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Reloading my 6mm ARC gas gun Login/Join 
I have not yet begun
to procrastinate
posted
I’ve accumulated enough fired brass from my 6mm to start reloading seriously. (New Alpha brass is waiting)
The Hornady Black 105gr load is 100% ALL THE TIME. Which makes sense since the Black load is specifically for ARs. The ELD-M and ELD-X not so much.

I called Brownell’s and asked if my rifle length gas tube combined with my carbine buffer weight/spring could be the possible cause of some of the factory rounds not feeding as reliably as they should.
The guy I talked to said increasing the buffer weight -adding mass- should help. Does this sound correct?
Once I get the Black load reliability replicated, where is the proper ejection pattern supposed to be?

I’ve got 3 different powders and 4 different bullets to try. Varget, CFE223, TAC - - ELD-X, Berger 105 hybrids, Hornady match 105s, ELD-VTs.
This should make a great antelope/deer load!


--------
After the game, the King and the pawn go into the same box.
 
Posts: 3979 | Location: Central AZ | Registered: October 26, 2006Reply With QuoteReport This Post
semi-reformed sailor
Picture of MikeinNC
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I’ve never messed with weights to adjust a gun, I know the factory guns are over gassed to be able to run any ammo. I put an adjustable gas block on my ARs to run with my ammo with a suppressor and load my ammo to mimic NATO M193.

The way I went about mimicking the factory ammo was by chronographing a magazine of it in my rifle (16”). And then loading my rounds up to that.



"Violence, naked force, has settled more issues in history than has any other factor.” Robert A. Heinlein

“You may beat me, but you will never win.” sigmonkey-2020

“A single round of buckshot to the torso almost always results in an immediate change of behavior.” Chris Baker
 
Posts: 11872 | Location: Temple, Texas! | Registered: October 07, 2006Reply With QuoteReport This Post
Sigless in
Indiana
Picture of IndianaBoy
posted Hide Post
quote:
Originally posted by MikeinNC:
I’ve never messed with weights to adjust a gun, I know the factory guns are over gassed to be able to run any ammo. I put an adjustable gas block on my ARs to run with my ammo with a suppressor and load my ammo to mimic NATO M193.

The way I went about mimicking the factory ammo was by chronographing a magazine of it in my rifle (16”). And then loading my rounds up to that.



Post deleted.

I thought you were talking about loading 6mm ARC specifically.
 
Posts: 14237 | Location: Indiana | Registered: December 04, 2003Reply With QuoteReport This Post
Sigless in
Indiana
Picture of IndianaBoy
posted Hide Post
quote:
Originally posted by KMitch200:
I’ve accumulated enough fired brass from my 6mm to start reloading seriously. (New Alpha brass is waiting)
The Hornady Black 105gr load is 100% ALL THE TIME. Which makes sense since the Black load is specifically for ARs. The ELD-M and ELD-X not so much.

I called Brownell’s and asked if my rifle length gas tube combined with my carbine buffer weight/spring could be the possible cause of some of the factory rounds not feeding as reliably as they should.
The guy I talked to said increasing the buffer weight -adding mass- should help. Does this sound correct?
Once I get the Black load reliability replicated, where is the proper ejection pattern supposed to be?

I’ve got 3 different powders and 4 different bullets to try. Varget, CFE223, TAC - - ELD-X, Berger 105 hybrids, Hornady match 105s, ELD-VTs.
This should make a great antelope/deer load!



My 6ARC is a rifle length +1 on a 20" barrel and with a suppressor. So my setup is going to be substantially different from yours.

Mine required a SUBSTANTIAL amount of gas bleed off from the adj gas block to function properly.

Before adjusting the gas block I found multiple instances of the heat shield tips on the ELD match ammo being bent and deformed, and one was even broken off. The issue seemed better once the gas was adjusted. The ELD-M factory ammo doesn't group very well out of my gun. 1.5-2 MOA. The Hornady Black is MUCH better. I am handloading 105gr Berger Hybrids for it now and it is a true sub MOA rifle with that bullet and the right load.

My accuracy load isn't particularly fast. I have some Varget on hand that I should try.

LeverEvolution is THE powder for max velocity in the 6 ARC but it burns so filthy that I want nothing to do with it.



I think your rifle might benefit from a heavier buffer. That is the easiest and cheapest way to tune a rifle, but doesn't allow the fine tuning of an adjustable gas block.


Details about what kind of malfunctions you are experiencing would help. An overgassed rifle, the bolt carrier moves too fast and the magazines can struggle to keep up. However, there are situations where a rifle isn't getting enough gas, and you will get a different set of malfunctions. Usually the culprit there is a misaligned gas block, loose key on the carrier, or bad rings on the bolt.


Based on your rifle being 100% with the Black ammo, and having issues with the other factory stuff. I would suspect that perhaps adding some mass with an H, or H2 buffer could help.


The ejection pattern should be similar to those for properly gassed 5.56 ARs.
 
Posts: 14237 | Location: Indiana | Registered: December 04, 2003Reply With QuoteReport This Post
Sigless in
Indiana
Picture of IndianaBoy
posted Hide Post
quote:
Originally posted by KMitch200:
I’ve accumulated enough fired brass from my 6mm to start reloading seriously. (New Alpha brass is waiting)
The Hornady Black 105gr load is 100% ALL THE TIME. Which makes sense since the Black load is specifically for ARs. The ELD-M and ELD-X not so much.

I called Brownell’s and asked if my rifle length gas tube combined with my carbine buffer weight/spring could be the possible cause of some of the factory rounds not feeding as reliably as they should.
The guy I talked to said increasing the buffer weight -adding mass- should help. Does this sound correct?
Once I get the Black load reliability replicated, where is the proper ejection pattern supposed to be?

I’ve got 3 different powders and 4 different bullets to try. Varget, CFE223, TAC - - ELD-X, Berger 105 hybrids, Hornady match 105s, ELD-VTs.
This should make a great antelope/deer load!



Do you have access to the load date for 6 ARC for gas guns? Be aware that there is a separate load data set for bolt guns. Gas guns max out at 52k PSI. There is bolt gun data out there that (if I recall correctly) goes up to around 60k PSI.

You would likely break a bolt in an AR if you approached those pressure levels for any significant round count.

https://static.hornady.media/s...as-58-105gr-data.pdf
 
Posts: 14237 | Location: Indiana | Registered: December 04, 2003Reply With QuoteReport This Post
I have not yet begun
to procrastinate
posted Hide Post
IndianaBoy
quote:
LeverEvolution is THE powder for max velocity in the 6 ARC but it burns so filthy that I want nothing to do with it.

Thanks for that tidbit.
Contemplating getting Accurate 2520 but not really hunting for it.
The initial stoppages were when the gun was new - after a 150 rds or so, they seemed to iron out but every so often a round (factory ELD-X, ELD-VT) doesn’t quite get a clean release from the mag and the ass is caught by the bolt.

I have the gas gun data from Hornady reloading. My 18” barrel gives me 2678 fps with Black ammo.
I’ll try the Varget first, (guy at tech help at Hornady likes 27gr loads) and see what the gun likes.

As MikeinNC was talking about, my 308 has an adjustable gas block. It was so overgassed from Krieger that it felt brutal to the action. That and I didn’t need brass flung into the next county.
I’ll try a heavier buffer first (cheap), then later the gas block…the thought of dealing with that small roll pin is why my local wrench turner gets my money for doing that.


--------
After the game, the King and the pawn go into the same box.
 
Posts: 3979 | Location: Central AZ | Registered: October 26, 2006Reply With QuoteReport This Post
Sigless in
Indiana
Picture of IndianaBoy
posted Hide Post
quote:
Originally posted by KMitch200:
the thought of dealing with that small roll pin is why my local wrench turner gets my money for doing that.



Wrap the jaws of a pair of vice grips in electrical tape. You can gently press the pin into place with gentle pressure instead of trying to get that little SOB started with a punch and a hammer.

The tape keeps the jaws from marring the gas block and it also allows the pin to sink in and be held steady. You want at least two wraps of tape.

The trick is getting the vice grips set so that there is just a tiny bit of tension when you close them to seat the pin initially. After that just tighten them a little bit at a time. They go in so easy like that. I use the same method for the roll pin for the bolt catch on the lower receiver.
 
Posts: 14237 | Location: Indiana | Registered: December 04, 2003Reply With QuoteReport This Post
Member
posted Hide Post
OP,
Load 2 rounds in a 6.5Grendel or 7.62x39 magazine.
Push 1 round out of the magazine by hand...slowly.
If the case mouth hangs up at the front of the mag body,radius the lip w/ a needle file.
Test again.

Load 1 round in the magazine & shoot.
BCG should lock open.
Ejection angle should be at 4;30 clock position.
Ejection angle from 3 to 12 o'clock will require an adjustable gas block &/or a heavier buffer.

Superlative Arms adjustable gas blocks have bleed-off capabilities if a suppressor is in use.

Odin Works heavy adjustable buffers are weight adjustable from 3oz to 7.2oz by adding or removing aluminum,steel or tungsten weight segments.

Sprinco(TX) manufactures several "color coded" recoil springs for the AR platform.

The Superlative,Odin,Sprinco components are in all of my AR15 & AR10 platforms of 223 to 50Beowulf chamberings.

Lubricate the BCG & upper receiver.
My preference is Super Lube aerosol spray lube for AR lubrication.
 
Posts: 131 | Location: Fbks,AK. | Registered: March 23, 2020Reply With QuoteReport This Post
I have not yet begun
to procrastinate
posted Hide Post
quote:
Wrap the jaws of a pair of vice grips in electrical tape. You can gently press the pin into place with gentle pressure instead of trying to get that little SOB started with a punch and a hammer. The tape keeps the jaws from marring the gas block and it also allows the pin to sink in and be held steady. You want at least two wraps of tape.

Nice tip! Smile

DansSIGs: Odin Works heavy adjustable buffers are weight adjustable from 3oz to 7.2oz by adding or removing aluminum,steel or tungsten weight segments.
Sprinco(TX) manufactures several "color coded" recoil springs for the AR platform.
- -
The Odin buffer is what I was looking at. Seems to be easily tuned for the price.
(Not that adj gas blocks are pricey outlandish)
Thanks for the replies!


--------
After the game, the King and the pawn go into the same box.
 
Posts: 3979 | Location: Central AZ | Registered: October 26, 2006Reply With QuoteReport This Post
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