Too Long - OAL?

[crewchef]

New to reloading and concerned I'm getting OAL wrong so looking for input. I've succesfully loaded several hundred rounds of .223 for gas gun but they were all loaded to mag length. Moving to my .308 (SPS Tactical, 20") and decided first thing I needed to do was measure to see what OAL should be. I'm single loading these so not restricted to mag length. Using Stoney Point/Hornady with modified case I measured 10 times. Average OAL 2.964, measuring with comparator to OGIVE average was 2.370. I was planning to start at .025 off the lands (using OGIVE) but wondering if I've got something wrong here. So sort of a sanity check. Is the throat on this factory barrel actually that long? And if it is, should I still be trying to get close to lands. I did load a dummy round (2.345 to OGIVE) and it slid right in chamber and bolt closed easily. Didn't see any marks on bullet when removed and it measured same before and after being chambered.

Appreciate any input!

 

[Fuzzball]

Re: Too Long - OAL?

"...decided first thing I needed to do was measure to see what OAL should be."

And how did you determine what the OAL "should be?"

Make it what you wish, if you can chamber it, it's good. But, develop the load at the OAL you wish to use because the closer you get to the lands the higher the intitial pressure will be for a given charge.

 

[crewchef]

Re: Too Long - OAL?

Guess that should read; decided I needed to measure freebore to get an idea of what OLA I should load at.

 

[Sako85]

Re: Too Long - OAL?

I went through this Crewchef and at first my COL measurements were garbage, however after some consideration I sorted the problem and got the measurement I needed. Don't forget though if you change your bullet heads the exercise will need to be repeated.

COL Measurement

 

[thespecialist]

Re: Too Long - OAL?

Don't worry, you're not hallucinating on that measurement. Remington is VERY generous with the throats on these rifles.

That being said, I wouldn't sweat trying to reach the lands. I've developed some damn accurate loads for my SPS at mag length. The mag will feed a 2.835"-2.840" round in most rifles.

 

[Sako85]

Re: Too Long - OAL?

One more thing I now use a comparator when measuring COL this has made a big difference, measuring to the bullet tip especially if they are soft points is not too accurate.

 

[crewchef]

Re: Too Long - OAL?

Appreciate all the responses. Still a little concerned so asking a little more direct question. If I load to OAL of 2.940 (2.345 at Ogive) which is .025 off lands; would it create any potential issues? I'm thinking of things they mention around loading under minimum load since I'm essentially creating more empty space in cartridge.

I know everyone says SMK's like to jump but even loading out to 2.840 (mentioned above) that would be .125 jump which seems like a longggg way. Maybe I need to look at having barrel set back?

Side note, this rifle has shot great groups with FGMM 168's from round 1 at 100 and 300, so it's a shooter if I get my part right. I see some vertical stringing at 500 though and hoping I can fix that with good hand load.

Thanks for patience with the newb

 

[notquiteright]

Re: Too Long - OAL?

Vertical using federal match is usually the shooter breathing.

What bullet are you reloading? Amax doesn't react to jump like some VLD's. fit the mag is a good length. A bunch of guys all used 2.82" OAL and are happy. Try that and see what you think.

 

[crewchef]

Re: Too Long - OAL?

Spent a lot of time searching and reading tonight, 2.82 or there abouts seems like best idea at this point. I'll find what it likes at that length and then play with seating to see if I can eek out anything more.

Loading 175 SMK, FGGM once fired brass, 210M and Varget. Starting load of 42.0 and working up to max in .3 increments.

You may be right on the breathing, I'll try to be more aware of that and see if I can work on improving the shooter too.

 

[Boomholzer]

Re: Too Long - OAL?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Crewchef</div><div class="ubbcode-body">Appreciate all the responses. Still a little concerned so asking a little more direct question. If I load to OAL of 2.940 (2.345 at Ogive) which is .025 off lands; would it create any potential issues? I'm thinking of things they mention around loading under minimum load since I'm essentially creating more empty space in cartridge.

I know everyone says SMK's like to jump but even loading out to 2.840 (mentioned above) that would be .125 jump which seems like a longggg way. Maybe I need to look at having barrel set back?

Side note, this rifle has shot great groups with FGMM 168's from round 1 at 100 and 300, so it's a shooter if I get my part right. I see some vertical stringing at 500 though and hoping I can fix that with good hand load.

Thanks for patience with the newb </div></div>

You have good results with FGMM and use that cartidge for comparison in measurements. I'd set-aside the maximum o-give length concern for that animal and load for optimal powder charge in step per target results at reasonable bullet seat to retain bearing surface across a few popular powders. Brass wash or clean the interior neck well after resizing, neck chamfer, before bulding the cartidge. You can't kiss lands so load for the jump. You don't want the bullet squirting out prematurely or added inconsistancy in dynamic neck tension due to short seating depth or any wax or lube. The results with proper, consistant, case prep will go farther with optimal charge. It's not difficult to best FGMM with basic reloading tools and some range time to evaluate your experiments.