Precision Loading for Gas Guns

I'm setting up to load for a 6.5 Grendel in the AR Platform. What don't I know?

I load on a single stage for my 6.5CM bolt gun with terrific results. Am not new to reloading by any means, but all of my progressive work has been for handgun loads; I've never loaded for a semi-auto rifle.


Progressive (Dillon 550B) or Single Stage?
FL or Neck size?
Prime on the machine or hand prime?
????






P.S......the 1st one of you jackalopes that says "go buy a manual" or "start low, work your way up" earns a free kick in the nuts.

There are some good videos out there about loading match grade ammo on a 550B. David Tubbs loaded his ammo on a 550B, he has won 11 NRA High Power matches at camp perry. He has won 30 national NRA Silhouette Rifle matches.

Definitely full length size. Other than that, all you need is a repeatable process. I would work up the actual load on the single stage, but I've run grendle through the 1050 with no problems. ES was a bit more, than auto measured drops from the Lyman.

1. Go buy a manual.
2. Start low and work your way up.

When do I get to deliver my free kick?

LMAO

wsfiredude said:

1. Go buy a manual.
2. Start low and work your way up.

When do I get to deliver my free kick?

LMAO

Click to expand...

I would basically follow brenchrest prep for the cases.
Start with 500 to 1000 cases from the same lot, look at match data to see what the top shooters are using.
Size primer pockets, de-burr the flash hole, FL size the case, trim to length.
Weight the cases and separate into groups, small batches use for preliminary load work, then fine tune using your larger batches.
Review match info for case , primers , powder and load used, bullet type and weight used.

Starting with 500/1000 prepped cases, you'll end up with a good long term load that should last you for a while before you need to start over working up the load again.
Remember, anything changes; case, primer, powder, bullet lot number, you need to back down and work back up.

Read up on what the benchrest shooters go thru

I’m loading on a 550B.

FL resize, the resize die is adjusted to push the shoulder back 0.002”. Forster dies

Berger VLD loaded ~ 0.008” off the lands.

Pink_Vapor said:

I’m loading on a 550B.

FL resize, the resize die is adjusted to push the shoulder back 0.002”. Forster dies

Berger VLD loaded ~ 0.008” off the lands.

Click to expand...

do you do all operations on the Dillon in one cycle?
Tumble, then move to the Dillon and...

Size/deprime/prime
Powder
Seat bullet

or do you

Deprime
Size
Prime

THEN move to the Dillon?

Tim said:

do you do all operations on the Dillon in one cycle?
Tumble, then move to the Dillon and...

Size/deprime/prime
Powder
Seat bullet

or do you

Deprime
Size
Prime

THEN move to the Dillon?

Click to expand...

All operations on the Dillon in one cycle:
Tumble, then move to the Dillon and...
Size/deprime/prime, Powder, Seat bullet
I’m pleased with the results, I’m using Lapua brass, BL-C(2) powder, CCI 41 primer & Berger bullets.
At 700 yards you may want to get more anal about details.
I’m looking forward to seeing what works best for you.

FL size every time.....normally after 5 firings from a semi auto....toss it or keep for a bolt gun.

Varget is popular with gas gun reloaders in common AR rifle cartridges.

Priming......whatever works for you, dillion is a good machine. Primers......some manufacturers make primers just for semi rifles...i think the cup is slightly harder to prevent a slam fire. I have never experienced this.....but i normally use cci primers which are less sensitive anyway.

Pink_Vapor said:

All operations on the Dillon in one cycle:
Tumble, then move to the Dillon and...
Size/deprime/prime, Powder, Seat bullet
I’m pleased with the results, I’m using Lapua brass, BL-C(2) powder, CCI 41 primer & Berger bullets.
At 700 yards you may want to get more anal about details.
I’m looking forward to seeing what works best for you.

Click to expand...

When/how do you get the lube off the cases when you're FL sizing?

Sas quatch said:

When/how do you get the lube off the cases when you're FL sizing?

Click to expand...

I don’t, tell me if I’m doing something wrong.
I’ve been using Redding Imperial Sizing Die Wax, touch the wax, then a very light coat on the brass. So far so good. By bumping the shoulder 0.002” and loading for accuracy, not top speed, the brass is holding up very well with multiple loadings.

I bought an AR with the intention of a reliable and accurate 6-800 yard autoloader.

Setting headspace is easy and as mentioned above, you should be full length sizing. Size some once fired brass but with the die backed out so the shoulder isn't set back and sort to find the case with the longest shoulder dimension. With the upper off, slide the sized case under the extractor and slide the BCG forward with just light finger pressure. Resize turning the die body down 5° at a time. 5° is almost exactly 0.001". When the bolt locks up with light finger pressure, your dies are properly adjusted with that press and shellholder.

With gas pressure critical, choosing a powder that gives both accuracy and reliable cycling adds another wrinkle. My project is now on the back burner, pushed there by a new toy when something as simple as an adjustable gas block might have been all it took to get good results. If you haven't already bought or built, definitely get an adjustable gas block.

In my opinion, loading 69/77gr for a 5.56 gas gun, start with a short chambered premium barrel so you can load close to the lands and still have mag length COAL.
It's frustrating knowing your gas gun will do great, but only single shot.
Oh, and buy a case guage. Very helpful setting headspace.

Yep some people, me included, have no problem leaving lube on after FL sizing. The solvents flash off and a dry film is all that remains from most spray lubes. The Hornady Oneshot spray on is generally recommended, says on the label does not affect powder or primers.

The return on investment is lower with a gas gun regarding benchrest level of detail (such as weighing brass or reworking load for a new bullet lot). May not be any benefit depending on your application. Lots of shooters in highpower doing well with minimal brass prep and thrown powder charges. I don’t have a progressive but would have no problem loading AR match ammo on one.

Bullet choice and jump to lands takes some thought because of mag length limit. You can cut the front of mags to get a little more OAL. Not sure if that is a problem in 6.5 Grendel but definitely is for heavy bullets in 223.

I’ll am also a fan of RCBS X-dies to eliminate trimming between firings if they make one for your caliber.