Slow Barrel?

[Paul762]

Ok I have worked up a load for my Remington VSSF in 308 Winchester. Barrel is 26" The load consistens of WW case, Remington 9 1/2 primer, 45.5 grains of RL-15 with a Nosler 155 Custom Comp Bullet.
The load shoots great under 1/2" at 100 yard. Best group so far is .284 at 100 yds.
Book Max is 46.0 grains of RL-15 Nosler's book
Velocity for 46 grains is 2900 fps

Here is the problem
Average velocity is 2644.9 fps
ES 16.5
SD 6.7
#1 thru #5
2637.6
2643.7
2654.2
2649.0
2640.2

Temp was 53 degrees
Altitude 1016 ft
Barimetric pressure 30.02

Is this barrel just slow?

 

[Timo Turl]

Re: Slow Barrel?

How long is the barrel ?

 

[Paul762]

Re: Slow Barrel?

26"

 

[codemancode]

Re: Slow Barrel?

That seems slow. My 20" remmy will push 168's to 2642fps with 44.5 grains of varget. I know that some remingtons are cut with long throats which causes the bullet to have to jump pretty far to the lands. This jump will cause a reduction in pressure and velocity.

How reliable is your chronograph? Maybe it's a slow lot of powder?

 

[308sako]

Re: Slow Barrel?

xxx

 

[Paul762]

Re: Slow Barrel?

not showing any signs of pressue yet just hard to move off of a <1/2" load.
But I need more velocity goal is 2900 fps

 

[shoot4fun]

Re: Slow Barrel?

I'm sure you know this but that other 1/2 grain (hell even a whole one) is not going to get you another 250 FPS. I notice the temp was 53 degrees. As much as I have heard about RL powders and temp sensitivity I would not be surprised if that is where some of the velocity went.
I would try Varget. It seems to give best velocity in 308.

 

[Paul762]

Re: Slow Barrel?

Seirra's book max for RL-15 is 44.8 for 2800 out of a 26" Savage

 

[shoot4fun]

Re: Slow Barrel?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Paul762</div><div class="ubbcode-body">Seirra's book max for RL-15 is 44.8 for 2800 out of a 26" Savage

</div></div>

Sierra's data is conservative.
Nosler's is not necessarily so.
At least that has been my experience.

 

[BuzzBoss915]

Re: Slow Barrel?

Answer: yes, some barrels are slower than others but as others have suggested, you can increase your charge weight until you start to see pressure signs if your goal is 2900fps, why not? Besides some barrels show the best accuracy with a max load, so it wouldn't hurt to try.

There are powders that will be better than others, in your chamber and your barrel, and it's your job to find it by trying at least several others. I have a 25'06AI that shows a 200fps difference between <span style="text-decoration: underline">max loads</span> of W760 and RL#2700 w/same 100 grain bullet. BB

 

[30SMK]

Re: Slow Barrel?

How many rounds are on the rifle? As stated if you are jumping the bullet into the rifling because of a long cut or worn throat you velocity will go down. Also if you are seating the bullets out far the reach closer to the rifling there will be a decrease in pressure will not build as much as the bullet exits the neck of the case.

I would say work up until you see pressure signs, there are several accuracy nodes that you will hit along the spectrum of powder charge weights, you just need to go up and hope your max is close to a similar accuracy node that you are currently on.

Further more if you are going to bump your load with RL-15 at the temp of 53 degrees, be careful when warmer temps come back.

 

[winxp_man]

Re: Slow Barrel?

How many rounds do you have through your barrel?






Aron-

 

[raythemanroe]

Re: Slow Barrel?

You should do a ladder test any who if your testing loads...Find your max and while your doing that find your high node..You may want to try a different powder..I had the same problem in my 243 win with 115g dtac..just couldn't get the speed everyone else was pulling with h1000 or h4350 so I tried rl-25 and loved it..

 

[Paul762]

Re: Slow Barrel?

My book shows 553 round down the tube.
Using H4895 (I was loading for my M1A)at the time
39.8 grains, and a Sierra 175 HPBT in a match LC case.
gun ran at 2469.5 fps.
All rounds measure out at 2.815