308 loads for SR 762

[All4abuck]

Looking for some 308 load ideas for SR762...
For accuracy from bench should I concentrate on high velocity?
I am new to AR platform and I want to make sure I won't end up having to single load due to feed issues or COL.
I have a hornady AP and getting ready to order their 308 die set.
Load Suggestions will be greatly appreciated.

 

[Mobuck]

Benchrest accuracy normally doesn't require(or even like) "high velocity". Since range shooting is usually at specific distances, the trajectory of the bullet is a known factor. If field shooting/hunting at unknown/estimated ranges, high velocity flattens trajectory lessening the possibility of holdover/under requirements.
The accuracy ammo I load for .308 is about 100 fps below what I can get out of my rifle. I prefer a moderate burn rate powder like BL-C2 or IMR 4895/4064 for 20-22" barrels but have gone a little slower for 26" w/o noticeable change in accuracy.

 

[tsubaki]

Welcome to the site!
Expect what you are about to get into, some semi auto's don't like certain powders and you might be compounding a problem with a 16" barrel.
What is the intended use and do you already have a bullet weight/range already in mind?

I've got an 18" carbine for deer hunting and have been fortunate to quickly find a combination that I can live with, a 150gr RN and a 150gr PSP using BL-C(2). Both giving 3/4" groups at 100 yards but 2" differing points of impact.
I'm also using the same powder in certain .223, 30-30 and 30'06 loads with good results.
If I run into a problem with availability my next powder choices might be Varget or RL15, so far there have been even better reviews of them than BL-C(2).

I'd suggest that you keep on hand some factory ammo of your choice on hand till you arrive at a load that suits you and the firearm, this may help in giving some answers. Also a chronograph would be nice.

The short barrel is expected to produce lower velocities than the published data. For instance the factory 150gr Remington PSP has a published velocity of 2820fps, my 18.5" barrel spits them out at 2630fps average.
The published data in a 24" barrel using 48.0gr of BLC-(2) with a 150gr Nosler BT is 2839fps, the 150gr Remington PSP using the same charge comes out of my barrel averaging 2625fps.
I'm not sure there would be more appreciable velocity loss with a barrel 2" shorter.

Just some things to think about, good luck, let us know what you intend to accomplish with the new baby!

 

[contender]

One more piece of advice,,,! You may need to consider a set of dies that are "small base FL." They will size the base of the cases down a bit more to make sure you get good feeding in a semi-auto.
I don't have any recipes for that gun as I don't have one.

 

[DGW1949]

IMR4895 and Varget come to mind.

DGW

 

[All4abuck]

Thanks all for the replys...
I hear you on shorter barrel and lower velocities..
Not sure if there are any choices for longer barrels for the 762, since its new.
I need to pull out the ballistics book and look at what is the best bullet weight and length for the 16" barrel and 1-10 twist.
Mean time I will get out there with a few boxes of factory ammo in different bullet weights and put them through the chrono to see what I get. That should both give me an idea of expected velocity drop as was mentioned, and also see what the rifle likes at various distances.
Will post results...thanks again...

 

[All4abuck]

so I got my first reloads shot and a had blast. I did the every 5, 10, 20, shot cleaning to break-in the barrel...not sure if it was necessary or mostly so I feel I did right by the rifle.

I loaded 45.5gr of RL15 behind 150gr hornady bullets, with WRL primers in hornady brass. loads cycled fine and no issues.

one thing I noticed however is primer dent from firing pin strike on the next cartridge chambered. This didn't cause rapid fire but still something to be worried about.

Is there a solution for this or is nothing to be worried about?

 

[OldePhart]

Okay...not an expert on this gun but I would be very worried about any gun that is leaving a visible firing pin strike on a chambered cartridge! It's only a matter of a few hundredths of an inch from that condition to full auto. SRS rifles, for example, are a bit famous for that because they have no firing pin blocker and the firing pin can become stuck forward under recoil if the bolt assembly is dirty.

I would do a detail strip on the weapon and make sure that all of the manufacturing crud, grease, etc. is cleaned out of the bolt assembly. If you still get primer dents after that - send it to Ruger for service!

Again, not familiar with the 762 and if it has a firing pin blocker - if it does then this is even more serious as it indicates that the blocker is not working for some reason...

John

 

[All4abuck]

thanks Oldephart...that clued me to the mod i just had done being the issue. I just installed a Hiperfire 24C trigger with 3.5# trigger springs. reading up on their site, seems that the manner i press the trigger or hold the gun does impact this primer dent issue. easier fix is to use the medium trigger weight spring set that they shipped with the trigger.