Maximum COL?

[Strong972]

I am new to reloading and just completed my first 3 rounds of .308. I did not trim the brass (once fired FGMM), as the case trimmer I am interested in was not available at time of purchase. The COL on the 3 bullets is 2.818, 2.822, 2.823.
My questions are:

1. Am I ok at that COL? I remember reading on another thread to keep it under 2.82 for an OBR but I’m not sure the reasoning. Hodgdon recommends 2.8 for my recipe, but they do not give a maximum. The FGMM rounds were between 2.8 and 2.810

2. If I need to shorten future rounds should I start trimming the cases, or seat the bullets deeper in the case? I setup the seating die according to the instructions provided by Forster.

I would like my reloaded ammo to at least be as accurate as the FGMM 175s the brass came from, but I am not looking for competition type accuracy (I use an FDAC card) and would like to keep things as simple as possible.

I am shooting an OBR, using Varget, SMK 175, Federal 210M primers, Forster Bench dies, Lee Classic Cast press.

Thx,
Jason

 

[jasonZ]

Re: Maximum COL?

Mine end up being about 2.825 to 2.830 to get me .010" into the lands on my rifle. I use a mag system so I can alittle longer then a factory internal mag system. I think you're fine on your length as long as they'll load in your rifle mag. I would insert a round and chamber it to see if you're in the lands yet. I like to load into the lands instead of the bullet jumping to the lands, but that's what my rifle likes. I would try to get more consistent on getting the same length no matter what you do. I know you said that you're not needed "target" type accuracy, but it will make any shot you take better if you know where it's gonna hit and don't have to guess if your rifle like a little longer load or a little shorter load. Consistency is the key to reloading, no matter what you're after. If your load repeats the same every time then you know a miss was on you.

 

[Strong972]

Re: Maximum COL?

Thanks TacticalJ. When I chamber a round, how do I know if I am in the lands?

I am leaning towards the Forster case trimmer with the 3 in 1 carbide.

 

[Beef82]

Re: Maximum COL?

Don't obsess over .010" total variance in OAL. Bullets are not perfect, seater dies push down towards the ogive not at the tip, consistancy at the ogive is more important anyway. I've found seirras vary allot. Cases don't need to be trimmed every time, and until they get too long don't effect much. Mnay factory loads and most load manuals give 2.8 as OAL because that's a Remington SA factory magazine friendly length.

 

[jasonZ]

Re: Maximum COL?

The only way to really know it to measure the chamber and distance to the lands. SMK's are really about on OAL, because the meplat or tip of the bullet, is not always the same. The only way to get it the same everytime is to use a tool to cut/trim the meplat so they are consistent or uniform almost every time.

I cheat and estimate. I simply start out and load a bullet, no powder or primer, in the brass. I can then pull the bullet and reload until I see the lands leave marks on the bullet. At that point, you have to use another bullet so see the lands marks again, but I measure the marks with a digital caliper and I estimate alittle. Is it exact, no, but I can get pretty darn close. Your rifle may or may not like loading into the lands or it may like a jump into the lands. The only way to find out is to try it. Precautionary part, reduce your powder charge some as it will increase pressure when the bullet starts in the lands. I reduced mine by a couple grains and then worked my way back up to what I think is right, based on signs read from the brass, I.E. brass flow.