hand,, busted the doe in the chest at 45 yards and the buck at 100 yards jumping and running sideways to me got one through the lungs less than 5 seconds later.
Made for a short gun season.

I thought about ordering a barrel but this one still needs some cut off of it due to the uneven bullet wear at the last .150" of the muzzle.
 

swampratt

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My .308 is now sporting a 20.5" barrel.
I will load up some of the same ammo i was testing before and see how it shoots and what velocity.
Do not know when i will get to shoot it.
 

swampratt

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Ok i shot it ..Dang it is windy!!! 25MPH winds. blew my hat off and blew the sky screne off my crony once.

I shot it at banner 100 yards. Looks like taking it from 24" down to 20.5" i lost 54 fps on the average.

First shot clean cold bore was out of the 5 shot group..it measured 1.860" center to center, count the other 4 shots only and the group is .695"
Not bad for the wind..Yes making excuses!
Now the next 5 shots had much less FPS spread 14 fps spread and .928" group.
FPS looked like this. Virgin Lapua brass i worked over.
2599
2613
2608
2609
2613....Barrel temp for this group starting was 99F and climbed to 104F

Then some necksized only brass that was once fired. Some bullets are on the lands and some are .005-.010 off the lands.
That was an 8 shot group that measured 1.185" barrel temp was 104F.
2615 fps
2628
2622
2611
2626
2645 in the lands a bunch.
2604

I feel i need to shoot on a calm day like i did before the barrel cut.
But that second 5 shot group was best virgin lapua 5 shot group at 100 yards i have.. and the worst day for shooting.
And even the 8 shot group was better than some of my 24" barrel 5 shot groups.
Overall i feel successful.
Muzzle jump is not any different than before.. maybe the 54fps loss counteracted it.
Or maybe i just do not notice.

All shots were back to back no cool down ..I had one hour to get to the range and back home.
Barrel temp started at 87F first shot and climbed to 104F after 18 shots.
 

swampratt

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The point of impact has dropped just a little bit at 100 yards.
Here are 2 targets one on top of the other.
The 20.5" barrel shot a little lower than the 24" barrel but just a little..
Almost No wind on the day i shot the 24" barrel and 25+ wind the day i shot the 20.5" would not make a great difference at 100 yards but the wind was blowing me and the gun...
I just figured a picture is needed.
hipoint45 027.jpg

Another picture showing 24" vs 20.5"
Now notice the speed of the bullets keep climbing in the super clean barrel It stabilized in the low 2600fps range. like 2608-2613.
I will not clean it ..next outing i will see if it stays in the low 2600 range right off the bat or see if barrel heat is doing it all.
hipoint45 028.jpg
 

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