My OCW

[Pinecone]

Rifle - Remington 700 PS-1 .308 in a Manners T4A with Mini Chassis, Vortext Viper PST 6-24x on a 20 MOA base.

Ammunition:

New Lapua Brass
Sierra 175 gr Match King
Federal 210M Large Rifle Match Primer
Varget

Range - 100 yards

I am thinking 43.5 looks good.

 

[RottenII]

I'd try 43.5 also.

 

[thrusty]

Agreed...give 43.5 a go with some 5-shot groups.

 

[oldfatguy]

As said, 43.5 looks good. Time to try different seating depths with 5 rnd groups.

OFG

 

[melloyello]

Yep, that's about as straight forward as you can get when it comes to OCW.

 

[shoot4fun]

I use all those components and 43.7 Varget. My results have very consistent from gun to gun. I am with the rest and think 43.5 would work fine. All my 308 guns feed from magazines so I measure OAL for seating depth. Try 2.85" COAL.

 

[Pinecone]

These were seated to 2.800" book length.

I figure I would try a round of 43.5 grains and 2.800 - mag length and see how they do.

If I have time. My wife and I are doing a Bang Steel course. With work commitments, I may only have time to load enough for the course.

 

[Pinecone]

A follow up.

I loaded a series of rounds to see the affect of seating depth. The original OCW was loaded to 2.810 COAL. This worked out to a length to ogive (Hornady comparator) of 2.227". So that was my baseline. I loaded in 0.020" increments, starting one increment shorter than the OCW test and out to 2.287" (max for the mag is about 2.295").

I shot 5 shot groups in a round robin.

Below is the target. Obviously, the longer the better. The numbers are on the target are the X in the length of 2.2x7". The high shot on the 2.287" length was a called flyer. But I also think the barrel was getting a bit warmer, the OAT was not conducive to cooling. The first 3 shots at that length were the 3 touching.

The lowest left was 3 rounds of Lake City M118 Match. And the Sighter was 4 rounds of PMC to warm up the barrel.

Started loading serious with a 2.290" length (I prefer round numbers ).

 

[Dan Newberry]

The OAL at group number 8 is where to be...

 

[Pinecone]

I figured.

But thanks for the look.

 

[1lnbrdg]

I would be leery of firing a different powder while testing as in the PMC ammo. Funny things can happen when shooting different powders down the barrel. For me, most powders take 2 ~ 4 shots settle down when changing to a different powder.

There's a list of powders that do and don't play well with each other on the National Match forum. Some of the data was mine, a lot of date from others.

 

[Pinecone]

I have never heard of firing different powders bing an issue.

But by firing orund robin, 5 shot groups, that should take care of that. The shorter round groups were not tight at all.