Question #1

[Varmint Hunter]

I finally got a chance to fire a new custom rifle in .308. Lawton receiver, Broughton bbl, McMillan stock and all the other goodies. Fired 20 rounds during a break-in procedure and then fired 2- five shot groups @ 200 yards.

175gr SMK and 36.5gr of Varget = 3.5" vertical string with .75" width
168gr Nosler Comp and 36.5gr of Varget = 3.6" vertical string with .65" width

I know that two groups don't tell much of a story about a rifle but these two are rather extreme for a custom rig.

Does this type of group indicate anything in particular?

I checked the receiver screws and found that they were not snug but weren't loose either.

What do you think?

 

[Geezer]

When i had a similar problem it turned out to be the scope moving vertically, due to the rear ring not seating on the base properly.

 

[Varmint Hunter]

When i had a similar problem it turned out to be the scope moving vertically, due to the rear ring not seating on the base properly.

Optically, everything seems tight. I'm using Burris double dovetail bases and Signature (insert) rings. The scope is a new Nikon Monarch. It has never been mounted or fired previously.

Looks like some additional testing is necessary.

 

[Lost creek]

That is a pretty light load you are using,maybe full pressure loads will tighten your groups up.

 

[WAMBO]

Good call on the load Lost creek, that does seem to be an extremely light load.
I'm using 44.5grs of Varget in Win brass and 43grs when I use Lapua brass in my custom 308 using a Mike Rock 5R barrel.

Wayne aka WAMBO

 

[Varmint Hunter]

Good call on the load Lost creek, that does seem to be an extremely light load.
I'm using 44.5grs of Varget in Win brass and 43grs when I use Lapua brass in my custom 308 using a Mike Rock 5R barrel.

Wayne aka WAMBO

Actually the load is a mid level load in the Hornady book. Starting loads use 32.0 gr of Varget. I believe that 43-44gr of Varget would be above the book maximum.

Either way, I'll try increasing the charge for the next session.

 

[davewilson]

sounds like a bedding or one of the lugs not making contact issue to me.

 

[WAMBO]

Varmint Hunter,
Ok, with Hornady bullets I'll go with their data but using Hodgdon's data for their Varget powder with the 168 SMK and the 175 SMK they list 46grs and 45grs as a max charge respectively for those bullets.
I definitely do not advocate using over max charges on these internet forums, you never know who will try something you recommended in their rifle without working up to it.
Good luck with your load development and keep us posted how it turns out.
Regards,
Wayne aka WAMBO

 

[Lost creek]

Most reloading data that i have seen calls for a starting load of 42grs.of varget with a 168gr.bullet for a 308

 

[Willys46]

Varget

I with every one else..I shoot the 175 SMK in a stock Rem PSS 43.5 gr. In your aornial post i thought that 36 was a mis print.

I strated load development at 42 gr up to 44.5gr.

 

[J E Custom]

Varmint hunter

I would start by chronographing your loads ,if the standard deviation
is over 20 ft/sec this could be your problem.

Next thing that I would look at is the position of the bipod or sand bags.
If they are to far out on the forearm then this could be the problem.

Bedding or lack of could also be causing this problem.

Last but not least is trigger control (To heavy,creep or inconsistant grip control.

Thats all I can think of to start with.

Good Luck
J E CUSTOM